Myford Dickson toolholder and 10mm tooling

Just bought a couple of standard Dickson toolholders from Myford Ltd, these will not lower enough to take my 10mm indexable lathe tools due to the tool slot base thickness. Could this be due to the age of my Super 7B, September 1966, do the the later S7 lathes with different saddle and slides suffer from this?

Standard problem I fear. Best way round it is to mill some metal off the bottom of the tool shank.

RDG did have some special 'Dickson' style holders that fit the '7' tool post designed to overcome your problem - they are deeper and have a cut-out at the bottom and can hang over the front of the top slide (so that they can take larger tools)..

I bought mine from their eBay shop, but can't see them at the moment. Might be worth a phone call.

Good luck.

I milled a bit off one edge worked for me.

Thanks for your comments everyone, curious about this as my Toolmex holders,  and two Piddington toolholders bought from Myfords at the same time as the standard ones do not have this issue, taking a 10mm indexable tool with about 10 thou clearance under the toolholder.

Edited By Peter Turvey on 18/02/2019 19:45:07

I have also just got a quick change tool post for my ml7 from rdg found to be 0.5mm above c/l with 10mm tooling took off top slide and milled 1mm now ok

Same here with a S7. I have a collection of toolholders gathered from different sources over the years, some of which wouldn't go low enough. Milled 50 thou off the topslide and problem sorted!

I'm always surprised when people alter the lathe to fit the accessory.

Pretty minor mod to be honest and lacking a surface grinder a lot easier than removing metal from the (8) problem toolholders!

There does not seem to be a definitive dimension for the slot position in these toolholders with the result that many of the copies have this problem. Around £50 for a genuine Dickson and £20 for a copy, works for me . . .

Guilty as charged, yer honour.

The Myford standard 4-way toolpost sits 10mm tooling about .020" too high. So I milled that much off the base of the toolpost. Now modern, readily available 10mm tooling will fit with out any further fussing about evry time I buy a new tool.

I've milled the bottom off 10mm tip holders but I don't think this is a fault of the tool holder manufacturers. I imagine that the holder was designed to hold a maximum 3/8" (9.5mm) HSS tool. There is quite a lot of variation with tipped tools, depending on how deep the tip sits in the tool and the thickness of the tip itself, making 10mm tip holders marginal even in original Dickson tool holders. I think 8mm tipped tools are probably a better choice for Dickson equipped 7 series lathes.

Cheers,

Rod

Edited By Roderick Jenkins on 19/02/2019 10:04:12

What Roderick said. It's a bit like buying wheels too big for your car and then being surprised you have to cut off the wheel arches to accommodate. 3/8th has always been considered the maximum on a Myford so simply buy smaller shank tooling. This just strikes me as the more obvious remedy although I accept machining the top of the topslide is a solution.

Thanks Roderick and Chris query resolved.

Edited By Peter Turvey on 19/02/2019 17:45:46

I have had exactly the same problem last week. Dickson type holder from RGD which supposedly takes a 10mm tool shank. This would be just OK if the insert was flush with the top of shank – this is rarely the case. I also resolved the problem by skimming 035” from the top of the topslide.

However, I have another post on the forum asking for reports on the Hemingway toolpost kit. Apparently the toolpost block has an overhang which allows the block holding the tool to drop below the top of the topslide. This would allow for a ½” tool – I know this size is probably a bit big for a Super 7, but I have many such tools that I would like to use.

Has anyone completed machining this kit and is it any good as a toolpost?