Drilling Graphic lens boards on a micro lathe

[BarryS]

I bought a well-used Micro Lathe (http://www.taigtools.com/mlathe.html) a few months ago and it's time for it to earn it's keep. I need to bore holes in some aluminum Graphic lens boards and if my little lathe can't do it--it may be headed to the bottom of the Potomac. :)

The chuck on the lathe is too small and unsuited to hold the boards, but I was thinking of a making a small wood jig--basically a square wood block that fits snugly within the lip of the lens board, attached to a wood cylinder that will fit into the chuck. Two screws and wood glue would be used to attach the cylinder to the block, and the board would be screwed to the block through a small center pilot hole.

Being that I have no lathe experience, I though I'd get some input before I tear off any of my appendages or put out an eye. Does my plan sound workable? Any better ideas? How about optimal speed and best cutting tool? Thanks.

Barry

[Jack Dahlgren]

I bought a well-used Micro Lathe (http://www.taigtools.com/mlathe.html) a few months ago and it's time for it to earn it's keep. I need to bore holes in some aluminum Graphic lens boards and if my little lathe can't do it--it may be headed to the bottom of the Potomac. :)

The chuck on the lathe is too small and unsuited to hold the boards, but I was thinking of a making a small wood jig--basically a square wood block that fits snugly within the lip of the lens board, attached to a wood cylinder that will fit into the chuck. Two screws and wood glue would be used to attach the cylinder to the block, and the board would be screwed to the block through a small center pilot hole.

Being that I have no lathe experience, I though I'd get some input before I tear off any of my appendages or put out an eye. Does my plan sound workable? Any better ideas? How about optimal speed and best cutting tool? Thanks.

Barry

I bet you could trade that lathe for a drill press and holesaw. I think that would be the better choice. Personally I use a jig saw and then a spindle sander to finish off the hole.

[onnect17]

Barry,
I also have a mini-lathe but I do not think is the best tool for it.
Check home depot. They have something called "General Tools Circle Cutter".
Also you will need a drill.
If you are interested I could post some pictures.
And please, keep the lathe for other tasks. :)
Regards,Armando

[Ron Stowell]

Barry
I have cut several of these lens boards and always used a hole saw and a drill press.
The fly cutter can be used for cutting holes to a size not covered by a hole saw, but also has some precautions that come with it. ie: very slow speed and keep your hands away from the moving cross shaft.

[Dave Hally]

Barry,
I have a Unimat Lathe, that converts to a mill, that would work with a cut-off bit in a fly cutter type holder.
I didn't have the lathe when I needed to drill a lens board though, so I used the method I describe in the Lens Mounting Service thread in Cameras & Camera Accessories- scribing the hole, drilling small holes around the circumfrence and breaking out the inside and filing it smooth. That worked very well.
PM me if you need more info.
Good Luck,
Dave

[GPS]

I use even a simpler method. I drill a series of holes around the inner edge of the hole, take a small fine file, connect the holes (if not touching themselves), take the inner surplus out and then file the bigger hole with a rounded file. With aluminum I easily get 0.1mm precision. Crude, quick and precise. (Sorry Dave, didn't see you post before writing mine...;-)

[domaz]

Try asking your question at CNCZone (http://www.cnczone.com/forums/). They also have an area where you can solicit work- it's often much cheaper than regular CNC rates from what I hear.

[Dave Hally]

I use even a simpler method. I drill a series of holes around the inner edge of the hole, take a small fine file, connect the holes (if not touching themselves), take the inner surplus out and then file the bigger hole with a rounded file. With aluminum I easily get 0.1mm precision. Crude, quick and precise. (Sorry Dave, didn't see you post before writing mine...;-)

Not a Problem, I'm surprised that more people didn't chime in with this method, in the three current threads about lensboards.
Dave

[c.d.ewen]

Barry:

You can get a lot more out of your camera equipment with some tools, but be aware that GAS attacks are not limited to photography.

The drill press + adjustable hole saw is the fastest/easiest method for drilling lensboards. It takes patience to adjust the cutter. Newbie hint: to avoid an unnecessary adrenaline rush, start at a slow speed; the cutter is not balanced.

