# A spider for the PM1340GT lathe



## Alan H. (Oct 18, 2017)

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.


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## davidpbest (Oct 19, 2017)

My dentist could use your skills.   Seriously, this is over the top.   Great job.


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## Tozguy (Oct 19, 2017)

Superb!


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## MonkMan (Oct 19, 2017)

Excellent work. I'm marking this post for my to-do list.
Thanks for the details.


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## rherrell (Oct 19, 2017)

Great job Alan, another project I can steal!!!!


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## Alan H. (Oct 19, 2017)

davidpbest said:


> 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.



Tozguy said:


> Superb!





MonkMan said:


> Excellent work. I'm marking this post for my to-do list.
> Thanks for the details.





rherrell said:


> 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.


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## peder.wennberg (Oct 19, 2017)

Artwork Alan!  Who is the manufacturer of your indexer and is that a 6" 3 jaw?  I need one


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## bss1 (Oct 19, 2017)

Nice work Alan!  Super clean and crisp looking. What insert did you use to produce that nice finish?


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## Alan H. (Oct 19, 2017)

bss1 said:


> 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.


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## Alan H. (Oct 19, 2017)

peder.wennberg said:


> 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.


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## peder.wennberg (Oct 19, 2017)

Alan - I already have an 8" Phase II rotary table I bought years ago with their 6" 3 jaw chuck and backing plate.  The rotary table is only vertical mount, otherwise I would use horizontally to perform drilling holes like you have.  Today I use V blocks in the vise and angle blocks to determine hole spacing.  An indexer would be far less time consuming, more accurate and versatile.  I'll give Matt a call.


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## firemaker76 (Aug 11, 2019)

Alan H. said:


> 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.
> 
> ...


Superb work Alan!  Truly amazing.  Thanks so much for sharing this.  This will be one of my first projects once I get my PM-1340GT up and running.  

-Mitch


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## epanzella (Sep 6, 2019)

Beautiful work, you could hang that on the wall!


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