Model Engine Maker
Engines => Your Own Design => Topic started by: dwulfe on July 16, 2018, 09:47:03 PM
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This was inspired by the Tiny IC posts and various others especially Rudydubya's.
It has 3" flywheels with a .5 inch bore by .75 inch stroke. It hand starts on Coleman camp fuel.
The valve springs are from retractable ball point pens. The gears where bought cheap (< $10) and modified.
It has cast iron piston and sleeve without rings. The crank is .25" with .188" rod journal.
Here is a video. It's running a bit rich but I like the slower speed. Notice how it picks up when I pull the draw tube out of the fuel.
https://www.youtube.com/watch?v=8CtceoPe2II
I've been experimenting with a mixer. This video is the second variation. I have since found that I can lean it out by inserting a .015" wire in the .020" id draw tube (brass bushing stock for clock maker). Not quite finished but getting close.
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Very nice a a good runner too. They are fun little engines for sure. Nicely done!!
Bill
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Very nice little engine. I have a couple of similar hit and miss engines that are running Viton O-rings on the piston. The Viton gives amazing compression, but it also creates a lot of "drag" in the engine, so I have never been able to get them to hit and miss the way I'd like them to. If I ever build another hit and miss engine I will try and do it with a lapped piston and cylinder, no ring, and see how that works.---Brian
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Beautiful little engine and a nice runner.
Have a great day,
Thomas
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Very nice! :ThumbsUp: Thanks for posting.
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Beautiful job. :ThumbsUp:
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Superb engine! Nicely done.
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Nice!
-Bob
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Nicely done! Looking forward to seeing it finalized. Will you be showing us any build pictures?
Regards,
Rudy
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Thanks Bill, Brian, Thomas, Sleddog, Zee, Propforward, and Bob for your comments.
Sorry Rudy, I didn't take any photos along the way. I would like to add a governor at some point but I need to finish the fuel system.
Brian, thank you for all your posts. I learned a lot from them. I had to make a 2nd piston for this one. I failed in my first attempt. I lapped the fresh off the lathe piston and sleeve with brasso on the first one. It was leaky. I could see fuel bubbling out from the back of the piston when I flooded it while attempting to get it started. I then spent an hour and half lapping the cylinder with a commercial lap and 320 grit. I took about 2.5 mils off. Went from .505 to .510. It took that much to get a uniform gray finish in the bore. Then I snuck up on the piston od using the sleeve as a gauge. Once the piston would wiggle in an few tenths of an inch I then parted off the blank and finished the other features. I then used brasso and oil to lap the two together until silky-smooth full stroke. Took a maybe a couple hours. It is a very good fit with enough compression to hand start.
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I added a C.Fellows type carb and a fuel tank.
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It runs to my liking now with the ignition timing slightly retarded and a silicone boot over the plug to prevent arcing.
I tried to count pops per 5 seconds and estimate about 400 rpm.
https://www.youtube.com/watch?v=80UcX6wioyI
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Sure has a sweet sound to it!! Even your shop buddy seems to like it :)
Bill
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Sounds great! Congrats! :ThumbsUp:
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That's a gorgeous engine, runs and sounds superb. Good to have a shoppe dawg in there too!
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I agree with everyone else, sweet runner and a great sound.
Have a great day,
Thomas
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Nice little engine. Sure is a sweet runner!
Chuck
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Its a beautiful runner! Thanks for sharing the video.
Its nice that your dog will join you out in the shop. Mine is an indoor girl. I used to try to get her to stay out in the shop with me - got her a nice bed set it in a nice spot... but she never liked being out there. She would just stand and stare at the door and doge inside quickly the first time anybody opened the door. So I've finally given up and she just stays inside with my wife, where its warm in the winter, cool in the summer, and there's no weird stuff going on!
Nice little engine!
Kim
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Running great, D. I love the sound. Thanks for the updated video.
Regards,
Rudy
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Must add my complements to the list, very nice runner.
I haven't completed an IC engine yet, have a few pieces of a Webster in a box on the shelf...
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The engine runs nice. I thought it was going to be a hit and miss engine. I must have misread the title --I haven't heard of a "hit" engine before.---Good job!!
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I don't think he claimed it was a hit and miss engine. It's a little hit engine.
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The style of engine you have built should be relatively easy to turn into a "Hit and Miss" engine. I think Gail in New Mexico actually did that.---Brian
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As far as I can tell the word "miss" is not in the title of the thread. It's a little hit engine. So I don't think anything is misrepresented. It's a nice little 4 cycle engine.
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Thanks guys for your encouragement.
Bill & Kim, my little buddies don't hang out in the shop much unless there is thunder.
Brian, When I first got it to run it was a hit or miss but not on purpose or by design. Lol
I hope to add some sort of governor to it at some point.
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I added a stator and disc magnet from a Sony Beta Max VCR. Brushless motors have fascinated me for a number of years especially to generate electricity. In boredom one day I decided to cannibalize an old sony Beta Max for grins. When I uncovered these parts I thought I might be able to retrofit it to my little engine. It took me over a year to figure out a way to integrate it with minimal modification to the engine.
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Nice tiny engine, that runs very smoothly, clever use of the brushless motor...
how about a video in action, what kind of electric output you have ?
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I'm not sure of the output. My a.c. multimeter gives erratic readings perhaps because the a.c. frequency is very high compared to 60 Hz a.c. . It gives a little more than 6vac per phase (2) at a moderate rpm (guess about 500). Higher rpms and the a.c. voltage gets erratic. With a bridge rectifier and a capacitor I measured 8.6vdc per phase.. Unsure of current but one phase will light an incadesent light bulb rated 12v @2.2 watts to about 50 to 75% of full brightness.
I'm getting some diodes to rectify both phases. Then I can test them in series and parallel to see what it does.
I plan doing a video after that is sorted out.
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I got the output rectified and wired the two phases in series. Not going to go off grid with it but it can do a little work and light up some LEDs
. Shown here running at a modest sustainable rate. Generating 7.5 volts with 40ma load. Ran for 25 minutes on 7ml of fuel
https://www.youtube.com/watch?v=GNO2DAE5Bzc