Work Holding for Drilling

[Lavcat]

Now that I have a squared and mounted vise, I am concerned how best to hold my extruded aluminum panels for drilling.

My drill vise is a Proxxon Primus 100:
PROXXON - PRIMUS

The jaws of the vise are not flat, but have V groves, as is common for drill vises. Is it considered good practice to use the horizontal V grove to hold a panel?

Would it be better to use a pair of parallels between the jaws and the work to give a flat surface, and to support the work on another pair of parallels?

Or should I consider getting a milling vise with flat jaws?

[Enzo]

SOme vises come with replacable jaw facings, or at least holes to mount your own. If you don;t want to scratch the work, then you will need some sort of padding on there anyway.

[bill_a]

The answers to your questions really depend on what you are drilling and the diameter of the hole(s). Is it a thick extrusion or relatively thin? Small-ish drills (<3/8") or a hole saw?

Given that your vise has those v-slots that are relatively large, it doesn't leave a lot of flat surface area. I think I would use some 1/4" flat steel stock as vise jaws. Parallels would work, but you risk warping them. Support the work on parallels, tighten the vise and remove the parallels. If you're not drilling big holes, that should work. If you're drilling big holes, leave the parallels under the work if there's room.

And depending on the size of the finished hole, drill a pilot hole. It'll reduce the pressure needed by a lot. The pilot hole should be as big or a bit bigger than the web on the finish drill bit.
Bill

[dave_gerecke]

From looking at the website link for the vise, they have a step in the top face of the vise jaws, for holding flat stock. Assuming that you don't need really tight tolerance geometric positioning of the holes, you could use the steps. If you are trying for some really tight G,D&T you really should be using parallels, and a vertical mill.

Peace,

Dave

[Lavcat]

Thanks, people.

The extrusion is 1/8 inch thick but it is not flat on the bottom. I cannot use the step at the top of the vise to hold it. Nor can I support the work with the parallels I have, because then the work is not on the flat part of the jaws. If I got taller parallels it might work.

On the other hand, if I got a milling vise with flat jaws the parallels I have should work OK.

If I use the Primus vise without any parallels I can grip the work by the thin part of the bottom of the extrusion (which I don't think is a good idea). Or I can grip the thick part in the top of the horizontal V, resting the thin part on the bottom of the vise. This is sort of like using parallels. If I use the parallels I currently have to support the work, the edge of the work hits on a non-flat part of the jaws. If it is OK to grasp the work in the V, then I don't have to buy more parallels and I don't have to buy another vise -- right now at least!

I have been worried about marring finish, but so far the powder coat has proved pretty durable.

I hope to be able to drill or ream up to a 12 mm hole, and there is clearance on either side for parallels if needed. I also need good tolerance on some of the smaller holes, which I plan to tap for M3 screws. For large holes I have punches.

Dave, what does "G,D&T" stand for?

[Lavcat]

Originally Posted by Lavcat

Dave, what does "G,D&T" stand for?

Duh, I can now answer my own question: "Geometric Dimensioning and Tolerancing".

I have to keep telling myself that all I want is a few holes in the right places.

[dave_gerecke]

Hello Lavcat, sorry I didn't get back to you, I have been less than regular on diyaudio (as opposed to the rest of my life). Now that you explained your setup and the specifics of your panel, I understand your question. Could you use a couple of plates between the jaws, aligned vertically, then put the panel you are drilling on the parallels you have? Just a thought.

You are correct on the definition of G,D&T. Most of the things here won't need that level of precision, but it's up to the individual doing the project to decide that. I did some at my last job. Most of the time necessary, sometimes the engineer just over specified the design.

Good Luck

Peace,

Dave

[Lavcat]

Originally Posted by dave_gerecke

Could you use a couple of plates between the jaws, aligned vertically, then put the panel you are drilling on the parallels you have? Just a thought.

Thanks again. If I understand you correctly this is the same procedure as what I meant by "Would it be better to use a pair of parallels between the jaws and the work to give a flat surface, and to support the work on another pair of parallels?"

Are we talking about the same thing?

Holding the panel in the V is still a possibility.

[Lavcat]

After further testing the part wiggles when held in the V slot. Probably not a good idea.

[dave_gerecke]

Originally Posted by Lavcat

Thanks again. If I understand you correctly this is the same procedure as what I meant by "Would it be better to use a pair of parallels between the jaws and the work to give a flat surface, and to support the work on another pair of parallels?"

Are we talking about the same thing?

Holding the panel in the V is still a possibility.

Hey Lavcat, after rereading your posts, yes we are talking about the same thing. Only I wasn't thinking of using something as precise as parallels for clamping plates.

Peace,

Dave