Er 32 collet issue

Welcome to the forum. What kind of lathe do you have? Most imperial lathes can cut metric threads with the right gears.

I find your original post confusing. It sounds like you are only measuring run out in the adapter and then surmising that there will be run out in the work. You need to measure something of a know OD to check for run out. Even if the work has run out to start with once you turn the work there won't be any run out in the turned part. For example 3 jaw chucks always have run out. They never hold the work concentric to the spindle of the lathe. Yet the work is always concentric to the lathe spindle after being turned.

Run out in the threads will not cause run out in the work held in the collet. The collet registers on the taper of the adapter. Not the threads for the collet nut. Look how loose the collet fits in the collet nut.

Tell us more about what you are making and how you intend to make it.
 
brino said:
Did you install the collet into the nut _before_ putting it into the MT-3 to ER-32 adaptor?

The ER-32 nuts have a small off-centre lip that needs to engage in the collet groove.
It is used to extract the collet from the taper and let go of the part.

If you don't do it in this order then that off-centre lip tries to push the collet off centre as you tighten the nut.

-brino
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Hi I had this problem with my er32 collet, but after I got a tip like yours everything worked fine perfectly,
Egil
 
@Pioneregil

You joined over a year ago, but this is your first post.

So, Welcome to the group!

-brino
 
thanks again for replys.. i have a craftsman 12" and thinking of facing some valves at a later date. the 8degree taper of the chuck runs dead on with an indicator at various depths in the 32 taper. collets snap into the bearing type nut nicely but with about .004 runout on the threads of the chuck im thinking that will put some side thrust on the collet when the nut is tightened. when i blued the internal taper and installed the collet and turned by hand i had great contact between collet and holder. ordered a couple gears yesterday 44 & 52 T to let me help true up the 1.5 pitch od threads.. thanks for replys stirboy
 
I have the 52/44 gears on my craftsman 12x36. They work great to cut the common metric threads. There is a thread chart in the downloads section of the forum. I have the chart taped to the cover on my lathe. This is a great forum. You should think about supporting the forum by becoming a member. The cost is nominal for the benefits received.

Before you start messing with the threads on your adapter you really need to check the run out on a piece of round stock held in a collet. That is the best test for run out.

Putting anti seize on the threads helps with getting the collet nuts tight. Anti seize is a high pressure lubricant.

I made an ER32 collet chuck for the spindle on my lathe. https://www.hobby-machinist.com/threads/no-excuse-not-to-make-an-er32-chuck-for-the-lathe.73804/ Or you can buy one from Beall Tool http://www.bealltool.com/products/turning/colletchuck.php The benefit of a collet chuck is that you can pass long stock through the spindle on your lathe.

You might want to consider making a spider for the outboard end of the spindle. Another one of my projects. https://www.hobby-machinist.com/threads/making-a-spider-for-the-lathe.88933/

Another project was to make what I call a chuck keeper. It will keep the chuck from unscrewing if you have to run the lathe in reverse for a project. See my post #25 in this thread https://www.hobby-machinist.com/thr...ith-a-screw-on-chuck.88487/page-3#post-795768

If you don't have a QCTP for your lathe you can make one. Another one of my projects was to make a Norman style QCTP. Lots of forum members have made them. Not hard to make. https://www.hobby-machinist.com/threads/norman-style-qctp.79705/

These projects should keep you busy for awhile. I would make the QCTP first if you need a QCTP.

Do you have a copy of the manual for the QCGB. If not I think that it is also in the downloads section of the forum. The manual lists all of the possible threads that you can cut through the QCGB by using different change gears.
 
stirboy01 said:
thanks again for replys.. i have a craftsman 12" and thinking of facing some valves at a later date. the 8degree taper of the chuck runs dead on with an indicator at various depths in the 32 taper. collets snap into the bearing type nut nicely but with about .004 runout on the threads of the chuck im thinking that will put some side thrust on the collet when the nut is tightened. when i blued the internal taper and installed the collet and turned by hand i had great contact between collet and holder. ordered a couple gears yesterday 44 & 52 T to let me help true up the 1.5 pitch od threads.. thanks for replys stirboy
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The collet nut only is used to press the collet into the taper. The runout of the nut threads are not relevant. The taper of the chuck and the taper of the collet (and the trueness of the hole in the collet) is what matters. My collets have a slight amount of play when in the nut alone. This play doesn't matter. I can wiggle the nut when screwing on to the chuck. It doesn't matter. All that matters is the rod runs true. So use a known good dowel pin, as suggested, crank down the collet nut tight, and report back your runout.

I guess what we are all trying to say is, don't fix what's not broken. The measurement of the dowel pin will tell you if anything is "broken". If something is "broken" or out of spec, then we can work from there. Use a dial test indicator (DTI) on the rod, and measure the runout (TIR). My "wobbly nut" ER32 collet measures under 0.0005" using a DTI on a 1/2" rod. Maybe yours does too. Measure it and find out.
 
well i received my two gears to allow me to cut the metric threads. on first pass they cut a 1.5 nicely but if i shut lathe off and reverse out there is enough wear in the train to allow the spindle to turn some b4 the lead screw begins to drive the half nuts and as a result the tool doesnt track out exactly in the first pass in. i can pull tool out at end of first pass and go back and pick up start of thread for second and remaining passes but lot of dinking around.. i have been looking locally for some dowel pins but they are not to be had and i really have no desire to order a bag of 25 or 50 so will just have to keep my eyes open .
 
For metric threads (on an imperial lathe) one needs to keep the lead screw half nuts engaged (at all times) while threading. Can't quite tell from your wording if you have done that. If you have, my apologies for stating the obvious. Picking up the thread is doable, but tedious at best.

What size dowel pin are you looking for? There's a bunch on eBay for relatively small money, some with free shipping. McMaster-Carr has them, but they are more expensive. Saw packs of 10 or less on both sites. I take it you have gone to a hardware store? How about an auto parts store? Might be a possible source, or a farm store to repair tractors or power equipment. Precision pins are often used to locate engine/tranny parts.
 
yes i was keeping the half nuts engaged but problem was i needed to back the cross slide out and then reverse back past my starting point to pick up where i started the thread. works fine this way. i should have sourced some pins during my working career as we had them all sizes and lengths but never dawned on me i would have use for them. almost brings a tear to my eye when i think of all the buckets of bolts we threw away and now have to buy a few at a time !! i will have to look again at ebay but they seemed expensive to me for one at a time..
 
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