A spider for the PM1340GT lathe

Alan H.

H-M Supporter - Sustaining Member
H-M Platinum Supporter
Joined
Sep 17, 2018
Messages
230
I finally built a spider for my PM1340GT lathe. It had been on my project list for many months. There are other posts here on the forum for a spider but I thought I would add this one to the list.

I used this project as an opportunity to apply Fusion 360 and learn a bit more about the latest generation of 3D modeling software. Learning Fusion had also been on my list for months. The drawings are attached here as PDFs for those who may want to use this spider concept as a start.

I built the spider from 4140 chrome moly heavy wall tubing.

As you may know, for the PM1340 you will need to open up the end cover a bit to accommodate the spider. I did that on my PM935TV mill with a boring head and it worked out quite well.

I turned/bored the spider using a recently acquired 4 Jaw combination chuck and was pleased with the accuracy of the chuck. I did the milling and drilling needed using my indexer on the mill.

The finished spider fits the spindle as hoped and the bores match up very well. I got a little carried away making some brass tipped “workpiece holding” set screws but this spider will hold down to a 0.110” diameter workpiece. Yes, this is small but I recently turned some very small copper tubing where this would have eliminated red rags stuffed in the spindle for support. When and if I need it, I may add an indictor mount on the end cover of the machine to center the workpiece.

Thanks to Mark J. (@mksj) for sharing his concepts so I didn’t have to start from scratch. Thanks to Brad (@bss1) for his idea for the brass jam nuts.

jam nut screen capture.JPG

spider drawing.JPG


raw material.jpg


boring.jpg


machining in 1340.jpg


drill in indexer.jpg


finished jam nuts.jpg


finished III.jpg


bore matches up.jpg


spider screws.jpg


way down.jpg
 

Attachments

  • Spider As Built Drawing AH.pdf
    387 KB · Views: 439
  • Spider Jam Nut Drawing AH.pdf
    297 KB · Views: 406
My dentist could use your skills. Seriously, this is over the top. Great job.
Thanks David,
I cheat! Truth is that I am fortunate enough to have some really good PM and Ellis equipment. I continue to be impressed with the accuracy and capability of my Precision Matthews lathe and mill. I remember calling you about a year ago to get your recommendations. Thanks for steering me in the right direction.

Excellent work. I'm marking this post for my to-do list.
Thanks for the details.
Great job Alan, another project I can steal!!!!:):):)

Thanks folks for the kind remarks. I would be pleased if it helps you and others. This forum is a treasure trove of information and helped me a lot, so just trying to give back a bit like many of the folks here.
 
Nice work Alan! Super clean and crisp looking. What insert did you use to produce that nice finish?
 
Nice work Alan! Super clean and crisp looking. What insert did you use to produce that nice finish?
Iscar CCMT 3-1SM IC907 - straight and boring; on boring it will take very small cuts if needed but I used a 1" boring bar with as little overhang as possible
Ceratizit CCGT 32.51FN-25P - chamfering - go easy and slow on feed, don't bump it. It is not really for 4140 but sharp as a razor and works well if you baby it.
 
Artwork Alan! Who is the manufacturer of your indexer and is that a 6" 3 jaw? I need one
Precision Matthews - 6", bought it with the mill.

Peder - figure out if you want an indexer or a rotary table or both! I am in the market for a rotary table as well. I'm glad to have the indexer though because I am going to make some gears in the near future.
 
Back
Top