Vacuum Chuck Again...

[Pete Staehling]

I have been happily using my Super Frugal Vacuum Chuck setup for a while and have been thinking about how to make my setup more versatile and easier to use.

For me the biggest hassle has been the fact that different bowls tend to want different plates to mate up with and it can be touchy getting them trued up well. While a well designed plate can be pretty versatile, it seems like a collection of plates would be nice. It also seems like it would be nice to not need to have another whole chuck to accommodate each plate diameter and shape. So I am considering making a chuck that takes a variety of plates all with the same groove that seals with a gasket or o-ring. The plates could be made on an as needed basis, but over time a collection to cover a variety of projects would be accumulated.

Has anyone done this? Is it a good idea or am I over-thinking this? Is there some gotcha I am missing?

As a luthier I am kind of a jig fanatic and have generally found than making custom jigs has been crucial to productivity, improved quality, and elimination of waste in my luthier work. I am not sure if this idea is a similar improvement or I am chasing my tail here :)

[Brice Rogers]

I bought the frugal parts that had a 2-1/2" and a 3-1/2" PVC coupler. Works pretty well with many objects. But then I had a little bowl with a deep recess. The little coupler was slightly too big to fit inside it and the larger one was slightly too large. So, I took a 1/4" thick x 8 inch dia. disk (had a hole in the center for storing) that I use for marking blanks for bandsawing and slapped it on the larger coupler. And then put a piece of Hobby-Lobby craft foam on the outside and stuck my bowl to it. So, for holding this sort of bowl this worked fine.

In fact, you could probably make a bunch of simple adapters to work with your existing couplers. I will be following this post to get some new ideas.

[John K Jordan]

I have several sizes of vacuum "chucks" made from various PVC fittings, each epoxied to metal flanges. One adapter fits the lathe spindle threads and threads into each flange. The rim of each PVC fitting has a ring of soft craft foam glued as a seal. Some people make various sizes of chucks from wood or MDF disks (with similar rings of foam) fastened to lathe faceplates.

Joe Woodworker sells a very good rubber seal that will probably last longer than the craft foam.

JKJ


I have been happily using my Super Frugal Vacuum Chuck setup for a while and have been thinking about how to make my setup more versatile and easier to use.

For me the biggest hassle has been the fact that different bowls tend to want different plates to mate up with and it can be touchy getting them trued up well. While a well designed plate can be pretty versatile, it seems like a collection of plates would be nice. It also seems like it would be nice to not need to have another whole chuck to accommodate each plate diameter and shape. So I am considering making a chuck that takes a variety of plates all with the same groove that seals with a gasket or o-ring. The plates could be made on an as needed basis, but over time a collection to cover a variety of projects would be accumulated.

Has anyone done this? Is it a good idea or am I over-thinking this? Is there some gotcha I am missing?

As a luthier I am kind of a jig fanatic and have generally found than making custom jigs has been crucial to productivity, improved quality, and elimination of waste in my luthier work. I am not sure if this idea is a similar improvement or I am chasing my tail here :)

[bobby stout]

I bought nuts the same size of my spindle 1 1/8 and glue them in a wooden block and them cut a grove and use all different sizes of PVC couplings with craft foam glued to the blocks and just screw them on my vacuum set up attaches to the rear of the spindle and vacuums through the spindle so for it has plenty of vacuum and has held some 16" bowls without flying into outer space

[Richard Dooling]

Please excuse my ignorance but do I need to get acme threaded nuts? Do I need any other info other than that my spindle is 1.25" x 8?

Thanks,
Richard



I bought nuts the same size of my spindle 1 1/8 and glue them in a wooden block and them cut a grove and use all different sizes of PVC couplings with craft foam glued to the blocks and just screw them on my vacuum set up attaches to the rear of the spindle and vacuums through the spindle so for it has plenty of vacuum and has held some 16" bowls without flying into outer space

[Thomas Canfield]

Its not that complicated. You can make vacuum chucks out of 2x6 construction material or better wood and thread with Beale tap. The foam sheets and hobby shops or Walmart with or without the adhesive back will give the flex for cushion and seal. I like to "seal" the wood and threads with a couple of coats of thin shellac. PVC couplings , or sections of heavy wall pipe set in groove and epoxied to the wood disks will allow for working in a bowl or hollow form. I hung a 12# 33"D platter on a 7"D chuck made entirely from 2x8 material - no problem doing finishing and hand sanding, but did not attempt any real force on outer area. I have not had a problem with thread seal but you could make a washer out of the thin foam to get a better seal at headstock if required. Adding a loose sheet of the foam to sheet attached to chuck will also help if surface is warped and not providing a good seal.

[Pete Staehling]

Its not that complicated. You can make vacuum chucks out of 2x6 construction material or better wood and thread with Beale tap
It also is pretty easy to epoxy in a nut with the appropriate thread into the wood.

Thanks to all for the suggestions and comments.

I think I will probably go ahead and try my little experiment with one chuck with an assortment of plates. I figure it will allow me to make quick custom plates for the odd sized or shaped bowl.

[John K Jordan]

Please excuse my ignorance but do I need to get acme threaded nuts? Do I need any other info other than that my spindle is 1.25" x 8?


No, acme threads are different, flat on the crest and valley, trapazoid in shape.

https://sawmillcreek.org/showthread.php?91496-1-1-4-quot-x-8-TPI-Nuts&p=919394#post919394

[Richard Dooling]

Thank you John. I appreciate it.


No, acme threads are different, flat on the crest and valley, trapazoid in shape.

https://sawmillcreek.org/showthread.php?91496-1-1-4-quot-x-8-TPI-Nuts&p=919394#post919394

[Thomas Canfield]

It also is pretty easy to epoxy in a nut with the appropriate thread into the wood.

Thanks to all for the suggestions and comments.

I think I will probably go ahead and try my little experiment with one chuck with an assortment of plates. I figure it will allow me to make quick custom plates for the odd sized or shaped bowl.

Check the leakage with the metal nut. You may need to provide a soft seal against headstock. Also, a tap may be needed to clean out any epoxy that get into the threads. The Beale tap is good to have for other items like jamb chucks/plates. It is all supposed to be fun for us amateurs, and I hate epoxy.

[Rich Aldrich]

I think someone else posted it but I didn't see it when I reviewed the threads again. You can buy a Beall tap for 1.25 x 8 thread. I have one and it works well.
Please excuse my ignorance but do I need to get acme threaded nuts? Do I need any other info other than that my spindle is 1.25" x 8?

Thanks,
Richard