Electric Starter System for Model Engines
- Thread starter Brian Rupnow
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As with chain tensioners. spring loaded tensioners work best when the spring provides a pre-load (all bar one pulley free to turn) then the position of the pulley is LOCKED in that position. Otherwise the system is very likely to "bounce" at some resonant frequency (varying with transmitted load). Resonances usually destroy something. This system has produced long-lasting and reliable belt and chain drives for driving valve gear since the 1960s.... Service intervals on Car timing chains is measured in the couple of hundred thousand miles for chains, and when "elastomer timing belts were used the precise tensioning in the factory, with LOCKED tensioners, produced zero warranty for 60,000miles service interval, and some were not serviced until much longer, but eventually the industry decided that even the best belts should be changed at 30~35,000 miles as after-market servicing did not give such precise belt tensioning - Thus fatiguing the belt, and risking an engine failure... The Sales and Marketing people wanted "longer lasting" engines, so the higher cost of timing chains was adopted across much of the industry. There is a lesson there.
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trlvn
Well-Known Member
There are a number of services for cross-border shopping (USA to Canada) that might let you save some money. Lately, we've been using one called Shipsy:
https://shippsy.com
Basically, you sign up for their service (no charge) and when you order something from the USA, you give them a Shipsy address which is in the US. Shipsy collects the package and brings it to one of several pickup locations. We use the one in Mississauga; the OP would likely want the one in Concord. They have been very prompt at retrieving the packages. You pay their fee ($7 for up to 10 pounds) plus HST on the value of the shipment. Then you go to their location to pick up your stuff. Or you can pay them extra to mail it to you directly.
So far, this service has worked really well. Especially when the US vendor wants to charge punitive amounts to ship a small package directly to Canada. Shipsy is quick, provides good communication, has reasonable price, and pickup has been hassle-free (although no Saturday hours).
YMMV,
Craig
As always, one has to check the amperage rating. If the amps are too high, an option is to do what cars do - low power switch to control a high power relay.
ajoeiam
Well-Known Member
Hmmmm - - - -Shipsy only works if you're in Ontario, BC or Quebec - - - so not of much use except if you live in those areas.
(There's plenty of canuckistan that isn't in those 3 provinces.)
Thanks for the info - - - maybe they will expand their services - - - dunno.
trlvn
Well-Known Member
As I said, Shipsy is what _I_ use. The first sentence of my post also says "there are a number of [such] services". Since your Location is "blank", you aren't making it easy for others to give suggestions that will work wherever you are.
Craig
Yesterday and today, I finished the drill mount on the sliding carriage. I spent most of yesterday drilling 1/2" holes thru 8" of aluminum material. I called over to my toolshop, and a new 10" long half inch drill costs $85.00. I decided to drill thru from both sides with my 4 1/2" long standard 1/2" drill. I hoped the holes would line up precisely with each other where they met, and as usually happens, they didn't. Only off by a couple of thou, but that's all it takes to keep a 1/2" shaft from sliding thru the resulting hole. I got it sorted, but it eat up half a day of my time. Today went smooth as silk, and I finished the other parts and assembled everything. I like the way it looks so far.
Okay, I'm finished and it looks really good. If you want a free set of detail and assembly drawings, email me at [email protected] and specify that you want the engine starter drawings. There are fourteen drawing sheets. Note--this cost more to build than I would have believed. By the time I bought the timing belt pulleys, the timing belt, the one way clutch bearing, the aluminum material, and the drill and the momentary contact switch it came very close to $430 Canadian funds.
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And here, just because I can, is a picture of an engine set up on the starter system. That's just a random engine of one of my shelves, but it shows exactly how an engine sets on the starter system. The top plate of the starter system will have to be drilled and tapped to the mounting bolt pattern of whatever engine I am starting.
Does it free-wheel when the engine fires? - Or simply re-charge batteries, or something?
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It freewheels, because that one way clutch bearing only transmits torque in one direction.
Oh happy day!!!--My engine starting system seems to function exactly as I had planned it. If you watch the video, then look at the text I have provided and it gives you a full story on what you are seeing. I am not finished yet--I still have to wire up the black button you see on top of the table to turn the start table on and off. The engine shown setting on the top of the table was designed before the start table, so I've had to build an outboard bearing support for the shaft with the large timing belt pulley on it.--This will not be necessary on future engines.---Brian
Hi Brian, I understand better now. It is not just an engine starter, but a variable speed drive to run the rngine, e.g. For running-in, etc.
I guess the variable speed drill can develop "speed" as well as "starting torque" ?
K2
I guess the variable speed drill can develop "speed" as well as "starting torque" ?
K2
Steamchick--The electric starter is only intended to be used for starting my engines. I wouldn't want to run the drill motor for any great length of time, as drill motors were never intended to do this. I'm not sure what you have for electric drills in your part of the world, but in Canada and USA, the 3/8" variable speed reversible drill is almost generic--Everybody who ever needs a drill buys one. They are inexpensive and seem to live forever.---Brian
I have worn out many.... but I still have some good ones that were from the "Olden days" of 60s and 70s when they had proper gearboxes and motors...
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But I have had to rebuild and replace triggers!
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The electric starter system is finished. I am happy with the way it performs. My material costs were about $420.00 Canadian. I had mistakenly posted earlier that it cost more than $600 but that was not correct. I may add a mechanical hold down for the "run button" in future, so I have both hands free to adjust engines while I am attempting to start them. Thanks to anyone who watched the progress of this build. Anyone who would like a set of free drawings to build this can contact me at [email protected]
This video shows my starting system for model internal combustion engines. The starter is powered by a 3/8" variable speed electric drill. The drill is bolted to a sliding carriage which allows me to tighten or loosen the drive belt, by means of a 1/2" threaded rod which has a knurled wheel attached to the end you don't see. The secret to this is the over-running clutch which fits internally in the top gear-belt pulley. It allows torque from the electric drill to start the engine, but it does not transfer torque from the engine to the drill. This means that after the engine starts, I can remove my hand from the start button, the drill stops, but the engine can keep on running with no load. I am very happy with this system.---Brian
Complete plans for the engine shown are in a model engine magazine published in USA "The Home Shop Machinist" . September/October 2023 issue and November/December 2023 issue.
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Do not let your neighbors or relatives know that your labour is free.
So you are your own employee, not your own boss
.Please open up a new thread when you start making pulleys, it will be very interesting.
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