How far does a Stanley reverse pedal travel? What foot pressure is required to move the pedal, with no steam pressure in the valve chest? Has anybody measured these? I am designing the reverse pedal and valve gear return spring for a similar engine, and some road-tested parameters would save cut and try later.

Peter

Peter
My 1920 Stanley
At the engine the Stephenson link pins for the valves on a 20HP engine are 3 inches apart. In the slide about 3-1/2 inches from full gear to full reverse. The pedal has a travel of about eight inches over all. I have never measured how far it takes to reverse the engine but I would guess at least six or seven inches or two to one ratio. I no longer have the car so I can’t go out and verify it.

Rolly

Which model of Stanley do you need the specifications for? They are not all the same.

Peter

Pedal pressure to reverse when steam chest is not pressurised is almost nothing, just the force needed to stretch the return spring.

Mike

Thanks guys. This one may not be as crucial as I was thinking, maybe just a matter of cut and try until I get a setup that works. There is room to try a wide variety of spring sizes in tuning.

Rolly, your link figures match the 20 hp Stanley blueprints I have. Thanks for the pedal travel & leverage estimates, those sound workable.

Pat, I figured the pedals would vary somewhat between years and models. Since I am not making a Stanley replica, but rather an original new design based on the Stanley, maybe a better question would be something like "what reverse pedal travel & spring pressure are the easiest or most pleasant to operate in driving?" Perhaps some years/models required unpleasantly long (or short) foot motion, or too much (or too little) foot pressure, or have been modified for better results. I have found that some gas cars have a nicer travel/pressure "feel" to the brake or throttle pedals. For example, personally, I don't like a brake pedal that is too light, like some overboosted power brakes, where the brakes lock up with the slightest touch on the pedal. My current-project engine/valve gear is roughly equivalent to the 3.25 x 4.25 Stanley (later "10 hp"). To be more precise, the valve gear is practically an 80% scaled version of the Model 740 valve gear, for my 4" stroke engine.

Mike, sounds like the reverse pedal spring is quite light. This makes sense, as there is(?) no need to allow the pedal to return while there is significant pressure in the valve chest. Maybe I should just spring it to overcome the mechanical friction & weight of the pedal, valve gear, and linkage. Plus a bit of extra spring pressure to allow for long-term spring fatigue. As long as road shocks or (hard) braking don't bounce the pedal to & fro, and the links/eccentric rods don't drop themselves into hookup or reverse due to gravity or engine bounce. My design is close enough to the late-10hp Stanley that whatever pressure/leverage those have, should work in mine too.

Peter

HEY,,,GUYS,,,HEADS UP,,,,What is the valve gear,,,piston v or flat slide D valve,,,,REMEMBER that the links will pull [ strongly ] in the direction the engine is go'in,,,,,even with the ball bearing eccentric straps,,,you pull to a grade crossi'n,,,hold the car on the throttl,,,,,she goes back a few inches,,,,WOW,,,,the pedal SLAMMMMMS down on your foot,,,enough that your toenail will fall off in a few months,,,,GRRRRR,,,NOW you have reverse on a chest full of steam,,,,NOW DONT YA WISH THAT SPRING WAS UNCOMFORTABLE STRONG,,, Down hill on a Loco,,,,Throw your leg over the tiller bar to go straight,,,and use 2 hands on throttle and reverse,,,, The reverse will not stay in the reverse position going down hill [foreward] LINKS WILL TEND TO GO IN ENGINE DIRECTION,,,,,Hey guys,,,remember where the hell you are before ya get us hurt,,,,i do like the reverse lever on the black racer,,with nice dogs,,,thanks BUCK,,, I LOVE IT,,,Cheers Ben///pardon errors,,,my screen went out of focus,,but I get this out anyhow,,,cb

How long in time DO you plan to reverse ? Yes a friend once drove 5 miles in reverse,,,around a rotary,,,,past the state police barracks,,,down main st center of town, and up county road,,,,'52 Chev convertable,,,had only park,neutral and reverse,,,and my garage had heat in Jan aaah,,,memories,,,Ben

