1 Steam Cars : Phorum
General Steam Car topics
Piston Rod Taper
Posted by: Peter Heid (IP Logged)
Date: June 16, 2004 07:35PM
<HTML>I was wondering if anyone had any idea how much temperature differential one could expect on a piston rod ?
Are piston rods normally machined with a taper to accomadate for unequal expansion ?
My engine is small and the clearance is only 0.001 to 0.0015 inches and to help with the sealing and alignment.
Peter Heid</HTML>
Are piston rods normally machined with a taper to accomadate for unequal expansion ?
My engine is small and the clearance is only 0.001 to 0.0015 inches and to help with the sealing and alignment.
Peter Heid</HTML>
Re: Piston Rod Taper
Posted by: Dick Vennerbeck (IP Logged)
Date: June 17, 2004 02:42AM
<HTML>Peter,
I'm no expert but I think that you should not need to consider piston rod expansion if you are using normal packing materials or even some of the new hi tech carbon fiber ones. I assume that your engine piston rods are less than 5/8" in diameter. Choosing the right packing material for the metal that your rods are made of is much more important. Stainless steel and teflon do not get along well together however Monel and Teflon seem to work just fine. There are lots more options including a water ring labrynth that will also work. What are your steam temperatures and what do you think the casting seal area temperatures might reach ate the rod gland?
Dick</HTML>
I'm no expert but I think that you should not need to consider piston rod expansion if you are using normal packing materials or even some of the new hi tech carbon fiber ones. I assume that your engine piston rods are less than 5/8" in diameter. Choosing the right packing material for the metal that your rods are made of is much more important. Stainless steel and teflon do not get along well together however Monel and Teflon seem to work just fine. There are lots more options including a water ring labrynth that will also work. What are your steam temperatures and what do you think the casting seal area temperatures might reach ate the rod gland?
Dick</HTML>
Re: Piston Rod Taper
Posted by: SSsssteamer (IP Logged)
Date: June 17, 2004 02:46AM
<HTML>When I have had our piston rods hard chromed, their surfaces are ground perfectly parallel the full length. I have done 10, 20 and 30 hp Stanley engines. While in use, the piston rod becomes hot the full lenght and there won't be enough of a temperature difference in the full length of it to worry about an uneven size. Keep the proper clearance on your cross head guides, and your piston rod packing will last longer.</HTML>
Re: Piston Rod Taper//brittle?
Posted by: Ben in Maine (IP Logged)
Date: June 17, 2004 10:53AM
<HTML>Hi Pat,,,Gotta ask,,for benifit of others,,,,Has there been any problems w/ Hydrogen embrittlement,,,a result of traped H2 under the plating,,,,we had a serious problem w/ motorcycle spoke breakage ,, spokes that were not heat treated after plating,,, ,,, ,,, Are you planning on being at Mt Washington ?? Can we convince Jim to come again,,?? We gotta show these ''modern '' guys that a Stanley is STILL the best bang for the BUCK,,,A'n tthat they dont need power steering,,,,,brakes,yes,,,but not power steering,,, haha,,Cheers Ben aaah,found my glasses,,did I leave my coffee over there ????cb</HTML>
Re: Piston Rod Taper//brittle?
Posted by: SSsssteamer (IP Logged)
Date: June 17, 2004 12:25PM
<HTML>Dear Ben, In over 25,000 of my steaming miles, I have not found any problems with hydrogen embrittlement What I have found is that you have to be carefull when you run the first piston tight against the end of it's threads. If you jam it too tight against the hard chrome, you can chunk some of the plating off. A little bit doesn't hurt because it doesn't reach the packing, but still, you don't need that happening. I lock my pistons on their piston rods with a high temperature Locktite used for installing piston sleeves. It is made for extreme temperatures. I hope to see you at the Kingfield auction, however, I won't be on the tour with a Stanley. To tow a Stanley three thousand miles one way, is way too expensive for me. I drive Stanleys because they are simple to maintain, and most any fix can be done on the road. The Stanleys are to the steam car world as what the Model T Ford was to the internal explosion car world. Both were affordable and both are simple to operate. Many Stanley have steamed coast to coast on tours. How many other steam car makes can make that statement?</HTML>
Re: Piston Rod Taper//brittle?
Posted by: Peter Brow (IP Logged)
Date: June 19, 2004 09:36AM
<HTML>Ben and Pat,
>Many Stanley have steamed coast to coast on >tours. How many other steam car makes can >make that statement?
None of the radically "modern" designs, anyway. Many have been built, often with much more advanced materials, components, theoretical/design expertise, and fabrication techniques than the antiques. You'd think that by now at least one modern steam automobile would have run a few 10,000s or a few 100,000s of miles, like the "crummy" antiques.
Did the antique designers know something we don't?
Peter</HTML>
>Many Stanley have steamed coast to coast on >tours. How many other steam car makes can >make that statement?
None of the radically "modern" designs, anyway. Many have been built, often with much more advanced materials, components, theoretical/design expertise, and fabrication techniques than the antiques. You'd think that by now at least one modern steam automobile would have run a few 10,000s or a few 100,000s of miles, like the "crummy" antiques.
Did the antique designers know something we don't?
