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: Jim on January 18, 2021, 06:13:29 pm

Title: Re: Probably a stupid question, but I'd like to know
Post by: crazydoug on January 21, 2021, 09:39:36 am
Simple solution, and it works! I sometimes drill holes in the corners of my hit/miss engine bases and stake them to the ground with screwdrivers at engine shows. I like simple solutions.
craydoug
Title: Re: Probably a stupid question, but I'd like to know
Post by: Alan UK on January 21, 2021, 09:10:05 am
I simply glued a couple of battens on to the sides of the wooden box. This allows you to easily clamp the engine to the bench you are running it on.



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Title: Re: Probably a stupid question, but I'd like to know
Post by: Jim on January 19, 2021, 08:16:05 pm
One big advantage of the ubiquitous 'domino box' is the small real estate that they take up on a shelf.
Title: Re: Probably a stupid question, but I'd like to know
Post by: Jim on January 19, 2021, 05:20:18 pm
Quote from: Scorpion2nz on January 19, 2021, 12:45:41 am
Are the bases crap pine ?
If then how about some of those dense aussie timbers that repel nails and screws

Dennis I have some ideas along those lines with some nice thick planks of Aussie Ironwood.

Still not sure 100% of the end design though.
Title: Re: Probably a stupid question, but I'd like to know
Post by: Adirondack Jack on January 19, 2021, 03:25:17 pm
Pics
https://youtu.be/P4BPBavpoT0
Title: Re: Probably a stupid question, but I'd like to know
Post by: Adirondack Jack on January 19, 2021, 03:24:14 pm
Physics won’t be denied. Think of this or any engine as a rotating mass that twists, such that it tries to take the surrounding mass with it. As the speed of the rotation is rapidly altered, the directing of the twisting force momentarily reverses, and the mass tries to hop. If that mass has a long enough lever arm on a short enough base, it will try to twist instantaneously, before relaxing just as fast, and you get a hop. 

My M91 isn’t the slowest or most steady runner, but it no longer hops. The longer, lower, most importantly longer, and heavier base defeats the torque.


Title: Re: Probably a stupid question, but I'd like to know
Post by: RedRyder on January 19, 2021, 07:41:36 am
Steps to ease this problem:


Jin used a very light pine box. It is too light and too short.  He knows this. However, I believe there has been an effort to make a complete running package that would fit in the 9x9x9 box and weigh 2 kg or less for large shipping discounts.

Gil
Title: Re: Probably a stupid question, but I'd like to know
Post by: 70Rcode on January 19, 2021, 07:08:32 am
Even using a Solid Oak block of same dimensions will Not keep it from firing torque kicking about on my year old M90 ! ...Doubling the stock base length + flywheel end offset Iron weight gets you Started !!
Title: Re: Probably a stupid question, but I'd like to know
Post by: Scorpion2nz on January 19, 2021, 12:45:41 am
Are the bases crap pine ?
If then how about some of those dense aussie timbers that repel nails and screws
Title: Re: Probably a stupid question, but I'd like to know
Post by: 70Rcode on January 19, 2021, 12:17:49 am
It's quite a torque "kicker" & needs a lot bigger box & counter weight than would seem !
Title: Re: Probably a stupid question, but I'd like to know
Post by: Jim on January 18, 2021, 10:30:10 pm
Cheers for the replies. I thinking of forming up some lead 'ballast' to make the box a lot heavier.
Title: Re: Probably a stupid question, but I'd like to know
Post by: Steam Technology on January 18, 2021, 10:01:46 pm
Unbalanced.
Lightweight materials.
No real base.
Size and measurements are easy to scale, not so gravity or torque or momentum.
Title: Re: Probably a stupid question, but I'd like to know
Post by: St Paul Steam on January 18, 2021, 09:19:22 pm
I tend to think its the robust combustion of the engine combined with the lightweight build materials of the engine combined with a light pine wood base... and "Viola"
Title: Probably a stupid question, but I'd like to know
Post by: Jim on January 18, 2021, 06:13:29 pm
Why do Jin's H&M engines jump around so much?

I've watched a heap of other home built Kerzel designs and they don't.