Dear Peter, on the last 10 hp Stanleys built, the pedal spring pressure to push both pedals into reverse on our model 606 is about 14 pounds. The release pedal only takes about 4 pounds to disengage the hook up. In full valve, the hook up release pedal stands about 2 " in front of the valve pedal. The valve pedal is depressed exactly 2" to engage the hook up notch for the hook up dog. From full valve to reverse, it is a total of 5 inches of pedal travel until it is all the way into reverse. The hook up notch and engaging dog fit very close into each other. A close fit is needed to keep them engaged. If it is a sloppy fit, you can more easily accidentally slip out of hook up and into reverse. As Ben said, they slip easily into reverse when given the slighest excuse. My fear of an unexpected backing up, isn't so much the black and blue toe nail that results from getting your foot trapped under the reversing pedal, but the sudden unexpected crunch of the new car that you just accidentally backed into when you had expected to pull away in a forward direction. Another reason for having a tight hook up notch is that with a loose notch, the pedals will rattle back and forth with each power stroke of the enginge. Our 10 h.p. valve hook up is in perfect timing. With over 25,000 miles that we have put on it, we know the car very well. I had to locate my hook up notch on my model 85. The first notch that I made was a little too far and it rumbles a little when used. The second notch that I made was just about right, but maybe hooked up a little too soon, so it might be wasting steam. So now I have two hook up notches and they are very close to one another. The discovery here is that there isn't much room between right and wrong in placing your hook up notch for your hook up dog. Two different ways to determine where to put your hook up notch is one: to grip vise grips on the quadrant where the valve pedal will be while in hook up and drive it.(on level ground) Keep adjusting the vise grip stop until you have found the smoothest and farthest hook up position. The second way is like what Jeff Theobald did for his model 85, he used a wedge between the floor board and the hook up pedal and adjusted the wedge until he found the correct hook up location. The vise grips worked best for me. Maybe if both methods were used, a person would end up notching the hook up quadrant only once?

Hi,, A friend of mine made 4 hook dogs,,,all different lengths,,they are not as simple as they look,,,nice job tho,, On reversing,,, That is why TAIL LAMPS are worth twice the price of sidelamps,,,Cheers Ben

Hi Ben and Pat,

This is some fascinating food for thought. Thanks! I was planning on piston valves for many years, but my current design has good old D-slide valves. That's a whole long story on its own. No offense intended to anyone's technological preferences, but personally I think that there are 2 kinds of steam car engine valves: flat slide valves, and valves which are impractical.

One of several changes from the Stanley in my engine design, which is now completely blueprinted except for some details of the outer case, is the cutoff lock. Instead of using a dog and notch like Stanley engines, I have a fixed quadrant plate with a locking pin (like a Yale lock tumbler but much heftier) that drops into a hole in the cutoff lever (more of a pivoting sector) at the short-cutoff position. This was a bit of an engineering job, calculating the strength of the Stanley setup and working out a lock-pin arrangement of equal strength (actually stronger for margin of safety). The whole thing is inside the sealed oil-bath crankcase to avoid excessive wear and corrosion from insufficient oil and plentiful road grit/salt.

With this, if the links decide to move themselves out of long forward cutoff, they will go to short cutoff, and then the well-sprung pin drops and locks them there. No continuing on to reverse or foot/vehicle damage (yowch!). I swiped Doble's idea of having the hand brake lever open the valve chest drain. Besides preventing a wandering car if the throttle leaks, and giving handy remote control of the drain valve, this can also double as an engine pressure relief. If she rolls back under pressure and you hear the pedal click, then you can vent the engine pressure (one click back on the handy handbrake = drain open, brakes not engaged, for cold-engine draining while underway), then unhook the pedal back to full forward. I have designed a vertical handbrake lever, whose handle is a few inches from the throttle lever for a quick instinctive grab if needed.

It occurs to me that this might not handle the equal and opposite situation, which is having the pedal down to reverse, and the car rolling forward with chest pressure and links reversing themselves back to forward, if that makes any sense. That could happen when backing uphill. However, at that point, you can "stand on the pedal" to stop it -- hopefully. I don't know if the kickback on the pedal would be more than I can resist. Then again, I've never seen or heard any mention of a problem with "self-forwarding" while backing uphill. The self-reversing problem is mentioned, I think in the 735 Owner's Manual, and some other places.