Peter</HTML>
Re: long distance testing '95
Posted by: Ben in Maine (IP Logged)
Date: June 19, 2004 10:28AM
<HTML>Hi ,, My personal hero still is Ameede Bollee,,,first to run the vintage class,,,Paris-- Bordeau--Paris ,,,about 730 miles I think in 1895 worse yet, it was on iron tires,,,,in his 1878 machine If I were to be asked to join in a trip of this sort today,,,I think I would pass,,,What a thought,,,wish I was younger tho,,,,Somehow,,were these people more adventurous??? Just a thought Cheers Ben</HTML>
Re: long distance testing '95
Posted by: Tom Lahey (IP Logged)
Date: June 19, 2004 02:48PM
<HTML>most steels/ irons have a thermal expansion of .oooooo59 inch/ def F...I typed this from memory, so double check me!!</HTML>
Re: long distance testing '95
Posted by: George Nutz (IP Logged)
Date: June 19, 2004 04:34PM
<HTML> 1020 steel has a coefficient of expansion of 8.4 millionths of an inch per degreeF and chrome has only 3.4 millionths. Some people have tried hard chrome plating and if running high steam temperatures the solid rod expands much more than the chrome(delta 5 millionths per inch per degreeF) and the thin layer of chrome is stretched/put under tension so much that it has had surface cracks that then give sharp edges to the failed chrome layer and chew up the packing glandsl. Glad to hear it has worked for some.
Something to ponder, George</HTML>
Something to ponder, George</HTML>
Re: long distance testing '95
Posted by: Peter Brow (IP Logged)
Date: June 20, 2004 04:40AM
<HTML>George, you must be psychic. That is something I have been wondering about, off and on, for quite some time. I(?) invented another way to stop steel rods from pitting and scoring, in case plating can crack from thermal or mechanical (flex) loads. Now I plan to try it. It is also cheaper than plating/grinding and should give the powerplant other advantages.
Peter</HTML>
Peter</HTML>
Re: piston rod taper
Posted by: David K. Nergaard (IP Logged)
Date: June 20, 2004 08:56PM
<HTML>Any good piston rod packing would be flexible enough to conform to any change in diameter the rod has in normal service, including the change in diameter from cold storage to the maximum useable superheat. If it is no longer flexible, it is time to replace it!</HTML>
Re: long distance testing '95
Posted by: Rolly (IP Logged)
Date: June 21, 2004 06:26PM
<HTML>Stainless tends to Gall. I only use Monel, for piston and valve rods, and its expensive. But you never have a problem. You need so little to building the engine. Compared to pattern and casting work its cheep.
Rolly</HTML>
Rolly</HTML>
Re: long distance testing '95
Posted by: Andy Patterson (IP Logged)
Date: June 21, 2004 07:12PM
<HTML>Hi Rolly
I think you could find a packing meterial that will work with Stainless. It is used in a lot of applications that should have galling problems. Don't know the alloy though.
Ceramics might also be used.
As my design is basicly a single acting all I need is a seal on the piston rod to keep my crank case sealed. I was planning on using a square configuration of four crank shafts with cylanders between. It's a variable clearance design. The clearance (and displacement) can be varied by varing the crank phase in opsite direction by a resolver mechanism. Using my crankrod idea would allow sealing the crank casses. After seing that Wabble plat type engine I posted a while back on the SACA site I have been trying to work a simular design that varies the wabble angle. It to will have stright line travel of a piston rod that can be sealed with cylander isolated from teh crank mechanism. I didn't like the resolver idea all that much. You have to get the phase angle way out to effect much change and the further out you get the more the effect until at the lowest power you need to control the phase angle in fractions of a degree. I think it to be just sensitive and even if I could get it to work initially ware would soon create so much slop in the resolver that you couldn't control it.
Andy</HTML>
I think you could find a packing meterial that will work with Stainless. It is used in a lot of applications that should have galling problems. Don't know the alloy though.
Ceramics might also be used.
As my design is basicly a single acting all I need is a seal on the piston rod to keep my crank case sealed. I was planning on using a square configuration of four crank shafts with cylanders between. It's a variable clearance design. The clearance (and displacement) can be varied by varing the crank phase in opsite direction by a resolver mechanism. Using my crankrod idea would allow sealing the crank casses. After seing that Wabble plat type engine I posted a while back on the SACA site I have been trying to work a simular design that varies the wabble angle. It to will have stright line travel of a piston rod that can be sealed with cylander isolated from teh crank mechanism. I didn't like the resolver idea all that much. You have to get the phase angle way out to effect much change and the further out you get the more the effect until at the lowest power you need to control the phase angle in fractions of a degree. I think it to be just sensitive and even if I could get it to work initially ware would soon create so much slop in the resolver that you couldn't control it.
Andy</HTML>
Re: long distance testing '95
Posted by: Peter Heid (IP Logged)
Date: June 21, 2004 08:30PM
<HTML>An interesting subject but still I wonder what a typical temperature differential might be, if it has ever come up in testing. In the Stumpf unaflow book, there are suggestions as to the varying thickness of the cylinder walls so the hotter areas have less metal to expand and equal expansion assured through out the cylinder. A consideration on my vehicle is the body of the 4 roller crosshead is aluminum and will be open to air flow which will tend to act as a radiator on the end of the rod opposite the piston.
