So I lost the spindle drive on my Omnimill. Stripped the pulley section off to find a worn out drive dog that doesnt exist on the parts list I have.

The drivre dog lives in the inside of the top pulley assembly.

Decided to have a go at making a new one from aluminium so made up a broaching bar and ground down a bit of HSS to match the spline shape. Made up a clamp of sorts to prevent the spindle from turning.

The hole on the aluminium plate was drilled off centre to allow the edges to fit into the splines and stop the shaft from rotating to allow mw to cut the new splines.

Carried on and cut the drive dog not realising that the cutting tool was slightly off square to the drive dog so the splines are a bit wonky but it still fits and works ok.

Cut the groove in the drive dog to allow it to be held by the same circlip that holds the bearing cover plate in place.

Greased up the bearings while it was apart and fitted the new drive dog and all is well again. First spline I`ve ever cut and happy that it works besides being a bit off.

In the pursuit of better accuracy and to follow on from the recent DRO, I fitted a ER32 chuck and a solid tool post in place of taper turning slide.

I discovered more gaps in my knowledge…

7mm twin flute still got pulled down in an R8 collet – which had been tightened this time. I'm not sure what an appropriate depth of cut/speeds/feeds is but I know it I took too much.

I can't power-tap M10 or even M6 in steel. If I hold tap in chuck then either tap spins in chuck or chuck spins on arbour. I will get a new sharp tap that fits a collet and give it a go.

I fitted the ER chuck with less than .01mm runout measured on the body, but 0.05mm on the taper. After skimming the taper I got it to less than 0.02 which will do for now until I feel I know better what I'm doing (the cutter was screeching which suggest something wrong) . Putting a 10mm mill in a collet gives .06mm runout – a little from the mill, but most from the cheap collets (cheapest set available). I will get a few better quality collets in specific sizes.

The 63mm shell mill I got for Christmas works a treat. Makes me think I should have gone for 80mm.

DRO is brilliant.

I was fortunate enough to be the only bidder for a 2-6" M&W micrometer on ebay. The blown plastic case liner is in a bit of a state

My 3d printer is not big enough to print the whole thing, so divided into 4 bits

Not sure now about the felt pad in the lid – might harbour damp. 2 of the collars for the standards where missing so I have printed those from PLA. The originals are rubbery so I will have a another go with TPU though not confident of success.

The ratchet thimble is missing from the micrometer head. Although I never use it, I feel it ought to be there. I guess I will have to make a matching ratchet to this

Happy new year folks,

Rod

Looks like a nice job Roderick. Should last for many a year. The other half keeps on at me to get a 3D printer but I have resisted so far.

regards

Looking good Stevie. What diameter are those steel fingers? And about how long are they? I might get around to making my own fabricated knock-off sometime.

Edited By Hopper on 10/01/2023 11:53:17

Lovely job Jason.

jason is it the base for a horizontal steam engine

ha ha no i dont know and miss googles images page doesnt either

Hi Rod

Nicely finished. I did one of those mainly for the filing function. I should really finish the bow for the saw blade but had a little trouble working out how to hold/register the casting in order to get the bores for the tensioning screw threads in line. I must admit to not spending too much effort to work it out and put it aside ‘until inspiration strikes’. It’s still there actually.
Maybe I’m being too finickity and it’s not that critical but I would be interested to hear how you machined yours. It’s an odd shape to hold actually.

regards Martin