Author Topic: Design and build side shaft hit and miss engine from bar stock  (Read 29593 times)

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #45 on: November 20, 2018, 09:59:39 PM »
My helical gears from Debolt showed up in the mail today, and I am very impressed. They look like good quality gears. The one which has an extended hub on one side will get a couple of set screws drilled and tapped thru the extended hub to hold it to the camshaft. I'm not exactly sure how to attach the other gear to the crankshaft at this point. I also stopped by my metal supplier guy today and picked up two 1" long cuts from a hotrolled 6" diameter mild steel bar for $25.00. In the background of the helical gears you can see the two 1/2" ball bearings that will support the crankshaft. The seals will be removed and the grease washed out, then a bit of light oil applied to them.                                     

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #46 on: November 20, 2018, 11:58:56 PM »
A plan is slowly working it's way thru my head---

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #47 on: November 22, 2018, 12:14:06 AM »
Well, it can't really be this easy but here it is with one flywheel hidden. 1" bore and 1 3/8" stroke with 6" diameter flywheels. The devil is in the details, and I haven't even thought too much about the cylinder head and cam yet, but I think it's kind of cute.

Online crueby

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #48 on: November 22, 2018, 12:31:07 AM »
Brian, is there a reason to use the helical gears on the crank and bevel gears at the other end? Do they behave differently, or is it just preference?


 :popcorn:

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #49 on: November 22, 2018, 01:08:00 AM »
Chris, I don't have a good answer for that. The only thing I think it may be, is that the helical gears have a lot more contact surface than a set of bevel gears. Theoretically, the helical gears should be capable of taking more stress than the bevel gears.---Brian

Offline asm109

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #50 on: November 22, 2018, 04:45:35 AM »
Actually, crossed helical gears have point contact. Used that way they have almost no load capacity.

Offline Jasonb

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #51 on: November 22, 2018, 07:22:22 AM »
Brian, will you cut out the frame under the bearing and possibly the bearing where the purple helical gear is clashing with the frame or move the shaft outwards?

You may also be able to de-clutter the other end by cutting the cam into the boss of the large bevel gear

Offline Jo

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #52 on: November 22, 2018, 07:28:21 AM »
Brian, is there a reason to use the helical gears on the crank and bevel gears at the other end? Do they behave differently, or is it just preference?

With Cross helical gears it is possible to mount the two 90 degree shafts closer together than bevel gears would allow. Yes Cross Helical gears have point contact so they have no more surface contact (=friction) than a standard set of spur gears.

Jo
Usus est optimum magister

Offline Jasonb

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #53 on: November 22, 2018, 08:21:41 AM »
Depends what you call closer together, Brian could have got his side shaft on the same ctr height as the crankshaft if he had used the bevel gears at that end and not a lot if any further out. Though had he sized the helical gears to suit his engine then they would not be so big which would bring the shafts closer together.

Offline Craig DeShong

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #54 on: November 22, 2018, 02:00:35 PM »
Craig--I'm not entirely happy with the governor.  The maximum travel I can get on the sliding collars is about 0.090". I have more "fettling" to do before I conclude whether this design is going to work for me or not. I only have a couple of small things to tidy up and a spring to buy to finish the governor, so I should know this week if I can make this work for me or not.---Brian

Brian- very little travel on the Myers engine also, I would venture to guess less than the .09 you have.  The lever that pivots out to lock the exhaust valve is long, and therefore the movement at the end of the lever multiples the collar travel.
Craig

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #55 on: November 22, 2018, 03:28:10 PM »
Jason--I have put cut-outs in the side of the part which is the water jacket to clear the large bevel gear. That cut out is below the area which holds water. I will also cut a clearance in the sideplate for the camshaft helical gear---Brian

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #56 on: November 22, 2018, 07:24:41 PM »
So, today we got a bit more serious about just how we were going to support the sideshaft, and ended up with two bolt on brackets complete with oilite bronze bushings. Yes, we had to carve a bit out of the side of the waterjacket to give clearance for the flyweights of the governor when they were spinning around. We also carved a bit out of the waterjacket and the sideplate a bit farther down to clear the largest bevel gear. A fancy top was whittled out for the waterjacket, and the tops of those swishy looking bearing caps were modified to something I like better. Everything fits so far. I had to move the sideshaft out away from the centerline of the engine to get the clearances I required. Thats alright though, because the helical crankshaft gear doesn't have to have the helical camshaft gear riding exactly in the center. It can move about 0.100" from center and still have all the teeth engage. The narrow vertical portion of the sideplates below the waterjacket seemed to be a bit skinny, so it got about 5/8" taller and cutout in the waterjacket part got 5/8" taller to accommodate it. I don't yet know just how I am going to secure the cast iron cylinder in the waterjacket, but will probably put a "head" on the end farthest from the crankshaft and a ring of counterbored shcs. to secure the cylinder.

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #57 on: November 22, 2018, 09:16:00 PM »
I'm getting right down to where the bear shat in the buckwheat now. I was originally going to leave the flywheel webs solid, but I didn't like the look, so added some holes. I tried a 1" diameter hole but it didn't look right, so I ended up with 1 1/4" diameter holes. That's all well and good on the computer screen, but the largest drill and end mill I have are only 1" diameter. I rooted thru all of my different cylinder head models, and ended up stealing the cylinder head, head gasket, valve cages, valves, valve springs, and valve retainers from the Rockerblock engine to use on this hit and miss engine. The cylinder head model got reworked a bit, but not a lot. I have to have all of the cylinder head stuff in place before I can start to think too much about the exhaust valve lockout mechanism.

Offline Ye-Ole Steam Dude

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #58 on: November 22, 2018, 10:03:30 PM »
Hello Brian,

I really like this new creation of yours and it should turn out to be a nice looking engine.

Have a great day,
Thomas

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #59 on: November 22, 2018, 10:21:54 PM »
Thanks Thomas--I'm glad you are enjoying the build. So far I've only done the easy stuff. The exhaust valve lockout is going to be interesting.---Brian