Gentlemen a problem for you to answer

[Michael CallaghanParticipant @michaelcallaghan68621]

Hi chaps. I am part way through building a locomotive build stand. This is based on a Genie lift. Part of the job is a turn beam which can be used to work underneath the loco by turning it upside down on the beam. And here lays the problem. As you all know a locomotive weighs a lot and the load on the pivot bolt would be high. To help out here I was thinking of bearing. This would help when turning the locomotive over on the beam. The problem I have is two fold. For the beam I am using 4×2 inch aluminium square 4mm thick. And a 12mm shoulder bolt. I could add 2 bearing housings to each side of the beam, or fit a tube running inside the beam carrying the bearings. What would be your best. Idea, and what would be the correct bearings to use. I have material to make bearing housings, but nothing for the tube if I go that way, and with the cost of metal these days and problems with delivery, would housings be the way to go. Thanks

[Michael CallaghanParticipant @michaelcallaghan68621]

[Jon LawesParticipant @jonlawes51698]

My locomotive spit isn't difficult to turn despite being on two plain bearings. In the interests of controllability it could be that a bit of friction is desirable.

I'm sure you have considered this but remember the CofG of the locomotive is much higher than the buffer beam once the boiler is on; its much nicer to have it pivoting around the CofG than trying to fight gravity! I don't doubt you have already considered this of course.

[Nigel Graham 2Participant @nigelgraham2]

First, you are not making a centrifuge! You will turning the loco through some angle, slowly, by hand, and only fairly occasionally.

So you don't need an elaborate bearing, just one that will take the load, and a plain brass, bronze or cast-iron bush carrying a mild-steel shaft (I assume the M12 bolt) would be more than enough.

In fact if an ordinary bolt will not be to ever-so-high accuracy even on the plain shank, and for this purpose it would not really matter if the bearing is a plain hole drilled through mild-steel the bearing-length of the shank. Drill it carefully to produce a reasonably smooth wall, and provide an oil-hole or grease-nipple in its top centre.

If you look at commercial engine-hoists, lifting-trolley etc. most don't have anything more than steel pins in steel bushes, though higher-quality ones may have reamed holes and hardened, ground pins.

(You can buy shouldered socket-screws with hardened and ground shanks, precisely for such purposes, and they are not very expensive. I am using two M6 versions for my steam-lorry engine's gudgeon pins… don't worry purists, it's an enclosed engine!)

'

Looking at typical loco lifts occasionally featured in the magazine, the fulcrum is usually set at approximately the loco's axis of mass, to balance the load to a large extent.

Some use a worm and wheel for rotation, though that's not essential provided you can control the over-turning and lock the assembly in place, easily. One way for anything like that is a large-diameter hand-wheel, clipped or loose-pinned to the shaft for safety in use, but readily removeable for access to the work itself.

'

Looking at your beam description, will that wide alumimium-angle, even with the deeper web pointing correctly downwards, leave sufficient access to the up-turned loco? Or is the beam a frame wider inside than the loco itself?

[Dave HalfordParticipant @davehalford22513]

I had a car rottisery mounted on four 1" plain plummer blocks, don't use ball races and make the buffer beam connector arm adjustable and a drilled circular disc to take a tent peg size locking pin.

[Michael CallaghanParticipant @michaelcallaghan68621]

Thanks chaps, interesting reply’s. Looks like I was trying to over engineer the thing.

[martin haysomParticipant @martinhaysom48469]

i built a 5.8 l v8 on an engine stand. the stands pivot is just a steel tube in a steel tube one end only. easy to turn

i dowt your engine is heaver. make it adjustable so it ready for next time

[Ady1Participant @ady1]

A cog with a worm operated by a handle would create a moveable non locking spit

[alan ord 2Participant @alanord2]

Michael, if you go into my photos you will see the version I made. Very simple and I made it in a few weeks. The design was published in an old ME mag. If you need the mag issue number etc. or a photo copy let me know.

Alan

[alan ord 2Participant @alanord2]

Michael, if you go into my photos you will see the version I made. Very simple and I made it in a few weeks. The design was published in an old ME mag. If you need the mag issue number etc. or a photo copy let me know.

Alan

[Speedy Builder5Participant @speedybuilder5]

I made a spit for a Citroen 2CV van body – used for welding and spraying. I just used a scaffold pole and clamps and a couple of "A" frames.

My loco frame was a couple of 3/8" ply triangles with a couple of bolts locating in the buffers and a third 6mm bolt for the axis. The only problem with that was access to the smokebox.

Bob

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