|
Post by ridleyian on May 26, 2007 13:37:33 GMT
I have just constructed a frame in order to be able to turn my 'Enterprise' upside down. I have made attachments to pick up on the holes in the buffer beams having removed the buffers. The 3/4" shafts on which the loco rotates meet these attachments mid way between the holes. I now realise that when I rotate the loco it has a great urge to rapidly 'turn turtle' especially now that the boiler is fitted, and it puts a great strain on the mechanism if I try to stop it at 90 degrees. Obviously I shoud have arranged the axis of rotation some height above the buffer beam. To save me having to make too many trial attachments while trying to work out the height of the centre of gravity, can anyone give me advice as to what this distance is likely to be?
|
|
|
Post by mackintosh on May 26, 2007 17:02:28 GMT
Would it not be easier to make some sort of locking device to hold it in the 90 deg position? otherwise it may be down to trial and error.
|
|
jackrae
Elder Statesman
Posts: 1,333
|
Post by jackrae on May 26, 2007 18:10:10 GMT
It's not a daft question but each and every answer is going to be try half way between the buffers and the boiler centre jack
|
|
ewal
Part of the e-furniture
Happiness is a good wife & a steam engine.
Posts: 293
|
Post by ewal on May 26, 2007 20:31:24 GMT
The number of times that I have turned an engine over , then realized that I have forgot to remove the oil tank, losing half a pint of steam oil.
E.W.
|
|
SteveW
Elder Statesman
Posts: 1,395
|
Post by SteveW on May 26, 2007 20:38:34 GMT
Ian,
It's got to be "science 1-o-1" territory. If you add a lever and on it enough weight to achieve a balance you have moved the CoG to design fulcrum. It should be a simple mass times length calculation to work out what you did and similarly where you need to be.
Or you could just guess.
Having some sort of mass balance device might be worth retaining for when you add/subtract the bits.
|
|
|
Post by mmaidnz on May 26, 2007 22:38:34 GMT
Hi,Ian.I'm about to start building a stand,so I've looked around for various ideas.One idea I'll use,proposed by a member of our club,is to have a disc at one end with 8,or even 12 holes.This is pegged to a bracket with a holding pin.This will allow the loco to be placed at any of up to 12 positions.As far as the turning turtle question,I had worries about that too.My thoughts are to put ,say,6 pegs around the disc,facing 90 degrees to the loco,and use a tube +- 20" or so on these pegs to control rotation.I hope you can visualise what I'm trying to describe.Please post some pics when you've got your stand done,I might pinch some of your ideas as well ;D regards,Hans.
|
|
|
Post by Shawki Shlemon on May 27, 2007 9:17:36 GMT
Hi I use a very simple stand and the loco ( frame ) is attached to the stand through the buffers . See Dukedog article . I use friction for locking but once the boiler is fitted no attempt is made to position it in any position other than up wright but if you wish to do that then all you need to do is to mount a temporary plate on one of the buffers with holes that will line up with the stand and a lock pin will do the job . I built many engines on this stand including some large once like GWR king .
|
|
|
Post by Tel on May 27, 2007 9:45:30 GMT
A worm and wheel set up to rotate it would solve all your problems
|
|
|
Post by ridleyian on May 27, 2007 15:17:55 GMT
|
|
|
Post by steammadman on May 27, 2007 15:55:29 GMT
looks like a good enough answer to me if it works then its ok! ! ! ! why waste time making a fancy rig you might not use again for months REMEMBER TIME IS IN SHORT SUPPLY, and, as you get older it becomes more valuable
|
|