Anybody ever modded a Bader small wheel onto a KMG style tool arm?

[Jason Fry]

I have a Bader small wheel attachment, but no Bader. I'm building a NWG. Anybody ever modded the two to go together? I've got two basic ideas.
One, have a machine shop fab an adapter, like a short stub of the Bader arm, and attach the adapter to the square tube of the NWG arm. Guaranteed to work, but costs machine shop time.

Two, I'm wondering if I couldn't just drill a hole in one side of the tubing to fit the big (3/4?) peg on the attachment, a small hole to fit the small peg, and thread a hole through the middle of the big peg. The whole thing would be held on by only one bolt that way, but you'd have two pegs covering the vertical forces, and the screw covering any horizontal forces. By far simpler, but will it work?

Anyone with experience here?

[Mahoney]

Well perhaps a silly question, but if you bought the Bader arm for the small wheel attachment, would it fit into the receiver of the NWG?

I'm not sure how hard the big peg on the Bader attachment is, it might be too hard to drill and tap. But you still have rotational forces to deal with, the pegs will be flopping around inside the thin walled tube. You can solve this by filling the tube with a tightly fitting block of hardwood...then drilling your holes....or welding bushings into the tube, which might be a bit more trouble. Also, instead of going to the trouble of dealing with the big peg, why not replace the small peg with a bolt going all the way through the tube and mount? The small peg on mine is a 1/4" roll pin so it seems this would be an easy swap. The only issue I can see would be tracking, if having the thickness of the mount on the side of the tube (rather than in a notch like on the Bader arm) takes the small wheel out-of-plane from the drive and idler wheels

[Jason Fry]

The Bader arm is 3/16 or 1/4 smaller than the NwG reciever. Leaves alot of slop top to bottom and side to side. I had thought about shimming it in, as I have a tool arm with a contact wheel that I haven't figured out a way to use yet. Hadn't thought about the peg hardness... good consideration. Also hadn't considered the alignment issue, will have to check that out. I had thought I might could bump out he roll pin and thread that hole also or instead. Thinking off the top of my head, if the roll pin hole is 1/4, I'd have to bump it out to a slightly larger hole then thread for a 5/16, correct? Can't put 1/4 threads in a 1/4 hole?

I got some hand-me-down, use them if you can, bader parts. One of these days I'll buy dedicated parts for my grinder that were made to fit it

[Mahoney]

If you've got Bader parts with Bader arms, what about changing out the NWG receiver to a size tube that will fit the Bader arms? 1 1/2" by 14 or 11 gauge ought to do it, if you are making other arms, just use 1 1/4" tube to match the bader stuff

[catcalls]

I'm sure you have thought of this already, however... wouldn't it be the easiest, and best to just sell the bader arm, and buy the necessary pieces for the specified machine. I've no idea the prices on the stuff, but wouldn't it be the safest route, and maybe you could make a couple bucks(or lose some). Anyways, best of luck
Jack

[AVigil]

Are you talking about something like this?

[Jason Fry]

Correct, AVigil. I think I can drill a hole for the big peg, then knock out the roll pin and put a bolt through there. Ought to work The bader parts weren't gifted, just loaned until I could make them work or not, then work out a purchase. Can't sell them and get NWG parts, and don't really want to mod the entire grinder to fit them.

[bladsmth]

Just make a solid bar arm to fit the small wheel tip. Use square stock that will fit your NWG. You can use steel or aluminum.

Drill the necessary holes for the small wheel fork, leaving about 1" extra length beyond the large hole.
Drill a perpendicular hole ( rotate bar 90°) 1/2" from the end with a 13/64 bit, then slit the end 1" past the big hole. Re-drill one half of the end hole 17/64 and tap the other half 1/4-20. Look at a Bader arm to see what I am saying.

[Jason Fry]

Best I can tell from your written description, that's what I had in mind for an adapter, Stacy. I drew one up just about like that. I had conceptualized it on about a 4" piece of aluminum square stock made to match the end of the Bader arm, that could then be bolted on to the NWG tube.

[bladsmth]

Make it a solid, one piece arm, not something added to something else.
Also, be sure to keep the alignment with the drive wheel and idler straight.

['71 Commando]

Stacy gave the best answer so far but it seems you want to do something simpler. I have made a few small wheel arms, one for a Square Wheel(an Olympic no less!) and one for a Space Saver. The first worked perfectly, the second not so much. When I sold the Space Saver I kept the arm and have since chopped it and welded a plate to it so it bolts to the tool rest holes on a KMG tool arm. Works great and I saved a few bucks, which is what I think you are after. If the arm is rigid and the alignment is good you should have no problems so build it and take a picture so we can see it! - H

[Jason Fry]

Bring this thread back.... I got it put together tonight. I ended up using a step bit to drill a 3/4" hole in my tool arm to fit the big peg. I knocked out the roll pin, drilled a 1/4" hole in the tool arm to match. One bolt through the roll pin hole, and we're good to go. Tracking/alignment is good. Pics maybe tomorrow.

[Jason Fry]

Like this



And my handy-dandy tracking knob