Quick change tool holders

Hi

I'm looking for more tool holders and I think the ones from RDG (what they call "Myford size" are correct for my tool post... does anyone know? I emailed them too but if someone here knows that would help.

These are the RDG holders: http://www.rdgtools.co.uk/acatalog/Quickchange_Toolpost__Separate_Tool_Holders_.html

These are the ones I have:

Edited By Nitai Levi on 02/01/2017 10:35:08

For Dickson toolpost sizing see the table here... **LINK**

The usual Myford size is S.00 but, without wanting to teach Grandma, not all toolholders are equal.

I'd wait for Lynam Engineering to have some (ebay seller lynamengineeringltd) which are not only cheaper but IMHO are superior to the official Myford ones (**LINK**) which are superior to cheaper Indian (Soba) or Chinese knock-offs.

I'm not sure whether all of the RDG ones are the same as the Myford ones.

HTH

Jon

Another recommendation for the Lynam tool holders, they fit the best of I've tried and are the equal of my original old myford holders. The toolpost they make is also excellent, I treated myself to one recently to add to my Hobson H7, very pleased. Usual disclaimer, just a satisfied customer.

And this link will give you the dimensions of both toolposts and holders.

http://www.rotagriponline.com/datasheets/toolposts.pdf

I bought a set of toolholders and a toolpost from RDG for my Boxford and I can honestly say that they are excellent and reasonabley priced. (I'm also tight fisted)

Brian

I bought several Soba toolholders for my Dickson toolholder (Colchester Bantam sized - "T2"?) from Chronos some years ago and they were fine. It seems the copies are a bit hit and miss, so perhaps I was lucky.

I've now bought a set of Multifix toolholders from Create ("A" size). Looking forward to using them soon....

Murray

BTW, there's a guy over on homeworkshop (Darren in Ipswich) apparently selling three "Colchester Triumph T2" sized toolholders. They sound like compatible holders, possibly the right size if they are T2. Don't know him myself but you could check what he has.

PS - sorry, I thought your machine was bigger than Myford. Previously you said you had a D1-3 nose, which suggested to me a centre height closer to 6". Worth checking which size you actually need before getting too clever and ordering anything. The lathes.co.uk reference doesn't seem to recognise "T" sizes which just confuses matters.

Edited By Muzzer on 02/01/2017 14:41:45

Thanks. I contacted Lynam and I'm checking if they have the size I need.

I'm not sure what the difference is between the S and T, but hopefully Lynam and RDG will be able to tell based on measurements of the holders I have. They seem slightly different from any of the ones in the tables in the links and some of the outside measurements don't need to be exact anyway.

Muzzer I don't think I said that and if I did it was a mistake. My lathe is larger than a Myford but still pretty small. I think T.00M is the correct size (closest one from the specs).

Edited By Nitai Levi on 04/01/2017 05:16:00

I have a collection of 14 Dickson tool holders purchased over the years at exhibitions, when I foolishly assumed they were all the same. Recently I needed to mount a 10mm insert type threading tool and couldn't get it low enough on my Super 7. Out of interest I measured the base thickness of all my holders to find the thickest was 0.264 and the thinnest was 0.222 which is one that I could mount said tool at the correct height. Only a couple of pairs were the same which were probably bought at the same time.

Anyone know the correct dimension?

Lynam used to make for "old" Myford and sold of stock when Myford changed hands.

Nitai and Peter Spink:

All the toolpost and holder dimensions are in the Rotagrip link I posted two days ago, further up this thread .

.

... and because it's so useful; here is the 'link' that David posted, as a **LINK**

http://www.rotagriponline.com/datasheets/toolposts.pdf

MichaelG.

Sorry, probably a silly question, but..

Why would Rotagrip & RDG parts necessarily be the same size?

There is no statement of compatibility with Myford parts in the RDG advert (or the Rotagrip pdf file for that matter), just that it will fit a Myford lathe. This could apply to fitting to the compound slide rather than Myford QC toolpost - there is nothing in the RDG advert that would give me any confidence that the the parts are compatible. If they were meant to be swappable I'd expect a Myford part number equivalence to be quoted.

I am considering one of the RDG QC toolposts at the moment to fit to my latest lathe so am interested, and don't feel I'm raising spurious concerns - I just feel, as the OP says that there isn't enough info in the RDG advert to make a sufficiently informed choice.

Regards,

Richard

Edited By richardandtracy on 04/01/2017 10:56:52

A caveat about Lynam toolholders. Having bought some a while ago when they first appeared for sale, and found them excellent, I was happy to order more recently.

However, these latest offerings, some didn't fit properly on my Toolmex/Bison toolpost. More worryingly, one did fit but others didn't, implying a lack of control.