As far as material, there are a few ceramic coatings that easily resist corrosion and wear in that application. My piston rod will be only 3/8 inches in diameter but the cylinder bore is only 1 3/4 inches. The piston rod packing guide is only going to have 0.001 - 0.0015 inch clearance and will be made of an AMPCO-45 phosphor bronze. The packing will be flexible enough to accomadate any sealing needed but much of the sealing will be acomplished by the packing guide its self. The phosphor bronze was chosen for its superior lubricating properties as no oil will be used in the engine. The minimum clearance was chosen to help support the piston and prevent the piston from touching the cylinder walls or at least minimize the forces.
I am going to shoot for around 600 degrees F. for my steam temperature and there will be no throttle valve. Throttling will be by cutoff alone and the boiler pressure will be at the heads at all times.
Peter Heid</HTML>
As far as material, there are a few ceramic coatings that easily resist corrosion and wear in that application. My piston rod will be only 3/8 inches in diameter but the cylinder bore is only 1 3/4 inches. The piston rod packing guide is only going to have 0.001 - 0.0015 inch clearance and will be made of an AMPCO-45 phosphor bronze. The packing will be flexible enough to accomadate any sealing needed but much of the sealing will be acomplished by the packing guide its self. The phosphor bronze was chosen for its superior lubricating properties as no oil will be used in the engine. The minimum clearance was chosen to help support the piston and prevent the piston from touching the cylinder walls or at least minimize the forces.
I am going to shoot for around 600 degrees F. for my steam temperature and there will be no throttle valve. Throttling will be by cutoff alone and the boiler pressure will be at the heads at all times.
Peter Heid</HTML>
Re: long distance testing '95
Posted by: George Nutz (IP Logged)
Date: June 21, 2004 09:17PM
<HTML> Anybody ever use a nitrided steel, very hard surface, takes very high temperature and has no apparent problems like a hard chrome. I myself would stay away from stainless rods as per Rolly's comment, have heard the same.
George</HTML>
George</HTML>
Re: long distance testing '95
Posted by: Andy Patterson (IP Logged)
Date: June 21, 2004 10:04PM
<HTML>S.E.S did some work on piston development. They had problems with the piston galling. Solved the problem using different combinations of alloys for the pistion and sleves. I think they used a stainless piston. Will need to check on that paper. Anyway that is why I segusted the right combination of meterials can be found that will work. Though they had grant money to research such things.
Andy</HTML>
Andy</HTML>
Re: long distance testing '95
Posted by: Peter Heid (IP Logged)
Date: June 21, 2004 10:33PM
<HTML>The other trouble with stainless is the cost of the materials to take the stress. I chose stainless for my poppet valves but it is an EV8 stainless forging that is coated with a very hard "Black Diamond" German material that penetrates the metal and has a very thin coating over it. Also a consideration of the weight of the material might determine it's suitability for a paticular application. My valves are small (5mm stem and 19mm head with an overall length of 60mm) and there is no spring weight to add to the reciprocating mass so weight is not too much of an issue in my valve design. The EV8 valves are sometimes offered with a hollow stem for IC racing applications.
Nitriding is a very good option for steel parts to reduce wear and prevent corrosion but the ceramics and other specialized coatings have less friction and a greater service life. The costs are now compairable also.</HTML>
Nitriding is a very good option for steel parts to reduce wear and prevent corrosion but the ceramics and other specialized coatings have less friction and a greater service life. The costs are now compairable also.</HTML>
Re: long distance testing '95
Posted by: Dick Vennerbeck (IP Logged)
Date: June 22, 2004 01:31AM
<HTML>George,
Now I know why Monel works so well. Thank You for the insight. Polished monel works well in my boat engine. I understand the boat engine temperatures are much lower and I think I'll try the same material in my Stanley. My boat uses a teflon braided packing that works very well and I have some new Carbon fiber / graphite to test in the Stanley. So far so good on standard rods.
Dick Vennerbeck</HTML>
Now I know why Monel works so well. Thank You for the insight. Polished monel works well in my boat engine. I understand the boat engine temperatures are much lower and I think I'll try the same material in my Stanley. My boat uses a teflon braided packing that works very well and I have some new Carbon fiber / graphite to test in the Stanley. So far so good on standard rods.
Dick Vennerbeck</HTML>
Re: long distance testing '95
Posted by: George Nutz (IP Logged)
Date: June 22, 2004 05:43PM
<HTML>Dick,
It would be unwise to use teflon above 400-500 degrees as it gets soft and draggy, several have had failures with it. Two years ago I had a long talk with the head old-time packing engineer at Garlock and he said that Garlock 95?/98? was still the very best for our purposes even with all the fancy newer packings available. Belive Jerry Hackett(Stanley Bus), Craig Standbridge(S-10 steam conversion) and Rolly are using it without any problems. Maybe Rolly can give the correct Garlock# as I am in Florida and away from my half-vast collection of steam information. Have fun steaming!
