Homemade Concentricity Gauge

Secrets, tips, tools, design considerations, materials, the "science" behind it all, and other topics related to building the cars and semi-trucks.
OOBigFish
Apprentice
Apprentice
Posts: 13
Joined: Sat Feb 15, 2020 12:51 am
Location: Bend, OR

Re: Homemade Concentricity Gauge

Post by OOBigFish »

I’ll add my improvement to this thread. I have a few different holes drilled into the block that allows me to change out the pin gauge size to match the wheel bore diameter. Using a properly sized pin gauge makes for less slop and gives you a more accurate reading of the wheel roundness.


Sent from my iPhone using Tapatalk
Speedster
Pine Head Legend
Pine Head Legend
Posts: 1972
Joined: Sat Feb 18, 2012 1:48 pm
Location: Toledo, Ohio

Re: Homemade Concentricity Gauge

Post by Speedster »

OOBigFish, What size Pin gage do you have for an AWANA wheel?
OOBigFish
Apprentice
Apprentice
Posts: 13
Joined: Sat Feb 15, 2020 12:51 am
Location: Bend, OR

Re: Homemade Concentricity Gauge

Post by OOBigFish »

Never used Awana wheels. I use .096 through .0985 pin gauges for BSA wheels.


Sent from my iPhone using Tapatalk
Speedster
Pine Head Legend
Pine Head Legend
Posts: 1972
Joined: Sat Feb 18, 2012 1:48 pm
Location: Toledo, Ohio

Re: Homemade Concentricity Gauge

Post by Speedster »

Did you ever get a BSA wheel bore to go over a pin gage larger then .0965 without intentionally doing something to the bore?
OOBigFish
Apprentice
Apprentice
Posts: 13
Joined: Sat Feb 15, 2020 12:51 am
Location: Bend, OR

Re: Homemade Concentricity Gauge

Post by OOBigFish »

Yes, the typical sizes I find are in the range specified. 97-98 being most prevalent.


Sent from my iPhone using Tapatalk
Kindintentions
Journeyman
Journeyman
Posts: 30
Joined: Mon Jan 13, 2020 9:02 am
Location: Cranford, NJ

Re: Homemade Concentricity Gauge

Post by Kindintentions »

Finally got around to making myself one for this year and beyond. I bought a new dial indicator from Harbor Freight with their 25% off Friends and Family coupon (valid through 12/6/20).

Now that I have it, the hole I drilled at 11/32 from the long edge (1" from the short edge) seems to allow too much of the indicator above the wood so I flipped it over and drilled a new hole centered at 13/32 from the long edge, installed it with a 1/4" bolt, washers and lock nut, but I still get a bit of rocking of the indicator up and down on the wood. I did use a 1/4" drill bit to drill the hole for the bolt to try and eliminate the slop in a 17/64" hole, but that should give it less play and a tighter fit. The lug back on the indicator is on a raised circle which is the culprit of the rocking.

If anyone else has run into this issue, what have you done to stop the rocking (shaved down a portion of the wood, or added some type of shim around the raised circle) or is the rocking expected and needed in this gauge? I would guess if I can get it as steady as possible that would be best but just wanted to put it out there in case anyone else has had a similar experience. Thank you.
Speedster
Pine Head Legend
Pine Head Legend
Posts: 1972
Joined: Sat Feb 18, 2012 1:48 pm
Location: Toledo, Ohio

Re: Homemade Concentricity Gauge

Post by Speedster »

Very recently I set out to build a run out gauge hopefully as simple as one could be built. I used Knothed's fancy gauge for the sample. Here's what I did.

One BSA Block - Yes, I could have cut a block, cut a slot, but I wanted it simple. I did nothing to the block.
Screwed a 3/32" drill bit onto the front slot per Knothed's design
Bolted the gauge on the block so it would meet a BSA wheel to give the read out.

I did not narrow the block so the shaft would line up perfectly to the farthest point of the wheel. The shaft is a bit off to the left of the wheel but it doesn't make any difference. I raised the wheel with a spacer I made and then put a teflon washer for the wheel to ride on. ( washer was 1/4 x .93 x .020 from Derby Evolution). I happen to have the washers but something probably could be gotten from a hardware store. The shaft rides on the lower edge of the wheel where the rear wheels will ride on the track if they have Negative cant.

Here's the Best part. I tested wheels on each of the 2 gauges and they both read the same. Knothed's gauge comes with .0965, Class ZZ Pin gauge. The 3/32" drill bit measures .092 as close as I can figure with my callipers. Both Pins are riding on the same spot in the wheel bore. I think the cheap 3/32" drill bit does just fine.

Questions and Opinions are very Welcome.
If anyone wants to talk or wants pictures, please email me.
Stay Safe.
Kindintentions
Journeyman
Journeyman
Posts: 30
Joined: Mon Jan 13, 2020 9:02 am
Location: Cranford, NJ

Re: Homemade Concentricity Gauge

Post by Kindintentions »

Well I think I solved my problem. Used a blank CD from a stack of CD-Rs I had lying around and was able to widen the inner circle and cut off the excess. I was able to reduce the rocking to a vary minor amount that I should be able to control by tightening the bolt. If anyone has any other ideas I am open to them, but this is something to try if you don't have an extra block lying around like speedster.
Post Reply