Unused Vertex BSO divided.

[LathejackParticipant @lathejack]

……………….I bought this Vertex dividing head new several years ago, maybe getting close to ten years. Not long after I purchased the Division Master along with a couple of stepper motors and motor mounts.

After reworking the rather roughly made motor mounts so that they could be used, the otherwise excellent Division Master was fitted to the dividing head, tested and then stored away unused for all these years.

……………….When it was finally needed recently I found that the stepper motor was struggling to rotate the head spindle, with a nasty grating sound and jumping of the divisions.

I suspected the Vertex unit, and once the stepper motor was removed the Division Master operated faultlessly. After removing the worm shaft it was found that the head spindle was quite tight and rotated roughly.

The spindle had been subjected to excessive preload at the factory. Although it appeared to work ok when first tested, years of sitting in the same position under pressure seems to have caused the line contact of the rollers to form faint indentations in the bearing races. This along with the ageing factory grease had proved too much for the stepper motor.

………….After pressing off the original bearing the new one is ready for fitting. Never throwing anything away means I already had a suitable new bearing lying about. All components of the Vertex are very well made.

[LathejackParticipant @lathejack]

Division Master struggles to rotate dividing head.

[LathejackParticipant @lathejack]

As I already mentioned, although the Division Master seemed to work ok when first fitted and tested, it did have a slightly slow initial pickup speed when indexing the divisions, which I took to be normal. When it is finally reassembled it will be interesting to see if it is a bit livelier when rotating the dividing head spindle.

The Vertex unit uses a single taper roller bearing at the front of the spindle, with a plain radial bearing at the rear end plus a needle roller thrust bearing at the back. As on some vertex rotary tables, there are no ball or roller thrust bearings on the worm shaft, just plain thrust faces. There isn't much room for them anyway and off the shelf bearings of the correct size do not appear to be available.

Edited By Lathejack on 13/07/2015 19:43:29

[JonParticipant @jon]

Yes same layout as the Vertex 8" used daily roughly 17 revs for last 16 years, stripped down twice in all that time. Might get a wipe over if in good mood or blast of air, that's it.

Bearings will have number on them some where and are readily available at most places in a variety of makes and tolerances.

[LathejackParticipant @lathejack]

Hi Jon.

The front spindle bearing and rear needle thrust bearing of the Vertex BSO dividing head shown are standard off the shelf items. The bearings I was referring to that seem to be unobtainable are ball or needle thrust bearings that will fit the worm shafts of the dividing head and some of their rotary tables.

Edited By Lathejack on 13/07/2015 22:41:20

[John Stevenson 1Participant @johnstevenson1]

Unfortunately it's the way of accountants and us wanting to buy cheaper all the while.

It's been a long while since I have seen ANY rotary tables or dividing heads in the ME range that have bearings on the worm shaft as standard.

The only ones I know of at present are the CNC converted ones sold by ARC which have twin needle roller bearings and two thrusts to control the load in either direction.

Unfortunately the 6" and 8" Vertex does not have enough meat around the worm shaft eccentric to fit bearings or thrusts other than skimpy home made bronze washers.

[Andy PughParticipant @andypugh44463]

A very old thread, know, but I was doing a bit of research prior to flogging my own stepper-converted BS0 on that eBay and found this thread.

It is possible to re-engineer the worm to add thrust bearings, I did so on mine.

I used a pair of double-row angular contact bearings preloaded by a nut. They actually work as single-row in this arrangement, but the double ones are available with a very thin section and rubber seals. I did also end up having to make a new eccentric flange, but that was to mount the motor.

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