Eccentric piston valve steam engine

[Bentwings]

Hi all .

I’m back to working on my two cyl double acting mill steamer from chilertern stem in UK this is a piston valve engine valve controlled by eccentric on crankshaft. There is no access to the ports in the steam chest without disassembling the entire thing . I am running on compressed air currently I was told this is ok and it should run on 30-35 psi just fine. The assembly instructions have a picture of the “ about “ position fo the eccentric with an all wrench sticking out of grub screw . Text says make it like the picture. LOL no kidding. After hours of fiddling around and additional hours of tease arching piston valves and eccentrics I did get it to run but a nut that holds the top of a piston came loose locking the engine up . This caused everything attached by grub screws to slip marring the crankshaft. It required entire disassembly. So it’s back together and by carefully moving the eccentric of one cylinder I can feel it try to turn over. I made a “ tool” threaded 1/4-40 that threads into the cylinder he’d so I can exactly position the piston at TDCor BDC and I can mark the fly wheel as needed by making the eccentric opposite on the second cyl is supposed to put air on the bottom of the #2 cyl. Thus making complet cycle. I have measured this dozens of times using my tool an very near digital caliper but no luck . I increased air pressure until it finally blew the line off stil “ no run. There are actually two of these engines that will be coupled together so twice monkey business. I’ve adjusted the eccentric through its entire stroke but the engine just won’t run let alone the second one which should be an identical one. I have no access to the internal ports so I don’t know where the exact “ lap” is or how much it should be . I found an interesting article on eccentric controlled piston valves. It would have been nice to have when I first assembled this kit . It looks simple enough but I just can’t seem to get the air directed to the bottom of the piston . I’ve checked the in let lines connections to be sure it is possible to have correct connections as I understand . Air intake and exhaust are easily accessible and easily changed

 

[timo_gross]

Can you disconnect the eccentric at the pin?
By moving the valve spool by hand you can check if the cylinder is moving in and out smooth. The picture from assembly manual shows that the allen key should point up when the cylinder is all the way in.
If the cylinder is not concentric with the slider (I am just guessing) it might move rel. free for most of the stroke. Then it binds on the last bit of travel.

Hope you get it to work.

 

[Bentwings]

The eccentric is two piece assemble that can be disassembled . Thank you. I YHINK I see where you are going here . Essentially operate the piston valve by hand untill it puts pressure on the bottom or back side of the piston . I’ll certainly give this a try I should be able to measure the power piston position exactly then duplicate it on #2 engine

Best advice yet . Gotta love this group.

 

[Charles Lamont]

Looking at the Chiltern website, most of these engines seem to have the exhaust port at the back of the steam chest. I presume the piston valve must be drilled to connect the two ends? Anyway, can you put a depth gauge down the exhaust port to measure the position of the valve.

 

[Bentwings]

I have a threaded to that I screw into th port to contact the piston I can measure this accurately with my digital very near then switch to the second cylinder . I’ve already don this part. The chilertern eccentric is a bearing with a flange in one side the you have th other side held in with screws the hub is secured with a grub screw. There realy is not much force against this grub screw . I have a replacement assembly that uses a clam secure nt system . Eventually all grub screws will be replaced by this method . I can accurately position the piston using the threaded stop. I’ve tried moving the eccentric to the point where it should apply pressure to the bottom or back of the piston but no success yet. I’m going to try the suggested method as soon as my home care has finished te settling me from hospital stay .

Thanks for comment .

 

[Bentwings]

I have a threaded to that I screw into th port to contact the piston I can measure this accurately with my digital very near then switch to the second cylinder . I’ve already don this part. The chilertern eccentric is a bearing with a flange in one side the you have th other side held in with screws the hub is secured with a grub screw. There realy is not much force against this grub screw . I have a replacement assembly that uses a clam secure nt system . Eventually all grub screws will be replaced by this method . I can accurately position the piston using the threaded stop. I’ve tried moving the eccentric to the point where it should apply pressure to the bottom or back of the piston but no success yet. I’m going to try the suggested method as soon as my home care has finished te settling me from hospital stay .

