Hot Air Engines

[ewal]

About 5 years ago I had a year off steam & did some experimenting with Hot Air. I'll post a few pictures.

E.W.

Attachments:

[isc]

[/img]Nice engine E. W. abit tidyer than my one, I made the hot end out of stainless steel, could'nt get a test tube. My one has a tube down through the steel wool and a space at the extreme end were it gets heated.

[ewal]

Hello isc When I read Your email my first thought was I'll send him some test tubes (I had to buy a box full) so I looked to see where You lived & found you were to far away. Can you post a photo of your engine as I'm not sure what type it is?
Having built the first horizontal I couldn't get it to work, so my son used a blow lamp as the source of heat , it worked & the hotter it got the faster but the glass started to melt. I used the blow lamp later on a larger twin piston .

E.W.

Attachments:

[isc]

Hi E.W. no its a bit far to walk to get here. I have 12 motors working ranging From 5/8" bore to 2 1/4", the two best for power are, one based on James G. Rizzo's Dyna, an the other a resently finished Ross Yoke Engine with a 35mm bore and 20mm stroke, they both have similar power.
Not quite sorted for photos yet. The motor I described above is similar to your first photo, one thing the stainless hot end wont break. It has'nt got much power, but I tryed scaling it up but that one did'nt work at all.isc

[ewal]

Ian I made successfully 2 horizontal & 1 vertical with the test tubes & 2 twin piston with Stainless steel tubes. They all had 7/8" pistons except For the larger twin which had 1 1/4". The twins were a variation on a Japanese design & were very successful. I had 4 or 5 that I couldn't get to work. You have some really big ones, I look forward to seeing them.

E.W.

Attachments:

[isc]

They are starting to appear on another site, havn't sorted this one out yet, the other site took a year to sort, I'v put some of my Ross Yoke engine on. isc Its the model engineering site.

[stirlinglad]

Hi ewal & isc, Ive just been reading your thread and like you ewal, i'm having a break from steam too, ive just acquired a myford ml7 which should be delivered in the next couple of weeks, so i can learn how to make some of my first love stirling engines..i need to learn a lot more about using the lathe first though.. i have loads of test tubes from repairs i done in the past, but does anyone have any easy,ish drawings i could follow while i'm learning machine craft techniques.?? the only problem is they would need to be cheap as the lathe has left me skint.. in fact any drawings of engines you guys think would be possible for a beginner to make would be greatly appreciated... i know its a lot to ask for from a newbie but i dont know how i'd get started otherwise.........yours Mike...

[isc]

Stirlinglad, get your self along to the library is proberbly the best way to get some good ideas, try James G. Rizzo, "The Stirling Engine Manual", or "Modelling Stirling and Hot Air Engines". There are some on Google. I don't use plans, I use the ratios and proportions set out by J. G. Rizzo in his books, and things sort of just grow,there are some photos in the albums on the ME web site.
I'm no machinist, and I use mainly scrap metal, I some times buy some bits of aluminium from a local supplier, usually off cuts of 'Tooling Plate', it machines much better than extruded bar, and much stronger.
You'll have to do what I do and get a few jobs for the lathe to help pay for it.
Look in Koichi Hirata- Lets build model stirling engines.
Jan Ridders.
Mick Collins, Fizgig, good plans you can print off free.
Jerry E. Howell, Model project plans & kits.
www.stirlingengines.org.uk/modeng/mod
there are more. isc

[stirlinglad]

thanks isc, some good pointers there ..the stirling engine link didnt work though..
but thanks

....Mike...

ps whats koichi hirata ?

[isc]

Koichi Hirata is a Japanese bloke think hes a proffesor at a Jap university, have a look on google, type in Fizgig hot air engine, or hot air engines or something similar, just type in something like that and wander around, getting lost, some times something useful turns up. isc

[ewal]

I did the same as isc & put stirling on google. They came up with this Japanese bloke & I more or less copied,l used what materials I had at the time. I to have no plans.
All the cylinders are brass & pistons aluminium, ball bearings except little end, & I use 2 Orings on the test tubes

E.W.

[isc]

I find that it is best if one is a collector of old junk, old VHS vidio recorders produce good bearings, about 6 mm, and other bits, you just have to hunt around, I buy very little. my pistons are cast iron in steel, or cast iron cylinders, except for one with a brass cylinder, and a aluminium piston with a teflon skirt so that no aluminium comes in contact with the cylinder.
The plans for Fizgig are very good if you are into building from plans, even if you are not they give you the dimentions that you can design an engine around.
I'm gathering up bits to build the ALPHA motor described by our Japanese friend in his artical on stirling powered boats. I have a GAMA motor of similar lay out in a boat about 600 mm long, but I think I should increase the power, at present it sails at a very slow walking speed. I believe in giving my motors some thing to do. isc

[isc]

Dr Koichi Hirata, senior technical officer, National Maritime Reserch Institute.
Some of his stuff is in Japanese, some in English, well worth going to google and type in his name.isc

[isc]

[/img]My Ross Yoke Engine with power hacksaw fitted.It's fitted with a junior hacksaw blade, and takes about 15 to 20 miniutes to cut through a 1/2" mild steel bar. isc

Attachments:

[jgb7573]

Well it took me the best part of 20 minutes to cut through half inch square BMS with a junior hacksaw last night so I reckon you're not doing too badly there!

[isc]

Ah yes JohnB, but you proberbly rested a few times in that 20 min. The little saw takes such fine cuts that leaves the surface almost polished. On another motor, I used the motor to power the saw to cut metal to make a new crankshaft, and con rods for its self. isc

[isc]

[/img]This is the other motor based on James G. Rizzo's Dyna. This was my second motor built in 1994, still going strong.
This is a concentric, or Beta motor. The bore is 1 3/4", the power stroke is 3/4", and the displacer stroke is 1 3/16". The flywheel is fabricated, and is 6" diameter. It has a radiator (its tubes are concealed by the electric fan that is powered by the motor driven generator). Heat is supplied by a camp stove burner in the fire box at the right hand end. The badge on the radiator stand is the prototype I made as a car bumper badge for our now defunct Motor and Machinery Club ( The final badge design was in brass). isc

Attachments:

[jgb7573]

Too right I did!
Your other motor looks good too.

[isc]

There are 13 more of them in all shapes and sizes. The one in the last photo has a generator that gives me 12V to drive the fan on the radiator, and a radio, and some incandescent lights. Or I can take the generator off, and fit the hacksaw. Another thing I'v tried with these two motors was, Dyna driving the Ross Yoke motor, on a day when the atmospheric temperature was about 20 deg C I got the hot end down to - 22deg C. I don't usually make pretty looking stuff, they are made to do work. isc

[isc]

It would be useful if our photos were returned to our posts, or are pics a waist of time. isc