Thanks for the interesting and very useful notes on locating the quadrant notch, Pat, and on lengthening the dog, Ben. At first I wanted an adjusting screw to pivot the cutoff lock pin housing around for fine adjusting of the short-cutoff lock position. Trying to design this into the available space, with the needed strength, drove me just about bonkers, like a lot of my other later-discarded Rube Goldberg initial ideas. So I went to a simpler fixed-position short-cutoff lock hole & pin housing.

My previous idea for accurately locating the lock pin hole & short-cutoff link position was to put a regulated trace of compressed air (perhaps a few oz per sq inch pressure) on the engine, and lock the engine with one of the cylinder ends at 28% of stroke (the reported Model 740 short cutoff). A test plug on that cylinder head would be open, with a thread hanging over it as an airflow indicator. Then move the links with a bolt-on fine-adjusting screw to find the valve closing position, lock & mark the quadrant, and drill/ream the hole in the sector with drill bit thru the locking pin guide. However, the wedge and vise-grip methods sound better, because they adjust for actual good running on the road, compensating for bearing slop, differential thermal expansion, machining tolerances, leakage, stretch/flex of components under load, and all the other things that sometimes gang up to make that dusty bottle of single malt look mighty inviting. Hope FE & FO didn't hear me say that. I will try the pedal wedge & visegrip. Maybe I can use the air and thread trick to find a beginning wedge/visegrip setting to fine-tune, assuming I get the thing built and ready to run.

===============

Mike: for some reason the above reminded me that I recently found some digital video clips I took during the H5 run in 2005. If I can figure out the video format & posting protocol (I'll need some internet coffeehouse PC wonk advice) -- no guarantees there -- I would like to post these on YouTube for public viewing, if that is OK with you. Lots of engine chuffing, burner howl, and legendary Stanley performance, not to mention that Yorkshire Moors "traffic jam" with the flock of sheep ("see a Border Collie at work", guess I'm a sucker for working dogs; darned impressive). One clip includes your recounting of the story of Dead Man's Hill. It was a lot of fun, really an unforgettable experience, and I think others would enjoy seeing a passenger's-eye-view of a tour in the legendary Stanley Gentleman's Speedy Roadster, in the stunning Yorkshire countryside no less. Now I wish I'd taken more video, but as it is I think I played the "Tourist With Camera" thing to the hilt.

Peter

Yes Peter that's fine with me - look forward to seeing it.

Just come back today from the wonderful Goold establishment having collected my engine following repairs needed when a piston rod let go at the end of August.

Failure was due to my using ball style crossheads in deference to originality - big mistake. The ball type, like the roller version introduces a nasty seesaw rocking action on the piston rod where it joins up with the crosshead - snapped clean off and fired the piston through the front end of the block. We changed it to a bronze slide crosshead, beefed up the rod and put a nice fillet, more like a blend, between the rod and the crosshead. That's the snag with the Model F / Model H light 20hp engine - its was just not strong enough for the work it can do. Just as well I'd already made a spare block!

Mike

The main reason that the ball bearing cross heads were first used was because of a dry crankcase needing hand oiling often. The hand oiling stayed with the ball bearing cross heads much longer than it would have with the wiping action of the bronze cross heads. I have ran the later style bronze cross heads without the engine cover in place and the bronze cross heads quickly become dry of oil where the ball bearing cross heads would still be well lubricated. On all my engine rebuilds where I have a wet crankcase, I always install bronze cross heads of the condensing car style. The bronze cross heads are easier to adjust, give better support, and there won't be any of the cross head ball bearings that can get loose and get into the crankshaft drive gears. It was more than couple of times that I had dropped the engine cover to find where a cross head ball bearing had knocked off it's stop and it was laying in the bottom of the engine cover.

Hi Mike,

Thanks; I will post a link here when I get the videos on YouTube. I am sorry to hear of your engine breakage, but glad that it is now all fixed up better than new. A fine running car to begin with, and now it's even better. I finally saw the Goold Model M video, man what a car, a great restoration job, and great video too. They know their stuff! The "seesaw" action is one thing I had wondered about with ball-bearing crossheads, which I was considering for a while. Currently my engine design includes Model 740-style "sliced piston" crossheads; hardened/ground crossheads on shim-adjustable cast-fit "best babbitt" slides. This type of crosshead (reportedly added to the 740 engine by Eric Delling) gives a sort of "U-joint" action, to compensate for engine frame flex. I also found a way to increase the crosshead bearing surface substantially without sacrificing mechanical strength or increasing the reciprocating weight.

