- Joined
- Jul 19, 2019
- Messages
- 116
Hi guys,
This is an outboard spider that I built for my Precision Matthews PM-1340GT lathe and wanted to post a few pics.
I know for a fact that there are a good number of these already posted here so there's nothing special about mine....I just wanted to share. With that said, first things first. This design was taken from plans designed by Mark Jacobs and featured in an earlier thread by Alan H, so thank you to both of those gentlemen for sharing.
The main body was turned down from a 6" piece of 2.5" OD 4140 heavy wall tube (annealed). Then I drilled the center and bored it to 1.590" per specs on the print. Once parted off, I swapped over to my 4-jaw chuck, flipped the part end for end, dialed it in and faced off to an overall length of 3.250". Once finished on the lathe, I moved over to the mill and chucked it up in the dividing head. Holes were drilled and tapped 5/16-24 every 90 degrees for setscrews where the spider slides over the spindle. I drilled one .250" hole at 45 degrees to accept the magnet for the hall sensor and then secured it in place with 609 retaining compound. From there, I flipped the spider around and drilled and tapped four holes for the 3/8-24 x 1.250" screws that would be used to dial in the stock.
For these screws, I held them in my 5C collet chuck and drilled the centers out to .125" x .200" deep. Then, I turned down some small brass rod to .126" (for a light press-fit) and pressed them into the screws. The jam nuts were made from .750" brass rod and then tapped 3/8-24. From there, I set them up in my dividing head and milled .060" deep grooves (every 15 degrees) with a 60 degree carbide bit. The aggressive grooves give them plenty of purchase for easily tightening down by hand. This project was a lot of fun, and I learned some very valuable things along the way. Thanks for reading!
-Mitch H
This is an outboard spider that I built for my Precision Matthews PM-1340GT lathe and wanted to post a few pics.
I know for a fact that there are a good number of these already posted here so there's nothing special about mine....I just wanted to share. With that said, first things first. This design was taken from plans designed by Mark Jacobs and featured in an earlier thread by Alan H, so thank you to both of those gentlemen for sharing.
The main body was turned down from a 6" piece of 2.5" OD 4140 heavy wall tube (annealed). Then I drilled the center and bored it to 1.590" per specs on the print. Once parted off, I swapped over to my 4-jaw chuck, flipped the part end for end, dialed it in and faced off to an overall length of 3.250". Once finished on the lathe, I moved over to the mill and chucked it up in the dividing head. Holes were drilled and tapped 5/16-24 every 90 degrees for setscrews where the spider slides over the spindle. I drilled one .250" hole at 45 degrees to accept the magnet for the hall sensor and then secured it in place with 609 retaining compound. From there, I flipped the spider around and drilled and tapped four holes for the 3/8-24 x 1.250" screws that would be used to dial in the stock.
For these screws, I held them in my 5C collet chuck and drilled the centers out to .125" x .200" deep. Then, I turned down some small brass rod to .126" (for a light press-fit) and pressed them into the screws. The jam nuts were made from .750" brass rod and then tapped 3/8-24. From there, I set them up in my dividing head and milled .060" deep grooves (every 15 degrees) with a 60 degree carbide bit. The aggressive grooves give them plenty of purchase for easily tightening down by hand. This project was a lot of fun, and I learned some very valuable things along the way. Thanks for reading!
-Mitch H
