Rider Ericsson Homemade Castings

[raveney]

Thank you both

Cylinder Sleeve & Displacer Cylinder

The materials for these pieces was very expensive at a bit over $200 online. The carbon steel piece was only $50 but the SS 304 with a bore close to 2.000 was way more than I wanted to spend. I couldn't see boring anything available to a consistent size. My plan is to make a mandrel that supports both parts internally so I can thin them down without crushing/distorting them.

The scrap pile didn't have anything useful for the 2 inch part, so I resorted to welding several pieces together. The center piece (red arrow) is some pretty tough SS that was threaded on both ends and very precise OD. I think it was a large valve stem so it only needed polishing and squaring of the ends with a countersink for the tailstock center. The other parts are carbon steel pipe (blue arrow) and plate (green arrow). I TIG welded them rather than silver brazing so I could avoid distortion and guarantee strength of attachment. They are removable so I can press the sleeves on and off, also allowing a trial fit for the cylinder sleeve to the cylinder (it has two machined fits). I will still use Loctite to ensure a leak-tight cooling water joint.

Nothing else special. I found that my clapped out 9" lathe worked best at 300 rpm with a higher than average feed rate and 0.007 depth of cut or less. Anything else would chatter and break inserts after a few passes. Must have been a weird natural frequency because of the hollow multipart mandrel. With 0.007 depth of cut it took forever (21+ passes)




In the end the part is a keeper and should only need a light honing because of the DOM tolerance. We will see

I started on the 304 SS part. It needed three 0.005 shims and some blue Loctite to fit my mandrel that was made for the CS pipe-size. Surprisingly to me, I can easily take 0.010" depth of cut using a slightly different feed rate. Most of the time the chips break, but sometimes I get a nasty birds nest. I got most of the material removed yesterday. The goal is to reduce it to 0.030" wall thickness to minimize conductive heat transfer upwards to the cylinder. I plan to silver braze a copper cap at the hot end.

 

[oldengineguy]

FWIW When I built this engine from the kit from Myers Engine ,I used the material supplied for the cylinder (DOM I think) and silver soldered a copper cap 060 thick on the outside of the sleeve. I made the displacer piston from 1.875 x .058 6061 aluminum tube from Aircraft Spruce. I closed the ends with discs of 6061 epoxied in place. The engine runs well and will easily pump a 6 ft. head of water up a1/4 in. tube, without the load the engine runs too fast even with minimal flame from a backpacker type propane camp stove (Amazon) .raveney, your castings look GREAT
Colin

 

[Jasonb]

I have use Stainless exhaust tube for displacer cylinders, 1.5mm wall seems to work oK on the Heinrici and Denny Improved and it is not expensive for a 12" length off e-bay.

15thou wall brass tube that is sold chromed for decorative basin waste pipe for the displacers.

 

[raveney]

Thank you Colin,
Would you mind sharing a picture of the campers stove you used? The book has a few drawings where they repurpose a propane torch which looks doable also.
BTW did you get the Nash 25 running reliably?

The SS pipe I bought was ridiculously over priced for my dumpster diving budget, but I didn't think about 2" exhaust pipe. Next time I will for sure. Thank you Jason.

 

[Jasonb]

I also use ebay portable camping stove burners like this, just remove all the bits you don't need

https://www.ebay.co.uk/itm/375447067615

For my 40mm dia bore engines they only just need to be turned on so there is more heat available. You can see them in these videos

 

[oldengineguy]

raveney: Sorry no pics for a while. Had surgery last week for detached retina so am out of shop for? don't know. Part # on camp stove X00323210X Wadeo HG0094 No progress on Nash25,put aside till urge strikes again Thanks for asking.
Colin

 

[raveney]

Jason,
thank you for the help. I really like the "weathered" finish on your Heinrici engine, and I will attempt that using the recipe you posted with the build log. Well done!

