Chuck

Looking ahead ,l am thinking of buying a mt3 collet chuck set , now the cheaper set that l have reading etc about seem to have more run out trouble with the er32 type and the er25 seem to be better ,any feed back on this please,l know that with the cheap sets you get what you pay for,for example the banggood ones are cheap and the rdg ones double the price ,but are they worth it ,its a mine field to know what to buy,so advice etc would be great.

john

Hi John,

It won't make any difference whether you have ER32 or 25. Cheap will be cheap!

Banggood will probably be ok (although someone will chime in with "once they bought something and it was no good, blah blab blah).

I've had good and bad from China. Best plan is stick to companies that sell mainly tooling.

Good luck.

Jim

Interesting.......quite a lot of members at Epping Forest Horological Club have recently aquired cheap(er) chinese ER sets and, while results are indeed mixed, I have noticed some repeating problems which can be listed under 'user error'.... Firstly, people often claim poor manufacture but when one of the more experienced members examine their set some of these defects are reduced or simple go away.

Firstly, the large number of slots in ER design allows debris to quickly upset accuracy as just one tiny piece of swarf will prevent the slots closing evenly and start to spoil accuracy. Next, people commonly try to mount the collet imperfectly and don't realise that there is a little ceremony in fitting the collet into the tensioning nut correctly first. Finally it's worth mentioning that in industry ER is used to hold cutters and its very common to 'clock 'n tap' to get proper needle placement by using a small hammer or mallet.

Additionally, it's worth mentioning that one has three options for ER collets, namely an ER chuck fitted to spindle,....a Morse taper ER mandrel that fits into the lathe throat and finally an ER fitting in a square or 6 sided block. For my small lathe I chose ER25 in a square block which I use in my 4 jaw chuck.....the drill is to grip the block, fit collet with silver steel piece, clock, adjust for accuracy.......much better than the 4 jaw on it's own IF you are going to do a session of collet work where you will need to make several changes of size etc., also, the ER is much better with the small sizes I use in clock making.

Exactly the same item is going to cost more from a UK supplier than a direct import, you will get much more in the way of support and advice from a UK source and should the item be unsatisfactory then repair, replacement or refund are simpler and you have the backing of UK retail legislation. I think that you get what you pay for is one of life’s truisms most of the time, the direct import does distort this.

Mike

Bought some cheap ER25 collets on eBay and whilst the larger sizes were OK everything below 4mm was rubbish, I didn't need to measure the run-out, I could see it! Ended up buying the smaller sizes from Arc who also do 1.5 and 2.5mm - much better. I bought an MT3 collet chuck from them as well, only complaint is the lack of spanner flats or holes for a tommy bar, so loosening collets relies on the grip of the Morse taper.

Brian

Many thanks for the help ,my feeling was that if it no good then its better to deal with a uk firm ,have never used them before but chronos do a set and they state that the ones they sell have a run out of no more than 0.015mm,and the price is good,so will sleep on that one ,you have been most kind.

john

If you require really high accuracy you’ll need to pay for it. These look good at £60 a collet!

**LINK**

Dead right about the ‘good luck”. You might need it!

I bought a collet system from them, expecting the collets would likely need fettling. They did and run-out was reasonable afterwards. However, the chuck 2MT taper was definitely not to Morse spec. It rattled in the machine socket and would have damaged the machine spindle if not rejected. Bang good customer service was non-existent.

I now avoid bang good like the plague. My advice is only buy from them if you can afford to throw the tat away if is is too far out of spec. I have other items that needed attention to make them work satisfactorily. I can get over most things, but not that taper. They sell a lot of items rejected by the more discerning buyers, so good luck is definitely needed.

Morning all,well had a sleep on it and more looking + reading posts,the plan is next week go with chronos and buy the er25 collet chuck with the bt40 taper as my mill is nt40 and also buy the er25 collet chuck set with the mt2 taper,that way l can use the collets on the mill and the ML7. I think l am more happy with dealing with a uk firm over this tooling and hope my luck is in .

john

For your ML7 rather than a MT2 chuck, (for which you would also require a drawbar), why not buy a ER25 backplate mounting chuck and suitable backplate, That way, if you are holding long stock you can pass it through and into the bore of the spindle, with MT2 you will be very restricted in what length of stock you can accommodate.

Gray

Hi gray, yes can se where you are coming from ,but the main thing was to get the mill on to collets, instead of just using the clarkson type as the cutters are pricey compared to the straight shanked cutters etc,so l would still need a set of collets and as they come with a chuck in the set ,l may as well have the mt2 one ,so that l can use it on the ml7 if needed ,hope that makes sense.Plus another thing that l se going to the collet system is l can make up tools like gear cutter an slitting saw holders.

john

John, you are missing the point. Get the BT40 for your mill and get a backplate mount one for the lathe which will leave the spindle clear unlike an MT2 which will block it.

BTW my MT3 ER32 that came from Chronos quite a while ago has 0.008mm runout of the internal taper and 0.01mm tested against a tool.

Edited By JasonB on 26/09/2019 07:48:17

Hi jason yes the back plate way will be nice ,but am trying to spread the cost it seems its cheaper to buy a set of er25 collets with the holder than without the chuck ? but will get a back plate set up when the funds are there,l am well over budget this last few months with ml7 repairs.

john

You do get a saving buying holder and collets so to start with get the holder for your mill with say 6 common size collets. Then add more collets and the lathe chuck as and when funds allow.

Buying precision collets saves a lot down the line. I suggest buying the highest precision collet you can afford at the time. Then buy more as you need them. Having cutters run better than .01mm every time is important and does make the cutters last longer. Also it means you have confidence is setting up a part and know it is concentric within the collets accuracy. I bought some AAA from China collets that are better than 0.005mm but not 0.002mm though.

Even though they seem expensive , precision collets really are time savers in the long run.

Neil

Neil,

Those collets linked to, for .002mm run-out, were only warranted that good on the nominal size.

.

Does that surprise you in any way?

MichaelG.

Well l am going to be brave and place an order for the bits in the morning, again many many thanks for all the help,and a big thanks to jason.

john

I have an ER32 3MT collet chuck along with numerous collets which were bought on ebay. They may not be toolroom standard but good enough for the work that I do and all at a price that will not break the bank.

My lathe, mill and rotary table all have 3MT spindles and the chuck can be used on all machines. Also very handy to take a job from lathe to rotary table without removing it from the chuck. The only problem being, if the collet chuck is being used to hold work in the RT, it is not available to hold a cutter in the mill and I have to resort to different methods. And why I am thinking about getting a second collet chuck.

Paul.

Careful Paul, you will then be wanting a second set of collets for when you want to hold work while cutting with a cutter of the same diameter