Threading 1/2 inch rod - how to hold?

[YY1]

I have a side project at work ( I'm the computer guy, but they recognize my mad mechanical skill set) - repairing a specialized cart that has poorly designed rear wheels.

They are 16", but very narrow- 1 7/8, and they are sheet metal disks with solid tires and ball bearings.

The problem is that the inside disk rubs the axle holder and eventually wears through the sheet metal. They appear to have been welded back together several times and even bolted completely through the disks.

I found some 16" solid tire wheels (that don't cost $100 each) at Northern Tool, but the hub is 3" wide.

I can get a longer 1/2 inch and gut to length, but I'll need to thread the ends.

That will likely require substantial rotational force.

How do I hold the rod tight enough to keep it from turning without chewing it up?

 

[Don Frelier]

Grind a couple flats in the unused section inside the wheel?
A picture would help.
My son would have it fixed before I even figured it out.

 

[BigBlock61]

How are you mounting the 1/2 rod to the cart? mount it then tap if possible.

 

[Ranger16]

Make a split sleeve out of a length of a length of copper water pipe to protect the threads while clamped in your vice or chuck.

 

[Bad Sport]

How do I hold the rod tight enough to keep it from turning without chewing it up?

If you have a really good vice with the angled jaws under the opening, get a piece of thick leather and put it around the part you want to protect. It may or may not work, but it would be easy to try.

 

[493 Mike]

I use aluminum sheet bent to 90* as insert jaws for my vise.
Mike

 

[Dako]

Why not

Grind a couple flats in the unused section inside the wheel?
A picture would help.
My son would have it fixed before I even figured it out.

Agreed...a picture would help.

Are you meaning there is an axle shaft coming from the cart, or is there a bolt that screws into the cart acting as an axle shaft? If it's the latter, just get a longer bolt. If it's threaded on both ends, what Don Frelier suggests (grinding flat areas...big enough to hold in a vise) is the easiest way to go.

 

[Evan Frucht]

Ya just stick it in a vice and really clamp down on it. My best guess is that it won't move.

If you want to be extra sure you could slightly flatten a section of it (not enough to compromise strength) so that its guaranteed not to budge. Or use some copper or aluminum as jaws that will compress around it when it tightened. Or cut a grove in two pieces of material (possibly even a hard wood) and secure the rod in between those grooves as you tighten down the vice. There are other ways if those don't cut it... but with a sharp die and cutting oil there won't be that much torque on the rod as you thread

 

[Cranky]

Know anyone with a lathe and knows how to single tool the threads?

 

[Cncguy1]

Take two nuts and lock them together then clamp in vise.

 

[69 GTX]

First make sure the rod O.D. is correct. If it's oversized it'll make threading a bitch!

 

[khryslerkid]

All suggestions so far are good ones! I've used wood also to cushion the clamp as not to mess up the threads.

 

[Evan Frucht]

you could also just use all thread? would be easy

 

[Don Frelier]

Put these on it

 

[kiwigtx]

Take two nuts and lock them together then clamp in vise.

That is what I would do.

 

[WP29440SE]

get adequate length and o.d. / thread pitch bolts and cut the heads off with a nut already threaded on and back the nut off the cut end to thread

 

[YY1]

The axle is 24" 1/2 inch rod, threaded on the ends.

It is clamped to the underside of the cart with two oddly shaped plates, each bent into a shallow V.

The wheels are secured with nylock nuts.

I will need a rod approximately 3 inches longer, with the last roughly 1/2- 3/4 inch on each end threaded.

These are some bizarre wheels. I will try to snap a pic when I'm at my shop.

My workplace has two other carts by the same MFG, and although slightly smaller, they use much heavier and simpler standard wheelbarrow wheels in the back.

The one I'm working on is made different and the wheel recesses will not accept a wheelbarrow wheel. They also have mechanical brakes, so there is not a lot of room for variance in size.

 

[YY1]

So far I'm liking the wood suggestion.

I had thought about cutting a copper pipe in half, but that would still be round, unless I drilled out a block and cut that in half....then why not just use that.

I have an "X" block for centering a drill press on round stock, and have thought about using that but am unsure as to it's strength. It does look very solid. If I had two, I might be done.

I think jam-nutting would likely, A- not line up the flats, and B- likely get turned from the die force.

My vice is a 5" Fuller. It does have a pipe vice under the main jaw, but IDK if it would work on small 1/2 stock, plus it would be horizontal.

 

[Evan Frucht]

the rotational force to thread half inch rod, if its mild steel, is not that much I think you will find. if its a hardened grade 8 rod or stainless then that's a different story

 

[mopar 3 B]

You could weld a nut on it large enough to slide on the rod at the back side of the wheel if there is room. Then there would be some thing to hold it while treading and also when installing the outer nut.