Pat and Ben:

Thanks for the spring force and late-10hp reverse pedal travel numbers. Also for the notes on migrating links. Very useful info, and much appreciated. I will design for that pedal travel. Yesterday I did some ergonomic experiments and found that pedal pressure doesn't start to feel "heavy" until about 50-60 lbs. 14 pounds of pedal pressure felt extremely light. So there's room for much higher reverse pedal spring pressure to combat link drift. Even the engine just hooking up on its own, without reversing, is undesireable. Like you said Ben, how long is the car going to be in reverse anyway?

One of the reasons I designed the cutoff lock-pin mechanism is that the dog-and-notched-quadrant looked like a tricky fit on the Schick blueprints. Lots of odd angles to mill on that dog; I'd probably be screwing around with precision jigs & fixtures for quite a while to get it right. The lock pin mechanism looks easier to build & repair, with tight tolerances and positive locking, even when worn. Once tuned/located, the lock pin hole will be drilled with everything in place on the engine; the pin guide bore acting as a long drill bushing.

Peter

Hi Ben,

At first I overlooked your comment about engines not staying in reverse while going downhill. Just noticed it. Is that just a Loco problem, or a problem with Stanleys too? A heavier reverse pedal return spring would make holding it in reverse harder ...

Peter

Hey, here's an idea. Separate reverse and short-cutoff pedals, which each lock in place when pushed. Engine also locks in full-forward gear if neither of these pedals is down. Then, a small separate pedal off to the left (or just above left foot rest) releases both the cutoff and reverse pedals, returning engine to full-forward gear. Add the brake pedal, and now you've got 4 pedals! An appropriately scary idea for Halloween, I think. Even scarier is the fact that this would actually be pretty simple mechanically, and it would eliminate all worries about Stephenson links with a mind of their own.

4 pedals isn't that bizarre when you consider manual-transmission gas cars with pedal-style parking brakes or (older models) horn, starter, or high-beam buttons on the floor.

This might actually be easier to operate than the Stanley setup with small release button inside the reverse pedal, and the part-way push to hook up. On this one, each of the 3 valve gear pedals is simply pushed as far as it goes, when needed, and no aiming your foot to hit or avoid a tiny release button. Reverse pedal for reverse, cutoff pedal for short cutoff, release pedal to release pedals to full-forward gear. Simple. :)

The release pedal could be called the "forward pedal" instead.

Great way to discourage car thieves, too!

Peter

Hi,,,All stevenson link reverse engines will tend to have the links follow the direction of the crank,,,so they put in ball eccentric straps,,which improves the situation but by no means eliminates it,,Locomobile had a detent of sorts as I recall,,,but in a pinch the lever will overpower the detent,,,whammo,,chest of steam and full gear ahead,,one [white] hand on the tiller,,,one hand on the throttle,,,1 foot on the brake pedal,,,ya got a spare foot,,,the infamous footloose,,haha,,,now I think ya got the idea,,,Stanley put the reverse on the pedal so that extra foot would have a job to do,,I think it was really a great stunt for Richard Dickey to have brought this early gymnastic manuuver of the earlydays, to light,,,Hang your leg over the tiller bar,,, and use the 2 hands on the throttle and reverse levers,,Isn't it wonderful that we have improved autos so that they are easy and CASUAL to opperate,,,hmmm,, A good lot of the early cars did not have either a parking brake or reverse,,Ya just picked it up by the front springs and turned it around,,,the rear,,boiler,engine end was the heavy end,,, Oh yes,,,Stanley went to pedal reverse in 1900--01 Locomobile did not,, Cheers Ben

Hi,,,I'll go with the WHITE latching levers,,,Ben

While driving forward, the reverse is easily applied for reverse braking and the pedal stays where your foot holds it. I have never had the hook up pedal being sucked out of reverse while rolling forward. But while rolling backwards the hook up pedal easily gets sucked to the floor. An interesting note about our 1916 Stanley Mt. Wagon. It has a hook up notch in reverse. While backing up, it is appreciated that you don't have to keep your left foot mashed to the floor while you are stretching you neck to see in reverse. The down side of a reverse hook up notch is if I forget to unhook from reverse, a few times I have accidentally started out in the wrong direction.

