Dickson tool post

[Bob AstillParticipant @bobastill76884]

Loose Dickson tool holders

[Bob AstillParticipant @bobastill76884]

I have a Dickson quick change tool post on my Colchester Master it has 3 sides you can fit holders on they are all different when you put a holder in one side the holder will tighten up no issues another it wont tighten up at all the 3rd is in the middle it is also different with different holders i have 20 some fit all 3 ? my question is can the post be adjusted ? or repaired? anyone have a drawing or know where there is a video on how it comes apart?

Many thanks

Bob

[Michael GilliganParticipant @michaelgilligan61133]

I don’t think I have ever seen a genuine Dickson which did not all fit together nicely, Bob

… But hopefully this will help: **LINK**

https://worldwide.espacenet.com/patent/search?q=pn%3DGB1127018A

MichaelG.

.

Edit: __ Patent is downloadable in pdf … just click the little column of three dots.

Edited By Michael Gilligan on 25/08/2021 09:08:53

[Micky TParticipant @mickyt]

Hi Bob there is a vid on YouTube that covers some repair

Quick Change tool post repair

MickyT

[Bo’sunParticipant @bosun58570]

Had the same on the Warco Dickson style QCTP bought with my WM240.

I fixed it by fixing some thin strips of shim stock (0.30mm if I recall) in the slots of the offending tool holders to increase the tongue (for want of a better word) thickness.

I used an Araldite adhesive for metal. Make sure surfaces are clean and abraded. Not sure how permanent it will be, but all (3 out of 12) still OK after 12 months.

Hope it makes sense?

[Bob AstillParticipant @bobastill76884]

Thank you Michael i will have a read of that later.

Bob

Posted by Michael Gilligan on 25/08/2021 09:07:01:

I don’t think I have ever seen a genuine Dickson which did not all fit together nicely, Bob

… But hopefully this will help: **LINK**

https://worldwide.espacenet.com/patent/search?q=pn%3DGB1127018A

MichaelG.

.

Edit: __ Patent is downloadable in pdf … just click the little column of three dots.

Edited By Michael Gilligan on 25/08/2021 09:08:53

[Bob AstillParticipant @bobastill76884]

Thank you Micky i did look at that but its only the top nut nothing to do with making the holder fit tighter.

Bob

Posted by Micky T on 25/08/2021 09:09:49:

Hi Bob there is a vid on YouTube that covers some repair

Quick Change tool post repair

MickyT

[Bob AstillParticipant @bobastill76884]

Thats a good idea mate thank you i will try it

Bob

Posted by Bo'sun on 25/08/2021 10:07:09:

Had the same on the Warco Dickson style QCTP bought with my WM240.

I fixed it by fixing some thin strips of shim stock (0.30mm if I recall) in the slots of the offending tool holders to increase the tongue (for want of a better word) thickness.

I used an Araldite adhesive for metal. Make sure surfaces are clean and abraded. Not sure how permanent it will be, but all (3 out of 12) still OK after 12 months.

Hope it makes sense?

[DC31kParticipant @dc31k]

You need to solve the problem in a systematic way. Number your holders and letter your slots. Try every combination and document pass or fail. Then you may see a pattern emerge.

This will allow you to identify if it is a holder problem or a post problem or a combination of both.

Undoubtedly, the mating surface against which the locking knob that is activated by the cam pulls will be a different measurement on some holders. Shimming that as suggested above will solve a lot of issues.

On the post itself, some logical swapping of the cams and locking knobs may assist (three cams, three knobs, and three positions).

[David George 1Participant @davidgeorge1]

Hi Bob I bought some spare holders from a show and when I put them on to the post they wouldn't all lock up as there was a discrepancy in the sizes relative to the original ones. I found that they were case hardened and I could just mill them with a carbide cutter and now they are all ok.

David

[Clive FosterParticipant @clivefoster55965]

First thing to do with a mis-behaving Dickson is to clean out the insides.

They seem to be a total magnet for fine swarf and chips which builds up inside and stops them working properly. Yearly clean out is a good idea.

Problems with genuine Dickson or industrial standard clones are rare although different breeds exhibit some variation in pullback tongue (on the post) thickness and tongue slot depth relative to the Vees on the holders themselves. Never seen enough variation there to stop mix'n match working, I reckon I have 4 or 5 breeds about the place. What does need verifying is the thickness of the lifting ring on the adjuster relative to the depth of the slot on the snail shaped thing on the locking stud. Even with industrial ones there is sufficient breed to breed variation that adjusters from thick collar breeds won't properly go into locking studs from thin collar breed posts. Because the edges aren't sharp the too thick adjusters will sort of start to enter the slot but bind up hence further turning of the lock stud deflects the adjuster stud so the holder cannot be pulled properly onto the Vees.