Half-Vast George</HTML>
It would be unwise to use teflon above 400-500 degrees as it gets soft and draggy, several have had failures with it. Two years ago I had a long talk with the head old-time packing engineer at Garlock and he said that Garlock 95?/98? was still the very best for our purposes even with all the fancy newer packings available. Belive Jerry Hackett(Stanley Bus), Craig Standbridge(S-10 steam conversion) and Rolly are using it without any problems. Maybe Rolly can give the correct Garlock# as I am in Florida and away from my half-vast collection of steam information. Have fun steaming!
Half-Vast George</HTML>
Re: long distance testing '95
Posted by: Rolly (IP Logged)
Date: June 22, 2004 07:23PM
<HTML>Hi George
Hear you go.
Garlock® Braided Compression Packing Construction
Gaskets,Packings, & Seals Inc.
P.O. Box 509
Parkersburg, WV 26102
Tel: 304-422-3880 Fax: 304-422-9476
[www.sealsolutions.com]
Rolly</HTML>
Hear you go.
Garlock® Braided Compression Packing Construction
Gaskets,Packings, & Seals Inc.
P.O. Box 509
Parkersburg, WV 26102
Tel: 304-422-3880 Fax: 304-422-9476
[www.sealsolutions.com]
Rolly</HTML>
Re: long distance testing '95
Posted by: George Nutz (IP Logged)
Date: June 23, 2004 10:32AM
<HTML>Rolly,
What is the # of the packing that some of you use, is it 95 or 98??
George</HTML>
What is the # of the packing that some of you use, is it 95 or 98??
George</HTML>
Re: long distance testing '95
Posted by: Dick Vennerbeck (IP Logged)
Date: June 29, 2004 01:15PM
<HTML>George,
Thank You. I know that teflon would not be good for the Stanley rods. I'll see if I can dig up some more information on the carbon fiber / graphite packing, meanwhile I'll follow up on the Garlock and try it out.
Thanks Again
Dick
ps Did you go to Florida to make sure that they get This election right?</HTML>
Thank You. I know that teflon would not be good for the Stanley rods. I'll see if I can dig up some more information on the carbon fiber / graphite packing, meanwhile I'll follow up on the Garlock and try it out.
Thanks Again
Dick
ps Did you go to Florida to make sure that they get This election right?</HTML>
Re: long distance testing '95
Posted by: Andy Patterson (IP Logged)
Date: June 29, 2004 02:08PM
<HTML>Here is a link to a GRAPHALLOY source:
[www.graphalloy.com]
It is both a seal and bushing.
[www.graphalloy.com]
Operation to as high as 1500 F in some casses.
Andy</HTML>
[www.graphalloy.com]
It is both a seal and bushing.
[www.graphalloy.com]
Operation to as high as 1500 F in some casses.
Andy</HTML>
Re: long distance testing '95
Posted by: Dick Vennerbeck (IP Logged)
Date: June 29, 2004 03:45PM
<HTML>George / Rolly,
Here is some info on the new packing that I will test in my Stanley.
[www.gtweed.com]
I'm using type #1585.
It looks to be excellent stuff although a little pricy. I purchased mine from MCMaster Carr. [www.mcmaster.com] page 3236
Let me know what you think. Has anyone else tried ysing this stuff?
Dick</HTML>
Here is some info on the new packing that I will test in my Stanley.
[www.gtweed.com]
I'm using type #1585.
It looks to be excellent stuff although a little pricy. I purchased mine from MCMaster Carr. [www.mcmaster.com] page 3236
Let me know what you think. Has anyone else tried ysing this stuff?
Dick</HTML>
Re: long distance testing '95
Posted by: Peter Brow (IP Logged)
Date: June 30, 2004 10:41AM
<HTML>Hi Dick,
Haven't tried it yet, but I bought a 10' roll of the same stuff (Palmetto) from McMaster a few months back for general use in the steam system. Don't need the temperature resistance for some planned aps (eg, pumps), but I like the pure graphite makeup. Graphite fills pits and plates surfaces with incipient corrosion. I'd be interested to know how it works in your Stanley.
Peter</HTML>
Haven't tried it yet, but I bought a 10' roll of the same stuff (Palmetto) from McMaster a few months back for general use in the steam system. Don't need the temperature resistance for some planned aps (eg, pumps), but I like the pure graphite makeup. Graphite fills pits and plates surfaces with incipient corrosion. I'd be interested to know how it works in your Stanley.
Peter</HTML>
Re: long distance testing '95
Posted by: David K. Nergaard (IP Logged)
Date: June 30, 2004 10:50AM
<HTML>I have been using graphited copper foil packing for a couple of decades in my Stanley engine. It is rather pricy but quite durable. There seems to be no need for fancy rod material, it works well on the original rods and the oil hardening drill rod I am using now.</HTML>
Re: long distance testing '95
Posted by: Dick Vennerbeck (IP Logged)
Date: July 01, 2004 03:12AM
<HTML>David,
Can you describe how it's put together and a source. I've used "Flexitallic Gaskets but have not foud copper. Your's sounds like the right solution.
Thank You,
Dick Vennerbeck</HTML>
Can you describe how it's put together and a source. I've used "Flexitallic Gaskets but have not foud copper. Your's sounds like the right solution.
