I would not like to machine a rim that is held on spokes only by Loctite, I would want something mechanically solid. Have you considered drilling and tapping the hub (small 1/4″ counterbore) and putting a thread on the end of the spokes. An M6 thread with a small shoulder on a Ø1/4″ spoke should not show afterwards. If you drill and ream through the pipe for the hub you can then feed the spokes through and screw them into the hub, Cut them off at the outside diameter before it is machined and put pin through the end in the hub before it is machined to prevent rotation.

Additionally it is probably better to aim to machine the hub bore and the outside diameter of the rim in one setup and by clamping the assembly onto a faceplate this would allow this and avoid the chatter that such skinny spokes could cause, facing the rims afterwards. The usual method is to clamp on the spokes and use light cuts. If you wanted to use a mandrel and Loctite and avoid chatter you would have to support the rim with a couple of suitable disks either side of it and hope nothing slipped inside when out of sight.

Martin C

1. I finish turned the rim but left the hub blank, loctite it all together, then gripped the hub in the 4 jaw setting the rim true and bored the hub. I’ll see if I can find some photos later on.

Assemble everything and then machine the OD, bore and one face in a single setting with the flywheel on a faceplate. Then the other side can be skimmed parallel to the first. It is possible to hold a flywheel for turning all important surfaces at one setting without needing additional holes:

The flywheel is located by the two diametrically opposite steel spigots, which also react the cutting forces. The clamps on the spokes are not particularly tight and are there solely to stop the flywheel falling off the faceplate. The flywheel is resting on three aluminium plates, which are screwed to the faceplate, so that the full width of the rim can be machined. It also makes it simpler to add the doming for a drive belt.

Andrew

The aluminium plates are held on by cheapo M6 crosshead builders screws, as just seen on the top pad.

The flywheel was assembled on the faceplate flat, with the faceplate resting on a piece of MDF on the lathe bed. For scale the faceplate is 18″ diameter so the resultant combination was rather heavy. So much so that when lifting the faceplate, together with the second flywheel, I pulled something that paralysed one side of my upper body and arm. It was rather frightening at the time and took an hour or so to go off.

Andrew

Nigel: I’d be very interested in more details of the crane, may be a seperate thread?

For some years I’ve known that eventually I will need assistance lifting accessories for the lathe and milling machines. That time is rapidly approaching, especially as I am having to deal with hernia issues at the moment. I’d sketched out a couple of U-shaped runners, with a short cross saddle, attached to the rafters and covering the lathe and both manual mills. The lifting mechanism would be a hoist, not sure if I’d go for electric or manual. I would plan for a load of 100kg. It would be sensible to weigh some of the accessories, but I suspect the bigger ones are comfortably over 50kg. The vertical head for the horizontal mill even has a lifting eye conveniently screwed into the top.

Andrew

Thankyou Andrew.

Yes it would be better as a thread of its own, but my crane basically uses a rectangular-section, open-frame cross-beam assembled from angle-steel, carrying the crab inside it, running on inverted-angle rails supported by square-section tubular columns secured to the workshop’s concrete-block walls.

The beam wheels are second-hand, flanged, hoist wheels intended to run on ‘H’-beams; linked by tubular axles running in hornblocks fitted with rubber-disc “springing” to ensure all four wheels stay in contact over any slight errors in the rails’ alignment.

I’ll have to take some photos of it to produce a more useful report.

I would not go to the expense of an electric hoist. Not for the low-height, occasional lifts we use – such as putting heavily-laden faceplates on lathes. Its only advantage over a manual chain-hoist is that the latter is a rather clumsy thing to use, especially around delicate loads.

Is the “Haltrac” hoist still made? An eight-fall cord and sheaves tackle, it was ideal for this sort of work.