Tool Holders for Dickson Clone

Hi all,

I have the warco dickson clone here: **LINK**

They are currently out of stock of tool holders. Does anyone know if any of the ones from the other suppliers fit properly?

Thanks,
Dan

Some do, some don't. I bought several Soba (Indian) holders for my genuine Dickson post and they fitted nicely but others haven't been so lucky. Must be more likely to find a mismatch if the post itself is a clone. Could you take it along to RGD, Chronos etc and try it in the flesh? Might be the safest option.

I have a number of clone tool holders for my Dickson clone post, a 'Bison' which were bought either from Warco or RDG at previous Harrogate exhibitions some with a 'M' or 'W'... which ever way you look at it, others with non descript dovetail/slots, & all have fitted the post without any hang-ups, or have I just been 'lucky' ... Just had a look on RDG site & they are showing QCTP holders in stock.

George.

Thanks for replies.

Not close enough to visit - have ordered one from RDG, will report back success or otherwise ...

I've just looked on the Warco website and seen this grubby speimen , it dosen't inspire me to buy one...................

An easily overlooked "gotcha" concerning fit of Dickson clone toolholders on different makes of tool post is fit of the height setting collar in the grooved flange under the hexagonal lock mechanism driver. If the collar is slightly too thick or too large in diameter it may appear to enter the grooved flange but will jam things up before the holder is pulled back cleanly onto the post. Relatively easy to fix once noticed.

Collar and groove variations are most common reason for poor fit on professional range clones. Judging by my collection there is probably something of the order of 30 thou variation from thinnest to thickest in the professional versions. Collar diameters vary too but I've not seen any too large to fit. My feeling is that the fit should be nicely free with at least perceptible slackness. The thinnest ones I have are distinctly slack in the Dickson posts, which have the widest groove, but this doesn't appear to affect performance.

I imagine its possible for economy range versions to be slightly tapered in collar, groove or both. Worth checking as it could cause binding just before the holder locks up. If you have any doubts as to fit I suggest that you remove the height setter before test locking the free floating holder on the post. Maybe use engineers blue to verify where contact occurs. The twin triangle arrangement is relatively tolerant of small dimensional variations but the various faces must be parallel to close limits.

Clive.

Hi there, all,

I have a Dickson-style tool-post on my ML7, it's branded 'Elliot' and I think it originally came off a Maximat V10-P.

I have several tool-holders for it, some of which fit well and some of which do not. These are from various makers/suppliers. The holders which came with the tool-post fit OK as do those I bought more recently from A&R Precision.

I find it somewhat very frustrating that many people offering tool-holders for sale do not give any dimensional information.

In researching this topic, I've found three tables of dimensions, one on Lathes.co.uk, one on the Rotagrip web-site and one in the MSC/J&L Tools' 'Big Book'. However, none of these tables of dimensions specify what I think is the crucial parameter i.e. the distance between the Vees (see the photo in Richard Green's post, above). Measuring that parameter is not aided by the fact that some male vees are flat-topped while some of the female vees are flat-bottomed.

One of the top items on my 'to-do' list is to find a pair of dowels and to measure the Vee-pitch on all my tool-holders - the emergence of this thread motivates me to do so sooner rather than later.

I shall be following this thread with interest.

Best regards,

Swarf, Mostly!

Hi Swarf, Mostly
I too have an Elliot QCTP (S.00 HB) on my Boxford and could do with a few more holders. My cam pin is 0.370" dia and the cam is 0.304"dia. I did find a new cam pin, but it was metric and too large. If anyone finds a supplier or source of suitable holders at a reasonable price, I would be interested too.
BobH

From my conversations with Rotagrip the Bison and Dickson cams are dimensionally different and they we abel to supply either and so witheir help was able to get the correct one. I have both geniune and Soba (from Chronos) and have not had any significant issues withthe Soba's but have the following observations

The knurling on the adjuster is very variable and the thickness of the flange on same also. When looking at the holder form above the T slot on them is also variable - some will not go on my stoage rack which relies on 1/4" pins. Although there is more than one height of T1 /S1 holder I think the Soba's are skinny on material.

That's just packing grease, although it wouldn't have done any harm to clean it up a bit!

