Best method for a tight, secure fit.

leftyz · Oct 6, 2010

I have a project in which a 3" long x .5" OD piece of steel tubing, protruding from some light steel, needs a tight, secure connection to a piece of 4.5" long 3/4" OD .510 ID steel tubing.

(ascii art not to scale :lol_hitti

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the dashes represent the inner tubing with OD of 0.500"
the equals sign represent the outer tube with the ID of 0.510"

So there is 0.010 gap total between them.

I can try to weld the larger tubing to the base, but I'm worried about blowing through the thinner steel without getting a good weld to the 1/8" (actually its .120") walled larger tube.

a few other ideas:

Drill a small hole through both outer and inner tubes and use a roll pin to secure them
weld some material to the inner tubing, then grind it down until hammering on the outer tube makes a super tight press fit.
bend the inner tube slightly
drill a hole through only the outer tube, and "spot" weld to the inner tube
some combination of the above?

Any other ideas or preferred methods for this?

I was originally going to have a machine shop turn out a .499 ID in some 3/4" OD round stock I had bought, but they wanted over $100 for this, so I went and bought DOM steel tubing for $11 and I'll make it work.

Thanks!

leftyz · Oct 6, 2010

I should clarify that the machine / fab shop I talked to wanted over $100 for 4 pieces hollowed out this way, not just one.

murph64 · Oct 6, 2010

What's the project? What forces will this whatsis be encountering?

Andy

leftyz · Oct 6, 2010

murph64 said:
What's the project? What forces will this whatsis be encountering?

Andy

It's for beefing up the axles on a radio flyer wagon, the new wheels have a 3/4 ID for the bearings, and the stock axles are the .5" OD tubing.

msnow · Oct 6, 2010

So personally I would probably drill a couple holes and plug weld them given what the end product was going to be. However if this was a fix that needed to be done on real machinery, one choice would be to buy a shaft sleeve. Shaft sleeves come in all sizes and they basically go around a shaft to increase its size kind of like a shim. Different ones install different ways but this would certainly be a serious option if this fix was happening on something other then a radio flyer wagon. Hope this helps.

zer01 · Oct 6, 2010

Can you cut the old axles off and put the correct size on?

spongerich · Oct 6, 2010

Marry a younger woman.

Rockford514 · Oct 6, 2010

zer01 said:
Can you cut the old axles off and put the correct size on?

x2 3/4" cold roll want cost much

leftyz · Oct 6, 2010

Rockford514 said:
x2 3/4" cold roll want cost much

I already have some.. I'll have to look at it again but I dont think thats a good option.

e3pres · Oct 6, 2010

spongerich said:
Marry a younger woman.

Post of the day. :lol_hitti

murph64 · Oct 6, 2010

leftyz said:
It's for beefing up the axles on a radio flyer wagon, the new wheels have a 3/4 ID for the bearings, and the stock axles are the .5" OD tubing.

This one -

How is the fit between the inner and outer tube - if it's fairly tight now, I'd mix some 2 part epoxy to keep the tubes together. Then when that dries, drill and tap for a small screw through both tubes.

What's going inside - kids or stuff? And how fast will it be going?

Andy

ironheadtom · Oct 6, 2010

I agree with the epoxy idea. As long as you keep it under 100mph. You would be amazed at the places I've seen chemical adhesives used by factories to bond stuff.

gorilla · Oct 7, 2010

How about some 3/4"x1/2" flanged oilite bushings pressed into the bearings on the wheels? I doubt that they would cost more than $1.00 each.

leftyz · Oct 7, 2010

murph64 said:
This one -

Actually it started out as this one

How is the fit between the inner and outer tube - if it's fairly tight now, I'd mix some 2 part epoxy to keep the tubes together. Then when that dries, drill and tap for a small screw through both tubes.

What's going inside - kids or stuff? And how fast will it be going?

Andy

Kids, and eventually stuff that will be pulled by the kids

(my son is only 6 months now).

No high speed maneuvering or anything like that.

ironheadtom said:
I agree with the epoxy idea. As long as you keep it under 100mph. You would be amazed at the places I've seen chemical adhesives used by factories to bond stuff.

I have some "quick" JB Weld that I've been itching to use, it sounds like a good time to break it out! There's only 5 thousandths of an inch on either side, so there is very little play, I am not even sure enough JB weld will stay in place to get a good connection but it is worth a shot.

gorilla said:
How about some 3/4"x1/2" flanged oilite bushings pressed into the bearings on the wheels? I doubt that they would cost more than $1.00 each.

That is a good idea, but the "stock" axle is not long enough for the new wheels, so this will not work for this application.