If you want to try drilling on the lathe, GAS-up a faceplate and set of clamps from Little Machine Shop. (http://littlemachineshop.com/products/product_search.php?critFast=faceplate) Your spindle is 3/4-16. Same slow speed start warning applies.

PM me if you have machining questions.

Charley

[onnect17]

Barry,
I also have a mini-lathe but I do not think is the best tool for it.
Check home depot. They have something called "General Tools Circle Cutter".
Also you will need a drill.
If you are interested I could post some pictures.
And please, keep the lathe for other tasks. :)
Regards,Armando

Here's the cutter and the results:

47136

47137

[Jim C.]

You don't even need clamps if you're using a face plate,
I've cut large holes in 3/16 aluminum plate to make a
holder for some Mole focusing spot attachments using
some double stick tape and a live center on my lathe
as well as some Bush pressman lens boards.

I definitely was wincing when I started but after the first it was
a piece of cake. I found the double sick trick on the MIT site -

.http://techtv.mit.edu/collections/ehs-videos/videos/172-machine-shop-10

The double stick tape trick is towards the end of the video.

Friendly advice, get very well aquainted with your lathe before attempting
any real work to avoid injury.

[BarryS]

Thanks everyone for the great advice. I'll keep my eyes open for a deal on a drill press and may try the lathe in the meantime with the face plate + clamps/tape after I make sure I know what I'm doing.

[onnect17]

Barry,
If your board is made of aluminum I can drill it for you. Just send me a PM.

[Fotoguy20d]

Barry,

Like several other posters, I use a drill press and hole saw. You should have a Harbor Freight somewhere near you - I use one of their $50 drill presses and $3 hole saw kits. I also have a $5 adjustable cutter (someone showed a picture of one from home depot). Their tools aren't great - wear out quickly, and come drenched in oil (or they rust). And, the drill press table lock doesn't grab well unless you really crank it down. But, for things you don't do often, they get the job done just fine (pick up a couple of their clamps - probably $3 each) to hold the board to the press table with a piece of 2x6 in between.

I just picked up 3 of heavystar's undrilled boards - the undrilled ones are easier to work with because the hole saw pilot bit has something to grab onto and it'll walk less.

Dan

[domaz]

You don't necessiarly need a drill press. I use fixed size metal-cutting hole saws (about $14 per size at Lowes) and a AC-powered drill. That's probably the cheapest possible setup if you only need to drill the standard shutter sizes.

[Ernest Purdum]

Going back to your original idea, as long as your jig holds the lensboard securely, and square to your spindle, you have a good setup for cutting your hole, certainly vastly more accurate than most other methods. I have used both flycutters in a drillpress and hole cutters. The flycutters want to dig in. The hole cutters are a little nicer to work with, but then you are limited to available sizes. Using a lathe, you can feed in much more smoothly and precisely than is possible with a drill press.

The tool bit you want is a "boring" tool. You could grind your own, but they are available all ready for use. These days many are carbide tipped, but either carbide or high speed steel is fine for your use.

[BarryS]

Ok, just as I was thinking I could make a good jig (or buy a plate and clamps) and use a live center and some double stick tape to hold them--I found the Graphic lens boards are too big for the Micro Lathe. After some research on using lathes, I think it would have been fine, but my lathe is too damn small! :) I may take Armando up on his generous offer until I can find a drill press. In the meantime, I'll buy a few tools for the lathe (thanks Ernest) and try to figure something I can make.

[Scott Davis]

Barry-

I've mentioned this before to you - I have a drill press and a variable-diameter wheel cutter. Let me know when you want to drill these lensboards and I can hook you up.

[BarryS]

Thanks Scott--I'd forgotten about that. I also have some Deardorff boards that need drilling, so maybe we can find a day to do those.

[Neal Chaves]

My drill press is still set up from a few days ago when I cut out some Graphic boards to #3 Copal.

I always make a jig to hold the board as shown in the photo. Cut a piece of plywood the width of the lens board (these are not square), then make cross cuts at the other dimension. Round off the corners and hold down the board with 1/4" wood screws and fender washers. Find the exact center after the board is mounted in the jig for the first time.

