Drill Press Head Repair

[Rick_B]

This WT drill [press head came to me with a broken pocket where the motor mount stud slides in. I have made a support bracket/strap that will span across the two holes on the back of the head. Now that I have a tentative plan for providing adequate support for the motor mount plate - I want to discuss the aesthetic repair piece of this.



I would like to fill in the broken area shown in the picture. Unfortunately I don't have the broken piece. My first thought was to insert a dummy rod in the broken socket that will be coated with something to prevent material from sticking to it - material being JB Weld, Bondo, Devlon steel epoxy or something else you smart folks are going to suggest. The dummy rod would be removed as the material hardens. I have some doubts that any of those would hold up over a wide span like I have. Thoughts?

Rick

 

[gard]

JB weld should work, Bondo is probably way easier to work with. You put a big glob on and as it starts to harden it can be shaped with a sure form plane, and sharp knives then files and sandpaper as it gets harder.
I would probably wrap a couple of layers of plastic baggie material around the shaft just to ensure there is some clearance. Or drill it out later. Or use a piece of round insulation foam backer rod.
If you wanted a perfect fit of the glue to a removable surface, use a "mould release agent" but in this case an air gap is probably good.

 

[Jake M]

My first thought was to insert a dummy rod in the broken socket that will be coated with something to prevent material from sticking to it - material being JB Weld, Bondo, Devlon steel epoxy or something else you smart folks are going to suggest. The dummy rod would be removed as the material hardens. I have some doubts that any of those would hold up over a wide span like I have. Thoughts?

Rick

I think you're right, that the filler here is going to be mostly cosmetic. What's lost is lost.

The locking bolts hold the rods to the inside of the hole, which you still have. And you've made the brace, so that the one that's missing it's bolt hole can still be pushed in the right direction. The outside (missing) part of that hole served only to hold the bolt in place, as the rods never touched it. So you've got some wiggle room here.

Based on those thoughts, I think that ANY of the solutions you thought of (and many more) would suit the job just fine. The first one that comes to my mind is JB Weld "Steel Stick". It's a thick, putty consistancy, heavy duty Play Doh if you will. You have to "nead" the parts together, sort of a PITA but not too bad, but to me (and it's an art, your mileage may vary), to me, the thick putty consistancy is easy to "sculpt" to a larger shape. And of course after it sets, it can be filed, sanded, polished, drilled, tapped, whatever you want to do with it. (Don't try to hold critical bolts in holes tapped in this stuff.......). But I think the "form" that the filler comes in will be more important to the outcome than it's ultimate strength, since this is not (I do not believe) a "glueable repair".

As for the "not sticking" thing, I'd probably shy away from a mold relase or zero clearance option. You're going to have MORE surface on the rod and less on the machine. You might be supergluing your epoxy patch back in place. The first thing that comes to my mind is a cling wrap layer over the rod. That'd buy you a few thousandths clearance, and even that might be a little tighter than you want it to be. And of course if it stays in the hole when you remove the rod, you can fish it back out.

The inside of the hole can be "flap wheel'ed" just as well as the outside can be sanded to shape. I'd say it's probably better to err towards too snug and "flap sand" it open if needed. But like I said, this surface is not a functional surface, so you've got leeway. The functional surface is what remains on the main casting.

 

[Weldingrod1]

If you make a steel plate that ties the two sides together, that will help the structural and keep load out of the cosmetic repair.

Sent from my SM-S911U using Tapatalk

 

[RaisedByWolves]

Your best bet would be Devcon (Love that stuff) and drilling and pinning the edges of the broken part.

I've fixed lots of things like this with good results.

 

[whitmore]

Instead of a dummy rod, I'd consider a thin tube; then nickel or copper-nickel weld/braze to fill the void.
That'd give a real structural buildup, and a narrowed rod could still be well clamped.
For 'extra credit' you might even bore out the tube after the work is cool, so as to use the
original motor mount parts.

 

[Rick_B]

Instead of a dummy rod, I'd consider a thin tube; then nickel or copper-nickel weld/braze to fill the void.
That'd give a real structural buildup, and a narrowed rod could still be well clamped.
For 'extra credit' you might even bore out the tube after the work is cool, so as to use the
original motor mount parts.

This doesn't need tto be structural. This head is pretty massive and I don't want to introduce any heat to it

 

[Rick_B]

Your best bet would be Devcon (Love that stuff) and drilling and pinning the edges of the broken part.

I've fixed lots of things like this with good results.

I ordered some JB Weld steelstik to give it a try. Devcon just seemed a bit too pricey. If the steelstik doesn't work I can always try other options

Rick

 

[gard]

Let us know how you like the steelstik, I tried it once and gave up, I found it too hard to mix, perhaps I gave up too soon. I found bondo much easier to work with but then I had years of experience and many gallons worth in my younger auto body days.
I love my WT drill press, it needed a lot of work but luckily no busted castings.

 

[Rick_B]

I completed the repair of the broken motor mount today.

Step 1 was to get the support bracket and head drilled and tapped for two 1/4-20 flat head machine screws. Started out as #10 but after I busted the tap I moved up a size. It took some fiddling to get the bracket installed and still be able to have the studs move easily but I eventually got there.







Then I needed to address the actual break - decided my first attempt would be with JB Weld steelstik - worked like a charm





I may need to do a little more sanding - not sure yet. I was also able to drill and tap the 1/2-13 hole for the locking set screw. This stuff is fully workable after 60 minutes.

Now I need to get back to normal business of painting the head.

I appreciate all the help and suggestions

Rick