Thanks for comment .

The piston valve does move freely even the eccentric rotates smoothly too

I have a threaded to that I screw into th port to contact the piston I can measure this accurately with my digital very near then switch to the second cylinder . I’ve already don this part. The chilertern eccentric is a bearing with a flange in one side the you have th other side held in with screws the hub is secured with a grub screw. There realy is not much force against this grub screw . I have a replacement assembly that uses a clam secure nt system . Eventually all grub screws will be replaced by this method . I can accurately position the piston using the threaded stop. I’ve tried moving the eccentric to the point where it should apply pressure to the bottom or back of the piston but no success yet. I’m going to try the suggested method as soon as my home care has finished te settling me from hospital stay .

Thanks for comment .

spel check messed up again. I do have a threaded rod that I can screw in to contact the piston then I can measure exactly where the piston is as well as mark the flywheel .

 

[Bentwings]

The piston valve does move freely even the eccentric rotates smoothly too

spel check messed up again. I do have a threaded rod that I can screw in to contact the piston then I can measure exactly where the piston is as well as mark the flywheel .

Spell check did it again. Yes I have a threaded rod I can screw in the port to exactly measure piston location . I have temporarily marked the flywheel TDC and BDC. Any setting off from this I can also mark for reference . With some math trickery I can measure the cord distance then derive the degrees again for reference . Eventually I’ll mark the edge of the flywheel . The flywheel is not keyed so so marking exactly where the the flywheel needs to be locked down is a bit more challenging . But I can measure the crank position then set the flywheel accordingly . Trying the “ free moving of the piston valve was on thing I was getting close to before this last round of med issues. Now my elbow acted up, and I’ve been in hospital 4 days and thankfully have senior home care so I get almost daily nurse visits to inspect the surgery on my elbow . I think years of sports is catching up with me . I’m bandaged up soni can only bend my arm 90 deg plus minus a little barely enough to hold coffee cup. Try shaving with non dominate hand and arm. Already cut my cheek . My steamers are mounted on a nice cast iron base so easy to move around . Just holding and operating my digital very near ( calipers) . Is hard .
M in the process of moving to my sons home in Tenn as he says I can get better med care there and I’ll have hobby help as well as help him with Rc models grand kids are just starting sports so I’ll be drafted to help them I’ll still have a hobby room to myself so it will be better I think . I found a neat e bike so I’ll be able to ride with kids and go to grocery store myself .


Thanks all for the comments. If I can get this steamer running I’ll get back to a boiler and use real steam. In college engineering we didn’t cover much on steam . Just some basic loco design and a note that steam was not something to play with . Study first . I can still get good materials but I sold my trusty TIG welder so I’m relegated to instructor now .

 

[tractor162003]

Do you have a link to drawing or photos of this engine. If this engine is what I think it is then I made one that is one cylinder. Is your Crank 90 deg or 180 between cylinder?

Tom

 

[Bentwings]

Do you have a link to drawing or photos of this engine. If this engine is what I think it is then I made one that is one cylinder. Is your Crank 90 deg or 180 between cylinder?

Tom

My post just crashed so I’ll try test post. I think it 90 deg.

 

[Bentwings]

My post just crashed so I’ll try test post. I think it 90 deg.

Try chilertern steam. Com 4 cyl mill engine

 

[Bentwings]

Try chilertern steam. I’m then select quad mill engine.

 

[tractor162003]

Did you adjust the rod length per page 3 and step 5? There is a video that show how to put this together it is at the 14.36 min mark in the video that is better I think. I also think they should have made a way to adjust the length of the valve rod. With the piston all the way forward the screw in the eccentric should be straight up. I hope this helps.

