GIB tool arm length?

[Brian.Evans]

I'm working on finishing up my GIB. I have spent very little money so far, getting the parts laser cut by a buddy and the wheels made by another friend here in town. I have several pieces of 1 1/2" square tube drops that i pocked out of the drop bin for free. One is heavy, 3/16 or 1/4" wall, the others are 1/16" wall. The heavy tube is 51" long, the thin wall pieces are 48".

What length are you guys running on your GIB/EERFs? I'd love to be able to make 3 arms from the heavy tube, but it seems that 17" is pretty short for a tool arm. I'd like to have 3 arms; flat platen, big wheel, small wheel attachment. If I can only make two from the heavy wall tube, then one of the thin walls will be for the small wheel. Also, I'm planning on using the thin wall for the tool rest.

I know what y guys are going to say, buy solid tube. Lets just pretend that's not an option right now. It may be later, but right now I'd like to use what I have on hand.

 

[Justin King]

They should be cut to the appropriate length for the attachment you are using, the small wheel will theoretically need the longest arm. Obviously there is some leeway because the tool arm holder has clearance behind it, so that the rear of the tooling arm can protrude a ways, but the length sticking out the front will change according to what is on the end of it, and how much belt length the wheel, platen, etc. takes up.

 

[tryppyr]

As Justin said, you'll want to cut to fit the needs of the platen(s)/wheel(s) you will be using. Using a standard platen you'll use a shorter length than if you just want a contact wheel. Using a multi-platen probably falls somewhere between. Don't just cut the tube and hope for the best. Assemble the platen(s) and size the arms so that you are able to get the right fit with your belts. Make sure you leave enough tubing to go deep enough into the channel to be held securely by the mount screws. I'd also leave some extra length in case something changes on the platen (e.g. replacing one wheel size with another or using a radiused platen).

 

[gredpe3]

The precut arms you can buy from USA are 19". I run 22" on a KMG.
Eddie

 

[elementfe]

I'm not sure the thinwall tubing will stand up to your locking screw- I'd expect the 1/16 wall (usually 060) to collapse and possibly deform the tube...I'd hate to have an arm stuck in the reciever because of that.

 

[Jeremy Evans]

I am uesing one for a KMG with a 10inch wheel it's 20 inches long and long enough for a flat platen should be ok for small wheel but I havnt tried one

 

[Jeremy Evans]

Here is one I made for the flat and multi platen uesing thin wall tubing its 19 inches and it works fine

 

[elementfe]

That's great news! I'm building one now, and ran out of the sturdier 1.5" tubing.
Can you include a photo of the other side? I'm curious about how you made the attachments on the platen end of the tube- perhaps I'm overbuilding it, but I was worried about how to make the attachment to the platen sturdy enough even with a .120 wall tube.

 

[Jeremy Evans]

I think this is what you want to see.
might be better to make a spacer to go inside the tubing to keep from crushing it where the bolt thru.

 

[elementfe]

Thanks for the photo!
That looks like .120 (1/8") wall tubing. "Thinwall" is usually used to mean 1/16" (.062)
I'd think either one would have the strength, but I like the idea of using 1/8 for the added stiffness.

 

[Brian.Evans]

Thanks guys. I will just cut the heavy wall in half and trim from there. A 2 ft piece of 3/16" wall is only $9, and that's if I can't find a drop.

I think I have a piece of tubing that the 1.5 thin wall will fit in. I'll drill a hole and make a mock up of the grinder arm and see if I can crush it with a bolt.