What is the best way to drill a hole(copal#0 size) on a piece of plastic?

[aaron_rocky]

I'm contemplating of a project to use large format lens on RZ67 w/

extension tube and use the extension tube cap as lensboard. How to

drill a nice round hole on that plastic cap?

[conrad_hoffman]

The *best* way is to chuck it up in a lathe and bore the hole. Perfect size and centering. The 2nd best way is to put it on the mill table and use a boring head. If you had a lathe and mill, you'd likely not be asking the question! You can get circle cutters for the drill press, but the cap has to be held as securely as possible, absolutely not by hand. High risk of damage, but it can be done nicely. Another way is to mark the circle, then drill a series of holes around the ID. Knock out the center piece, then sand the hole smooth with a Dremel tool and 1/2" diameter sanding drum. Yet another way is to use a Greenlee punch, normally used for sheet metal. You drill a small hole in the center, then screw the punch halves together through the hole. If all else fails, get a piece of metal tubing of the right size (or make it out of flat brass from the hobby shop), hold it with something insulated, heat it with a torch, and melt your way through. That's how they refill laser copier cartridges. Finally, you could mount the cap on a soft wood post, get a 30-06... If it was me, I'd find somebody with a lathe to do it perfectly.

[jim_galli4]

I've done it with a router on a router table. Still have both my hands so far but I attribute that to dumb luck.

[thirteenthumbs]

Now that you have heard the best, another work-around is a hole saw. Choose the closest to the size and the mandrel for it. Mount it on the mandrel, install in a variable speed drill or drill press, mark and clamp work piece in place and drill slowly. DO NOT use the multi set with blades held in by set screws. A 1 1/2 inch hole saw will be a little large,about 1mm, but the retainer ring should hold it securely. A 1 1/4 inch hole saw will be about 3mm too small requiring use of a dremmel as mentioned in a previous post. Circle cutters for drills are designed for a drill press and are difficult to control in a hand drill. Another, but more expensive, bit would be an adjustable head bit such as Irwin 45002, designed for wood, but should work in plastic, harder to use than a hole saw but easiet than a circle cutter.

[audidudi]

If you don't have access to a drill press and the material you're drilling isn't too thick, then you might consider a Uni-Bit. They're not inexpensive but they do drill very nice round holes in thin stock...

[pvp]

A flycutter in a drill press works well on aluminum Cambo lensboards, so it should have little trouble with a plastic lenscap. A cheaper and possibly saner way given what you're working on, might be to mark the desired cutout, drill and saw it out a bit inside the line, and then finish out to the line with a Dremel.

[Jochen_S]

Wood drills work fine on plastic. There are adjustable ones. But I'd suggest it's better and cheaper to ask a lathe operator to spend a few minutes for a bottle of vodka.

[tim_curry]

If you use a drill press and fly cutter, hole saw or other type of bit please use a clamp to hold the part on the table. Too many people think they are "just drilling one hole" and try to hold things by hand. When the part starts spinning with the bit, hunks of skin will go into the mix as well.

 

Check with any local cabinet maker. The bit used for drilling "european style hinges" in the back face of a door is just right for a copal one shutter.

[Glenn McCreery]

Use a 1 3/8 inch hole saw, which is commonly available. This, I recall, should be close to the right diameter, although I do not have a number 0 lens board in front of me to measure. Hole saws are available in 1/16 inch increments from, for example, McMaster-Carr, www.mcmaster.com. Hole saws are more tollerant of errors than fly cutters. Unless you clamp the lens board tightly and use the correct cutting speed with a fly cutter, you will end up with a piece of scrap metal (from personal experience).

[terence_m.]

I second Conrad's (4th?) option. I've used a Dremel and a small bit to drill out a series of holes just inside a circle marked with either a template or the retaining ring (or flange) itself. Snip the small pieces betwen holes with a cuticle scissor (if the material is thin enough, or tin snips/ wirecutter if not) and knockout the waste. Clean up the edge with a sanding bit, removing a litle material at a time and constantly checking the fit. I've done it in thin metal, plastic and tempered hardboard (the toughest of the three). The hole might not be the prettiest thing, but none of them leak light and they were cheap and easy.

[pvp]

<I>If you use a drill press and fly cutter, hole saw or other type of bit please use a clamp to hold the part on the table.</I><P>

I shoulda said that.

[aaron_rocky]

Thank you for the suggestions! Here is the picture of first stage, still waiting for the tube to come.

 

http://www.geocities.com/chnphotog/lf.html

 

I'll use the RZ mirror up function. Can anyone foresee any problems(jamming etc) to do something like this?

[edward_burlew]

Use the flu cutter on the drill press use a slow speed and then when you are about half through flip the piece over adn cut from the other seide I have done this for lense boards adn it is very neat. The hole saw will be a mess and overheat and warp or burr. I have done about a dozen tis way . It also works well on wood and aluminum. Of course get it centred and do a test and do a couple with the set up then you can borrow other lenses from businesses and friends to fit your camera.

[max_wendt]

I just did the "drill a series of holes, punch out, sand" method last night. It's not pretty (or much fun to do), but it works and it's light tight.

[max_wendt]

(forgot to add: but I agree almost any other method would be better - I just don't know anyone with a lathe and I didn't want to buy anything just now... so drill-punch-sand it was, and it worked out.)

[todd_west]

<p><i>The hole saw will be a mess and overheat and warp or burr</i></p>

 

<p>Then fer crying out loud drop the RPM on yer drill. I did all three of my (plastic, Copal 0) lensboards with an arbor saw. No problems.</p>

[william_wiseman1]

I use a 1-3/8" Forstner (flat bottom) wood bit and a drill press. I clamp the 1/8"

acrylic to a 1" board and put the board in vise. I have drilled several this way with no

problems and they fit the Copal #0 fine.

[allen_whittier]

"I use a 1-3/8" Forstner (flat bottom) wood bit and a drill press. I clamp the 1/8" acrylic to a 1" board and put the board in vise. I have drilled several this way with no problems and they fit the Copal #0 fine."

 

Great advice!!!

 

I don't think anyone has talked about eye protection. Wear good safety glasses!! I don't think they make an eye patch with a focusing loop built in.

 

I have a machine shop, but I'd do it this way since it's just plastic. These bits don't move around or grab as bad as regular bits. Use a slow speed and don't let it heat up. Machinists frequently freeze plastic before machining to make it cut better. A squirt or to of water while your drilling works great too. Find a friend with a drill press for best control and remember CLAMP CLAMP CLAMP! And protect your eyes!!

[lbi115l]

For the record, just use a hole saw on a drill press. It's how I mounted my lens. Use a machnists' vise to hold it, centered. First mark the center and drill a pilot hole, then use the hole saw. For plastic, you want the slowest speed the press has.

 

If you don't have the equipment, here's what I suggest as the cheapest way. Walk into your local hardware store, the place the contractors go to. Tell the guy behind the deak that you need someone to drill a hole in a small piece of metal for a few bucks. I'm sure someone will do it.