Colin,
Wishing you a speedy recovery on your eyes. The engine can certainly wait

Flywheel and Crankshaft

I had a small bit of cast iron that I used to make the crankshaft, and it took me two attempts to get the shaft size just right to fit all 3 of the tight press fits (flywheel, bearings, and crank) but I'm super happy with it and it runs perfectly true. If I had the right bearings like the book suggests, and undersized (-.001) reamers the crank would have been just a cut piece of drill rod. The modified part has stepped shoulders that will register the correct amount of endplay so it looks like I did it on purpose.

I used my faceplate for the flywheel so I could bore it and surface the outer and inner rim and one side all at the same setup.

 

[raveney]

Walking Beam and Support

These two parts required a lot of attention when making the patterns and came out very accurately. For the support, I was able to spot the mounting legs by eye and true the ends in one setup, then flip over and anchor to a fixture plate and finish the bearing saddles in another setup. I did not have a large enough piece of bronze for the bearings so I decided to use ball bearings hidden inside a piece of brass that I did have on hand. I also made fake shaft stubs to complete the deception. Should help eliminate the friction and any rod knocking with these bearings.

The walking beam sat level when clamping directly to the mill table using the center webs and 123 blocks. Faced the surfaces and drilled and reamed the holes. Some fettling required to make the two ends look right. It bottomed out at the first fit-up and had to relieve some of the excess center webbing to get the full 2 inch stroke. A trip to the sandblaster will blend it together later. I will also need to make some period correct fasteners in place of the socket head cap screws.

 

[creast]

Lovely work

 

[raveney]

Thank you Rich!

Does the engine run when spinning the flywheel "over" the crank? I made the connecting links using dimensions in the book, but it seems like one should be double checking to ensure that the phase of power piston to displacer is near 90 degrees.

 

[raveney]

Power Piston

used a 1" thick rectangular piece of stock to turn this part rather than purchase a 2-1/2" round bar of 6061 aluminum. The interrupted cut was too much for the 9 year drive belt on my little 7x14 mini lathe and it started making terrible noises. I replaced both belt pulleys as well as the shaft and keys based on the noises and backlash that was felt. I ordered all the parts for what I felt was reasonable from the company I originally bought the lathe from.
LittleMachineshop.com

After the repairs the piston was carefully brought down to dimension by feel until it was a nice sliding fit in the cylinder. Put a piece of electrical tape over the center hole and tested it as shown in the video below. This is with no packing in it, just 0.020" grooves and dry.

the power piston top ring was then fabricated along with the top ring from 360 brass. I ended up fabricating a 0.080" brass flat washer to move the top of the piston down so it was flush with the top surface of the engine at TDC. The washer went between the piston and the center. A primitive spanner tool is used to tighten a flat round nut once the center is properly indexed in the piston. This is a great design as it eliminates the reliance on the threads being true and concentric. I prefer to just use dies rather than single point thread if I can get away with it.




Next up was the connecting links fabricated from brass. I chose to buy 3/4" square stock for this rather than cast them. The process is fairly easy when using a simple jig that holds the parts based on the journal holes. I elected to make hardened filing buttons to radius the ends rather than use the rotary table because they were all the same size. (0.251 hole and 0.500 outer diameter) The crankshaft link needed to be off center like many other builders encountered. Weird because it should have only needed a 0.037" offset according to my CAD model. I didn't bother chasing down where the error occurred and just rolled with it. I also field measured the length of it to compensate for the 0.214" mismatch of the flywheel bracket in respect to the cylinder.



I made the yoke according to print, but then bored the bottom pivot hole out and used two ball bearings because it felt funny with the cast aluminum running on the 1214L crankpin. Removed the rubber shields on the ball bearings and soaked in them in diesel to remove the grease. Much better now

got caught up a little bit on the period correct fasteners by making the square head studs to replace the setscrews in the walking beam and made studs and hex nuts for the bearing caps of the walking beam support. The walking beam support was then clamped to the cylinder and tapped about to determine the best running location while spinning everything about. Once it felt good, I punch marked the mounting holes, held my breath, crossed my fingers and drilled the holes in my cheapo drill press without disassembling anything. It seems to spin nicely, but I wonder about the correct lead/lag of the piston to displacer criticality. No mention of this in the book or other build logs.