Tom

 

[Bentwings]

Did you adjust the rod length per page 3 and step 5? There is a video that show how to put this together it is at the 14.36 min mark in the video that is better I think. I also think they should have made a way to adjust the length of the valve rod. With the piston all the way forward the screw in the eccentric should be straight up. I hope this helps.
Yes I followed exactly. The cyl piston is supposed to have about 1 mm thread showing then the nut goes on the nut is about 1mm thick I blue lock tite the piston and nut this time. The ort piston has a threaded hole in it too. That’s adjusted as shon or noted . The hole makes it hard to use the very near to set depth so made the threaded rod to screw in the port in the cyl head this woks for the depth measurements

So I can make both cylinders the same and adjust as needed . I just wish they would have provided more exact method. I did call them and they suggested it ting flats on the crankshaft but you have to know exactly where to it them . Steam power would be better but considering it doesn’t take much pressure to drive it I don’t realy understand that simply turning up air pressure would do the same thing . Hot stem has more energy , yes but adding a few psi would accomplish the same thing I think . It doesn’t need to run very fast to just be fun to watch all the moving parts . I have at least half a dozen stepper motors I can convert into generators and another half a dozen model generators that my little steam turbines run these turbines don’t have a lot of torque unless geared down then run at higher speeds. They do sound neat . Some day I will make a video if I get everything running together . Once I get moved I’ll have a much better area to work in.

I had a little steam engine and boiler as a kid that was my favorite toy . I kept it polished like a new car

 

[Bentwings]

So I can make both cylinders the same and adjust as needed . I just wish they would have provided more exact method. I did call them and they suggested it ting flats on the crankshaft but you have to know exactly where to it them . Steam power would be better but considering it doesn’t take much pressure to drive it I don’t realy understand that simply turning up air pressure would do the same thing . Hot stem has more energy , yes but adding a few psi would accomplish the same thing I think . It doesn’t need to run very fast to just be fun to watch all the moving parts . I have at least half a dozen stepper motors I can convert into generators and another half a dozen model generators that my little steam turbines run these turbines don’t have a lot of torque unless geared down then run at higher speeds. They do sound neat . Some day I will make a video if I get everything running together . Once I get moved I’ll have a much better area to work in.

I had a little steam engine and boiler as a kid that was my favorite toy . I kept it polished like a new car

I had to go back and look at my print out drawing instructions . I did see that I had checked off that I had followed the page and step . So that is done in my mind. All ofvthe manifold piping was done as shown . That was a project in itself . They deleted the lock nuts as no necessary soni did use Teflon tap as needed to seal up leaks. I now have a small box of fiber washers as well as brass nuts. These pies are all 1/4-40 ME. Thread. The fiber washers slip right on and I had ordered nuts that I could retread to the 1/4-40 ME thread so the assembly looked pretty close to the instructions . Even the Allen wrench was about the right position . It did start and ran about a minute or so before one of the piston nuts came loose. That pretty well stopped everything in its tracks. I carefully disassembled the engines and have reassembled one complete back to original all bearings are unharmed and it turns over easily I used Teflon tape on the packing as noted. Actually it will be better to go back and twist it like a string for better adjustment and sealing however it seems sealed now .

Some time ago I got a paper on how to set this type of piston valve. The issue is finding exactly where it is relative to the port . Even if part of the steam chest is removed it’s hard to determine the “ lap” distance . With my threaded rod I can actually get a pretty fine adjustment so I’m hoping I can get the thing to run then I’ll worry about fine tuning. I’m sure you can see there are a lot of small parts and lots of screws . I did get the optional stainless screw set . This just means big finger holding screws doesn’t work I have a nice forecepts and a couple tweezers
So much easier . I’ve oiled everything up for temporary moving storage . At best I can take out “ steamer” box and work-on my my kitchen table. The number of hex Allen drivers I now have is huge. The little pencil size power driver is a big help .

Once I get officially moved, I have another small project related to retractable landing gear on our giant scale Rc planes the bomber is 120” wing span and about 50 pounds.

This involves installing an Rc car shock absorber inside of the gear leg strut . Obviously there is a stout spring in each strut . On landing the compressed spring causes a rebound putting the plane in bad spot . So rebound control is needed. After all these years you would thing the gear mfg would have fixed this . Just as the full size builders did . Hydraulics won’t work as you don’t need leaking system Rc car shocks at good as you can adjust the rates on them. I’ll get more into this at a later date .

