Myford (Coolmex – made in Poland) 3 jaw chuck – are the jaws reversible?

[David MorrowParticipant @davidmorrow53687]

Fellow listers- I am still learning on my Myford S&. Question: I have Myford's Part No. 76096 Coolmex (made in Poland) 3 jaw chuck. Are the chuck jaws reversible in this model? It doesn't appear so, but thought I'd ask before I move on to the 4 jaw chuck.

thx. Dave

[David MorrowParticipant @davidmorrow53687]

3 jaw chuck

[JohnFParticipant @johnf59703]

David, no they are not but you should have or can get a set of reversed jaws for larger work. If you don't have them try Rotagrip for replacements, by the way you will find its a Toolmex chuck.

john

Edited By JohnF on 18/08/2014 07:56:41

[David MorrowParticipant @davidmorrow53687]

thx John. With your guidance and my searching a little deeper into the previous owner's kit, I found a set of hard outside jaws. They were very nice. That makes my day

thx. Dave

[David MorrowParticipant @davidmorrow53687]

John – I've inserted the hard outside jaws, they went in nicely, did my little job and now want to remove them and problem. In using the chuck wrench, the jaws move nicely out until they reach the outside diameter of the chuck and then I am getting significant resistance. I presume the spiral scroll has tightly engaged with one of the spiral scroll teeth of the jaws. Any suggestions. I fear really cranking on the chuck wrench will break something.

thx. Dave

[JohnFParticipant @johnf59703]

David, not so easy to advise when not "on site" however maybe some swarf has got into the chuck or look at the exit ways for the jaws and look for damage, not so likely given that you inserted the jaws OK. It can be that the chuck becomes tight when removing jaws so maybe a little extra effort will remove them but I would close them again first then try removing them again and see what happens. Quite right not to force thinks too much and see if there is a solution first.

hope this helps a little, where are you? Nothing on your profile but Maybe there's a member close by who can advise.

Regards John

[Ian S CParticipant @iansc]

David, sometimes I have found a similar problem with my three jaw, and I find that wind it in a turn or so, then back out a few times clears the swarfe or what ever is jambing it. When changing jaws, it pays to clean out the scroll, and make sure the jaws are clean.

Ian S C

[Neil WyattModerator @neilwyatt]

If it really won't come free it's a good excuse for a proper strip down, clean and re-lube. Access if from the back and the scroll should lift out which will free the stuck jaw(s). Take care that pinions etc. all go back in the same holes.

Neil

[David MorrowParticipant @davidmorrow53687]

thx folks. I'll work with the idea there is some swarf caught. Perhaps vacuuming the chuck, blowing with compressed air and flooding with some oil will dislodge it.

Dave

Amsterdam, NY

[David MorrowParticipant @davidmorrow53687]

thx Neil. I have it apart and have the jaws moving nicely and now removed, But I see what you mean. Filthy looking oil, grease and swarf. Certainly time to clean. Probably never been done. What is the recommended solvent to soak this in? Is it recommended to take the pinions out for a thorough cleaning or can I soak them as is? Also, regarding lubrication, I see the debate about oil, not oil, grease, not grease, other types of lube. What would be your recommendation?

thx, Dave

Amsterdam, NY

[HopperParticipant @hopper]

Kerosene or degreaser should do the the job. I put 5 bob each way on chuck lubing:

Wheel bearing grease inside on the bevel gears and crown wheel etc. It has more chance of staying in there and not flinging out the key holes like oil does.

Hydraulic oil on the spiral and jaws so the swarf is less likely to stick to it.

Works for me.

[Chris TriceParticipant @christrice43267]

Given your apparent lack of experience with three jaw chucks, it might be worth bringing to your attention that both the jaws and the slots they fit into are numbered. You may find that fitting and removal is a lot easier if you match the right jaw to the right slot and, more importantly, the chuck will hold more accurately.

[David MorrowParticipant @davidmorrow53687]

thx much Chris. All thoughts are welcome. In my instance I was aware of the numbering system. Turns out this chuck was way past the need to tear down and clean. What are your recommendations for lubrication?

Regards, Dave M.

Amsterdam, NY

[The Merry MillerParticipant @themerrymiller]

Afternoon Dave M.

The leaflet that came with my Pratt Burnerd chuck states:

Clean and lubricate the chuck at regular intervals (whatever they are!)

To obtain maximum benefit the chuck parts should be cleaned thoroughly with Trichloro-ethylene or Carbon-tetrachloride.

I don't believe either of these two chemicals are readily available any more but I stand to be corrected on this point. (H&S and all that guff)

I would be extra careful when using kerosene or paraffin (they are different oils) but there are quite a few proprietary degreasers readily available.

Lubricant recommended by Pratt Burnerd is Molycote-D or grease containing molybdenum-disulphide applied with a clean brush.

Len. P.

[Clive HartlandParticipant @clivehartland94829]

Molycote D is like a dry dark paste and is not like a grease which is slippery and does not stick to a surface.

I use Molycote D and regularly clean out the spiral and the jaws and re-apply the Molycote D. Be aware that if you use a solvent that does not completely evaporate, when you begin to use the chuck it will throw out any solvent you have used! You want to see a couple of my shirts.

Clive

[Neil WyattModerator @neilwyatt]

In blissful ignorance of Molycote, I use standard moly-grease on my chucks.

Neil

[TrevorhParticipant @trevorh]

Hi Merry miller, the 2 chemicals you mention are not easily found as the first one is carsonagenic and is due to be banned and the 2nd one if gets hot turns into phosgene gas – very deadly

please dont be tempted to use either with out lots of Protective equipment

[Chris TriceParticipant @christrice43267]

White Spirit, cellulose thinners or even petrol is good for cleaning old gunk off chucks. Obviously all the usual caution about naked flames and preferably outside.

[JohnFParticipant @johnf59703]

Brake cleaner is a good degreaser and easy to obtain at any motor factors, Trevor is quite correct about carbon tet but I have to smile in the 1960's we used to mix it with coconut grease and use as a cutting fluid when machining low carbon steels—-still here to tell the tale ! Worked extremely well and gave a super finish.

Edited By JohnF on 20/08/2014 20:46:45

[David MorrowParticipant @davidmorrow53687]

thanks for all the feedback. It's been soaking in kerosene all day. now to clean it and off to the store for the suggested lubricant.it isn't until you take one of these chucks apart that you really appreciate the quality. Nice tool!

Dave M.

[David MorrowParticipant @davidmorrow53687]

Epilogue…after thorough cleaning and reassembling, the scroll still caught some and even jammed on one try. Took it apart again and scrutinized the inside surfaces. Found several pieces of swarf embedded into the chuck wall and some digs on the scroll. I had a #4 riffler file to remove the swarf and smooth out the surface. Few grits of abrasive on the scroll and all is running smooth again. Now for the moly D grease…and then on to boring that hole in the mainspring barrel that started this whole experience.

thx much for the feedback

Dave M

Amsterdam, NY

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