Thank You,
Dick Vennerbeck</HTML>
Re: long distance testing '95
Posted by: Peter Brow (IP Logged)
Date: July 01, 2004 06:46AM
<HTML>David,
I have considered drill stock for piston and valve rods, but wonder about the higher(?) carbon content and brittleness(?). At the same time, the higher surface hardness sounds a definite plus for wear resistance. How many miles do you have on the drill stock rods so far? Any problems? I also wonder about machinability, as I can't find carbide bits in the right size for my prehistoric lathe, and therefore use cobalt (& sometimes HSS)-- OK for hi carbon steel but the less bit sharpening the better. Saw some stainless in the bins at my local metal supplier today, and shuddered.
The copper packing sounds good, I hereby second Dick's question about where to get it. The premium Palmetto packing sounds almost identical to highly-recommended and reportedly long-wearing Garlock 98 (ie, 100% graphite, hi temp rating). It is rather deluxe, but doesn't add much to the cost of an engine or complete powerplant. What did the Stanleys, White, Doble, etc use originally in engine stuffing boxes?
Peter</HTML>
I have considered drill stock for piston and valve rods, but wonder about the higher(?) carbon content and brittleness(?). At the same time, the higher surface hardness sounds a definite plus for wear resistance. How many miles do you have on the drill stock rods so far? Any problems? I also wonder about machinability, as I can't find carbide bits in the right size for my prehistoric lathe, and therefore use cobalt (& sometimes HSS)-- OK for hi carbon steel but the less bit sharpening the better. Saw some stainless in the bins at my local metal supplier today, and shuddered.
The copper packing sounds good, I hereby second Dick's question about where to get it. The premium Palmetto packing sounds almost identical to highly-recommended and reportedly long-wearing Garlock 98 (ie, 100% graphite, hi temp rating). It is rather deluxe, but doesn't add much to the cost of an engine or complete powerplant. What did the Stanleys, White, Doble, etc use originally in engine stuffing boxes?
Peter</HTML>
Re: long distance testing '95
Posted by: Rolly (IP Logged)
Date: July 01, 2004 09:38AM
<HTML>Peter
Read in Walton’s book on Doble pages 148 through 150. Doble recommended high carbon steels of .4 to .5 percent. He also required stuffing box length of four to six times rod diameter. But most importantly he compressed the packing in a die to specific tolerances.
He does mention the galling of high nickel steels. As is stated earlier I only use Monel as it does not Gall nor rust or pit and is very strong.
Rolly</HTML>
Read in Walton’s book on Doble pages 148 through 150. Doble recommended high carbon steels of .4 to .5 percent. He also required stuffing box length of four to six times rod diameter. But most importantly he compressed the packing in a die to specific tolerances.
He does mention the galling of high nickel steels. As is stated earlier I only use Monel as it does not Gall nor rust or pit and is very strong.
Rolly</HTML>
Re: long distance testing '95
Posted by: Peter Brow (IP Logged)
Date: July 02, 2004 09:59AM
<HTML>Hi Rolly,
Interesting stuff. Pre-compressing the packing should reduce or eliminate the need for take-up with new packing. Longer stuffing boxes increase engine size, weight, and cost, so the costs and benefits need to be carefully weighed.
Higher carbon steel, and Monel, sound like excellent piston rod and valve rod materials for classic steam car engines and other steam engines of relatively traditional design. In my engine, I think/hope that the special seal design (which is very cheap and simple, and possibly patentable) will give standard steel rods the wear-resistance and corrosion-resistance improvements of drill rod and Monel. Drill rod or Monel rods could still be used with the special seals, but with little if any extra improvement if the special seals work as projected, and they are approximately 2 and 16 times the price of mild steel, respectively. Monel would add something in excess of $50 to the cost of my engine, relative to mild steel rods.
In some places however, newer alloys are justified, as in frame rods, where 4140 Chromoly is only ~40% more expensive than the (already very cheap) plain steel rods.
Peter</HTML>
Interesting stuff. Pre-compressing the packing should reduce or eliminate the need for take-up with new packing. Longer stuffing boxes increase engine size, weight, and cost, so the costs and benefits need to be carefully weighed.
Higher carbon steel, and Monel, sound like excellent piston rod and valve rod materials for classic steam car engines and other steam engines of relatively traditional design. In my engine, I think/hope that the special seal design (which is very cheap and simple, and possibly patentable) will give standard steel rods the wear-resistance and corrosion-resistance improvements of drill rod and Monel. Drill rod or Monel rods could still be used with the special seals, but with little if any extra improvement if the special seals work as projected, and they are approximately 2 and 16 times the price of mild steel, respectively. Monel would add something in excess of $50 to the cost of my engine, relative to mild steel rods.
In some places however, newer alloys are justified, as in frame rods, where 4140 Chromoly is only ~40% more expensive than the (already very cheap) plain steel rods.
Peter</HTML>
Re: long distance testing '95
Posted by: David K. Nergaard (IP Logged)
Date: July 03, 2004 04:34PM
<HTML>Oil hardening drill rod is easily machined with HSS bits in the annealed state, as it is when purchased. Its surface is good enough that only the end fastenings have to be machined, threaded in my case.