I appreciate the help y’all have given me . It keeps me charged up .

 

[Bentwings]

I had to go back and look at my print out drawing instructions . I did see that I had checked off that I had followed the page and step . So that is done in my mind. All ofvthe manifold piping was done as shown . That was a project in itself . They deleted the lock nuts as no necessary soni did use Teflon tap as needed to seal up leaks. I now have a small box of fiber washers as well as brass nuts. These pies are all 1/4-40 ME. Thread. The fiber washers slip right on and I had ordered nuts that I could retread to the 1/4-40 ME thread so the assembly looked pretty close to the instructions . Even the Allen wrench was about the right position . It did start and ran about a minute or so before one of the piston nuts came loose. That pretty well stopped everything in its tracks. I carefully disassembled the engines and have reassembled one complete back to original all bearings are unharmed and it turns over easily I used Teflon tape on the packing as noted. Actually it will be better to go back and twist it like a string for better adjustment and sealing however it seems sealed now .

Some time ago I got a paper on how to set this type of piston valve. The issue is finding exactly where it is relative to the port . Even if part of the steam chest is removed it’s hard to determine the “ lap” distance . With my threaded rod I can actually get a pretty fine adjustment so I’m hoping I can get the thing to run then I’ll worry about fine tuning. I’m sure you can see there are a lot of small parts and lots of screws . I did get the optional stainless screw set . This just means big finger holding screws doesn’t work I have a nice forecepts and a couple tweezers
So much easier . I’ve oiled everything up for temporary moving storage . At best I can take out “ steamer” box and work-on my my kitchen table. The number of hex Allen drivers I now have is huge. The little pencil size power driver is a big help .

Once I get officially moved, I have another small project related to retractable landing gear on our giant scale Rc planes the bomber is 120” wing span and about 50 pounds.

This involves installing an Rc car shock absorber inside of the gear leg strut . Obviously there is a stout spring in each strut . On landing the compressed spring causes a rebound putting the plane in bad spot . So rebound control is needed. After all these years you would thing the gear mfg would have fixed this . Just as the full size builders did . Hydraulics won’t work as you don’t need leaking system Rc car shocks at good as you can adjust the rates on them. I’ll get more into this at a later date .

I appreciate the help y’all have given me . It keeps me charged up .

Uber the steam engine list at chilertern .uk you can find the assembly instructions as well as exploded assembly view . My engine is the 4 cyl mill engine . It’s actually two engines connected together.

 

[Bentwings]

Uber the steam engine list at chilertern .uk you can find the assembly instructions as well as exploded assembly view . My engine is the 4 cyl mill engine . It’s actually two engines connected together.

Sorry I had to go back and correct the site. It’s chilertern steam . UK this should get you to the steam engine section

 

[metalmangler]

do you mean this one ?

 

[Bentwings]

do you mean this one ?

No I YHINK that’s a beam engine mine is called 4 cylinder mill engine. Actually 2 twin cylinder engines linked together.

 

[tractor162003]

He mean this one.

Tom

 

[Bentwings]

He mean this one.

Tom

Yes that’s it I have two of the multi groove flywheels plus a plain brass one . Not all installed On the same or connected shafts . The large multi groove one is supposed to connect the two engines they line up perfectly when on the cast iron base. If you look into the instructions you can see where I got confused by the hex wrench sticking out of the eccentric grub screw. I’ve created a threaded rod to measur TDC and BDC piston location as well as piston port piston. I’m right in the middle of getting ready to move to Tenn. so I’m carefully packing things soni know exactly what is where.
Lately I’ve Ben in hospital and have something med everyday for the next two weeks thankfully senior health care is helping schedules and transportation as I’m not supposed to drive . The last ride flew over the speed bump near my walkway RE tinjuring my fresh operation . I was furious and bleeding as I entered my home I did complain and entered zero stars on the driver survey. Once I get moved I’ll have my own small shop to work in. My son has his upstairs from where I’ll be . He has a large landscaping business and is planning on adding a maintenance shop to the machine shed. So maybe I can add a few things
Two med things yet today