Attach Contact Wheel

johnnyjump

Active Member
#1
I have an Oregon Blade Maker, Bader Style grinder and just bought a 4" rubber coated contact wheel with a 1.18" (30mm) inside bearing bore. I'm in a bit of conundrum as to how to attach it to my tooling arm, which has 1/2" and 5/8" threaded holes. I thought a 30mm diameter shoulder bolt that stepped down to 1/2" or 5/8" would be the answer, but can't find anything close to that online. Any suggestions? Thanks.
 

John Wilson

Well-Known Member
#2
Maybe I’m missing something so please correct me if I’m wrong.

Wouldn’t you put 30mm OD bearings in there with the correct size ID inner race to take a standard 3/8” bolt, or similar?

Or are you saying the bearings are already in the wheel and the inner race has a 30mm bore for a 30mm shaft?

I’d change the bearings.
 

johnnyjump

Active Member
#3
The bearings with the 30mm inner race are already in the wheel. I’ve never replaced the bearings in a wheel. I take it they are pressed in. Is that a difficult job?
 

John Wilson

Well-Known Member
#4
No. Bearings are not hard to change. They are just pressed in. Using a rod or pipe that is the same diameter as the outer race, take a hammer and drive the old ones out. Might take a good knock to get them moving but then they ought to come right out. Put the new ones in the same way. The key to the whole thing is to only apply force to the outer race, not against the inner race or you can damage the bearing.

If they are super tight you can take the wheel to any mechanic with a press and have them pushed out.

The trick will be finding bearings with the outer / inner diameter you need. Look for those first. If you can’t find them then your idea of having a shoulder bolt made at a machine shop is a good solution. Or, have a piece of 30mm round stock drilled through as a bushing for the bolt you want.
 

John Wilson

Well-Known Member
#5
If you want to try the bushing route, I can turn you one out of aluminum and we can give that a shot. It would be a simple solution to try.
 

johnnyjump

Active Member
#6
Well, you are right on finding the right size bearing. I need to find a bearing with 1/2" or 5/8" id, and 62mm od, which I don't think are even made to those specs, or anything close that might fit a shoulder bolt. Gee, if you have the tools to turn out a 30mm aluminum round stock drilled out to 1/2" or 5/8" that would be fantastic, and willing obviously to pay you for your time and expense.
 

John Wilson

Well-Known Member
#7
I figured that would be a crazy bearing to find.

Turning a bushing will be easy. I just need the OD / ID / Width and I’ll knock it out. I figure by using aluminum I can turn it a few thousandths over. If it won’t press in you can put the bolt in and chuck it up in a drill press and sand it to fit.

No charge, man. It’s just a chunk of aluminum. I’ve got a bunch of round stock laying around. All I have to do is turn the outside and drill the center in the lathe. I’m kind of excited to see if it works. I can’t see why it won’t.
 

John Wilson

Well-Known Member
#8
i’ll cut a step on the tool arm side of the bushing and make a washer for the bolt head side. That ought to keep the wheel from walking off the bushing over time. If the bushing doesn’t hold up we’ll try something different.
 

Gliden07

Well-Known Member
#9
Why dont you make a new tool arm? And drill it for the Metric bolt? I bought a made tool arm for 35 bucks plus shipping so about 50 total? Just a thought? Better than messing up your wheel!
 

bladegrinder

Well-Known Member
#10
That's what I did, I just bought a piece of A36, I think it was 2.5 Ft. for about $30.00 to the door.
I've got a Bader III so I probably had the same problem your looking at.
you need a decent drill bit and drill press though to put a nice square hole thru it.
But if John's offering to make you a sleeve....you can't beat that { way to go John ! }
The main reason I did it this way though was so I wouldn't have to be changing wheels and platens, now my 12" wheel is on it's own tool bar so I can just slide whatever I want to use into the machine
 

johnnyjump

Active Member
#12
I figured that would be a crazy bearing to find.

Turning a bushing will be easy. I just need the OD / ID / Width and I’ll knock it out. I figure by using aluminum I can turn it a few thousandths over. If it won’t press in you can put the bolt in and chuck it up in a drill press and sand it to fit.

No charge, man. It’s just a chunk of aluminum. I’ve got a bunch of round stock laying around. All I have to do is turn the outside and drill the center in the lathe. I’m kind of excited to see if it works. I can’t see why it won’t.
Wow! That is very generous. The wheel is 2" wide. The bore of the bearing is 1.18" (30cm). The tooling arm has two holes tapped at 1/2"-13, and 5/8" -16. I'd think an OD of 30mm turned a few thousandths over like you suggest would be good, and an ID of 1/2" would work well, with a width of 2" should do the trick! Thanks so much!
 

johnnyjump

Active Member
#13
The tool bar idea is also a very good idea. Could be a plan B if the bushing doesn't work, but I see no reason why it shouldn't.
 
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John Wilson

Well-Known Member
#15
Hey Johnny, here’s what I came up with. The first one is a hair undersized (1.168 in/29.7 mm) and the second one is a hair oversized (1.209in / 30.71 mm)

The bore is .500 in

The bushing is 2 inches with a .250 thick stop. If that causes you alignment issues you can just grind that down thinner. The outside washer is the same .250 thickness. I figured the shoulder/washer would keep the wheel from walking off the bushing if it ever tried to.

Shoot me your address and I’ll get these out to you.
 

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johnnyjump

Active Member
#20
Hey Johnny, here’s what I came up with. The first one is a hair undersized (1.168 in/29.7 mm) and the second one is a hair oversized (1.209in / 30.71 mm)

The bore is .500 in

The bushing is 2 inches with a .250 thick stop. If that causes you alignment issues you can just grind that down thinner. The outside washer is the same .250 thickness. I figured the shoulder/washer would keep the wheel from walking off the bushing if it ever tried to.

Shoot me your address and I’ll get these out to you.
John, you are incredible! I can’t thank you enough. Your generosity leaves me speechless and most grateful!
 
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