Hi,,,,Hmmm,,,,I have had 2 different engines/cars,,,and the wrong loose eccentics were fitted !!! One car would usually but NOT always reverse,especially when cold,,,and the other would always reverse,,BUT not always go foreward,,,NOW heres the glitch,,,full gear ahead,,open throttle no go,,600# IN THE CHEST,,,iF YA PUSH THE PEDAL,,,IT WILL BE AWFUL TIGHT,, BUT IF IT MOVES ENOUGH TO OPEN A STEAM PORT ALL THAT PRESSURE WILL CAUSE THE ENGINE TO REVOLVE AT LEAST A REV OR 2,,backwards,BRISKLY,,,There goes another taillamp,,,grrr,,,Same senario the other way round,,,JUST remember if it don't go,,OPEN THE CHEST DRIP FIRST,, I think the owners manual says something about''''USE EXTREME CAUTION WHILE BACKING",,,,hohoho,,, Weather,temp=20d at 7am water temp at Portland 51d,,,Mood ;-{ If my mood goes downhill,,dont take it personally,,,Cheers Ben

SSsssteamer Wrote:
-------------------------------------------------------
> The main reason that the ball bearing cross heads
> were first used was because of a dry crankcase
> needing hand oiling often.


That's why I have a lot of drip feeds on my engine and am now working on a few more to help the slides.

Mike

Ben, did White use a hand lever for reverse and/or cutoff? I only have the '09 M/O manual, and that shows a pedal for cutoff, with Joy gear by that time. I think the Stanley brake lever was better, with the release lever behind the main handle (in driver's palm) instead of in front (under fingers) like White and many others. The latter approach has 2 hand jives to operate, different for setting and releasing brake; the former has the fingers going to the same place either way. Looks easier to get your hand around the Stanley style brake lever handle. Some years ago I read that squeeze-release levers take a hair less effort than thumb-button levers. Thumb buttons won out because they were pennies cheaper to mass-produce.

I considered a hand lever for reverse/cutoff control. One option was "three on the tree" (F, R, & Cutoff, the indicator would be a "FRiCk" rather than a "PRiNDLe"), lever on steering column. I may yet try 3 on the tree, or 3 on the floor, but for this project I plan to use a reverse pedal to keep my hands on steering wheel & throttle.

The Locomobile gymnastics you mention remind me of the many photos I've seen of early racers hunching over in their horseless carriages to reduce air drag -- which made a difference. Automobile driving was a whole different thing "back in the day". More athletic, and sporting, than with today's cars. The same type of driving experience today requires a motorcycle -- or antique car.

Pat, I am glad to hear that Stanleys don't slip from reverse into forward. A reverse-hookup as in your Mountain Wagon should not be necessary, just hold pedal down for reverse, and release pedal to go forward again. Personally I'd rather back up with my left foot on a reverse pedal, than risk forgetting to unhook a pedal (or a hand lever) from reverse. One less operation to go from reverse to forward. Foot and pedal on floor are constant reminders to driver that the car is in reverse.

Hope I don't jinx it by mentioning this before dimensioning/blueprinting, but I sketched up a reverse pedal with hook-up button which looks and operates exactly like a condensing-Stanley reverse pedal. However, this design incorporates an extra gizmo under the floorboards to automatically lock the valve gear in full-forward and short-cutoff positions, with automatic release. Looks simpler than it sounds. I think that this will eliminate the nuisance and hazard of a Stephenson link engine slipping into reverse under some conditions. This pedal (~5" travel, ~14 lbs spring) would still be held down for running the car in reverse. Possibly retrofittable to Stanleys, though that would also require valve gear modifications.

Peter

The reversing pedals require two springs, not just one 14 pound spring. The main reversing pedal requires one spring with a 10 pound pedal resistance, and the latching pedal requires one spring with a 4 pound resistance. When you push the reversing pedal towatds the floor, you have the combinded effort of both springs to push, or about 14 pounds. To release the hood up dog, it only requires 4 pounds of pedal pressure to lift the hook up "dog" out of it's notch to returned the pedal to full admission.