The location geometry of Dickson type tool-holders is quite cunning and well matched to sane production methods. The tight tolerances are angular and so should be well controlled by the set up of the machine(s) whilst the distance ones, which are inevitably subject to variation due to tooling wear, are more flexible. The most precise requirement is that the Vee surfaces are all mutually parallel which should be pretty much a given if all can be done at the same set-up.

Geometrically the classic three point contact ought to guarantee proper location provided they aren't all on one surface. In practice 5 point contact will do so unless serious manufacturing errors are present. Assuming sane machine production. If its been filed from solid all bets are off. Generally two lines and one point will give enough location for moderate cutting loads. Two points and one line being pretty much equivalent. Someday I must take time to blue up mine and see what contacts where but casual inspection of my three posts and 16 + holders shows polished areas indicating pretty much complete two wide line and most of a third is the normal state of affairs. The fourth face appears to have spotty contact.

I have Dickson and Rapid T2 size posts. For Dickson, Rapid and probably at least two other brands of holders the position of the lock-up flange shows negligible variation between various combinations of holders and posts. The final position of the locking spanner handle when locked up for use showing maybe 10 degrees variation between various combinations. Nothing you'd notice although obviously I've not done exhaustive tests. Three posts, 16 holders, three positions per post adds up to 144 combinations. Life is too short. Judging by previous threads on here and comments elsewhere its the inner flange thickness and position relative to the Vee surfaces that is most likely to show unacceptable variations with budget range mixes. Fairly understandable as that's the hardest dimension to control but also the most important if solid lock is to be achieved.

Clive.

A while back I bought a "Rapid Original" QCTP for my Boxford ME10, it came with one tool holder,

My plan was to make a nice set of 4 tool holders to fit it, and put the whole process on the ME website,

This is where I'm up to at the moment,

Richard.

so .... no.

RDG version arrived, but does not fit well enough. The v-surfaces appear to be a decent fit, but the cam action does not pull it in far enough to lock solidly.

Ho hum.

From what Tony says above, it sounds as if Soba are stocked by Chronos. As all 4 of my Soba holders fit well with my genuine Dickson post, it may be worth trying one of them. I bought a few things from Chronos in the past, so most likely that's where mine came from.

BTW, I have a Bantam - can't recall the size. T2 possibly??

Follow up:

I checked the Chronos ones as suggested my Muzzer, but they were out of stock at the time. Ordered one a few days ago once back in, and it fits without any problems.

Inevitably, I got a notification from Warco a day later saying they had them back in stock, but still useful to have an alternative for next time.

Dan

Hi Swarf Mostly,

The Rotogrip website (which you mentioned) tool holder dimensions on at the beginning of page 2 seems to give the distance between vees as 48mm, 62mm, 82mm or 100mm

Martin

I can't remember where i bought it but my dickson clone seems fine, i've never had any of the problems described. Lucky winchester maybe? the one that actually worked?

I don't doubt that there are defective ones but at times it seems like a thinly veiled attempt to slander any attempt at a reproduction even when it's decently made. They want to be the club with genuine dickson toolposts! and dont want to share the glory with anyone else. 

Michael W

Edited By Michael Walters on 15/07/2016 14:52:51

Surely 6-pont contact is the counsel of perfection? 1 plane, one line and one point.

But dovetails work a different way.

Don't forget the depth stop counts as a point

Neil

Fundamentally, it's impossible for the Dickson system to mate perfectly, as it uses 2 vees and is thus statically indeterminate - unless you can achieve zero tolerances of course. And the clamp also requires deadly accuracy on the dimensional position of the internal face of the tee slot relative to both vees. The clones don't seem to be able to achieve the accuracy of the authentic Dickson components, hence the problems we see.

My other reservation is the (lack of) rigidity of the locking cam. With heavy loads and long tool overhang, the cam has to withstand some pretty high forces yet the cam spindle isn't very robust and there is very little to provide resilience (preload) unless you count the flex in the cam spindle.

Rather than spend more money on hit and miss clone toolholders, I've instead invested in a Multifix system.

I think the type that push out are simpler, and therefore more reliable (also much easier to make). As they share the same double vee location system it is no better and no worse than Dickson in that regard.

I suspect the Dickson design was chosen simply because it is so hard to copy accurately.

Neil