Geared horizontal twin engine

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
An aside.... Because I mentioned those "great" engineers - well Engineers and machinists - Honda.

- Enjoy!

Did you know that in the 1980s the Honda engineers used doppler-shift anemometry to develop a quieter starter motor? - Bosch and Lucas used "Human ears" - but as the engineers were old they couldn't hear the higher frequencies made by the smaller higher speed motors Honda's supplier was developing? - and didn't care about the noisy traditional designed European parts.The Honda starter was 20~25% lighter, more reliable (on comparison bench durability tests), 20% lower cost, more efficient (starter torque per amp), but made a quieter but different noise to the "old design" so we bought the Bosch part - German engineering - that was least reliable, but had the best returns and replacement policy for Europe as a whole! I missed the point of that decision.
K2
 
Now, if you squint your eyes real hard, you can see the two cross head guides, turned to correct o.d. and cut to length.--I still have a bit of work to do on them tomorrow---
dsck2n.jpg
Didn't squint - put my glasses on and read the drawing!
I like someone who has a calculator on his bench. Just surprised there are no blue finger-prints on the keys....
I have a scratch and slate - actually, I use it with chalk. It works, but slower. But I can do drawings on mine!
Is there a clever balancing trick to get the flywheel over the edge of the bench without toppling-off? - Or are the gears sufficiently massive to counterbalance the flywheel?
I do appreciate your work. Keep up the good thread!
Thanks!
K2
 
So, as I was saying, these are probably the prettiest cross-head guides I have seen. There is a world of work in machining one of these, and it all has to be done in the correct sequence or you paint yourself into a corner and find that you have nothing to hold onto for the next machining operation. One done, and one more to go, tomorrow.
nwe3v1.jpg
 
Steamchick--That's not a flywheel. That is an 8" v-pulley. I power the v-pulley with a 1/2 horsepower electric motor for a half hour to "run in" the shafts, gears, and bearings, so as to have minimum drag when it is assembled with the engine.---Brian
 
Clever...
Thanks Brian. (I assumed it was a V-Pulley being used as a flywheel to check the smooth running of the gears - didn't appreciate the "running-in" process!). So I guess the gear shaft mount is bolted to the bench - or something (to take belt tension?)? - Which would explain why it doesn't fall off the bench?
Cheers.
K2
 
No, it was just posed on the end of my desk to get a shot of all the components finished so far. I will post a family shot of all completed pieces by the end of the day.
 
And that, my friends, makes two beautiful cross head guides. I'm very pleased with the way they both turned out. I started this morning at 8:30 and machined until 3:30 to finish the second cross head guide. (That included time to eat my lunch and walk sixteen minutes on the horrible treadmill. We have 9" of snow here now, so my fat mans walks in the bush trails are ended for this winter. Not sure what part I will make next, but I have to check my stock and see what material I have.
RSsl2K.jpg
 
I think I'm going to dive into the Rupnow fortune and buy some brass tomorrow. This engine almost demands that the flywheels be made of brass. Almost all of what remains to be built can be steel or aluminum, but I really like the color contrast of brass. I wish that there was some other cheap, exotically colored metal, but I'm pretty well stuck with two predominant colors. Steel and aluminum are very similar in color, no contrast there, and the lovely yellow of brass really makes it "pop". I'm not a huge fan of paint, and anodizing or black oxide coating is too expensive for my tastes.
 
You could make steel flywheel tires for shrink fit on aluminum wheels.

Polish up the steel, heat it until it's a pretty color, drop the aluminum in and let it shrink.

It should give some corrosion resistance while you're at it.
 
This morning I loaded my wheelbarrow full of money and went shopping for material. The place I usually shop did not have any 5" x 3/8" brass (for flywheels) nor did the have any 1 1/2" x 1" brass (for cylinders). The 3 pieces you see in the picture cost $60. Then I went to my other metal supplier, and they had no 6" x 3/8" brass, but they did have a piece of 1 1/2" x 1" brass x 12" long, and it cost $71 and won't be here until tomorrow. That means that I now have to go and see the local robber-barons and see if they have any 5" x 3/8" brass to make flywheels.
dR95O8.jpg
 
If I could get it cheaper for you I would, but trans-Atlantic postage and Customs would rob you blind anyway!
I try and buy from a scrap-yard when I can get something of a suitable size. You just don't know the grade of material - but sometimes that doesn't matter on a model. (Just "Does it polish nicely?"). But the last one sold stuff at £5 per kilo and has since gone the journey of time. I need to find a new "non-ecological" scrapyard that can sell stuff "because they can". - Just realised... most scrapyards are VERY ecological - because they recycle everything they can! (for money).
Ho hum.
K2
 
Somebody suggested that I buy cast flywheels. Remember--I'm in Canada, home of the brave and the penniless. For me to buy a cast iron flywheel , eat the currency exchange, the tax, and the shipping, I might as well use brass. An executive decision has been made. The flywheels are going to be made from hot rolled steel (which is dirt cheap) and painted the color of my choice. The amount of machining will be exactly the same, the weight will be almost the same, and the painted flywheels will look like they might be brass. In fact, maybe I'll lie!!!--I'll paint them and tell people that they are made of brass.--Who's going to know??
 
Along with running around town buying material and walking on the horrible treadmill for 20 minutes, I was able to finish a base for the geared engine. I would have rather made something on my lathe, but it's nice to have a baseplate to assemble all the pieces on.
B5iF9H.jpg
 
So--Today we are taking our lead from Sesame Street. Today we are going to make round things. Four cylinder end caps to get the ball rolling, and then maybe a a couple of cross heads.
P3HtVN.jpg
 
Last edited:
So today I picked up my piece of brass to make cylinders from, along with a piece of 6" x 1/2" hot rolled steel flatbar 12" long which will become flywheels. That cost $87.74 along with the $60 I paid for the other steel and aluminum and brass. So, it looks like the butchers bill for this engine is going to be around $148 and that doesn't include the material that I already had when I started this build.
 
Making round parts went quite swimmingly--Until I broke off a #10-24 tap. Tried all of my usual tricks to remove it, and none of them worked. Will remake that part tomorrow morning. BAH!!!----HUMBUG!!!
UVZ1wI.jpg
 
No scrapyards in your area? There's one just down the road from here that sells steel, copper, brass, and aluminum by the pound. Of course, it's often mystery metal (although I do have some 6061 from them that came marked).

Granted, I haven't checked to see if they're still here given COVID.
 
hate that on the tap breakage. bah humbug is a very clean version of what i would have said.

on the base plate. the nice rolled edges, how did you do it? a round over end mill, a router bit or ?

looks good.

and oh yeah on the brass, i know your probly tired of hearing it but yep, scrap yard or i have a guy who takes down burned homes, old radio towers etc. in other words home demo. he often brings me brass. i am surprised to find out how much of that stuff is in old homes and business's. actually large stuff. radio towers in specific


now if you go to s scrap yard, may i recomend looking for oxygen concentrator machines. those tote around oxygen machines you see some having. the larger ones for home use not the little portable ones. they have some pretty large brass cylinders in them. 2 per machine that i have found. and have fitting pistons with teflon rings to go with them. and usually cheap as the dont know about that, they just want the electric motor out of them
 

Latest posts

Back
Top