Ben, never mind my question about the White reverse lever. I just reviewed the M/O booklet, and spotted the locking reverse lever. Don't know why I thought the cutoff pedal would do the reversing too. White steam cars are very different from Stanleys in many ways. Interesting control cluster on those models of Whites: 3 pedals and 3 hand levers, plus of course a throttle _wheel_. No more complex than most gas cars of the day, of course. Come to think of it, not too bad by today's standards, when you consider gas, brake & clutch pedals, and handbrake and gearshift levers.

Pat, thanks for the clarification. Oddly enough, I had already specified an off the shelf 4 lb spring for the lock pin, before I even knew the 10hp Stanley hookup spring tension. OK, so that and a 10 lb pedal spring, 14 lbs _total_. The mechanism I am working on, to lock the links in both full forward and hooked up positions, can be used with either 2 pedals "side-by-each" (as in early Stanleys), or one pedal with a hookup button on it (later Stanleys). Is there any difference in ease of operation, maintenance, etc between the 2 setups? Now is the time for me to consider these kinds of things, to avoid as many already-known problems and redesigns/rebuilds as possible, down the road.

Peter

Because they were a later developement, I would assume that the later pedals with a hook up release pedal would have the least problems. Make sure that your new springs are no shorter than 7 inches between the eyes. The longer the better gives you more of a linear pull through out the pedal's travel.

Spring length depends on leverage and availability, as I hope to avoid custom spring winding, but yes, the longer the better, for more consistent spring pressure/resistance throughout pedal travel, and also for less spring fatigue, important for durability. One rule of thumb I've seen in a few engineering books is about a 30% maximum flex for decent spring life. Preferably less, where possible. It's not just a worry-wart or perfectionist thing. Some firearms designers flagrantly disregarded this in the interest of compactness, and as a result various springs in the firearms they designed fatigue like crazy. Magazine springs in the 1911 Colt Automatic (even the brilliant Mr. Browning goofed on this!) & many other pistols, and all the springs in the 1896 "Broomhandle" Mauser pistol, are prime examples. The Mausers are noted for "eating" springs. I've replaced almost all on mine, and occasional "stovepipe" jams and 2 or more shots per trigger pull, tell me I still need to replace the firing pin and magazine springs, which are tricky to fit and costly, respectively. Spring fatigue is why some folks hold an auto pistol sideways (often seen in movies but laughed at in target ranges), and/or won't load a magazine to full capacity, and others (like me) still prefer revolvers for reliability.

The point being, spring fatigue is a very important factor to consider with any machine design using springs. I recently had to readjust the clutch switch spring on my "automatic stickshift" VW Bug, I'm pretty sure for spring fatigue reasons, as there was no other trouble that I could find.

Peter

Hi,,,the brake lever thum latch on White is on the front side because it uses "System Panhard" that is,, push foreward to engage brake,,,,, The early Stanley brake lever seems to have a more user friendly feel,,,some of the condenser cars have let go on me,,,not yet happend on earlier car,,,Pierce Arrow had a superb lever,, right up to and including the model 36,,in 1928,,Packard were ok as long as you kept sand from falling on the ratchet plate,,Meanwhile DON' PUT YOUR FINGER BEHIND THE LATCH on a Rolls Royce,,,as you pull back the latch goes ALMOST to the handle ,, Speaking of mousetraps,,,and it wont let go,,,and they never changed it,,,The Panhard levers work nicely,,including the "Progressive " in line shift,w/top button,,,just dont forget the JAKE BRAKE used around 1906--1914,,,really,,,Cheers Ben

Ben,

Would you share what you consider to be the best material/finish that has been used on these exposed levers, as to maintaince and feel.

Also, considering the different models and makes of cars you have experience with were more of these cast, forged or machined?

Thanks for your time!

Great topic guys,

Caleb Ramsby

Hi Ben, System Panhard brake levers, man I learn something new every day. At least when I'm listening and thinking ... which isn't always ... As Emily Litella used to say (apparently one of my unintentional role models), "Oh, that's different. Never mind". Some early brake levers had the teeth on the bottom of the ratchet, to avoid the sand problem. That's what I'm planning to do. Interesting to consider which is easier, pushing or pulling the lever. When researching this recently, I was surprised to find that thumb-button brake levers were used at least as far back as 1922; I found a bunch of them in my 1922 Dyke's Motor Manual. Come to think of it, probably a lot further back than that. Previously I had always assumed that these showed up sometime around the 1930s. Wonder how many Rolls mechanics were called out in days of yore to liberate careless chauffeurs from mousetrap brake levers? Yowch. I better leave a bit of finger room in there ... Jake brakes, neat stuff, effortless coasting down endless miles of mountain grades, but a bear to design/build.

