Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Hi

I got the Jin Rider Ericsson a couple of weeks ago and just decided to try and make it run.  I have watched several videos and they seem to just start right up after the furnace runs a bit.  I cannot get mine to do anything.  There is no binding it does not even try to run.  The pump is the only thing giving an strain and it is virtually none.

I have built the 1/4 scale Rider, and it takes about two or three minutes to get rolling. 

I have until tomorrow to return it. 

Anyone have any suggestions before I do that. 


Bob

Its the R01.  It is not from Jin but from dtjsteam but the listing says jin+steam+engines so not sure who it is from. Yes I put oil on the displacer rod.  I put oil about 4 very small drops from the end of a pin on the walls of the cylinder.

I take it there are differences between the models?

Bob

Hi Bob, dtjsteam is Jin.
dtj are his initials for Dong Tu Jin.

Bob

Sounds like you well know what you are doing messing about with model engines.

Certainly, any kind of a leak in a Stirling Cycle engine is its death knell.

I do truly enjoy mine, so if you can get a replacement or repair, it should be worth it in the end!

All

Here is the resolution of the issue.  Jin asked me to disassemble it and clean out the cylinder.  I did that and found when disassembled that the cylinder really looked clean, as well as the piston. 

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I cleaned the cylinder and piston first with mineral spirits, then acetone.  Last I used isopropyl alcohol to clean up any residue.  When I made the first pass cleaning the cylinder the cloth came outwith a residue on it.  Upon drying the cloth it looked like brass dust.  It was on the piston as well as in the bottom of the cylinder.

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I reassembled the engine and fired it up.  It took off running just fine, a bit on the fast side. 

So I am happy with the engine and told Jin all is well.

As an aside, the speed is a bit much.  Having worked with my 1/4 scale the issue is likely the size of the burner, way too much heat and I cannot crank it down far enough.  The 1/4 scale called out a 2" diameter burner, I made 3/4" ceramic burner and it moves along very nice, does not overheat.  I may fiddle with that someday.  The pump is another issue, those little drips and dribbles, in my opinion do not provide enough cooling.  The stroke on that pump should have water flowing out.  My guess is the check valves leak badly both the ball in the bottom and flap valve on the piston - at least my guess on the design. Checks in something that small require some construction finesse. Another item to put on the list for improvement some day.

It is a cool little engine, now back to building my Breisch air cooled ignitor hit and miss engine. I think I may need to move the 1/8th scale Rider Ericsson castings up on the construction list.  Having 3 of them running next to each other would be a great little display.

Bob

Very well done Bob..!!

It's nice to know how to fix that problem.
I wonder if replacing the metal check ball with a rubber ball would immediately improve the sealing and performance of the pump on these?

Actually I do not think it would.  Maybe for a while but you need to fix the real problem.  If it is a bad seat ie burrs the ball will get chewed up.  Without taking it apart and fiddling with it you do not really know the issue.  I can guess that the seat is not fitted correctly, or the ball is sitting on the seat and there is no chamber around it to keep it from falling off, or  minimizing vibration.  Or it could be the flap valve on the piston rod. That little engine vibrates a lot.

Here is bottom of my pump on my 1/4 scale. I used a Teflon ball (just an experiment,no real reason) in a restricted cage.  It has a top with a little pip that keeps the ball from coming completely off the seat.  There is a trick, taught to me by long time builder of live steam locomotives, to making a seat.
You form the seat hole from the bottom not the top.  If you drill from the top the vibration of the messes up the seat.  After you get the hole drilled.  Next is to ream from the bottom.  Next you take a ball the size of the one you are going to use, preferable a ball bearing since it is round, put it on the seat and give it a rap with brass hammer and brass rod.  This is an art, it must be a dead blow no bounce, takes some practice.  Now through away that ball and use a new one in the hole.  My Ericsson has been running since 2015 (about 600 hrs) so far no issues with that Teflon ball.

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Here are all the parts and finished pump, the pump started out as a block of Aluminum and was carved out so to speak on mill and lathe (no CNC just by hand).

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Pump is about 1 x 1 x 4 not including the prime cup or top clevis etc.

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Bob