Member postings for Bob Astill

A nice tool and quite handy for honing rods,pistons Etc It shows no sign of a mounting so I would take it is hand held, I have used the interior ones to hone bores using paraffin as the lube and to wash debris away. Interesting ! Noel.

i assume 46 is a fair bit thicker than the iso 32?

Yes, 46 is noticably thicker than 32.

The Gildemeister lathes at work use 46 hydraulic oil for spindle gearbox lubrication & the difference in thickness can be seen over 32 (kept for hydraulic top-ups) when decanting from barrel to jug.

Hopefully changing to the correct grade will sort your problems.

Nigel B.

WHAT OIL SHOULD BE USED ? what oil did you use ? Noel.

Hi Noel I can't remember a friend gave me it saying it would do I think I am going to have to change it to find out I just wondered if its thicker would that be the problem?

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

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

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

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).

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?

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