Bent adjuster studs are a sure fire identifier for this problem. Fix it by thinning the collar down and replacing the stud with a straight one.

Non-industrial standard and model engineer friendly priced imports can be something of a crap shoot. Back in the day there were some awful sets around. So much so that it was considered wise to buy your lifetime supply of holders and a post in one go hoping that everything would come from one batch with minimal variation. Regrettably the holders not all being interchangeable on all stations of the post was not unknown even when brand new sets were purchased.

Rather than mess about swopping holders between slots its far better to work out a way of measuring things with your equipment to identify variations. Fortunately with a Dickson there are only two parameters that actually matter.

One is that the Vee geometry is correct in that they are parallel with depth and width being constant. Generally a careful eyeball inspection of the post backed up by some basic calliper measurements will suffice to verify the toolpost. Off line or up'n downhill Vees are very obvious. If the post is good then a basic blue check will verify the holders.

The other is the position of the inner flange surface of the locking tongue slot in relation to the engagement lines on the Vees. Tricky to do directly but you only need relative measurements so use a parallel across the outer sides of a pair of same size rods in the Vees for your reference. Measure the distance to the back of the slot and subtract the depth of the slot to give the position of the locking flange relative to the parallel. Be worried by significant variations. A gash, no longer wring together, set of gauge blocks can be very useful in this sort of exercise.

Measuring the thickness of the locking tongues themselves is easy as is determining actual pull back when the cams are turned.

My practice is to draw the basic measurement and operating geometry out in my CAD program and put a text note of actual measured values on the same sheet. Very easy to get completely muddled up if not methodical. Ifind the drawing exercise help concentrate the mind on what is happening. If you can't draw it you don't understand the geometry.

Clive

[Dave HalfordParticipant @davehalford22513]

Bob,

I have the same problem with an A&R Precision Dickinson clone. The tongues seem to bend if you crash a parting tool.

[Bob AstillParticipant @bobastill76884]

Posted by DC31k on 25/08/2021 10:24:40:

You need to solve the problem in a systematic way. Number your holders and letter your slots. Try every combination and document pass or fail. Then you may see a pattern emerge.

This will allow you to identify if it is a holder problem or a post problem or a combination of both.

Undoubtedly, the mating surface against which the locking knob that is activated by the cam pulls will be a different measurement on some holders. Shimming that as suggested above will solve a lot of issues.

On the post itself, some logical swapping of the cams and locking knobs may assist (three cams, three knobs, and three positions).

OK Thank you i will look at this.

Bob

[Bob AstillParticipant @bobastill76884]

Posted by Clive Foster on 25/08/2021 12:00:41:

First thing to do with a mis-behaving Dickson is to clean out the insides.

They seem to be a total magnet for fine swarf and chips which builds up inside and stops them working properly. Yearly clean out is a good idea.

Problems with genuine Dickson or industrial standard clones are rare although different breeds exhibit some variation in pullback tongue (on the post) thickness and tongue slot depth relative to the Vees on the holders themselves. Never seen enough variation there to stop mix'n match working, I reckon I have 4 or 5 breeds about the place. What does need verifying is the thickness of the lifting ring on the adjuster relative to the depth of the slot on the snail shaped thing on the locking stud. Even with industrial ones there is sufficient breed to breed variation that adjusters from thick collar breeds won't properly go into locking studs from thin collar breed posts. Because the edges aren't sharp the too thick adjusters will sort of start to enter the slot but bind up hence further turning of the lock stud deflects the adjuster stud so the holder cannot be pulled properly onto the Vees.

Bent adjuster studs are a sure fire identifier for this problem. Fix it by thinning the collar down and replacing the stud with a straight one.

Non-industrial standard and model engineer friendly priced imports can be something of a crap shoot. Back in the day there were some awful sets around. So much so that it was considered wise to buy your lifetime supply of holders and a post in one go hoping that everything would come from one batch with minimal variation. Regrettably the holders not all being interchangeable on all stations of the post was not unknown even when brand new sets were purchased.

Rather than mess about swopping holders between slots its far better to work out a way of measuring things with your equipment to identify variations. Fortunately with a Dickson there are only two parameters that actually matter.

One is that the Vee geometry is correct in that they are parallel with depth and width being constant. Generally a careful eyeball inspection of the post backed up by some basic calliper measurements will suffice to verify the toolpost. Off line or up'n downhill Vees are very obvious. If the post is good then a basic blue check will verify the holders.

