Rider Ericsson Hot Air Question

[davidyat]

Almost finished with my build of the Rider Ericsson 1/4 scale hot air engine. Am looking for information of where to get parts and supplies for the SandyC Ceramic burner to power it. Have the parts for the propane bottle but need to find a supplier for the copper tube base(2 inch OD X 2 inch length), copper disc (2 inch X 16 gauge) and the gas jet (Number 8 Gas Jet / Calorgas or Taymar). Or since the plans call for brass deflectors in the base, can I use brass tubing instead of copper tube for the burner?
Thanks,
Dave
*discussion*

 

[Blogwitch]

David,
I gather from your questions you don't come from the UK as we can get all those bits with no problems at all.

When I used to build my own propane burners for boilers, I made the deflectors out of a piece of brass angle with the corner facing towards the gas inlet, I found just one was plenty good enough if placed in the correct position, which I did by firing it up while still on the bench and gradually adjusting it's position until the sweet spot was found then it was then silver soldered into position.

John

 

[BobsModels]

Hi
I have attached my hybrid design based on Sandy’s and Brad Smith for the ¼ scale Rider.

I have not updated the document with my further tests on the burner. The key to my modification was to make it small so the heat was concentrated on the end of the hot tube. Ignore the references saying I was going to try some modifications. I have not. I left it as I built it. The engine runs all day at shows ie as long as 5 to 6 hours or more. At the end of the day you can put your finger on the base next to the cylinder and keep it there. I never change the water or add ice. I run the engine at about 80 to 100 RPM. I keep the pressure on the regulator at about .8 to .9 PSI.It has been running like this for two years’ worth of shows about 80 to 90 hours each year. I will have it at the Northeast Ohio show in Zanesville this weekend.

I abandon the regulator from Gentec, it would not hold the pressure at the range I was using. I got some old Coleman Catalytic converter regulators off of ebay and they work just great see attached photo. You have to get one that is actually a regulator and that is why I use ones off the catalytic converter, the newer ones are fixed PSI, the old ones were regulators.

Here is a link to the Ceramic board – get the larger one they are handy.

https://contenti.com/jewelry-soldering-supplies/jewelry-soldering-tools/soldering-boards/hard-ceramic-soldering-board

If you have any other questions let me know. I did a complete build here is a dropbox to a large PDF that has all my info, including changes to the design.

https://www.dropbox.com/s/fzv8noejdirmrqd/Rider-Ericsson%20Hot-Air%20Pumping%20Engine%20Build%20Complete.pdf?dl=0
Probably more info than you need but it is there if you want it.

Good Luck – look forward to seeing a Youtube

Bob

View attachment Rider-Ericsson Hot-Air Pumping Engine Burner.pdf

 

[davidyat]

Thanks for the info. I did buy a regulator that screws onto a propane bottle that looks very similar to the photo. I like it as it has a 1/4 inch compression fitting on the exit and I can tailor it to my needs. Since you mention brass angle, I'm thinking of going to my local metal supply house, getting a chunk of 2 inch round brass and just machine the body of the burner on my lathe and not have to worry about silver soldering the bottom to it.

 

[davidyat]

Bob,

Just finished going through your PDF file. Gads, I wish I had it during my build. I'm just a neophyte machinist, learning from a retired master machinist and some how stumbling through a learning process. I am in the process of making an 1890's model machine shop like the one you see in the PM Research catalog. I'm trying to upload a MS Word file with one picture of the start of the model machine shop. Will try to get a photo of my progress to date. By the way, where did you find the priming cup and the globe for water hammer in your photos?
Thanks,
Dave

View attachment Model Machine Shop 3.doc

 

[BobsModels]

Dave

I have not made a an air hammer globe yet. The pictures you are referring to are of a full size one to show how I came up with the pump design. If you look at the red pump the primer cup was made by me.

I do have a set of drawings for the air hammers. I have not made them yet. When I do they will get published, if I get time this winter.

Bob

 

[davidyat]

Thanks Bob,

After going through your PDF file, I did see you making the primer cup. Making one myself should be fairly easy so that's what I'll do.

David

 

[davidyat]

Bob,

Was just wondering, do you have any more builds on this site that I might go through and get ideas for my next build? I always want to see what others with much more experience than me are doing. That's the only way for me to learn more.

David

 

[BobsModels]

David

No, I do not. I may do one of my next project, depends if I can keep up.

Bob

 

[BobsModels]

David

I was thinking a bit about my burner. The small size was dictated by the design of my hot tube. It has a stainless body, with a heat dam about .25 down from the top that takes the OD down to about half the thickness for about .1. It has a .025 copper bottom for maximum heat transfer where you need it i.e. the bottom.

If you made the hot tube all steel, or with a stainless bottom the heat transfer dynamics will be different and may dictate a larger burner. The goal is minimum amount of heat to make it run. Mine runs on the lowest flame i can get without putting the flame out.

Bob

 

[davidyat]

Bob,

I've made my hot tube and power piston per the blueprint specs. I've just purchased a 2 inch round, 2 inch in length solid brass rod. I'm planning on machining out the pocket for the ceramic and deflectors so I don't have to silver solder a bottom on it. Based on your experience, what dimensions would you suggest for the size of the pocket (depth, length and diameter)? Thanks for all your help.

