Drilling a lensboard?

[mitica100]

A question that I'm sure has been asked before and replied to. Please direct me to the right thread, if you know of any.

Otherwise... My question is about a DIY lensboard and drilling the right size hole for a particular shutter. The lensboards that I'm making are of aluminum and found that cutting them to the specs is not a problem as much as drilling the right size hole. I've already 'sacrificed' two (may the Gods of the lensboard-making be generous with me now) by trying to drill with a hole saw cutter, which I hate to say, doesn't work well. I have a drill press but still it does not work well. I have discussed this matter with another DYI person and he suggested using Forstner bits. And now, the question: Are the Forstner bits strong enough to go through the soft aluminum? Because if they are not, I'm not willing to lose the bits by dulling them.

Thanks for any input.

Dimitri

 

[matti]

I would try a jig saw, and then file a bit to get it right.
/matti

 

[k_jupiter]

A question that I'm sure has been asked before and replied to. Please direct me to the right thread, if you know of any.

Otherwise... My question is about a DIY lensboard and drilling the right size hole for a particular shutter. The lensboards that I'm making are of aluminum and found that cutting them to the specs is not a problem as much as drilling the right size hole. I've already 'sacrificed' two (may the Gods of the lensboard-making be generous with me now) by trying to drill with a hole saw cutter, which I hate to say, doesn't work well. I have a drill press but still it does not work well. I have discussed this matter with another DYI person and he suggested using Forstner bits. And now, the question: Are the Forstner bits strong enough to go through the soft aluminum? Because if they are not, I'm not willing to lose the bits by dulling them.

Thanks for any input.


Dimitri

No. A forstner bit isn't worth the price of any lensboard.

GO down to the local Hardware store, get the closest hole cutting saw bit and use that, after clamping down your work piece on the drill press talble.

And forget about using jigsaw as a solution. If you have a drill press, you have the tools necessary. If you have a lathe, you are even more empowered.

tim in san jose

 

[bdial]

Forstner bits are strong enough to cut aluminum. BUT keep in mind that its removing quite alot of material if you don't predrill the center. Also, the speed and feed rate needs to be very slow.
I used a woodworking lathe to cut one of my boards, I now have a drill press, but even on its slowest speed it would be way too fast.
Finally, use lots of lubrication, oils meant for drilling/machining would be best, but I used what I had whch was spray Tri-flow.
The bit came out of it OK, I've used it since for cutting wood.

 

[Ole]

I use ordinary hole saws on a hand-cranked drill. The old antique gives slow enough speeds (I can't crank any faster), and I notice immediately if anything starts binding.

Use the closest size smaller than the hole you want. Then file the hole until it fits.

 

[Monophoto]

Forstner bits are intended for use in wood. These bits have two cutting blades - one does a cut perpendicular to the surface in the diameter of the bit. The other is a planer blade that shaves away material from the center of the circular cut. I suspect that outer blade would easily cut through aluminum, but the inner (planer) blade would probably bind in the material. Good forstner bits are expensive, and trying to cut through aluminum probably will shorten their life considerably.

What size opening are you trying to cut?

Since you have a drill press, I suggest either a hole saw or one of those adjustable fly cutters (the kind you have to swear at continuously to get them to work). Cut a hole smaller than the opening you want, and then carefully enlarge it to the desired size using a file or Dremel tool.

 

[L Gebhardt]

I used a hole saw to cut a 00 hole in an aluminum lensboard with no problem. The type I used came from the local hardware store and had a central guide bit which was used with different sized saws. I think the central bit helped out significantly over they types I have seen for wood that lack the bit. Just securely clamp the board and use a very slow speed on a drill press.

 

[photographs42]

I have successfully cut two holes in Linhof boards for copal #3 shutters using an adjustable hole cutter (the type with a small center drill bit and an adjustable cutter blade) and a drill press. One key to success is to hold the aluminum board to a wood board which is in turn clamped to the drill press table. Use a very slow speed and light pressure. I used large round head wood screws around the edge of the lens board. The wood back-up stabilizes the operation.

I would think a hole saw would work as well using the same set-up but finding the correct size might be a problem. Drilling small and filing is a pain.

Jerome

 

[Curt]

I use a hole saw, several manufacturers make them, available at Lowes and Home Depot and hardware stores. Get a small drill press, cheap is ok, and get a spindle sanding drum, it fits in the drill press. They come in different diameters so if you can't get the exact hole drilled, get close, then put in the drum sander and hand held sand the inside out so the shutter fits. It's important to clamp down the aluminum, I make a sandwich of thin plywood aluminum plywood and clamp it down tight. The sandwich does two things, one is to give the crisp cut to the aluminum with no burrs and the second is to give a clamping surface so you don't mar the aluminum. This works and is easy with a small drill press, the smallest they make is fine, a hole saw, Lenox etc., two clamps and drum sander, or set from 1 1/4 to 3 inches etc.. Clamp to drill and hand hold to sand on low speed.

