Vertex BS-0 Dividing Head 1-1/8” BSW Myford Spindle Nose

[Michael O’ConnorParticipant @michaeloconnor78257]

Hello,

I just purchased a Vertex BS-0 Dividing Head with the 1-1/8”-12 BSW Myford spindle nose from Rotagrip. Wanted the capability to transfer the chucks and other spindle tooling from my Myford S7 to a dividing head directly. Because I live in the USA and returning this would be very expensive, I emailed and spoke with Rotagrip directly to make sure this model would have a Myford spindle nose. They assured me it does indeed.

Upon inspection, it does have the correct thread and a spot on 1.250” register diameter. Spindle is heat treated and the threads and register are ground. Threads need to be deburred at both ends, but everything is in order. Except the distance from the end of the spindle to the register shoulder. The Myford lathe spindle is a nominal 1” length and the dividing head is 0.865” or approximately 1/8” shorter.

The problem with the missing 1/8” of thread is that the Myford Burnerd chucks, faceplates, etc. only engage 2-1/4 turns. With a thread lead of 0.083”, that is only 3/16” of thread engagement. With a hardened D/H spindle thread and cast iron chuck backplates, that could be a potential problem with cracking or failure of the cast iron internal threads.

My questions to other BS-0 D/H owners: Are your D/H spindles 7/8” long and has this ever been an issue for you?

Another odd thing with this unit is that it came with a lathe dog, I am guessing, instead of a proper dog driver. See photos below. The 2MT center has the short parallel diameter to attach the dog driver. Not a big deal to make one, just curious that it wasn’t included. The blank chuck backplate has a 1.250” register diameter that is too short to be mounted on the Myford lathe spindle but it doesn’t have a slot to drive the supplied lathe dog. Any work dog would need to be held captive on a D/H, so that probably isn’t what was intended. Have other owners received a proper dog driver?

Ian at Rotagrip told me this model of BS-0 (Model T) has been discontinued and he believes this was the last one he had in stock. I wanted to ask of others experiences with this model before contacting Rotagrip.

Thanks for taking a look.

Regards,

Mike

[Michael O’ConnorParticipant @michaeloconnor78257]

[lfoggyParticipant @lfoggy]

I bought one of these from Rotagrip a few months ago but mine was the type where the chuck bolts onto a backplate fixed to the 2MT spindle. Like you, I received a lathe dog and the centre like in your picture but I didn’t get the dog driver. This puzzled me as well.

Your spindle issue must be very annoying, but I think you would easily get away with using your Myford chucks on this short spindle nose. If you are using the device for indexing, then the forces on the chuck and the mounting will be much less than on a lathe. I would be more worried about unscrewing of the chuck occurring with uneven cutting forces of milling etc.

I am very pleased with mine. It’s lovely to use, accurate and rigid. Was using it to cut some gears earlier today in fact. The only mod I have made is a little detent to hold the plunger back on the indexing device which makes using it a bit more convenient.

[BazParticipant @baz89810]

I purchased a similar BS-0 dividing head about ten years ago, I cannot remember who supplied it but it is identical to yours so they have been supplied with that spindle nose for quite a few years. I feel that they should be advertised as similar to Myford because it is most certainly not a Myford spindle nose. I have used Myford chucks without any problem but have not heaved them up very tight because of the minimal engagement. I also remember that the internal taper was described as brown and sharpe taper, not morse but don’t know how true this is, I have never used a centre in the head itself. I have recently fitted a chuck to the supplied thin backplate so I now have a dedicated for the head, I made a thin plastic washer and put that on the Myford lathe spindle and then screwed the chuck backplate up tight against it, not ideal but good enough to machine the chuck register.

[Tony Pratt 1Participant @tonypratt1]

My BS0 D/H spindle is just the same as yours, no problem after ten years, not really sure why they didn't just copy the Myford nose?

Tony

[SaxalbyParticipant @saxalby]

Again bought my BS-0 about ten or so years ago and it has a 2 mt spindle. Have never had a problem with an attached Myford chucks even with heavy milling cuts.

Also made a Myford to Boxford spindle adapter to use the Boxfords chucks.

[John OlsenParticipant @johnolsen79199]

My Vertex BS0, purchased about 40 years ago by my father, has a threaded nose that is not Myford, and has the Brown and Sharp taper. Since then they have changed the thread, and I think possibly some also have the Morse taper.

No matter what the thread or taper, I think the nose setup is wrong. Experience tells me that under even light milling loads, the drive plate or chuck can move on the thread, and the driver that clamps onto the taper can turn the taper in the socket. Not to be trusted. I have drilled the small end of the centre so that a draw bar can be used. I also made a backplate to suit so that I can use a spare chuck, but it would be nicer if I could turn a job on the Myford and then just transfer the chuck or faceplate over to the dividing head.

John

[Michael O’ConnorParticipant @michaeloconnor78257]

Thank you Ifoggy, Baz, Tony, Saxalby and John for your replies. Much appreciated!

In the past, I had a Vertex BS-0 that had an 1-1/2”-8 UN spindle, which is what they sell in North America. That one had a No.7 B&S spindle taper. The Brown & Sharpe spindle taper was traditionally used in the past for dividing heads. I have a much larger Ellis D/H that I use on my Bridgeport milling machine. It is 1950’s vintage and has a No.9 B&S taper in the spindle nose. I think Vertex and others originally used the B&S taper in their B&S D/H copies but recently changed to Morse taper because of the difficulty in sourcing B&S tooling these days and the Morse taper tooling is so much more common. Try to find an ER collet chuck with a B&S taper. Maybe they actually listened to their customers feedback. Makes more sense anyway.

Totally aware of the threaded chuck unscrewing potential problem. Wouldn’t use this D/H for heavy milling. Mostly second operation work like drilling, milling flats and gear cutting. With the limited thread engagement, only light duty work would be attempted. Mainly wanted a smaller D/H to use on a smaller Rockwell horizontal milling machine I have. The table is only 6”x 24” and my Ellis D/H is a bit too big for it especially if there a setup that requires a foot stock (tailstock).

Thanks again for the replies!

Edited By Michael O’Connor on 08/02/2019 21:31:40

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