I must try and find catalog numbers for the packing I use. More later.</HTML>
I must try and find catalog numbers for the packing I use. More later.</HTML>
Re: long distance testing '95
Posted by: Mike Clark (IP Logged)
Date: July 03, 2004 08:33PM
<HTML>David,
You say oil hardening drill rod - do you harden it and if so do you need to straighten it after.
Doesn't it corrode?
Does anyone know the SAE number for this steel?
Mike</HTML>
You say oil hardening drill rod - do you harden it and if so do you need to straighten it after.
Doesn't it corrode?
Does anyone know the SAE number for this steel?
Mike</HTML>
Re: long distance testing '95
Posted by: Peter Brow (IP Logged)
Date: July 04, 2004 09:26AM
<HTML>Hi David,
Minimal machining is a real plus, though the Schick blueprints say assemble and turn the rods concentric with the pistons (not necessary?). Glad to hear that the drill rod comes annealed; thanks for the machining tip. Yep, drill rod, and cold-rolled rounds, mike out dead-on, rarely do I find a piece that is even a tenth off of nominal. Sure would be nice to just cut rods to length, thread the ends, and screw 'em into the valves, valve stem jaws, pistons, & crossheads -- unless Schick was right about turning for concentricity. Then again, almost any engine, even a "rigid" design at light load, probably flexes more than any miniscule concentricity error from the simplified "thread and screw" approach.
Has anybody tried hi-temp Loctite (or the like) on threaded ends of valve and piston rods? (I'm not planning to rely only on thread lock compound).
Mike, I second your questions; anything except Monel probably does corrode under the right/wrong conditions; McMaster calls their oil hardening drill rod "Grade O-1", no "SAE" in sight.
Peter</HTML>
Minimal machining is a real plus, though the Schick blueprints say assemble and turn the rods concentric with the pistons (not necessary?). Glad to hear that the drill rod comes annealed; thanks for the machining tip. Yep, drill rod, and cold-rolled rounds, mike out dead-on, rarely do I find a piece that is even a tenth off of nominal. Sure would be nice to just cut rods to length, thread the ends, and screw 'em into the valves, valve stem jaws, pistons, & crossheads -- unless Schick was right about turning for concentricity. Then again, almost any engine, even a "rigid" design at light load, probably flexes more than any miniscule concentricity error from the simplified "thread and screw" approach.
Has anybody tried hi-temp Loctite (or the like) on threaded ends of valve and piston rods? (I'm not planning to rely only on thread lock compound).
Mike, I second your questions; anything except Monel probably does corrode under the right/wrong conditions; McMaster calls their oil hardening drill rod "Grade O-1", no "SAE" in sight.
Peter</HTML>
Re: long distance testing '95
Posted by: Ben in Maine (IP Logged)
Date: July 04, 2004 11:19AM
<HTML>Hi,,Can a few of the boys tell us what they find for piston bore clearence,,,,My memory says its a loose fit,,,if ya call it a fit at all,,,,Seems like there was varience too,,,Making a oversize piston and turning on centers to get it conenteric ,,,this would be easier I think,,,,If you are to machine the rod ,, it should be ground,,unless you are good at NOT getti'n a barrel shape on a long shaft,,,,follower rest etc, If youve got a new lathe ,,that helps too Most of my work has been done on lathes of same age as the cars,,,,haha,, ,, Cheers Ben</HTML>
Re: long distance testing '95
Posted by: Rolly (IP Logged)
Date: July 04, 2004 01:29PM
<HTML>Hi Ben
I always take the final piston cut with the piston on the rod and the rod held in a collet and the piston end in a center. I leave five thou clearance all around between the piston and wall with Iron pistons and around ten for aluminum. It depends on the diameter of the bore. On the big seven-inch low pressure of my big compound I left around fifteen. The ring does the sealing. I assemble the engine without rings and make sure the piston goes up and down with the same clearance around the top as well as the bottom. It’s the only way to make sure the cross head is aliened with the bore.
I then pull the wrist pin and pull the piston up out of the bore to install the rings. Again it depends on the type of engine your working on. On some engines the cross head is all one with the rod. Others the rod is one with the piston. Most marine engines the rod is one shaft and the piston and crosshead block are separate parts. When I use aluminum pistons I heat them up in peanut oil to the expected running temperature of the cylinder and mike the diameter to make sure they still fit the cold bore of the cylinder with a few thou.
Rolly</HTML>
I always take the final piston cut with the piston on the rod and the rod held in a collet and the piston end in a center. I leave five thou clearance all around between the piston and wall with Iron pistons and around ten for aluminum. It depends on the diameter of the bore. On the big seven-inch low pressure of my big compound I left around fifteen. The ring does the sealing. I assemble the engine without rings and make sure the piston goes up and down with the same clearance around the top as well as the bottom. It’s the only way to make sure the cross head is aliened with the bore.
I then pull the wrist pin and pull the piston up out of the bore to install the rings. Again it depends on the type of engine your working on. On some engines the cross head is all one with the rod. Others the rod is one with the piston. Most marine engines the rod is one shaft and the piston and crosshead block are separate parts. When I use aluminum pistons I heat them up in peanut oil to the expected running temperature of the cylinder and mike the diameter to make sure they still fit the cold bore of the cylinder with a few thou.
