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Need ideas to fix a part

Dave K

Diamond
Joined
Mar 21, 2004
Location
Waukesha, WI
I screwed up. Drilled and tapped a hole in an aluminum part, looking at the left had print, when I should have looked at the right hand print. It's a 10-24 tapped hole, 1/2 inch deep. It's in the edge of a .344 thick plate. It is off location by .128. So, if I were to plug it, and drill and tap in the right spot, I'd cut approximately 1/2 way into my plug when drilling and tapping the correct hole.

I need some of your ideas on a way to fix this. Basically need to "move the hole over" by .128.

This part will be anodized when completed. I have 75 of these things to fix. I don't want to start over, I have too much time and money into these parts. And yes, I will be checking with engineering in the morning to get an ok for any fix.

I could possibly have it welded shut, but seeing if you guys have any other magic tricks?
 
Short of welding hole shut, green loctite aluminum stud in already finished hole (McMaster carries them) and when set drill and tap new hole. Would likely need your engineer buy off on this.
 
Short of welding hole shut, green loctite aluminum stud in already finished hole (McMaster carries them) and when set drill and tap new hole. Would likely need your engineer buy off on this.

Yeah, I'll be checking with engineering. I think it's just a hole to hold some sheet metal gaurd, but not sure. This is the only solution I can think of also, but was kinda scared about the fact that 1/2 of that plug will be cut away with the new hole.
 
The problem is going to be with annodize, welding plugging with give you a different appearance.
had a similar problem a bunch of years ago on pill manufacturing machine parts. except it was there engineers fault. plates were approx 20x20 x 1/2. we told them the anodize would show up uglier than hell, they proceeded anyway. there boss's saw it they said make them over. so we did them again.
 
Maybe insert larger and and off location so the plug covers both the incorrect and correct location.

Sent from my SM-G960U using Tapatalk
 
Maybe insert larger and and off location so the plug covers both the incorrect and correct location.

Sent from my SM-G960U using Tapatalk

Edit: ** OOOOPSSSS I just reread he said on edge of part, and the thickness is .344, nothing going to work unless the allow weld/plug. sorry


off location would look like crap with out haveing the 10-24 in the center of the insert.
you could run a 1/2 threaded od plug with a 10-24 id thread in center and it would clean up. a .225 plug would clear up the holes.
however with a plug you have the problem of pulling it loose when tightening down the 10-24 thread. also on both you will have a problem making it fit flush on both sides.
depending on how many parts a threaded plug would be the way to go and still function normally and look nice. but you have the time of making the threaded plug to size and installing them. someone might sell such a insert but you might have to cut down the length. if theres more than one 1024 threaded hole it would look sucky if you didnt do them all.
after all is said and done depending on the size and quantity you might be cheaper to run from scratch and just eat it. sucks but it happens.
 
Start over, aluminum goes dead soft when you weld it. Not what you want for threads. The weld will look like hell after you anodize it. When I was a kid I always wanted to use a machine and Dad would say that all that machine was going to do is help me make my mistakes faster!
 
I screwed up. Drilled and tapped a hole in an aluminum part, looking at the left had print, when I should have looked at the right hand print. It's a 10-24 tapped hole, 1/2 inch deep. It's in the edge of a .344 thick plate. It is off location by .128. So, if I were to plug it, and drill and tap in the right spot, I'd cut approximately 1/2 way into my plug when drilling and tapping the correct hole.

I need some of your ideas on a way to fix this. Basically need to "move the hole over" by .128.

This part will be anodized when completed. I have 75 of these things to fix. I don't want to start over, I have too much time and money into these parts. And yes, I will be checking with engineering in the morning to get an ok for any fix.

I could possibly have it welded shut, but seeing if you guys have any other magic tricks?

Parts are so damned close to having bi-lateral symmetry you could even make the error to begin with? Could a bit of re-ingineering finish the job and make them identical - reduce risk of scrap AND cost of production?

Guessing, of course. PM musta turned your foto blank white.

:)
 
How far off the edge is the hole
If it is a bit more as 4mm(0.16) you could drill a hole minimun 9 mm better 10-11, counterbore it on the opposit site and glue in a plug with a head and drill/tap it
That way you cannot pull out the plug

Another way is make a slotted hole wider on the opposite side to hold a nut
It may look original design

Peter
 
If they do let you plug the hole then use an aluminum bolt. Loctite, screw the bolt in hard, saw it off, rivet the end with a punch. Should stay put.

Ed.
 
I have made a similar mistake a few times. I would consider boring a hole in the correct location that is large enough to cover the mistake hole. I would then turn a plug out of the same material and press it into the hole. I have made that press fit so tight that I had to beat it into place with a hammer. I then decked off the plug dead flush with the surface. Because it was a damn tight press fit, there was almost no witness line between the plug and the part after anodize. I don't think all the kings horses and all the kings men could pull out a press fit plug with a 10-24 threaded hole.
 
perhaps a binocular bolt? How close is the hole to the edge? If the plate is .344 and you're .128 off location, that doesn't add up. If you haven't yet checked with engineering, maybe they could slot the hole in the mating part (sheet metal?) That would be the simplest fix. Otherwise your plug is going to need to be big enough to cover the bad hole and the good hole. When we have to do it, we make a plug threaded on the od, but we thread it with a round adjustable die tweaked out t o make the threads a little oversize. Loctite it in and it ain't ever coming out. But, as already noted, after anodize it's going to stand out like a sore thumb
 
I like Seaman's idea, that may be easiest. You need to weigh if it's really worth the added time to fix the parts. What time is worth is up to you and your bosses, of course. My first choice would be to drill it out, press in a plug of the same alloy, then re-drill and tap.
 








 
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