What do I need to bore a hole?

[johnnywalker]

Whatever you use, you'll get a cleaner cut if you sandwich the piece you want to cut between two pieces of scrap, and clamp it all very tightly.

 

[Lee L]

Be sure you use a drill press with one of these, and make sure you clamp the work to the table - DO NOT try and hold the work yourself. A drill press has quite a bit of torque, especially at low RPMs, which is required for a cutter like the one Lee suggested. If you're using your hands to hold the workpiece, and the cutter binds, you could do some damage to your hand....

That said, I have the same type of cutter, and it does work quite well.

Ken is absolutely correct about the low speed torque with this tool in a press. There is no way on earth you could stop it by hand, so clamp everything down tight and keep your hands well away from the work.

I think that if you drilled a pilot hole the same diameter as the twist bit at the center of this cutter (1/4 " on mine), and used relatively thin plywood, say 3/16 or thinner, you could probably make the perimeter cut spinning the tool by hand or with a hand brace. One other trick is to start the cut from one side and go until you get a clean edge started, then flip the work and come from the other side, using the pilot bit in a hole that goes through the work. That prevents tear-out when the perimeter cutter punches through the back side.

Lee

 

[wilhelm]

One other trick is to start the cut from one side and go until you get a clean edge started, then flip the work and come from the other side, using the pilot bit in a hole that goes through the work. That prevents tear-out when the perimeter cutter punches through the back side.

I've used a cutter like this for wood, and never had a problem with tear-out if I used a backing board. In fact, I'd say johnnywalker's suggestion of using two boards to sandwich the work would probably be even better, especially on something as thin as a lensboard. They don't necessarily need to be all that thick, but they do need to be *there*.

Using one of those cutters on an aluminum lensboard is pretty scary. I had to cut a hole for an Imagon in a Compound #5 shutter - man that was one HUGE hole. The "pop" at the end when the cutter finally broke all the way through, that scared the heck out of me.

 

[Lee L]

Using one of those cutters on an aluminum lensboard is pretty scary. I had to cut a hole for an Imagon in a Compound #5 shutter - man that was one HUGE hole. The "pop" at the end when the cutter finally broke all the way through, that scared the heck out of me.

For a hole that size in aluminum I'd probably hand it off to one of my machinist friends, as I'm set up more for woodworking than metal.

Keeping the feed rate and RPMs low are good ideas in any case. Once you get these circle cutters past the beveled point into thicker wood with larger diameters, they tend to heat up quickly. Pulling the bit out and cooling frequently is a good idea; same with large diameter Forstners.

Lee

 

[RichSBV]

I've used the circle cutter, in a drill press, to cut the aluminum Graphic lens boards quite a few times. Even the thicker Graphic View II boards.

The trick, as mentioned, is slow speed and backing out very often. Basically, after the cut is start, you just drop the bit and 'tap' the board a bit then back right out.

The easiest method I've found to 'clamp' a Pacemaker style board, since they only come with a 29mm pilot hole new, is to place them on a larger backing board. Then place 3 or 4 sheet metal screws into the wood on the inside circumference of the pilot hole with the screw heads holding down the lens board to the wood board. Nothing holds the outside of the lens board. When the hole breaks through, the lens board will break free and care must be taken. I've had no problems with this though. Slow speed, keep the bit i the wood (lightly) and shut off the press. Or, very quickly raise the bit...

Drilling wood is much simpler ;-)

 

[Emile de Leon]

I just used a 5" hole cutter on my hand drill to put a huge Dallmeyer f3 in a Deardorff board. A little off center but not as hard as I thought it would be.Emile.

 

[Jeremy]

I actually use a RotoZip and actually cut 2 lensboards with one yesterday.

 

[RichSBV]

Jeremy, a Rotozip is an interesting idea since I bought one recently for minor construction work. I never thought od using it for lens boards?

