Tips on getting holes perfect in line mag drill

[Thebeast]

Hi not sure if this is in the correct place but if not i apologise.

Just wondering if any fabricators could help me out. How do you get holes from a mag drill perfectly in line with each other? I punch and pilot hole and mark them out pretty spot on but I always end up with at least one hole slightly out to the rest when doing multiple

 

[Erie Fred]

"Perfectly" ?
How are you aligning the mag drill ?

 

[Welderpaul]

The centre pins are quite often a loose fit inside the cutter. Make sure it is a tightish fit. Locate the drill carefully and raise and lower the drill a number of times before you start cutting to make sure the cutter is truly centred. Start the cut for a few seconds then stop and raise the cutter to make sure it is actually cutting on the centre mark.

 

[Thebeast]

"Perfectly" ?
How are you aligning the mag drill

I mark out putting a small 3mm pilot, then I use a 7mm drill bit and lower the centre pin of the annular so it fits pretty snug and I cut. My mag drill doesn’t have a bottom support so if I don’t lower the centre pin into a 7mm hole then it drifts off. Was just wondering if there is a more accurate way as a few mm difference is knocking things off :-(

 

[Welderpaul]

Sounds like your drill is causing you the problems then. They need to be tight on the gib strips and not slop about.

 

[roofman]

I mark out putting a small 3mm pilot, then I use a 7mm drill bit and lower the centre pin of the annular so it fits pretty snug and I cut. My mag drill doesn’t have a bottom support so if I don’t lower the centre pin into a 7mm hole then it drifts off. Was just wondering if there is a more accurate way as a few mm difference is knocking things off :-(

Make sure your gib screws are as tight as possible but not binding...a good center punched mark for the pin should be enough and make sure the pin is ground to a good point

 

[roofman]

Sounds like your drill is causing you the problems then. They need to be tight on the gib strips and not slop about.

too late..you mentioned the gib 1st

 

[Erie Fred]

too late..you mentioned the gib 1st

He got.....wait for it ...."First Gibs"......

 

[Thebeast]

Sounds like your drill is causing you the problems then. They need to be tight on the gib strips and not slop about.

Yeah think it must be time for a new drill. I got it second hand didn’t have the bottom support on it. Had a look for parts but unfortunately can’t find one anywhere :-(

 

[Welderpaul]

Yeah think it must be time for a new drill. I got it second hand didn’t have the bottom support on it. Had a look for parts but unfortunately can’t find one anywhere :-(

Which drill is it?

 

[Thebeast]

This is the part missing it likes to shift around without it. My only way to get it to stay on track is like I said drilling a hole a little bit bigger than the pin for the pin to keep it from moving about too much.

 

[Thebeast]

Which drill is it?

 

[Onoff]

The simple answer I guess to your original question is probably have the tool intact and it'll do the job!

As with a lot of these cheaper brands, getting spares down the line can prove tricky if not impossible. Your best bet might be to find somebody local who can fabricate the missing part or close match to it. Part 73 or 73A. PDF attached too:

 

[Ton-up]

Drill a hole in a piece of 10mm plate. Clamp or tack that to your job and use it as a guide for the cutter. Use the edge of the plate against a guide to get a straight run.

 

[Mark 2]

I just centre the wobble.