I need to affix a fastener deep inside a tube

[jmarkwolf]

I agree that the feet thing looks wiggly - any vibrations are carried by 4 points, maybe four 1/2-13 bolts. The bolts in the tube through the base are not really doing much of anything structurally, more positionholder. Rule of thumb for plug welds: min diameter is 1.5 times material thickness for structural applications, let's you get some heat in the hole before you close it up.

The bolts through the base of the mill are 1/2-13.

The leveling feet assemblies have 5/8in diameter studs and are rated at 4500lbs capacity each. They will only be carrying 600lbs each statically. I think there is plenty of margin on the leveling feet.

 

[David S]

Wow guys lots of neat ideas. I still think one long flat bar the length of the tube would be real easy and no welding required. It could be captured by the out rigger screws. May cost more though.

David

 

[GL]

Woke up at 2a thinking about this. The whole plan is to raise the mill up so you can get a pallet jack under it. The wider is also to accommodate the width of the jack. What happens if you go sideways - since the mounting holes in the base of the mill are further apart front to rear than they are side to side. May be a space issue.

The other think I was thinking about was the hardware to hold the bars/tubes on. What happens if you use flathead bolts going from the bottom up. You will need some more meat than the tube will give you for the countersink on the bottom - so weld in a tube with the countersink on one end through a clearance hole on the bottom, nut on top. No tapping required. The down side may be that you have to lift the mill up far enough to get the bolt in the hole.

Lots of ways to skin the cat.

 

[jmarkwolf]

Woke up at 2a thinking about this. The whole plan is to raise the mill up so you can get a pallet jack under it. The wider is also to accommodate the width of the jack. What happens if you go sideways - since the mounting holes in the base of the mill are further apart front to rear than they are side to side. May be a space issue.

Glad you're thinking of me at 2am... I think!

Until now that's how I've been moving the mill is with the pallet jack from the side, but my mill has the lathe on one side and benches with toolboxes on the other. It's a major ordeal to make room for the pallet jack. From the front is the best solution for my situation.

 

[jmarkwolf]

I thought I may be on to something, but after working up scale CAD drawing it's a no go.

I thought I may be able to fish a standard nylock nut past the leveling foot stud with one of those curved wrenches, but no worky. A straight wrench definately won't work either.

Looks like some drilled and tapped flat stock plug welded is the most many way to go.

 

[extropic]

Drill the rectangular tube 1" diameter through both walls and weld, on both sides, a piece of 1" diameter steel rod through the tube. Grind flush on both faces, drill and tap to your hearts desire.

 

[cg285]

i don't see why you don't just tap the existing holes, get tap bolts of the appropriate size, round the ends, cut some square plate, run a ball end mill in the middle of the plate to match the tap bolt, done.

 

[woodchucker]

i don't see why you don't just tap the existing holes, get tap bolts of the appropriate size, round the ends, cut some square plate, run a ball end mill in the middle of the plate to match the tap bolt, done.

As he replied to me, he is only going to get 3 threads, and is concerned that won't be enough. maybe with a fine thread it might make it.

 

[jmarkwolf]

As he replied to me, he is only going to get 3 threads, and is concerned that won't be enough. maybe with a fine thread it might make it.

Correct.

13 threads per inch (1/2-13 bolt) in 1/4in thick material is just 3 threads engagement.

I'm leaning heavily towards Bear's idea of plug welding an interior threaded plate.

I also like the idea of welding a round threaded "bushing" through the tube. My welder still doesn't have the capacity however.

 

[cg285]

worked on my bridgeport. don't remember but probably 3/4" of threads