Actually, it isn't a real Vertex, it seems to be a clone from Axminster.
I have seen a few of these with steppers attached, typically retaining pretty much all the original dividing gear and worm shaft bearings etc.
Typically the stepper-powered versions are not being used for cuts under power, so the original worm thrust bearing arrangement is adequate. I want to use mine for hobbing gears, so many of the moves will be under cutting forces. For this reason I decided to convert to angular-contact bearings adjustable for zero backlash.
It took me a while to find suitable bearings, but eventually I settled on 3801 bearings. These are double-row but I couldn't find single-row with the right thickness ratio. I am basically using them as single-row bearings.
I also decided that I wanted the motor to stick out as little distance as possible from the head, and after a lot of head-scratching and CAD-fiddling I settled on a scheme that uses a hexagonal socket in the end of the worm shaft, and a hexagonal coupler on the motor shaft. In this setup almost the entire motor shaft is inside the worm shaft.
First I modified the worm shaft, shortening it and reducing the diameter to suit the bearings. It was hardened, but a CBN tip dealt with that, and by the time I was down to finish diameter I was through the hardening.
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I then needed to make a hexagonal hole in the end.
I have a way of doing that on my lathe, but pressing in a machined-down cap screw head would probably work.
Doing it on the lathe meant that I could have an 8.5mm hex, however. (I was tempted to use a pentagon or heptagon just for fun)
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I made a new version of the eccentric housing. The adjusting arcs need to be concentric with the eccentric
spigot on the reverse side, not the motor mounting bore, which is why things look a bit squiffy.
![]()
This image shows the two mating hexes disassembled:
![]()
The finished article can be seen doing its thing on a rather dull Youtube video:
BS-0 Dividing Head conversion to CNC - YouTube
I have seen a few of these with steppers attached, typically retaining pretty much all the original dividing gear and worm shaft bearings etc.
Typically the stepper-powered versions are not being used for cuts under power, so the original worm thrust bearing arrangement is adequate. I want to use mine for hobbing gears, so many of the moves will be under cutting forces. For this reason I decided to convert to angular-contact bearings adjustable for zero backlash.
It took me a while to find suitable bearings, but eventually I settled on 3801 bearings. These are double-row but I couldn't find single-row with the right thickness ratio. I am basically using them as single-row bearings.
I also decided that I wanted the motor to stick out as little distance as possible from the head, and after a lot of head-scratching and CAD-fiddling I settled on a scheme that uses a hexagonal socket in the end of the worm shaft, and a hexagonal coupler on the motor shaft. In this setup almost the entire motor shaft is inside the worm shaft.
First I modified the worm shaft, shortening it and reducing the diameter to suit the bearings. It was hardened, but a CBN tip dealt with that, and by the time I was down to finish diameter I was through the hardening.
I then needed to make a hexagonal hole in the end.
I have a way of doing that on my lathe, but pressing in a machined-down cap screw head would probably work.
Doing it on the lathe meant that I could have an 8.5mm hex, however. (I was tempted to use a pentagon or heptagon just for fun)
I made a new version of the eccentric housing. The adjusting arcs need to be concentric with the eccentric
spigot on the reverse side, not the motor mounting bore, which is why things look a bit squiffy.
This image shows the two mating hexes disassembled:
The finished article can be seen doing its thing on a rather dull Youtube video:
BS-0 Dividing Head conversion to CNC - YouTube