The other is the position of the inner flange surface of the locking tongue slot in relation to the engagement lines on the Vees. Tricky to do directly but you only need relative measurements so use a parallel across the outer sides of a pair of same size rods in the Vees for your reference. Measure the distance to the back of the slot and subtract the depth of the slot to give the position of the locking flange relative to the parallel. Be worried by significant variations. A gash, no longer wring together, set of gauge blocks can be very useful in this sort of exercise.

Measuring the thickness of the locking tongues themselves is easy as is determining actual pull back when the cams are turned.

My practice is to draw the basic measurement and operating geometry out in my CAD program and put a text note of actual measured values on the same sheet. Very easy to get completely muddled up if not methodical. Ifind the drawing exercise help concentrate the mind on what is happening. If you can't draw it you don't understand the geometry.

Clive

This makes a lot of sense is it a hard job to strip the post i have never had one apart?

Bob

[Dave HalfordParticipant @davehalford22513]

Bob,

The answer to your question is in the link posted by Micky T at around 1.25 mins that you have not watched.

Special tools required are two thumbs and 1 index finger in working order

[JasonBModerator @jasonb]

Just push the "tee" shaped ram that retains the toolholding back into the body against it's spring and the wriggle and pull the cam up and out

[Bob AstillParticipant @bobastill76884]

Posted by JasonB on 01/09/2021 08:49:06:

Just push the "tee" shaped ram that retains the toolholding back into the body against it's spring and the wriggle and pull the cam up and out

Ah ok looks simple enough thank you.

[Bob AstillParticipant @bobastill76884]

Posted by Dave Halford on 01/09/2021 08:45:48:

Bob,

The answer to your question is in the link posted by Micky T at around 1.25 mins that you have not watched.

Special tools required are two thumbs and 1 index finger in working order

Thank you i missed that

[Bob AstillParticipant @bobastill76884]

Hmm maybe mine is not Dixon as it is different? but it cam apart the same its now in the bath for a good clean is it just a light oiling on rebuilding?

[Clive FosterParticipant @clivefoster55965]

Nice picture from Jason showing how itty-bitty teensy weeny swarf builds up inside the post and around the locking device. It doesn't take a lot to upset smooth, easy operation of the post. Too much inside and it won't hold tight.

My practice is to pull and clean yearly and before any "knock, knock, knock" type rough turning jobs. As Dicksons are so easy to pull apart there is no sense in letting rubbish build up. I often wonder what the innards of Multifix, wedge and other types which aren't so easy to unbutton get like after extended service.

Best practice is to wipe down the Vees and behind the locking tongue before installing a holder and clean off the holder before putting it back in the rack. Something I've been known to be lax about when doing the multiple tool, multiple part, shuffle. Which always bites me in the end! After 40 + years you'd think I'd get the message. Must be a slow learner.

The post in Jasons picture is very clean. I've never pulled one out for regular service with less than 3 or 4 times as much stuff in it. The one that came with my S&B 1024 had so much brass swarf inside that it was a serious struggle to get enough movement on the locks to strip it.

Clive

[Clive FosterParticipant @clivefoster55965]

Bob

Round tongue on the locking device is usually a pretty good indicator that its a genuine Dickson.

Most clones are rectangular. Certainly "all" the industrial standard ones I've encountered are.

I usually lightly grease the pivoting and sliding surface innards of mine figuring that it will trap the swarf and prevent it migrating too far inside. Other folk say assemble dry because grease or oil will reduce the friction between surfaces on the lock so its less secure. Which is a good point. Maybe best to leave the actual lock cam and bore dry.

But I've never had problems with a very light wipe as in smear on and wipe almost clean. Spoon feeding advocates may say different..

Clive

[Bo’sunParticipant @bosun58570]

Posted by Clive Foster on 01/09/2021 09:40:38:

Bob

Round tongue on the locking device is usually a pretty good indicator that its a genuine Dickson.

Clive

My Warco QCTP has round tongues, and I have every reason to believe, it's not a genuine Dickson type.

[JasonBModerator @jasonb]

I had always assumed mine was a genuine one as it was fitted to an Emco bought secondhand back in 1985 and all the holders with it had the "W" on the back which is said to be the mark of the original makers. Maybe its not but it's served me well.

[Clive FosterParticipant @clivefoster55965]

At that date Jasons is almost certainly original.

As I recall it the ME friendly priced clones didn't start appearing until mid 1980s anyway. Chester I think were first to bring them in.

Bo'sun

Thanks for the information about Warco being round tongue.

I'm not that familiar with the affordable varieties.

Clive

[Bo’sunParticipant @bosun58570]

The tongues on my Warco QRTP are round, and I have every reason to believe, it's not a Dickson one.

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