Rolly</HTML>
Re: long distance testing '95
Posted by: Mike Clark (IP Logged)
Date: July 04, 2004 05:25PM
<HTML>Rolly,
Aluminium pistons???? I feel another thread starting! Has anyone tried them in a Stanley? One of my engines had them when I got it but I took them out as I was a non believer.
On piston clearances - after I broke a block I had to use another which was very worn, at least 10 thou oval towards the bottom and corroded as well. It seems to work perfectly with the exception that the engine is a bit more prone to lock up with steam both ends when manoeuvering - just have to open the cylinder drain and restart. Once moving I can't find any difference from the original block which was almost unworn in the bores.
Mike</HTML>
Aluminium pistons???? I feel another thread starting! Has anyone tried them in a Stanley? One of my engines had them when I got it but I took them out as I was a non believer.
On piston clearances - after I broke a block I had to use another which was very worn, at least 10 thou oval towards the bottom and corroded as well. It seems to work perfectly with the exception that the engine is a bit more prone to lock up with steam both ends when manoeuvering - just have to open the cylinder drain and restart. Once moving I can't find any difference from the original block which was almost unworn in the bores.
Mike</HTML>
Re: long distance testing '95
Posted by: Rolly (IP Logged)
Date: July 04, 2004 07:05PM
<HTML>Mike
Aluminum should be fine in a Stanley; you just have to watch your clearances. It would reduce the reciprocating weight. You might want to install a shoulder insert at the threads.
Rolly</HTML>
Aluminum should be fine in a Stanley; you just have to watch your clearances. It would reduce the reciprocating weight. You might want to install a shoulder insert at the threads.
Rolly</HTML>
Re: long distance testing '95
Posted by: Peter Brow (IP Logged)
Date: July 06, 2004 12:55AM
<HTML>The guideline I saw for iron piston clearances in a steam engine was .001" (each side) per inch of bore. Aluminum pistons in steam engines, hm. Longtime steamerites tell me no. Maybe for low-pressure saturated steam. Even if you compensate for thermal expansion, aluminum's strength drops off pretty quick as you approach typical steam car engine temperatures. You might have to "beefitize" too, eating up some weight savings. I also wonder about wear and corrosion. Cast iron is much harder and absorbs oil for corrosion resistance. Lots of room for improvement around a steam engine, but carefully.
Erratum: the steel rods I have been looking at are cold drawn rather than cold rolled. Rolled rounds don't have the same close manufacturing tolerances as drawn.
Ben: right on, another reason to start with accurate stock and just thread the ends, like David does, instead of doing the travelling rest thing.
Rolly: good idea. Wonder if putting the rod end in a Jacobs chuck would do as well as a collet? 4-jaw would probably be better than either, though slower setup.
Peter</HTML>
Erratum: the steel rods I have been looking at are cold drawn rather than cold rolled. Rolled rounds don't have the same close manufacturing tolerances as drawn.
Ben: right on, another reason to start with accurate stock and just thread the ends, like David does, instead of doing the travelling rest thing.
Rolly: good idea. Wonder if putting the rod end in a Jacobs chuck would do as well as a collet? 4-jaw would probably be better than either, though slower setup.
Peter</HTML>
Re: turning piston rod/collet
Posted by: Ben in Maine (IP Logged)
Date: July 06, 2004 09:24AM
<HTML>Hi,,,The collet will hold pretty close,,,the jacobs chuck wont even come close,, ,,, 4 jaw to collet,,,,a toss up,,,is the 4 jaw a modern one,,what shape is the lathe in / is the stock on size ? ,,and is it a good fit in the collet,,? or are you prepared to bore a collet to size [as in a pot collet],,worst case,,to put on the faceplate and a drive dog to get enough power to make the cut,,,I'd probably suffer through w/ lighter cuts,,,,Cheers Ben</HTML>
Re: turning piston rod/collet
Posted by: Peter Brow (IP Logged)
Date: July 06, 2004 09:58AM
<HTML>Hi Ben,
The 4-jaw is original to this 1965 Craftsman/Atlas, not sure how modern that is, but about as old as my car too, which is far from modern, dials in perfectly and no taper that I can measure, the lathe that is. I'll look into collets, some parts/accessories that fit this thing are getting hard to find (well, found nice new Bison 3-jaw & live center), dog and faceplate doesn't sound too tough ("he said wishfully"). Pot collet, hmm, do have a full set of boring tools ...
Peter</HTML>
The 4-jaw is original to this 1965 Craftsman/Atlas, not sure how modern that is, but about as old as my car too, which is far from modern, dials in perfectly and no taper that I can measure, the lathe that is. I'll look into collets, some parts/accessories that fit this thing are getting hard to find (well, found nice new Bison 3-jaw & live center), dog and faceplate doesn't sound too tough ("he said wishfully"). Pot collet, hmm, do have a full set of boring tools ...
Peter</HTML>
Re: long distance testing '95
Posted by: Arnold Walker (IP Logged)
Date: July 06, 2004 05:34PM
<HTML>You using soft jaws or hard for the 4 jaw.