Many thanks for the replies chaps but even from the drawings I cannot see a definitive dimension for the thickness of the lower part that the tool rests on (which is quite critical on my machine). Maybe that's why some of mine are different - the knock of merchants couldn't work it out either

Measuring all mine again, the favourite dimension seems to be 0.230 max. which, with a 10mm tipped tool holder gives 0.025 clearance for adjustment between the holder and the topslide.

Note to self: take a pair of calipers to exhibitions in future!

Peter

The following will contain some assumptions - I don't like assumptions, as they can be a fancy word for 'guess', but unless someone comes up with some more definitive data, that's the best we will have to work on.

I am not sure if there is an industry standard for the tool posts and holders, certainly I have never seen a drawing showing the taper dimensions for one, which are one of the critical parts of the setup, and one of the biggest single factors I believe in getting different makes of post and toolholder to mate properly.

So, the first assumption, that Dickson probably set the standard, and if another post or holder is to be compatible, it should be machined to a Dickson dimension. Rotagrip sell genuine Dickson, and also Toolmex/Bison. I have a genuine Dickson toolpost for my S7, and Toolmex/Bison holders, which fit perfectly.

Bison toolholders can be identified by the fact that they normally have (for example, for a Myford standard toolpost, S00/T00 fit) '4494 - 48' etched on the front lower face of the toolholder.

There is a further data sheet on the Rotagrip site, and it lists machines and their correct toolposts:

**LINK**

Firstly, the T and S prefixes to toolposts and toolholders are effectively the same - so, an S00 is the same as T00.

I believe T00 M is Myford fit, and T00 B is Boxford fit.

If you have the correct toolpost, that dictates maximum tool setting height, but the really critical measurement, as pointed out by Peter, is the thickness of the base of the toolholder that the tool sits on, since that dictates getting the tip of the tool low enough to be on centre of the material being turned.

In theory the bottom toolholder thickness will be G minus E in the dimensions on the data sheet. For a S00/T00 this would be 17mm less 10mm tool, so a maximum thickness of the toolholder base of 7mm (.275" ), but I think this is suspect.

In an earlier post Peter you said the minimum base thickness of any of your toolholders was .222. For your info, that is exactly what my Bison 4494 - 48 toolholders measure.

In summary, I know Bison holders fit a genuine Dickson toolpost perfectly, because that is what I use.

Lyman seem to be well recommended (noting Robbo's caveats above), but personally apart from those I would only trust Bison to accurately fit a genuine Dickson toolpost, and to be accurately machined.

Or, to put it another way, if you are trying to mate RDG or Chronos or whatever posts to holders you are probably perfectly ok to mate same supplier to same supplier posts and holders, but if you are trying to mate Chinese or Indian toolposts to anything, or Dickson/Lyman/Bison to Chinese/Indian etc, expect potential problems.

I would also say that I mention Dickson and Bison not as a plug for either, only because I know they are cross compatible; and only mention Rotagrip as supplier of both, and the source of the datasheets.

Edited By David Standing 1 on 04/01/2017 22:38:16

Edited By David Standing 1 on 04/01/2017 22:38:44

Edited By David Standing 1 on 04/01/2017 22:45:28

Thank you Michael, and as you will see from my above post I have now subsequently figured out how to post a link myself .

Whoops - editing my original post somehow reproduced it totally here in a new post!

Edited By David Standing 1 on 04/01/2017 22:47:03

All interesting stuff, many thanks.

All seem to fit OK but just four that are too high.

Be nice to get them all in the ball park. Is 0.020" too much to take off with a surface grinder?

Thanks very much!

I checked again and behind a layer of dirt and some rust was a S00/M hidden on the tool post
It looks like maybe there was a company name somewhere on the post too, but that is too worn out to read anything... so much that I'm not sure it's even there.

The holders don't say anything but obviously they should fit the S00/M size... unless not all S00/M (or T00/M) would necessarily fit the same post...

Re the measurements on the Rotagrip website, yes I looked at that link and the post and holders I have are not exactly the same as any of the ones mentioned there (or the other page showing S models). Some of the more important measurements are not shown (things like overall length or depth aren't that critical anyway, but I guess they are used to match holders which then should fit... in theory).

I checked the holders on the Rotagrip website. They have both S00 and T00, both with the exact same (outer, somewhat less important) measurements. Both are much more expensive than any of the others. No other measurements are mentioned. The T00 is made by Bison. The S00 has no details. The S model is for some reason more expensive than the T. They seem to have the same photo. More detailed specifications lead to that same page David Standing already linked to.

The thickness of the bottom of where the tool is on my holders is approximately 5.9mm for the regular ones and 7.5mm for the V one (excluding the V).

I'll check with Rotagrip and see, maybe try them too.

Thanks again