Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Scale Model Gas Engines - Hit & Miss - Throttle Governed - Non-Compression – etc => Topic started by: njrich50 on August 24, 2019, 12:47:35 pm
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Can some one give me a idea how to adapt a drill to start the HORIZONTAL HIT AND MISS COMPLETE ENGINE ? I saw a video where Jin uses a 1/4 drill drill to start his vertical hit and miss.
Thanks.............
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Bonjour,
I successfully rolled a thickness of 2 mm of rubber at the end of the axis of the engine and then tightened it with the chuck of my hand drill. Bad luck, it was perfectly running but on the wrong way, my old drill has no reverse mode.
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Someone should ask Jin how he made his?
Gil May know the best way to contact him.
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It looks to me that Jin took a u joint for a boats line shaft (he sells them) and disassembled it. It would be one of these below, but drilled for an 8mm shaft.
http://www.microcosm-engine.com/5mm4mm-universal-joint-couplings-p-195.html
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You need an overrun mechanism, the drill engages to turn the engine and once it starts the coupling is automatically disconnected, think vintage car hand cranks.
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You need an overrun mechanism, the drill engages to turn the engine and once it starts the coupling is automatically disconnected, think vintage car hand cranks.
I agree that you could trim the drive side to make it release as the engine fires, but Jin is just pulling the drive side off in his video. I'm not fond of having the ball side of the u-joint attached to the crankshaft as Jin does, which is why I went with a pulley and string method to start mine more easily. Another solution would be to use something like a model airplane starter - a friction cup on a spinner. I'm going to hang with my low tech string - I'll always have one available if I store a spare string in the base with the batteries.
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After seeing Gils replacement crankshaft, i would advise not using a drill to start the M91. The high torque of a drill can cause the 5 piece crankshaft to loosen where the shaft is pressed together, causing continual timing changes and other problems. I learned this the hard way, and started making rope start pulleys for any engines that don't have a 1 piece crankshaft.
crazydoug
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How do you make a rope style start?
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https://www.officeofsteamforum.com/general-discussion-scale-model-gas-engines-hit-miss-throttle-governed-non-compression-etc/m91-vertical-hit-miss-signed-and-numbered-1-2/msg13975/#msg13975
If i did this right, this link should show it!
crazydoug
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After seeing Gils replacement crankshaft, i would advise not using a drill to start the M91. The high torque of a drill can cause the 5 piece crankshaft to loosen where the shaft is pressed together, causing continual timing changes and other problems. I learned this the hard way, and started making rope start pulleys for any engines that don't have a 1 piece crankshaft.
crazydoug
Oh my - I hadn't thought about that. The string start system works so well there really isn't a reason to consider a power starter (unless there is limited access - like is it were installed in a boat).
Motor on!
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Following Slow Arrow's lead, I modified an existing pulley so that it would allow a "rope" (string) start. Video below shows just how this looks and works for anyone contemplating doing the same. Pulley needed requires an 8 mm bore to fit the shaft on side opposite the governor weights.
https://www.youtube.com/watch?v=iIYLXSmOweI
It seems the perfect way to easily start either the M91 or even the M90 which is generally easier to start anyhow, but the string makes it a little more fun!!!
Rog
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Bonjour Roger,
Well done, as I have no tool, I have to find a rriend who will make one for me, I agree with you, this engine is not obvious to start with the hand only.
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There are a number of ebay and Amazon vendors in China selling pulleys that would work well if the 3-6 week leadtime doesn't bother you. At under $6.00 USD each, I have just ordered two...one for the M90 and a spare for the M91. Only critical measurement is the 8 mm bore.
Rog
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Can you give me a link for the pulleys?
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There are a number of ebay and Amazon vendors in China selling pulleys that would work well if the 3-6 week leadtime doesn't bother you. At under $6.00 USD each, I have just ordered two...one for the M90 and a spare for the M91. Only critical measurement is the 8 mm bore.
Rog
Can you give me a link for the pulleys?
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There are a number of ebay and Amazon vendors in China selling pulleys that would work well if the 3-6 week leadtime doesn't bother you. At under $6.00 USD each, I have just ordered two...one for the M90 and a spare for the M91. Only critical measurement is the 8 mm bore.
Rog
Can you give me a link for the pulleys?
Here are the ones I just ordered thru Amazon:
https://www.amazon.com/gp/product/B07T6ZMMVY/ref=ppx_yo_dt_b_asin_image_o00_s00?ie=UTF8&psc=1
Roger
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Love how well it works Rog! 8)
You really wouldn't need to cut the notch in the side of the pulley, it's just a nice extra touch. Once you had a complete wrap around the pulley, the string would hold it in place enough for a quick pull-start.
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Bonjour Roger,
Well done, as I have no tool, I have to find a rriend who will make one for me, I agree with you, this engine is not obvious to start with the hand only.
Raphael, the only tool I used was an electric drill. I put an 8 mm diameter drill bit into the pulley, tightened the two set screws on the pulley AND added a couple of drops of CA glue where drill bit passed thru the pulley. Then I put the drill bit into the drill, locked the running electric drill in a vice and used a couple of hand files to make the cut you see in the pulley...first a coarse file and then a finer one to remove most of the machining marks. I finished with some fine sandpaper and voila...a rope start pulley after about 20 minutes of grinding.
Roger
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Love how well it works Rog! 8)
You really wouldn't need to cut the notch in the side of the pulley, it's just a nice extra touch. Once you had a complete wrap around the pulley, the string would hold it in place enough for a quick pull-start.
In my experience, simple wraps of the string will not start the engine. Maybe if you roughed up the inside of the pulley, but without catching the slot, the string slips
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Bonjour Roger,
Presented well, it seems really simple, thank you for the detail, I have only to find the pulley ;)
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Bonjour Roger,
Presented well, it seems really simple, thank you for the detail, I have only to find the pulley ;)
Raphael, I ordered two from Amazon...here is the link:
https://www.amazon.com/gp/product/B07T6ZMMVY/ref=ppx_yo_dt_b_asin_image_o00_s00?ie=UTF8&psc=1
One will be for my M90 and the other a spare...perhaps Jin will have another Hit and Miss in the future!!
Roger
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Bonjour Roger,
Many thanks again, this link will also be useful for lot of members.
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Bonjour Roger,
Presented well, it seems really simple, thank you for the detail, I have only to find the pulley ;)
Raphael, I ordered two from Amazon...here is the link:
https://www.amazon.com/gp/product/B07T6ZMMVY/ref=ppx_yo_dt_b_asin_image_o00_s00?ie=UTF8&psc=1
One will be for my M90 and the other a spare...perhaps Jin will have another Hit and Miss in the future!!
Roger
Thank you very much Roger.............
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Bonjour Roger,
Many thanks again, this link will also be useful for lot of members.
Hi all,
I got my vertical ET1 some weeks ago and i did some experiments on it. After replacing the piston rings and re inserting the crankshaft it started only withe a rope.
My mistake was, i didn't pay attention for the timing of the exhaust valve. The valve should start opening close before the bottom dead center. The ingnition should be short before the TDC.
After all i need only one turn by hand to start reliable. Depends on your needle valve. 1/4 Turn open. Eventually you can choke the Carburator with your finger.
Excuse my poor english.
Greetings from a hit&miss guy
Thomas