Did you use the circle cutting attachement or go free hand or some type of template? I also bought the circle cutting attachment, mostly because I like attachements and ity was relatively cheap ;-)

 

[Jeremy]

Rich, I just draw a circle on the wood that I need to cut out and go to town free hand (with the lensboard clamped down). This is all that is needed if I'm just putting in a flange or it has a retaining ring, but if I need the hole inset like needed for a Copal 3 shutter then I grind down the back free-hand with a dremel tool. I'm all about utilitarianism and not cosmetics when it comes to my lensboards

 

[RichSBV]

Thanks Jeremy. Dremels are our friends! ;-)

I'll have to 'play' with the Rotozip and see how it works. I know I went off-line with it a few times notching 3/4 plywood last time I used it ;-) But flanges are also a wonderful thing ;-)

 

[Charles Webb]

My 10 inch South Bend works well for wood or Aluminum. Johnnywalkers "sandwich" idea is a must in my opinion, I even use it with the lathe and mill. Charlie.............

 

[k_jupiter]

I have several ways to bore lens holes. My favorite is with my lathe and a coleman chuck to place the undrilled lens board in. Cut a hole smaller than the lens diameter and enlarge it until it just fits. I just made an enlarger lens board for my MCRX and a 150 Schneider tonight. I have also made many boards for my older Speed Graphics.

The other way suggested is to get a small tabletop drill press, somewhere in the vicinity of $100. A lot of money but you'll be suprised how often you use one when you have one. Just be sure to use clamps on the workpiece or be prepared for flying lensboards. Be careful with larger bits as they can grab the work and hurl it, hurting you badly.

tim in san jose

 

[photobackpacker]

.410 bore, full choke= Copal "00"
20 guage, modified choke= Copal "0"
12 guage, full choke=Copal #1
12 guage, improved cylinder=Copal #3
10 guage, modified choke=Acme & Universal #3
10 guage, any choke, both barrels should give you a hole big enough to ream for Betax #3 and Ilex and Betax #4 &#5 shutters.

______________
note #1= always wear ear protection and safety glasses.
note #2= On ranges where water quality is an issue, steel or bismuth shot may be required.;-)

Gotta be a skeet shooter if you know 410 is a bore - not a guage (67 guage)

 

[Imke]

What do I need to bore a hole?

Hm, a bad joke maybe?
(Couldn't resist ... )

Imke

 

[chiller]

Slightly O/T How many apugger's -----

So how many APUGGER's do you need to change a light bulb??

 

[Frank Petronio]

I didn't read the entire thread but I thought I was needed to add some support to the impressive minds at work here.

 

[glbeas]

We need all the help we can get!

 

[barryjyoung]

We all have our own ways of drilling lens boards it seems. Here is mine. It works very well indeed with absolutely correct size, no tear out whatsoever and it is quick. There is a catch. You must have a metal lathe to do it.


I lay out the board. In other words, I find the exact center of the board by either drawing lines with a machinists scale laid across the corners and make a small mark in the center or measuring from the edge on boards with radiused corners with a digital height gage on a surface plate. Once the center is marked precisely I chuck the board in the four jaw chuck and use a wiggler with a fine point mounted in the tailstock. I put the tip of the wiggler into a center punch mark in the center of the board. I revolve the chuck slowly by hand with an indicator tip near the end of the wiggler point. This allows me to dial in the board within a few thousandths of an inch. This takes care of locating the hole precisely.

Next I use a hole saw mounted in the tailstock that is at least .250 inch smaller than the hole. This gives me an approximate hole to start with.

Rather than trying to drill to size, I use a boring bar with a carbide insert to bore the rough thru hole and any counterbore for the retention ring.

Now my trick. After I have everything within about .010 from finish size I swab the inside of the bore and counterbore with superglue. This keeps it from tearing out.

Then I finish the bore and counterbore and sand away any residual super glue.

This works very well. Hope it helps

Barry Young
cameramaker.com

 

[jimgalli]

Sheesh! All these answers and nobody does it how I do it which is the best and easiest of course. 3/4" Carbide fly cutter on a router table. Draw the size you want on the board. Plunge that thing though. Gradually and carefully enlarge in a circular motion until you've got whatever aperture you want. Lower the cutter and make whatever undercut you want for the jambnut to drop down into. Bingo, multiple cuts with correct recess for the nut in minutes. I do these freehand. Have probably done 60 of them at this point.

 

[Curt]

Do it right, use a hole saw in a drill press. Clamp the board, wood or metal, and use a piece of plywood under it to get a clean exit and it will be clean and smooth. The drill press doesn't have to be a big expensive one either. I make ones out of wood which is easy. I make ones out of aluminum which are really nice. It just depends on you application.