I finish off the hole with the sanding wheel at right.

[Tracy Storer]

My drill press is still set up from a few days ago when I cut out some Graphic boards to #3 Copal.

I always make a jig to hold the board as shown in the photo. Cut a piece of plywood the width of the lens board (these are not square), then make cross cuts at the other dimension. Round off the corners and hold down the board with 1/4" wood screws and fender washers. Find the exact center after the board is mounted in the jig for the first time.

I finish off the hole with the sanding wheel at right.

Nice simple jig Neal ! DIY'ers take note. (and make sure you clamp the jig down once it's centered, it looks like Neal used Stove Bolts to do this, which is fine, I only mention it because it may not be obvious to some that it is clamped)

[Jim Andrada]

I bore mine on a wood lathe. I chuck the hole cutter in the tailstock so it doesn't rotate (and it doesn't matter that it's not balanced)

I have a Coleman clamp faceplate that one uses for bowl turning - it has a bunch of soft fingers that tighten down on the lens board, then I just advance the tailstock and I'm done.

For my off-center Linhof boards I made a wooden plate with four small pieces of wood holding the lens board a few mm off-center. Also works fine. Takes at most 3 minutes or so.

[Pierre 2]

Really appreciate all methods listed here but, for the sake of completeness, I believe that a bigger lathe probably remains the easiest AND most precise tool to use, that is, If your floor will support 1700 lbs (and up) and, that you are careful enough not to let it grab a piece of your clothing, followed by whatever is associated with it... Short sleeves rule.

[Tin Can]

I have done many with hole saws and a hand held 1/2" Drill motor. BUT I CLAMP IT ALL DOWN REAL GOOD! Real good! And have a second handle on the drill motor as hole saws can grab and twist the drill right out of your hands.

I finally bought a small drill press, much easier in all ways. My hands thanked me.

[AtlantaTerry]

"I have done many with hole saws and a hand held 1/2" Drill motor."

Which standard hole saws are needed to drill Copal holes?

[Tin Can]

"I have done many with hole saws and a hand held 1/2" Drill motor."

Which standard hole saws are needed to drill Copal holes?

The short answer is, all that data is extant.

I rarely bore Copal sizes as they are easily available.

I use Technika, Horseman boards for Copal. Then DIY adaptors to most of my LF cameras.

I also bore those boards and homemade up to 9X9" plywood boards for a variety of odd sized barrel lens flanges, usually not rings.

Since a barrel flange screw mounting surface allows a 'fudge' factor, one can center a lens easily in a slightly too large or off center hole.

Even off center holes are not so bad if used like a Technika board for a good reason. Turn the board and achieve shift, rise, fall.

I also bored large holes in my walls for camera obscura lens usage. Not toward the neighbors, but the busy street.

[Roger Thoms]

"I have done many with hole saws and a hand held 1/2" Drill motor."

Which standard hole saws are needed to drill Copal holes?

Terry, most if not all of my hole saws are stamped with both metric and fractional inches. Just choose the one which closest, preferably erring the small side. Then use a half round file to fine tune it. When in doubt bore a test hole in a piece of scrap and test the fit.

The chart in this link should be helpful. http://www.lenoxtools.com/pages/bi-metal-speed-slot-hole-saws.aspx

Roger

[Tin Can]

Most copal shutters require a relief/rebate surrounding the hole, as the threaded mounting ring for the shutter rear has a limited thickness range. Not all, some.

Either the lens board must be that thin or a relief diameter on the back is necessary.

Sometimes it's all simple, sometimes it's not.

[Henrim]

I have a drill press, a lathe and a mill with a rotary table but i prefer to use a jewellers saw for cutting the lens board holes. Less time, less hassle but more than decent result. I just mark the center and draw a circle with a compass then drill a pilot hole and cut the hole with the saw, just inside the line. Finish up with a fine toothed file. Granted it takes some practice to master the saw but then again so does the macninery. Although I would set up the mill and the rotary table if I needed to do a few boards at the same time. If I needed to do ten or more then I would use the lathe :)