I appreciate the help! :beer:

leftyz · Oct 7, 2010

and to help put it all into perspective for ya...

murph64 · Oct 7, 2010

Are the bearings in the new wheels removable? If so, can you see if the local good hardware store has bearings that fit both the wheel and the old axle?

edit - the stock axles - aAre they sturdy enough for the wheels, but not long enough? Can you get some threaded rod, epoxy that inside the axles, then use a bushing to make up the difference between the OD of the threaded rod and the ID of the bearing?

Andy

leftyz · Oct 7, 2010

Same issue as my last part of the last post, the old axle isnt long enough for these wheels :-/

charle10 · Oct 7, 2010

I'd suggest splitting the axle in the middle, then use your JB weld and oversized tube to tie it back together (or drill through and put a pin through it for extra insurance). That way you can make your axle longer rather than having to extend it at the wheel bushing. Then you should be able to get away with using your 3/4" OD tube as a bushing or space filler at the wheel. You wont really have to worry about that tight strong fit at the wheel.

What ever you do, try it out before you load it up with kids.

zer01 · Oct 7, 2010

I still think that replacing the axle is the best way. Don't the axles just go through the sheet metal brackets and are welded? Cut the weld drill out the hole for the larger axle and re-weld. I did the same thing with a little bit older wagon.

murph64 · Oct 7, 2010

leftyz said:
Same issue as my last part of the last post, the old axle isnt long enough for these wheels :-/

The axle maybe short, but the threaded rod can be as long as you make it. Provided the stock axle tubes are strong enough to handle the added leverage/weight.

Andy

leftyz · Oct 7, 2010

zer01 said:
I still think that replacing the axle is the best way. Don't the axles just go through the sheet metal brackets and are welded? Cut the weld drill out the hole for the larger axle and re-weld. I did the same thing with a little bit older wagon.

That would work, I've already got the new axles cut down to 4.5 inches long and I'd like to try to get this done with the materials I have on hand. I've already dumped way too much money into this little wagon!

If I'm unable to get these axles working up to snuff, I'll end up going this route.

scbird94 · Oct 7, 2010

I have already been dealing with the OP on this, but here is what he's trying to accomplish. (this is on my daughters wagon)

Leftyz your wagon is going to be sweet! I know what you mean about NOT CHEAP. Trust me

Note the roll pin inserted and ground flush to secure inner and outer axles.

3/4 stock center bored to .499? to press fit onto stock 1/2 axles.

Finished product is on the left in this picture

And if its ok with the op, i will maybe post a link to my radio flyer build thread? I CANNOT resist the temptation to show these things off... to anyone. lol.

http://www.garagejournal.com/forum/showthread.php?t=47731

leftyz · Oct 10, 2010

I got the axles on this weekend.

First I tried the JB Weld. It worked really well for the front axles, but not for the rear, since the rear has some extra pieces that get in the way and dont allow a nice bead at the end.

I decided to try to do a couple rosette (spot) welds on each axle. I drilled two 1/4" holes in the outer axle and tried welding it to the inner axle.

I failed miserably, I got no penetration to the original axle and nearly ruined the new outer axle. I was able to grind it down though.

I finally ended up laying down a little weld material on the old axles, hammering the new axles on, and this seemed to work pretty good. I wasn't completely happy yet though so I went to Ace and bought four 1/8" x 3/4" roll pins. I drilled a 1/8" hole through the axles and used a roll pin punch to drive them in, one pin per axle. (no pics yet)

I am very confident this will hold, if anyone has any other thoughts or suggestions they are more than welcome...

mdbeck1 · Oct 10, 2010

Use a die to thread a couple inches of the old axle.
Use a tap to put mating threads on the interior of a piece of pipe the correct diameter.
Weld a NUT on the end of the pipe.
Place lock-tite on the threads and assemble.

mdbeck1 · Oct 10, 2010

....or
Thread the inside of the current pipe (axle).
Place NEW pipe/axle over the existing axle.
Put a bolt in the old axle that will keep the new axle in place. Again I'd suggest lock-tite.

Rentawrench · Oct 10, 2010

Well this will not fix your's . BUT you can build one for you an the Wife .

http://www.ktuu.com/news/ktuu-radio-flyer-car-092910,0,1784245.story

leftyz · Oct 11, 2010

mdbeck1 said:
....or
Thread the inside of the current pipe (axle).
Place NEW pipe/axle over the existing axle.
Put a bolt in the old axle that will keep the new axle in place. Again I'd suggest lock-tite.

That would probably be one of the better methods, that would also allow you to put a washer on the end to keep the wheel in place, instead of using a cotter pin like I did.

Next time...

Best method for a tight, secure fit.

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