If soft you are right about trueness on an old machine.
Use to light cut them and the stand pads on the VTL lathes doing much larger parts.
Than you are talking on 50 year old machines.
Would come truer everytime on 4ft gears and 12ft shafts.</HTML>
If soft you are right about trueness on an old machine.
Use to light cut them and the stand pads on the VTL lathes doing much larger parts.
Than you are talking on 50 year old machines.
Would come truer everytime on 4ft gears and 12ft shafts.</HTML>
Re: long distance testing '95
Posted by: Terry Williams (IP Logged)
Date: July 06, 2004 06:36PM
<HTML>I think a collet would be best. With the piston up close to the headstock, what do you indicate off of to set up the 4 jaw?</HTML>
Re: long distance testing '95
Posted by: Peter Brow (IP Logged)
Date: July 07, 2004 07:29AM
<HTML>Arnold: Hard jaws.
Terry: I'm going to try it between centers w/dog and faceplate. It's the most accurate way. A recovering Atlas lathe aficionado just told me that he thinks suitable collets cannot be had for my lathe anyway.
Peter</HTML>
Terry: I'm going to try it between centers w/dog and faceplate. It's the most accurate way. A recovering Atlas lathe aficionado just told me that he thinks suitable collets cannot be had for my lathe anyway.
Peter</HTML>
Re: long distance testing '95
Posted by: Terry Williams (IP Logged)
Date: July 07, 2004 10:15AM
<HTML>Use 3AT collets for your lathe. The adapter and closer are expensive, however.</HTML>
Re: long distance testing '95
Posted by: Ben in Maine (IP Logged)
Date: July 07, 2004 10:44AM
<HTML>Hi,,,Make a test piece on junk scrap,,,to see that you don't turn a taper,,,,I cant recall everyones expertese,,so some of my comments are for the penut gallery,,,Good luck,,Ben</HTML>
Re: long distance testing '95
Posted by: Peter Brow (IP Logged)
Date: July 09, 2004 09:18AM
<HTML>Thanks Terry! Too small for my piston rods (need 5/8"), but these might come in handy for some other jobs ...
Peter</HTML>
Peter</HTML>
Re: long distance testing '95
Posted by: Andy Patterson (IP Logged)
Date: July 09, 2004 07:38PM
<HTML>Hi Peter
You might be able to use these:
[cgi.ebay.com]
Is your chuck adjustable to center. I have a Buck chuck and it has set screw adjustment to true up center. A dial gage and a little tweeking in the chuck adjustment screws and it can be dialed in to true.
Some times a rubber mallet helps.
Andy</HTML>
You might be able to use these:
[cgi.ebay.com]
Is your chuck adjustable to center. I have a Buck chuck and it has set screw adjustment to true up center. A dial gage and a little tweeking in the chuck adjustment screws and it can be dialed in to true.
Some times a rubber mallet helps.
Andy</HTML>
Re: long distance testing '95
Posted by: Peter Brow (IP Logged)
Date: July 10, 2004 09:30AM
<HTML>Hi Andy,
Well whaddya know, it does. After reading your post, I dug up the intriguingly-translated 24 pp instruction manual for the Bison 3-jaw chuck, cut open the sealed plastic bag ("when all else fails, read the manual"), and found a section about adjusting the "desired accuracy". A bit like reading one of those cryptic WW2 flying saucer blueprints. Apparently this is a more sophisticated device than I had noticed at first, with 3 adjusting screws, a lube fitting, and various and sundry other curious features. I am used to a simple 4-jaw chuck, and had figured this was just a big version of a Jacobs chuck for quick-setup low-precision work. From the serial-numbered Euro-font "Inspektion Card", I take it the Machine Masters of Gdansk have done their precision magic already, as I'm sure "Mr. Starrett" will confirm. A few whacks with ye olde Leather Mallet and I'll really need the adjusting manual. :)
Will it hold its center adjustment, or would I have to true it up every time I change workpieces?
From The Manual: "Turning on the machine tool with the wrench engaged in the chuck is forbidden." LOL. Forbidden. Well, that's one way of looking at it ...
Peter</HTML>
Well whaddya know, it does. After reading your post, I dug up the intriguingly-translated 24 pp instruction manual for the Bison 3-jaw chuck, cut open the sealed plastic bag ("when all else fails, read the manual"), and found a section about adjusting the "desired accuracy". A bit like reading one of those cryptic WW2 flying saucer blueprints. Apparently this is a more sophisticated device than I had noticed at first, with 3 adjusting screws, a lube fitting, and various and sundry other curious features. I am used to a simple 4-jaw chuck, and had figured this was just a big version of a Jacobs chuck for quick-setup low-precision work. From the serial-numbered Euro-font "Inspektion Card", I take it the Machine Masters of Gdansk have done their precision magic already, as I'm sure "Mr. Starrett" will confirm. A few whacks with ye olde Leather Mallet and I'll really need the adjusting manual. :)
Will it hold its center adjustment, or would I have to true it up every time I change workpieces?
From The Manual: "Turning on the machine tool with the wrench engaged in the chuck is forbidden." LOL. Forbidden. Well, that's one way of looking at it ...
Peter</HTML>
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