Dividing Head for a Tom Senior Light Vertical

[RichardM]

I'd just go for a 4 jaw and spend a couple of minutes dialing it in.
ER collet chuck in the MT centre for smaller stuff

 

[Agroshield]

ER collet chuck in the MT centre for smaller stuff

Or ER chuck bolted directly to the RT. More rigid, shorter and for stuff up to the diameter of the small end of the MT considerably deeper. With an ER on a Morse shank, you need two spanners every time you open or close it as the grip of the taper is not enough to resist the torque needed on the ER nut. The only time I'd use a MT shank on the RT is when it is vertical as in Seadog's picture. It is also risky just relying on the taper to resist the cutting forces.

See: https://www.arceurotrade.co.uk/Catalogue/Collets/ER-Lathe-Collet-Chucks/ER40-Lathe-Collet-Chucks

Very cool would be a bolt-on adaptor to D1-4 so he can transfer his lathe chucks. Short of making your own, a spindle out of a scrapped machine can provide this.

Just a thought on Rob's point form an earlier post, "The hole in the centre of the backing plate fits a pin that is a snug fit in the rotab centre hole, makes lining it up quicker if precision isn't needed." It is advisable to put a female thread into the pin so that you can extract it once you have done the lining up. It gets tedious when you align the chuck with the pin, bolt the chuck down, put the stock in, realise the pin is stopping the stock going down far enough and have no other means to pull the pin out other than unbolting the chuck...

 

[not done it yet]

It is also risky just relying on the taper to resist the cutting forces.

That is why one uses a threaded MT arbor (so that it can be secured with a simple draw-bolt) - the way that all milling operations should be carried out. The only operations, without a drawbar, would be for drilling axially.

 

[Rannsachair]

The Vertex arrived today, seems perfect:

Made in Taiwan ( thought that used to be a bad thing!)

Someone has 2 laminated copies of:

Does that look right @Agroshield ?

Fits on the bed nicely:

 

[not done it yet]

My bed only has two T-slots (the Centec), so the spacing was not close enough. Taiwanese was considered less good, compared to British engineering and Japanese offerings - at that time. Of course, China has since taken over a lot of the supply. Taiwanese is definitely considered better than chinese.

IF that table is original, there are probably at least a couple of errors in there.

The maths is so simple, once you decide which hole circle you will be using for any particular tooth count. You know the number of holes per circle chosen, so just multiply that by 90 (turns) for the toal number of holes for 360 degrees and then divide that total number by the tooth count/spaces required. Convert that to whole turns and ‘holes’ - and there is your answer. So very simple…. If it doesn’t work out to an exact whole number of holes (actually ‘spaces’) you know you have got it wrong!

 

[addjunkie]

My bed only has two T-slots (the Centec), so the spacing was not close enough. Taiwanese was considered less good, compared to British engineering and Japanese offerings - at that time. Of course, China has since taken over a lot of the supply. Taiwanese is definitely considered better than chinese.

IF that table is original, there are probably at least a couple of errors in there.

The maths is so simple, once you decide which hole circle you will be using for any particular tooth count. You know the number of holes per circle chosen, so just multiply that by 90 (turns) for the toal number of holes for 360 degrees and then divide that total number by the tooth count/spaces required. Convert that to whole turns and ‘holes’ - and there is your answer. So very simple…. If it doesn’t work out to an exact whole number of holes (actually ‘spaces’) you know you have got it wrong!

Also make sure you wear your reading glasses when setting it all up. Trust me when I say a 29 tooth wheel and a 28 one look very similar. And you dont realise until your finished.

 

[not done it yet]

Also make sure you wear your reading glasses when setting it all up. Trust me when I say a 29 tooth wheel and a 28 one look very similar. And you dont realise until your finished.

They may look similar, but they will be of different diameter for the same DP/MOD.

Was counting the teeth your error?

 

[addjunkie]

They may look similar, but they will be of different diameter for the same DP/MOD.

Was counting the teeth your error?

No picked the wrong set of holes with out my glasses

 

[Agroshield]

The laminated chart is correct.

It is the one in the factory manual (purple cover) that is said to be suspect.

Any chance of a close up of the chart top left of your picture? It looks similar to the union flag plot Pete. showed beofre for a surface plate.

Attached is a text file giving divisions per hole hole count per plate, as well as all divisions possible and missing divisions to 100. It's not worth printing out but might be useful for reference if you need to see at a glance if a certain value is possible.

 

[Rannsachair]

The laminated chart is correct.

It is the one in the factory manual (purple cover) that is said to be suspect.

Any chance of a close up of the chart top left of your picture? It looks similar to the union flag plot Pete. showed beofre for a surface plate.

Attached is a text file giving divisions per hole hole count per plate, as well as all divisions possible and missing divisions to 100. It's not worth printing out but might be useful for reference if you need to see at a glance if a certain value is possible.

Thanks.

Top left sheet is: