Dividing head advice

Hi

To go with my nearly refurbed horizontal mill I will be looking for a dividing head. I feel I need a flexible one but something small - it’s a small mill and most dividing heads seem to be large and very heavy.

The two I’m currently considering are the smallest Vevor semi universal (but generally I go with vintage stuff and refurb them) or a VDH - they quite often seem to come up on eBay.

any thoughts on these or similar others?

Steve

Edited By Steve355 on 28/12/2021 10:26:54

The BS0 100mm centre height size is still pretty heavy.

Universals tend to loose their gear sets and weigh even more.

Don't forget it's your headroom - 100mm - 40mm = what size range you can cut on a horizontal.

Edited By Dave Halford on 28/12/2021 11:49:20

Wonderful old dividing heads show up on eBay, usually missing foot stock, and plates, When one turns up with the full kit there is a feeding frenzy and you have to decide between a dividing head or another blunderbus. I usually go for the blunderbus.

I bought the Vevor with the 4" chuck. The 5" looked unnecessary and rather clumsy. I have to remake the catch plate.

NB: I usually get the wrong word, it's an age thing, may not be a catch plate at all

I have a Vertex BS0, which IMO is simply the VEVOR in a different guise at twice the price, and also a VDH with the additional differential dividing facility. It's 'horses for courses' really, if you are doing relatively heavy work like chewing out involute gears blanks on the milling machine, then the BS0 would be your best bet because the VDH, like all GHT designs is a bit light and flimsy, again IMO. Being an amateur project the VDH will come in a variety of qualities from the professional toolmaker to the back-shed butcher so you would have to be very careful about selecting the one you might buy, and you don't get to physically examine many things on eBay before you buy. I have only ever used the differential facility on the VDH once in the last 30 years and that was to make Myford plates 3 & 4 to complete the set for the Myford dividing attachment.

If you have limited head room and don't already have a rotary table think about one of those. If you want to hold round stock in a chuck and drill a series of axial hole sin the end of the stock a dividing head will need a lot more head room than a rotary table with a chuck on it

Hey, if you gotta source for blunderbusses that can compete with used divvy heads on price, please share!!

Thanks for the comments. I would imagine that it has a decent amount of headroom, looks like 8”? So a 4 inch centre height DH would allow a gear up to 7” or so to be cut, in theory. Which is bigger that I had in mind, so fine. In fact, a 4 inch centre height DH is probably what it is designed for.

Apparently Burke made a dividing head, which was probably actually designed for this mill. Apparently America is awash with them, but I can’t find one online, for sale anyway.

Edited By Steve355 on 28/12/2021 13:26:44

More like a 6" PCD gear. Diameter equals ctr height to valley of the tooth.

You could do bigger with a rotary table

You ought to look at a small rotary table designed to mount on its side first as it will provide you with dual function. Lots of them have dividing plate kit available.
Only progress to a dividing head when you are making enough gears to warrant it. Decide if you need one that tilts (semi-universal). Another variable is the taper, which of MT2 or MT3 etc might be more useful to you.

Quite a few smaller ones that don't tilt around including a couple of ME designs (Sparey, George T) for which castings are available. Also possible to DIY based on old headstock, old tailstock, spin indexer etc. So many options the problem is deciding which way to go.

Another variable is the nose thread if it doesn't come with a chuck fitted. The early BS0 from 'chindia' may have copied the original Browne and Sharpe thread but somewhere along the line it occurred to a UK importer to offer a Myford compatible thread for a bit extra. So they could be something different, including 55 or 60 degree thread even if the right tpi,

Before plumeping for a BS0 I suggest making a cardboard mock up to see how it fits, there must be dimensions on the net somwhere.

A fully universal enables you to index primes but nowadays you can just as easily 3d print a custom plate to enable you to do that on a plain head (see Thingiverse for a plate design you can customise)

The horse appears to be in front of the cart. Before deciding that a dividing head is required it would be useful to decide what one wants to make.

According to the Vevor website the BS0 is 9.5" long and the tailstock is 6" long. That's 15.5" gone before a workpiece is inserted. How long is the table? Also the BS0 is 7.5" wide, so it may not pass the column. My gut feel is that the BS0 is too big for the mill, and it will be difficult to make full use of it's facilities.

Andrew

Body is only about 100mm wide, additional width is the plates & handles that can possibly face the front. But would be a good 10" tall if you wanted to use it vertically

For starters I’d like to make a gear to repair a vintage grinding wheel that I have, about 4 in diameter, lots of teeth (but not as many as it should have). Then I have some projects I’d like to try involving different designs for a woodworking tail vice, which would involve bevel or worm gears. All of it is for fun, nothing serious.

You are right, the BS0 is too big. The smallest model is 9 in long including chuck, and the tailstock 6.6in. The mill table is 16 inches. So that’s out.

Steve

If you can find one, the Myford DH is nice.

Pictures here: **LINK**

Sits very low on the table or can be put on raising blocks for larger diameter items. Mandrel as MT2 socket and standard Myford nose fitting for chucks or collet closer. I generally use ordinary MT2 collets with a draw bar.

Mine is fitted with a stepper drive that I use on my VMB but also on the little CNC machine as a 4th axis.

There are 4 listed on eBay now.

You don't have to use the chuck, mount the gear on an arbor supported on a dead ctr and driven by the supplied driving plate and a suitable dog. Likewise although the supplied tailstock is easy to use an angle plate and home made ctr will only add about 1" to the length if the leg of the angle faces inwards.

Hi Steve this is my dividing head.

It has two positions taller for larger diameters on its side for more clearance under spindle. I bought it from the last Doncaster show for about £40.00 but I had to make two more plates for the gears I needed to cut.

David

A spur gear should be no problem. For bevel gears the blank needs to be presented to the cutter at an angle, so a semi-universal dividing head is ideal. A worm wheel would usually be free hobbed where the worm wheel is driven by the hob as the teeth are cut. Simple supports are all that is needed. However, for an accurate worm wheel it is essential to gash the tooth spaces before hobbing. For that a dividing head would be needed. In an ideal world the gashes would be at the helix angle of the worm. That means the dividing head and/or table need swivelling relative to the arbor.

A quick search indicates that original Burke dividing heads are quite basic, similar to that shown by David.

Andrew

The pics I saw of the Burke head looked like it was semi universal, I’ll try to find one.

Unlike some Burke #4s, mine doesn’t have the table swivelling mechanism. But for a constant angle, making up a fixing plate shouldn’t be too hard.

more research….

This is where you will run into problems with the small horizontal mill , as the dividing head is angled upwards your work gets closer to the spindle height as that 100mm ctr height when horizontal will be 175-200 when the head is at 45deg so no chance of fitting under the cutter.

Which is why, I reckon, Burke made a dividing head specifically for it, otherwise rendering it a much more limited tool. Looks like there were fixed and semi universal types. If only I could find one.

I assumed that one would use the complementary angle and cut vertically, using the knee, rather than horizontally.

Andrew