Hoffman Universal Dividing Head – helical drive shaft seized

[Adam HarrisParticipant @adamharris13683]

I have an old Hoffman Universal Dividing Head (the small 100mm one) with the extra gear shaft extending to the left for helical milling and differential indexing. This shaft seems seized solid and does not engage or interfere with the operation of of the main handle/worm screw movement when indexing. Am I missing some procedure for engaging it? Or is this due to a common point of failure that can be addressed upon dismantling?

Edited By Adam Harris on 06/01/2018 15:11:36

[Adam HarrisParticipant @adamharris13683]

[Tony Pratt 1Participant @tonypratt1]

From memory you need to undo the black plastic ring that clamps the division plate, turning the plate will turn the shaft.

Tony

[Adam HarrisParticipant @adamharris13683]

So I swivel around the outer casing that encases the dividing plates? Hmmm that makes some sense as there is a notch in it and a clamping screw (mine is brass not plastic). I will check it out and revert . Thanks . I wonder why they had an engagement process whereas the "standard" Victoria/Elliott saw fit to have it permanently engaged?

[Adam HarrisParticipant @adamharris13683]

no that does not relate

[BazyleParticipant @bazyle]

The Victoria/Elliott has a little plunger pin that engages the dividing plate but that means the plate can only be in one orientation as the (as supplied) plates only have one such hole. The K&T has a brass clamp ring which enables the plate to be held in any position and the aux shaft can have a small handle attached for rotating the plate and hence work for alignment prior to locking and plain dividing. Sounds like your Hoffman is the same as this.

[Tony Pratt 1Participant @tonypratt1]

If you release the division plate so it can rotate & then turn it the shaft will then turn.

Tony

[Adam HarrisParticipant @adamharris13683]

All sorted! – Good old fashioned seizure – rust, gunk etc.. Thanks anyway Tony for your attempt at help

[Adam HarrisParticipant @adamharris13683]

Thanks Bazyle – discovered Hofmann helical shaft is indeed permanently engaged by bevel gear with dividing plate mounting (bevel gear at back) , just rusted and seized. Plenty of WD40, working back and forth, and now hydraulic oil and all running smoothly

[Author]

Posts