Hope this helps,
Curt

 

[Curt]

Be careful, if you are not used to working with fly cutters if you should choose to go that way, they can be extremely dangerous. Always clamp and wear safety glasses.

 

[jmcd]

drilling aluminum

I think a hole saw is the way to go, using a drill press, slow speeds and slow even feed. The work needs to be clamped securely, and you need to apply oil where it cuts to keep the work cool and to prevent catching and chatter. Aluminum is very sticky.

 

[Ole]

The best coolant when cutting aluminium is alcohol, not oil.

 

[jmcd]

"The best coolant when cutting aluminum is alcohol, not oil."

Would that be grain alcohol, or denatured alcohol, Ole? Thanks for the tip!

 

[Curt]

Aluminum cutting lubricant can be obtained at the hardware store also and would be the correct solution for the project at hand. The proper tools makes the job much easier.

Good luck, you will save a lot of money and gain the freedom to make it to specs, your specs, and you won't have to depend on someone else.

Curt

 

[k_jupiter]

Aluminum cutting lubricant can be obtained at the hardware store also and would be the correct solution for the project at hand. The proper tools makes the job much easier.

Good luck, you will save a lot of money and gain the freedom to make it to specs, your specs, and you won't have to depend on someone else.

Curt

I agree... the proper tools do make the job easier. Using a fly cutter on aluminum is possible. And Possibly quite deadly. That bit catches a burr and you might just be toast. I don't care how firmly you might have the blank clamped down, a fly cutter can snap the pilot bit and swing that puppy across the room so fast, you head will spin. If you are lucky and are not in it's path.

The proper tool for amateurs like us is a hole cutting bit. If the workpiece grabs, it goes around in circles. Keep your fingers away, on the off switch and you'll live through this episode.

Think I'm a wimp for suggesting this? Imagine how I know. And I was lucky.

tim in san jose

 

[mitica100]

Ooh... Great ideas! Thanks. I did try in the past a hole cutting thing-a-majig bought at the local Hardware store (rhymes with Face) and the shaft of the drill was bent from the get go. Of course I returned the tool for a refund. I did find hard Forstner bits, I bought a set (didn't have to make a loan at the local bank) and used one of them for a Copal #0 hole. Clamped the aluminum with wood onto the drilling bed and drilled with the Forstner bit. Slow, slow and slower. And it came out fine! The bit survived too...

Thanks to all for the ideas! I now have a very nice drilled lensboard.

 

[Jim Noel]

I have successfully cut two holes in Linhof boards for copal #3 shutters using an adjustable hole cutter (the type with a small center drill bit and an adjustable cutter blade) and a drill press. One key to success is to hold the aluminum board to a wood board which is in turn clamped to the drill press table. Use a very slow speed and light pressure.

I cut all of my holes in lensboards using one of these "Swing" cutters. The secret is:
1. go slow
2. use a cutting oil to keep the bit cool
3. drill most of the way through one side. then finish the hole by turning the board over.
4. Sharpen the cutting bit after each hole.

Don't attempt to use one of these cutters unless the work is clamped with two clamps.

 

[razzledog]

"The best coolant when cutting aluminum is alcohol, not oil."

er sorry, Ole.......

Now this appeals to me......should one drink it whilst cutting?

My advice is to use a decent hole saw, the type that screws onto a threaded arbor (Sutton). This is great for sizes up to 1 1/2 inch, then I use a device that will handle cutting a hole up to 8 inches in diameter. Just attach a router to your drill press and use a turntable to rotate the job.

I lube the aluminium with CRC or similar, even kerosene is OK. Make sure the work is securely clamped.

Cheers, (hic)

http://homepages.ihug.com.au/~razzle/

 

[rshepard]

The responses all are sound.

I make aluminum lens boards for my Galvin (and am about to make an adapter for the Cambo so I can use the Galvin boards on it.) I, too, use a bimetal hole saw in the drill press. Set the drill at the slowest speed, and use a little bleach as a lubricant; wear an apron just in case.

The 1-3/8" size is just about right for a Copal-0 shutter; the 1-5/8" is a tad large for the Copal-1 shutters, but it works.

I took a piece of scrap wood and put two small screws at each corner of the aluminum plate to be drilled. Tighten the screws to hold the plate and clamp the wood base to the drill press table. Remove two screws to remove the aluminum, and the jig is ready for the next one.

I file by hand with a half-round file, but a drum sander will do the job, too.

Don't forget you need room for the lock ring's inner edge around the threads of the shutter.

Rich