Steel size for project

[Pooh_Bear]

I'm building some new wheel supports for my finish mower. The original ones got bent.
For the spindles I am using 1.5 inch DOM tubing. The wheel fork spindles are 1.125
The wall thickness of the DOM tubing is .120 Is this too thin? Will there be too much slop in the spindles.

Thanks. ~Pooh Bear

 

[BukitCase]

Sounds pretty sloppy to me - might work better if you can

Add zerks to the DOM so they can get greased

Maybe find some .040 to .050 shim stock, put a tight fitting washer over the fork spindle, wrap the shim stock around the spindle and shove it into the DOM - the lower washer should keep the shim stock from slipping down (shim should be about 3 times the spindle diameter so it can't "walk away" -

Just a thought, since you probably already have all the parts - otherwise, I'd look for a bit tighter fit - say, around 15-20 thou instead of 135... Steve

 

[Pooh_Bear]

I haven't bought the steel yet. I was gonna try to pick it up tomorrow.
I called today to see what they had in stock at the nearest steel supplier.
I could order it online but the cost of shipping is horrible.

Pooh Bear

 

[David Devuono]

Just go to Northern Hydraulics or a local Hydraulics place and by some Cross tubes and Pins. Cross Tube will come with a hole to press a grease fitting in. Fit will be good and about .250 wall thickness on the cross tubes.

 

[Pooh_Bear]

We have a Northern Tool over in Chattanooga where I will buy the steel.
If I call Northern Tool to see if they have what I need, what do I ask for?

 

[EddieWalker]

You can get everything you need at McMaster Carr McMaster-Carr

Eddie

 

[chim]

The tube you listed makes it difficult to find bushings of the wall thickness you need between the 1-1/8" shaft and the ID of the pipe. You could go with 1-1/4" SCH 40 pipe (1.38" ID) and flanged bearings/bushings top and bottom. Drill & tap the pipe in the middle for a zerk and pump grease in the void. That's similar to the way my RFM's came from the factory.

 

[Pooh_Bear]

My current factory set up doesn't have bearings. And there is at least .125 slop in the hole. It does have a grease zerk.
It is currently just a vertical steel tube welded to 2x2 rectangle stock.
Here is more of the project I am trying to do: http://www.tractorbynet.com...finish-mower-wheel-supports.html

I'll probably just take a wheel fork with me to the steel supplier and see what they can find that fits.
The OD is not too critical. But the ID has to fit the fork spindle.

 

[Baby Grand]

How about finding a piece of bar stock that fits the ID of the 1.5 DOM tubing nicely. Then cut the bar off of the fork spindle and weld on your new piece of bar stock?

 

[Pooh_Bear]

I can't weld that good. And sometime in the near future I need to replace the wheel forks and tires.
I called some more places today. Hard to describe what I need over the phone.
Looking online I found some 1.5 DOM tubing with a center of 1.124
How hard would it be to drill it out to size. And what size am I looking for?

 

[BukitCase]

For that little distance, I would use a brake cylinder hone instead of a drill - I'd shoot for a clearance of around 20-30 thou (>.030), but for that type use you could just hone a bit, try the fit, repeat.

You want enough "slop" to keep a grease film between them, but not a lot more. Keep in mind, it's not like that fitment is gonna be turning 6,000 rpm or anything... Steve

 

[Pooh_Bear]

How about 1.5 OD and 1.260 ID from Mcmaster-Carr? 7767T431
That's a little over .125 slop which looks like what I have now.
I guess I need to measure what I have.

 

[Baby Grand]

I can't weld that good. And sometime in the near future I need to replace the wheel forks and tires.
I called some more places today. Hard to describe what I need over the phone.
Looking online I found some 1.5 DOM tubing with a center of 1.124
How hard would it be to drill it out to size. And what size am I looking for?

Aha - I see. Then how about changing the DOM size?

Speedy Metals - 1-3/8" OD {A} x 1.135" ID {B} x .120" Wall {C} DOM Steel Tube

this will give you a .010" nominal diametral fit. Just watch the heat when you weld it to the rectangular tube or it'll distort and you'll get something less than .010" nominal - maybe too much less. If that happens, then you'll be wanting a reamer (or brake hone) to open it back up.

 

[Pooh_Bear]

That's what I need right there. I haven't bought the materials yet. I needed the sizes first.
I plan to do all the cutting and drilling and fitting and then just tacking it together.
I'll let somebody with more experience do the actual welding.

I wonder if I could drop the square tube down a size to 1.75 inches.

 

[BukitCase]

Depends on the weight of the mower and the wall thickness of your tubing - if you can find 1-3/4 tubing with a .120" wall thickness, it should be plenty strong to support a few hundred pounds with that span - but you might be better off going with RECTANGULAR tubing, say 1-1/2 x 3", same wall thickness - that works just the same as headers in a house - if the wide dimension is the vertical one, you get more weight support... Steve

 

[Baby Grand]

BukitCase is right about the advantage of using rectangular tubing like a header. Most of the loading will be vertical, so that's where you want the long side of the section. Consider using a 2x3 with .120 wall (if it will fit). Then you could drill a 1 3/8 hole clear thru and slip the DOM tubing thru the hole. This will allow you to weld the DOM to the rectangular tube in a circle around the top and bottom of the rectangular tube, rather than along the sides of the DOM tube. Much easier to get a consistant weld joint gap, keep everything aligned and less distortion this way.

 

[muddstopper]

what I have done in the past to tighten up fit and something easy to try. I take my sawall and saw the lenght of the tube, on just one side. Then heat the tube up with the torch, not redhot, but to hot to hold in your hand Then I take my welder and weld up the slit. This will usually pull the tube tighter, Not an exact science or fit, but it gets me by in a pinch.

 

[Pooh_Bear]

Instead of bigger tubing how about thicker tubing; 2x2 with .25 wall.
Currently it has 2x2 with .125 wall.

 

[BukitCase]

Sure, if the .120 wall 2x2 is what bent then double thick should work - I would still go with Baby Grand's suggestion on drilling the tubing and doing full circumference welds at TOP AND BOTTOM ONLY - if it's done well, I doubt you'd see enough distortion to even NEED cleanup after... Steve

 

[Pooh_Bear]

I got the steel today. 2x2 square tubing with 3/16 wall, 54 inches long,
and 1.75 DOM tube with .25 wall. I ended up with 1/8 of slop in the spindles.
I can live with that. Now to start drilling holes.