Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Largest Manufacturing Technology Community on the Web
Stay Connected:
Centering a hub and bolt circle
- Thread starter Marc1122
- Start date
- Replies 51
- Views 3,919
Dan from Oakland
Titanium
- Joined
- Sep 15, 2005
- Location
- Oakland, CA
If you don't have a rotary table, calculate each hole center, find the center of your hub and use those dial things on the machine to move to each hole center and drill/bore the new holes. Millions of parts have been made on machines with no DRO. If you struggle with finding the hole centers, I'm sure there is a bolt circle calculator out on the web somewhere.
Gordon Heaton
Titanium
- Joined
- Feb 19, 2007
- Location
- St. George, Utah
Without a DRO, you'll definitely need to step up to Pepsi. There is a utility that will generate X,Y moves you can make with the dials once you get the hub centered. I'll try to find it but its been a long time since I used it.
fciron
Stainless
- Joined
- Oct 14, 2009
- Location
- Louisville, KY, USA
Transfer from another wheel?
There are bolt circle formula in the Machineries Handbook to calculate X-Y positions of the holes.
There are bolt circle formula in the Machineries Handbook to calculate X-Y positions of the holes.
LKeithR
Stainless
- Joined
- Sep 1, 2011
- Location
- Langley, B.C.
Years ago I created a bunch of spreadsheets for various bolt circles. Machinery's Handbook lists
the coordinates for circles with a diameter of "1" so with the spreadsheet you enter the diameter in
one cell and it calculates all the values for the required diameter. Takes a bit of work to enter all the
numbers the first time but once you have it you can use it for any diameter. I've used it long enough
that I have spreadsheets for most of the common bold circles--I even made one up for a 23 holer...
johnoder
Diamond
- Joined
- Jul 16, 2004
- Location
- Houston, TX USA
And before all the nice ready made stuff we were just expected to do it ourselves
jerholz
Cast Iron
- Joined
- Sep 24, 2015
- Location
- Dallas, Tx
Assuming you know how to find the center of the hub and use the hand wheel dials to measure x and y offsets from there, post the bolt circle radius and number of holes and I'll do the trig for you.
Sent from my Nokia 7.1 using Tapatalk
Sent from my Nokia 7.1 using Tapatalk
crazygoat
Stainless
- Joined
- Sep 23, 2017
plastikdreams
Diamond
- Joined
- May 31, 2011
- Location
- upstate nj
I'll be honest...if I had to use just the dials I'd bring it to someone who had a dro...or buy one
Last edited:
EmGo
Diamond
- Joined
- Apr 14, 2018
Did you go through that ? Bob Moderow ? Those guys were great. Still have fond memories.
crazygoat
Stainless
- Joined
- Sep 23, 2017
When I first started we didn't have the luxury of dro's.
You used dykem on the ways and a scribe to draw lines, arrows and numbers to make sure you had the slack going in the right direction. Saved having to count the number of revolutions. It wasn't that hard when that's the only way you knew.
Of course that was just slightly past caveman time!
johnoder
Diamond
- Joined
- Jul 16, 2004
- Location
- Houston, TX USA
November '64 to August '68 in East Hartford (less than four years to do the 8000 hours) - but the name rings no bells. "Class" names MA 32 and T&D 16
EmGo
Diamond
- Joined
- Apr 14, 2018
Ah. ITW ran a school, too. It was great. Looks like P&W used some of their stuff. Much shorter term but pretty intensive. Bob Moderow was the ringmaster.
Congrats on the certs, by the way. Those are pretty, and I bet they made you work for them !
eKretz
Diamond; Mod Squad
- Joined
- Mar 27, 2005
- Location
- Northwest Indiana, USA
And before all the nice ready made stuff we were just expected to do it ourselves
View attachment 325544
Ditto. Even got the same exact book.
markz528
Hot Rolled
- Joined
- Sep 25, 2012
- Location
- Cincinnati
And before all the nice ready made stuff we were just expected to do it ourselves
View attachment 325544
I think I have one of those laying somewhere - was my dad's. He didn't work for P&W but he did a ton of work for them. He was basically the lead machinist at United Tool & Die in West Hartford for many decades. He retired when he was 78. He officially ran the Jig Bore Department but did a lot more. That's where I got started - P&W Jig Borers.............
Maybe I`d do down and dirty approach. If you have access to any 2D cad, draw that pattern with dots, print 1:1 cut any reliefs for hub nut if any. Then tape it or glue it over the hub. Center punch by using the printed dots. In the mill using pointed edge finder locate punched dents and that`s it. Not super accurate, but should be enough for wheel bolts..
Just my 0.02 cents..
Just my 0.02 cents..
plastikdreams
Diamond
- Joined
- May 31, 2011
- Location
- upstate nj
That's pretty cool, we make parts for p&w engines.