=======

Getting the "classic look" with the new reverse pedal got annoying, and I gotta get going, so the heck with it, I'm going "form follows function" with a modern-looking reverse pedal. It's a modern project car after all, not an authentic antique replica. Reverse pedal is looking kinda like the Auto-Stick Beetle oddball brake pedal: twin legs to pivots on the floor, one leg at each end of a wide squaroidal pedal with curved ribbed rubber pad. As I recall, Eastwood has some black casting rubber for custom/resto pedal pads, etc, that's an easy mold. Hookup button inboard, as in 740s. Left foot rest in wide footwell, next to reverse pedal. At least you can't get your foot under this pedal, less painful in case the lock quits and the pedal sucks to the floor. The double-link-lock mechanism is now in the pedal, above the floorboards, with dust cover. Easier to design/build, and easier for service access too, though a little strange looking. I try to design things so a monkey can make them in 10 minutes for a nickel, with Soviet-tank-style primitive ruggedness. If it looks funny, oh well. Brake pedal can be identical to reverse pedal, except no lock mecha of course, and plugged hookup button hole. Why design 2 different pedals? No silver-faced custom gauges either, alas, probably dorky modern paper-faced industrial units instead, with standard brutal late-20th/early-21st C. industrial font and hooded dash lamps for night runs. Fortunately a number of other vehicle details look much easier to do "classic/retro style" than with plastics etc: off the shelf wood/brass Model T repro steering wheel, brass throttle lever (w/wood knob) and quadrant, brass-handled early-Stanley style brake lever, solid wood dash. Add a vaguely White/Packardish condenser grille with functional fill cap (easier than stuffing condenser under slick bodywork, form follows function), blended Rolls(or 70s-Mopar)-like into a retro/modern custom coupe envelope body, and it should be a weird mix of ancient and space-age. Possibly side-opening split hood, with piano hinge and prop rods, like Cadillac did with a recent concept car. At least that's my vehicle concept so far.

Peter

A brief follow-up. I designed the reverse pedal with locking positions in hookup and 60% forward cutoff. Looks very buildable and workable.

However, I am going to try the car without this new mechanism, just a standard hookup lock and 50 lb return spring (measured at pedal). Stronger spring, as Ben suggested. This is 5x the force to resist eccentric drag and link-reversing, relative to Stanley, yet it still gives a very reasonable pedal pressure to reverse. I suspect that this will eliminate the self-reversing problem, though a heavier spring might be needed. Also, as previously mentioned, I think that my lock-pin mechanism will stop the engine from reversing itself anyway. At worst, it would just snap into hookup, and then pressure is easily relieved with brake lever/chest drain, and the pedal unhooked.

This should be easy to test on a grade. Hold car uphill with steam, then let her roll back. I'll make sure the road is clear behind me first!

I am also planning on 1920s "Stanley look" (me like) brake and reverse pedals. I found a simple way to make them, and steel-faced pedals are more durable than rubber pads. Also 2" minimum clearance between reverse pedal and floorboards in case the pedal does "suck to the floor". No chance of foot injuries.

Has anybody tried and tested heavier-than-stock reverse pedal return springs in Stanleys, to eliminate the self-reversing problem? Seems like a simple mod that somebody must have tried at some point. Maybe the problem is simply that stock Stanley reverse pedal springs are too light.

Peter

Peter Don’t get carried away thinking this is a big problem. This is rare and the eccentric straps on the eccentrics would have to be two tight. The eccentric and strap are a bearing and, on a Stanley engine it’s a ball bearing. There is a certain amount of friction pulling the eccentric strap in the direction of rotation, but the strap is long and is attached to the link bar and that has the dog inside with more friction, It does not take much to overcome the drag of a ball bearing on the outer race, (the eccentric strap)

Rolly

Hi Rolly,

Thanks, yes I do get carried away with perfectionism sometimes. Sooner or later I tend to ask myself just how much cost/effort is justified to eliminate a particular problem, especially considering that some problems are very rare and/or easily-handled, and that with proper operation, steam cars are lots of fun, warts and all. It is an odd balancing act between doing the best I can do, and going overboard.