Any good tips from the Stirling Builders out there?

 

[creast]

It's coming on beautifully.
I seem to remember having to tweak quite a few parts during my build partly from the plans and partly my errors in casting etc.
But I cannot remember all the details of which was which.
I am sure it will run!
Rich

 

[raveney]

Getting a little closer.
Thank you to Bob Nawa -Bobs Models, for the idea to use a grill stone displacer. I didn't want to thread the full 6 inches of displacer rod, so I just grooved the top and used a circlip to fix the top of the displacer. Sprayed the pumice stone with Hi temp black engine paint to cut down on the crumbliness and this did help a lot. I needed a 1" gasket as a spacer to make the clearances just right.

Brazed copper plate on the end of the SS hot tube once the clearance was figured out on the displacer. The engine turns over much harder once the hot end gasket was put on, but it does feel bouncy so it should be okay. I halfway tried to run it using a small flame on a propane torch, but didn't want to undo my copper endplate.

I'll make the stove box and drill the water jacket out so I can have some cooling before attempting to run it again.

have a nice day!

 

[raveney]

Firebox
the template in the book was printed, measured and then enlarged using the scale feature and reprinted on 11x17 paper. Glued to some cardstock and then trial bent and taped. I added some overlap on the ends and then cut out of 18 gauge steel. I used 1" round bar to make the radius' corners as there was some spring back. Clamped and then TIG brazed using 1/16 electrode and 1/16 bronze wire at 60 amps. The frame was bent in 4 separate pieces and also tig brazed. I set it aside because the fold-up camper stove arrived and attempted to run the engine for the first time.

These camp stoves pack quite a punch as it unbrazed the copper cap fairly quickly. I also shattered the tip of the displacer cylinder playing around with the end clearance adjustment.


I happened to have some furnace cement left over and was able to piece it back together and secure it to the rod better. I turned it down a little more to get it concentric and tried again.

It runs! After quieting several rod knocks down by remaking several shoulder bolts it was pretty hot so I drilled the water jacket and improvised a cooling tank. Wow it definitely starts and runs better with water! Still a bit noisy and not sure why. All of the clearances are a good balance of a running fit without adding too much friction. I may try putting some graphite packing in the top land of the piston as it sounds like its coming from there as it rocks. Strange because the piston to cylinder fit is near perfect. Feel like its on springs when you turn it over.

 

[raveney]

firebox continued...

made a oak buck to bend the firebox chimney support in a more controlled manner. This worked really nicely holding the metal square while I TIG brazed the seam. I torch brazed the endcap and chimney spigot. The chimney is just a 12" piece of 1-3/8" brass tube.

The firebox door was fabricated by silver brazing several small parts together and the hinge is 1/16 TIG wire. JB Weld on the gaps to simulate fillets and then sprayed with stovepipe black paint. I will need to disassemble the engine to drill and tap the support rods, so I will likely paint all the parts before reassembling again.

 

[Richard Hed]

firebox continued...

made a oak buck to bend the firebox chimney support in a more controlled manner. This worked really nicely holding the metal square while I TIG brazed the seam. I torch brazed the endcap and chimney spigot. The chimney is just a 12" piece of 1-3/8" brass tube.

The firebox door was fabricated by silver brazing several small parts together and the hinge is 1/16 TIG wire. JB Weld on the gaps to simulate fillets and then sprayed with stovepipe black paint. I will need to disassemble the engine to drill and tap the support rods, so I will likely paint all the parts before reassembling again.



View attachment 161055View attachment 161056View attachment 161057

So what is this for? A boiler? It looks sort of like a special type of rocket stove

 

[raveney]

Its for a scale model of the rider Ericsson hot air engine
the original part was a casting lined with firebrick and had a stovepipe chimney. I believe they could burn kerosene or coal or wood. I am using a tiny foldup camping stove and canned fuel.