dom tubing

#1
I understand DOM tubing is more accurate than cold rolled, but how accurate? I assume close enough for steering head and bronze bushings, but will a bearing fit inside close enough? Thinking of building a hub and I don't have a lathe. Having problems finding a premade hub with a 4 on 4" bolt pattern for the wheels. Any sources?
 
#2
I understand DOM tubing is more accurate than cold rolled, but how accurate? I assume close enough for steering head and bronze bushings, but will a bearing fit inside close enough? Thinking of building a hub and I don't have a lathe. Having problems finding a premade hub with a 4 on 4" bolt pattern for the wheels. Any sources?
Like this?

https://www.OldMiniBikes.com/3-4-id-bearing-steel-hub.html

Or these?

https://www.OldMiniBikes.com/mini-b...arings-and-bushings/?sort=bestselling&page=10

And DOM tubing is usually very consistent in size. You will have to figure the OD less the wall thickness doubled to get the ID.

These folks are a good source for DOM tubing.

stockcarsteel on eBay

Doug
 
#4
Like this?

https://www.OldMiniBikes.com/3-4-id-bearing-steel-hub.html

Or these?

https://www.OldMiniBikes.com/mini-b...arings-and-bushings/?sort=bestselling&page=10

And DOM tubing is usually very consistent in size. You will have to figure the OD less the wall thickness doubled to get the ID.

These folks are a good source for DOM tubing.

stockcarsteel on eBay

Doug
Ya, like those, but with a hub for a sprocket or band brake, and wider. Other than then that,, just like those, lol And I would like 3/4 or 1" axles. I think for my purpose 5/8 might be borderline. But I had thought of using a grade 8 bolt if I can find one long enough. 15-16". Every site I went to claims DOM tubing is really accurate, but no specs. Plus or minus a couple thousands, or within a 1/4 inch? Glad some one else had the same idea.
 
#5
Ya, like those, but with a hub for a sprocket or band brake, and wider. Other than then that,, just like those, lol And I would like 3/4 or 1" axles. I think for my purpose 5/8 might be borderline. But I had thought of using a grade 8 bolt if I can find one long enough. 15-16". Every site I went to claims DOM tubing is really accurate, but no specs. Plus or minus a couple thousands, or within a 1/4 inch? Glad some one else had the same idea.
Like this?

https://www.OldMiniBikes.com/rear-hub-assembly-without-bearings.html
 
#6
Maybe, what is the bolt patterns? I ordered a pair that I thought had 2 different patterns,,, but both ends were 2 7/8 ? In the picture they looked different,,, after a couple beers. Now that I have them and looked again, it was my mistake. If I had a piece of DOM tubing that would accept bearings, and I weld a couple flanges on it, hopefully without being too far out of round, I could make any width, without spacers and put them where I want. I am using a 22x11x10 tire, so wider than most. and on the front I think I want a band brake, or disc, so need two flanges there too.
 
#7
Well..... I think you are going to need to buy a lathe....... You aren't going to weld flanges on to tubing and have them come out even reasonably true. The heat will pull the tubing and pull the flange no matter how careful you are. It will have to be faced on the flanges and bored for bearings after it is welded up.

Doug
 

WLB

Active Member
#9
I don't know if it is still available to see or not but in the 2015 BuildOff I posted several pictures of building a set of wide hubs from scratch. If I remember right the DOM tubing has a .007 tolerance and I could not just press in bearings. My son milled the 4 on 4 flanges for me on the CNC mill. I made a welding fixture to hold the tubing and flanges in alignment and it was probably close enough for my big tire, slow speed bike but I did make a truing cut on the flanges
 
#10
Well..... I think you are going to need to buy a lathe....... You aren't going to weld flanges on to tubing and have them come out even reasonably true. The heat will pull the tubing and pull the flange no matter how careful you are. It will have to be faced on the flanges and bored for bearings after it is welded up.

Doug
I know, that's what I'm worried about. I ll keep looking. One thought I had was pillow blocks and a keyed shaft, use go cart hubs. No machine shop here n town, and all my friends with a lathe have went to the happy machine shop in the sky. I was even looking at the drill press and modifying it to true something up.
 
#12
Well the tubing I have is not DOM, and is probably HREW (maybe CREW). I did make my own wheel hub, with sprocket flange, despite the discouraging words I've read in years past about this subject, ( You'll never get it right!!! It's not possible with only hand tools I.E. hole saw, calipers, TAPE MEASURE!!!) Don't ask me to do it twice but Bingo Bango! Walla!!!... See pics Below:thumbsup:





Something Screwy!! with the site!!! ARRGGHH!!! Somthings WRONG!! Can't pst Pics CorrectlyI, don't think it's me but MAYBE???
 

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#13
Well the tubing I have is not DOM, and is probably HREW (maybe CREW). I did make my own wheel hub, with sprocket flange, despite the discouraging words I've read in years past about this subject, ( You'll never get it right!!! It's not possible with only hand tools I.E. hole saw, calipers, TAPE MEASURE!!!) Don't ask me to do it twice but Bingo Bango! Walla!!!... See pics Below:thumbsup:





Something Screwy!! with the site!!! ARRGGHH!!! Somthings WRONG!! Can't pst Pics CorrectlyI, don't think it's me but MAYBE???
How did you true it up? Any issues with out of round? I have a dial indicator and access to a plasma cutter. Was thinking if I used 1/4 plate and a plasma I could cut the flanges without too much distortion. Then a couple spot welds and the dial indicator, some creative hammer work, maybe round enough. But, the jackshaft and go cart flanges is starting to look better. One issue with that is the pillow block bearings do not lend themselves to being able to adjust the chain easily. So an idler sprocket with adjustment or a dirt bike chain tensioner. Maybe that is not any harder than making adjusters for a moveable axle? Got part of the frame welded up yesterday. I will grind and prime it today. Ran out of steel, need to go to the big city next week for more. While laying out my original idea in wood I kept finding problems with it. So changed plans. Plans are good, we should have plans, we should follow plans, but not be a dam fool about it. Changing plans can be a good thing. A bit more thinking involved then I first thought, lol. First version had all the answers, great ground clearance, and a seat height only a pro basket ball player could deal with. Second version still has 7-8 inches of clearance, low seat height, tho it does take K-Y jelly to get the motor in and out. If I get time today I'll post a few pics so you guys can have a laff at my expense! And thanks again for the comments. BTW, That turned out to be a nice clean hub, what I was thinking of making.
 
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#14
Ok, I was out welding, grinding, and cussing and made a corporate decision, it gets a pair of flange bearings, 1 inch axle, go cart hubs. When I get everything where I want, it gets welded in place.
 
#17
Hopefully some of the current and retired machinist's will chime-in on your lathe thread. There are a bunch here that are spot-on and can offer some more insight and options.
Man, do you need a lathe and a mill or milling attachment. You might as well start clearing some space in the shop...
Steve
 

Bird Brain

Active Member
#18
D.O.M. is superior in strength because it is seamless. Gives no place for concentrated failure. Use it where it makes sense. Steering neck, axle supports etc.
 
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