Monster Articulated Arm Hollowing Tool

[Matt Owen]

I've been looking at the Monster Articulated hollowing tool, and I'm curious to know how and where the ball bearings are mounted in the "arms" and in the tool post. If anyone can give me a description, or better yet a picture, I would greatly appreciate it. Thanks,

Matt

http://www.monster-wood-tool.com/wst_page6.html

 

[Randy47360]

Why don't you ask the builder? He might tell you.

 

[Garmar]

Just buy one from Randy, I did and it is EXCELLENT!!! You won't regret your purchase.

 

[Dave Schell]

Hi Matt, I'm trying to build my own version of an articulated hollowing arm and asked the same question on another forum. From what I can tell, most of the systems use a flat thrust bearing, either with ball bearings or needles. Each joint uses two bearings. I think the Monster uses ball bearing type thrust bearing and the Elbo tool uses needle type bearings. Hope that helps - but I agree - some pictures of would offer us a better view.

 

[Richard Baker]

Matt,
Just looked at my Monster Art. Arm, and best I can tell the bearings are held in place with Privett clips. Am pretty sure these are only available from the manufacturer.

 

[Matt Owen]

Thank you for your replies. I've decided to press fit the bearings into the arms, and then add a little epoxy to make sure they stay put. I don't know how well that will hold up, but if it doesn't, I've got a few more ideas to make the bearings stay put.

If I can get it to work, I'll post some pictures.

Thanks again for your help.

Matt

 

[Dave Schell]

Matt, what type of bearings are you planning to use?

 

[Matt Owen]

Dave,

The bearings I'm using are from VXB. I buy them off of Ebay.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110358681766&ssPageName=STRK:MEWNX:IT

I've not used this size before, but I have other sizes from this place, and have been very satisfied.

If you want to flip for the extra money, you can get stainless, but I don't know that I'll really need it. I just have to make sure I keep them oiled.

I've got the bearings installed on the arms, and so far everything seems to be working. I haven't cut anything with it yet, but it seems to be very solid and smooth, so I don't see any disasters waiting to occur. I'll try to get some pictures up tonight or tomorrow.

Matt

 

[Steve Worcester]

Thank you for your replies. I've decided to press fit the bearings into the arms, and then add a little epoxy to make sure they stay put. I don't know how well that will hold up, but if it doesn't, I've got a few more ideas to make the bearings stay put.

If I can get it to work, I'll post some pictures.

Thanks again for your help.

Matt

If it really is a press fit, the epoxy will squeeze right out when you press them.

 

[Matt Owen]

If it really is a press fit, the epoxy will squeeze right out when you press them.

Most of it did. The bored wall is not perfectly smooth, and as such has small (very small) surface irregularities. The epoxy should squeeze into those voids, and provide some extra support. May not help much, but I didn't get any in the bearings, so it didn't hurt, either.

Also, I used a small amount of epoxy around the outer side edges of the bearing, creating a small fillet weld with epoxy. This was a little dicey, as I could have gotten epoxy inside the bearing, but fortunately, did not.

Matt

 

[Matt Owen]

Below are a couple of pictures of the finished (but unpainted) tool. If you click on the link, you can (hopefully) see a couple of other pictures and a short video of the tool pivoting at the joints.

http://s100.photobucket.com/albums/m6/mmowen78/General Woodworking/Articulated Hollower/

The bearings are placed slightly below the surface of the steel, and I use a thin spacer on each side of the bearing that contacts the inner race of the bearing only.

For the joint on the post, there are two bearings separated by a thick spacer that contacts only the inner race of the bearing. The outside of the bearings each have a thin spacer, as with the other joints.

If you have any questions, please let me know.

Matt