In this case, I am thinking that a 50 lb push on the reverse pedal is still very light, similar to typical clutch & brake pedal pressures, and it is a simple change. I tested the 14 lb push that Pat reported, and it seems practically nothing, like Mike said.

This leads to another issue, which is that I am currently planning seamless babbitt eccentric bearings, poured to fit and run-in, rather than ball bearing eccentrics. I talked to a number of people who have made these, and the consensus is that this is the best bearing one can make in a small shop. I also picked up all the Lindsay books on Babbitt bearings, and after reviewing these, I think that it looks very practical to do in my shop.

However, with these, it is possible that at low speeds, the eccentric drag and chance of self-reversing might be more of an issue for my engine than for a Stanley engine. On the other hand, my eccentric bearings are large (3" diameter, & 3/8" wide vs ~1/4" wide ball races), with polished journals "stepped out" in the middle (not coned) for good oil retention and to keep straps on eccentrics, and I'm planning to use a little graphite in the (clean, sealed-) crankcase oil. The bottoms of the eccentrics will dip into the oil too. So surface loading should be low and surface finish and lubrication should be very good.

I would rather use ball bearing eccentrics, but this would require either radical engine redesign for standard bearings [impractical engine width, etc], or custom ball bearings, because the bearing size needed is wildly nonstandard. Radical engine redesign radically reduces the chance of success, and custom ball bearings cost a fortune to shop out, and for me custom ball bearings are a bear to make myself, at least to make good ones. Poorly-made or poorly-adjusted ball bearings, or dirty ones, or in poor condition (pitted, brinnelled races, pitted balls etc), could easily have more drag & shorter life than a well-lubricated, good babbitt bearing.

I also wonder if oil/grease retention in "dry" engines was a factor in Stanley's original selection of ball bearing eccentrics, as with ball bearing crossheads as Pat notes. When they decided on ball eccentrics, all their engines were "dry" and hand-oiled, with sealed oil-bath engines not yet in sight.

I have blueprinted ball bearing crankpins and needle roller mains, BTW. It is hard to beat off the shelf modern antifriction bearings for the big rotating loads. Link ends of eccentric rods will carry hardened/ground shaft stock pins, flush with rod ends outboard and retained by set screws (unusual construction) in links, for mechanical clearance reasons. Pin-honed bearing bores in eccentric rod ends. I thought of pressing in bronze bearings there, prob alloy 660, and still can, but that may be gilding the lily. I found synthetic bearings for (clip-retained, straight ground/hardened shaft stock, not coned) wrist pins, with incredible load ratings, looks worth a try, and a hair of perfectionism got through with plain thrust bearings between conrod arms and crossheads, also on crankshaft. I found room to increase bearing surface areas just about everywhere, often substantially, without sacrificing component strengths or increasing costs, fabrication labor, or reciprocating weights.

There is one curious feature in the Stanley engine which I still haven't figured out. I am duplicating it in my engine, however. Bruce Green warned me about these engines being full of small details which look pointless at first glance but are actually important. At the ends of the curved slot in the Stephenson/Howe link, at least in Stanleys, there are little semicircular cutouts. Looking at the specified clearance/slop between the sliding block and the slot bearing surfaces, my guess is that the sliding/pivoting block tilts just a hair into these cutouts to help keep the link and block from sliding out of full-forward and full-reverse positions?

Peter



Edited 1 time(s). Last edit at 11/08/2008 01:09AM by Peter Brow.

I had noticed in the past the oversized hole at the ends of the Stephenson links too. I had deducted at the time that it was for the square block to get the fullest travel for the length of the link and yet for the end of the Stephenson links to not have any square corners to crack out from. That is why there aren't any square corners in airplane body designs. The windows, the doors, just about everything in the airplanes body has rounded out corners for added strength to prevent a corner from which a crack starts from. By drilling an oversized hole at the end of the link, the sliding block also can get closer to the link's end.

Hi Pat,

I think you are right. I should have noticed that I didn't need to add radiuses at the ends of the slot. Compactness and light weight are very important in automobile engines.

Peter



Edited 1 time(s). Last edit at 11/08/2008 07:09AM by Peter Brow.