-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
New PM-1236T Lathe has arrived
- Thread starter riveter
- Start date
I measured the spindle taper runout to be about 0.0001". Axial runout is about the same. That's one tenth of a thou.
And one more spindle runout test after mounting lathe on the stand. About 0.0001". I also checked the axial runout. None measurable.
I also measured the 3 jaw chuck with a 1/2" drill blank inserted. This is an economy chuck, so I was not expecting much of it. It is nearly 0.004". I know now this test means little or nothing.
So I will be shopping for a good Asian made replacement. Shars has some options.
And one more spindle runout test after mounting lathe on the stand. About 0.0001". I also checked the axial runout. None measurable.
I also measured the 3 jaw chuck with a 1/2" drill blank inserted. This is an economy chuck, so I was not expecting much of it. It is nearly 0.004". I know now this test means little or nothing.
So I will be shopping for a good Asian made replacement. Shars has some options.
Last edited:
- Joined
- Dec 26, 2015
- Messages
- 2,151
BISON 7-803-0634 6
Bison D1-series Direct-mounting Standard 3-jaw Chucks. Bison direct-mounting chucks have a universal semi-steel body, i.e., they are made of high-class cast-iron. These Camlock spindle D1-series chucks can be mounted directly and do not require adapter plates. The chucks' jaw teeth, pinions, and...
www.travers.com
Have you seen any positive comments on this one? Apparently it can be dialed in to run true.BISON 7-803-0634 6
Bison D1-series Direct-mounting Standard 3-jaw Chucks. Bison direct-mounting chucks have a universal semi-steel body, i.e., they are made of high-class cast-iron. These Camlock spindle D1-series chucks can be mounted directly and do not require adapter plates. The chucks' jaw teeth, pinions, and...
6″ Adjustable Ultra Precision 3 Jaw Chuck, D1-4 Mount
- Joined
- Oct 16, 2019
- Messages
- 6,892
In the past when faced with wide pallet/narrow hoist legs situation I've managed to lever the pallet up and onto the legs of the hoist. From there I've hoisted off the pallet and carried on.
I've also taken the outriggers off and moved them outboard using some appropriate sized stock as long pins sleeved with black iron pipe in the space where the outrigger normally goes.
(I hope that makes sense...)
- Joined
- Dec 26, 2015
- Messages
- 2,151
I'd post a new topic specifically asking about that chuck. That will get more responses that you'll get in this thread. What I can say is that I would avoid a chuck made on mainland China, and focus exclusively on one from Taiwan, or from Europe (Bison, TMX, PBA) if you can afford them. Make sure you get one with 2-piece jaws. Having Set-tru (Adjust-true) facility is a real plus.
When I bought my PM1340GT in 2015, Matt (at PM) was able to supply a 6", 3-jaw, 2-piece, Set-Tru type chuck made in Taiwan by Chandox for me. It's a terrific chuck and I love it. Here's a photo of the chucks PM supplied - the 4J is nothing special, but does the job (I wish it had 2-piece jaws).
This is the Chandox ((after adding shop-made adjustable chuck-stops):
Compared to my Bison 6" (on the rotary table), the Chandox is every bit as good in accuracy and build quality. Two years later, I tried to buy a second one from Matt and he said he could no longer source from Chandox. You might ask Matt how his current 3-jaw adjust-true from Taiwan compares to the Chandox. Don't expect a 3-jaw scroll chuck to give you repeatability tolerances better than 0.003" TIR - for that you need and Adjust-Tru type.
At some point, you are likely to want a collet chuck (either 5C or ER40) for your lathe. Read the attached before deciding.
- Joined
- Dec 20, 2012
- Messages
- 9,422
You cannot assess the accuracy of a 3 jaw chuck by measuring runout on a pin held in the jaws. This is not how a 3 jaw works. A 3 jaw is intended for first operations work so you need to chuck something in the chuck and turn it, then measure the runout of that turned piece without removing it from the chuck. It will be zero or should be unless something is seriously wrong with the chuck.
You also do not need a set-tru or adjust-tru chuck unless you are doing multiples of a given diameter in a second operation.
- Joined
- Dec 26, 2015
- Messages
- 2,151
Mikey speaks the truth here. A 3-jaw is unlikely to provide repeatability to under 0.003” TIR remounting the same material. For tighter TIR you will need a Set-Tru and be willing to dial it in, or use a 5C or ER collet chuck.
I understand. I would lose concentricity only when I take the turned part out of the chuck. I have occasionally marked the part and one jaw so I could get it close when returning the part to the 3 jaw chuck. It has been a while since I had a lathe, so I will have to do some reeducation. Thanks for that.
I do have the P.M. 5C collet chuck. I installed it and indicated it in to about 0.0005". I think I can get it closer when the time comes to use it. I also checked spindle play by pulling up and down on the chuck with my hand. I am getting about 0.0005" of play as I deflect it with hand force. What should I expect for spindle play in the PM1236T lathe?