David

 

[BobsModels]

David

Since I have only made one of these burners I am certainly not an expert. I actually had assumed I was going to make at least two to get it right. Fortunately the first one worked. Not really sure what kind of advice to give you. Maybe go with a small one first and see how it goes. Or do what I did at the start. I used a alcohol burner from and old toy steam engine for the first test runs with no furnace at all. I just set it up on the fire brick and tried something's. I even used a candle, which did work. Here is a shot of the test. It is just a frame from a video clip. When I saw how fast it ran I just decided on the small burner. You might want to try some tests like this first. Especially to work out "bugs". At this test point was the first time it ran. I found some bearings that clacked away (oversized), the pump leaked, the main crank kept coming loose, the flywheel key came loose. All kinds of things needed attention that were not apparent with just flipping it around by hand.

Bob

 

[davidyat]

Absolutly the best advice you've given me. Start small and work out the bugs and go bigger as needs dictate. I can't thank you enough for your help and thanks for the picture. I will make it a point to post a picture of my progress so far in this thread and hopefully in the future a video of mine actually running. And yes, I did turn the flywheel by hand and at least it pumps water with a small leak (easy to fix) where the pump attaches to the cylinder. Oh, and by the way, the only modification I made to my engine was where the flywheel and axle slide into its' carrier, I machined a pocket so that I could insert a thrust bearing for the flywheel to run against it.

David

 

[davidyat]

Bob,

I see your setup in the above picture for testing the engine. I just tried with my burner (without the water pump installed) to see if I could get any movement. No go. What is the procedure to get the pump to run? Do I have to have the water pump installed and primed? Also, I'm having some slight binding problems, not heavy, but it's there. How free does the whole movement have to be? Should I have absolutly no binding and the movement have to almost be totally free to move? And should there be the teflon gasket around the piston installed before I try any heating? Thanks for any advice.

David

 

[davidyat]

Also, are the Sand No Mor sanding blocks still available? If so, where?

David

 

[fcheslop]

Iv seen the sand no more blocks on ebay also a suitable stainless tube at least in the uk
http://www.ebay.co.uk/itm/48mm-1-1-...750860?hash=item3f38ac3a4c:g:bx0AAOSwGiRTrXjM
Im slowly reworking a badly machined set of castings for this engine and have built many Stirling engines and would say the packing would have to be fitted unless the piston is a very close fit and its the piston that has me a wee bit concerned as the spec is alloy and the expansion rate concerns me .
Cheers

 

[BobsModels]

David

I used a Pittsburgh corning corporation Grill-Brick:

http://grill-brick.com/index.htm

Somehow I got a box of them from a distributor. I just called
and lucked out in that they sold me a box. I had to buy the whole box
that contained maybe 10 or 12 I do not recall. I use them on my grill
now, almost all gone.

Never thought about ebay, here they are. Get at least two I screwed up several and you can always use them on the grill:

http://www.ebay.com/itm/grill-brick...279999?hash=item1a1f3d97ff:g:2DMAAOSwtnpXpB1j



Yes you need the gasket, I would just use graphite yarn, not the Teflon. Get a piece of packing and undo it to get a single thread. I think a wrapped it around twice. You want it too seal. If you cover the bottom to make it air tight the piston alone with no linkage attached should stay put when the gasket is lubricated (silicone oil be careful if you get this oil on an area you want to paint it will not stick, maybe use regular oil 5w or 10w for the testing). If it slowly moves down you need to use your judgment, try another wrap. When you remove the cover the piston should drop through.

My engine will not run without the water cooling system, turn the flywheel by hand to get the water pumping, and yes you may have to prime it. If it will not suck water up an easy way is to force water into the intake of the pump until it flows out the overflow, ie use a piece of tubing and a mouthful of water and blow. Once it is coming out test your pump by rotating the flywheel to make sure your pump actually works.

Friction is the enemy of hot air engines. It must be eliminated. Here is a video of my engine at an early stage testing the linkage smoothness. I did this at each stage of adding an item. That is I started with the beam and it had to move smooth no bind, I set up the flywheel with the crank on it and had it run smooth, next the link to the beam, and that was made to run smooth. Each step required some effort to get a smooth action. This video is the only one I made of my testing, but it just continued. Only one thing added each time and then worked to get any binding out. When I added the Piston I did it with out the gasket until it ran smooth, the pump the same way, no ring or packing on it until it was smooth no binding.

https://youtu.be/ay3CiJNrX_Q

I am only going to leave this up on ytube for about a week.

Bob

 

[Blogwitch]

For people in the UK who are wondering where to get some of these items, here is the cheapest in the UK. It just so happens it is advertised from where I live.

http://www.ebay.co.uk/itm/Grill-Brick-GRIDDLE-STONE-BRICK-/261510920707

John

 

[davidyat]

Thanks. I just ordered the grill block. I was taught by someone wiser, when you get frustrated on a project and pick up a ball peen hammer, you're angry and your project looks like a nail, put the hammer down, get out of the shop, open a beer and finish it. If you go back and pick up the hammer again, repeat the procedure with a beer. Eventually, the light bulb goes off in your head and you see, maybe, where you made your mistake in your thinking. I will go back with a fresher mind to look at my project.
David

 

[Steamchick]

If I did that I'd be either an alcoholic, broke, or both by now! - 50 years of Engineering experience tells me "it just ain't worth getting your paddy up about". So you are right, walk away and shut the workshop door until your mind wanders to a different project - or come back another day after a good night of sleep.
I call it the "Round Tuit" principle - when my brain gets "round tuit" it will all work out as it should, but if I try and do it when my brain is all muxed-ip (or tired!) then I can drill square holes, cut curves with a straight blade, break anything supposedly "unbreakable" (especially taps and drills!), Bruise myself with hammers and spanners, etc., Upset my wife, cut a finger with a piece of paper, etc.
Music helps...