Cutting holes in lensboards

Jim Jones said:

You have an even better reason to buy a metal lathe.

Click to expand...

You men like this one ? : ( I don't like cutting wood on it - too messy with sawdust sticking to the oil and grease)

If you mount your grinder on the cross slide, you can also do external cylindrical grinding.

I have yet to do wood work that creates hot chips that burn one's hands.

Never broke a drill bit in wood either.

I guess I know my limits...aluminum and 2 drill bits

richard ide said:

"All right !! I finally have a reason buy a wood lathe - not a "great" reason, but it's a start"

I didn't know one needed a reason to acquire a wood lathe.

Click to expand...

Exactly and your wife will never complain when you hand over a freshly turned walnut bowl. Of course she may not be keen on the ever growing piles of wood all over the place.....

Murray@uptowngallery said:

I have yet to do wood work that creates hot chips that burn one's hands.

Never broke a drill bit in wood either.

I guess I know my limits...aluminum and 2 drill bits

Click to expand...

Murray, that's one of the reasons why I use a hand-powered drill. No broken drill bits, and very little heat. It takes longer to make a hole, but I'm not in a hurry!

I'll second the suggestion for using a Forstner bit. Ones with stepped shanks can be used in portable drills and they can also be used in hand powered braces. For the 1/8 or 1/4 inch depth of most boards, drilling by hand isn't much problem.
I even used one to cut the hole in an aluminum board, though for that I mounted the board and bit on my woodworking lathe and lubricated it liberally. (getting the lens mounted, and thus the hole drilled, was worth more to me than the value of the bit).
barry

athanasius80 said:

So I've realized I have too many LF lenses I've not shot yet. I can make acceptable lensboards with local hardware store lumber, but does anyone have a good trick for cutting the holes in the center.

Click to expand...

It may be overkill for a wooden lens board, but I vote for a turning lathe!

I have no wife, therefore I use my metal lathe. I also do not have to ask permission.

I find it easiest to mount the board (after making it from three pieces of fine hardwood glued together with a close fitting tongue and groove joint of course instead of using PLYWOOD!!) into the four jaw chuck. Then using a .0005 test indicator, get the board centered within about .003 inch. Then use a forstner bit up to 3 inches in diameter depending upon the size of the shutter being mounted in the tailstock to rough the hole to size. Then bore with a very sharp high speed steel boring bar to a very precise slip fit on the retention ring. I think that is the correct way, at least that is how I have done it for the last ten years. If someone knows a way to do the job more precisely or better, plese email me.

Jim Jones looks amazingly similar to Donald Qualls

Thank you.

I find using hardboard(same stuff peg boards are made of, minus all the holes) works really well. Its available in several thicknesses, and one is the same thickness as several of my lensboards, and when cut to their liking fits perfectly light-tight onto my LF camera. One drawback is cuts into it are somewhat rough, like cutting cardboard where it shreds a little. Hasn't bothered me and keeps light out, which is all that matters.

Jim Jones ~ Donald Qualls.

I wonder if it's the Ansel Adams beard thing...

there's a guy at work who does LF and he looks like them too.

But there are two other guys who do LF that do not...not a sound theory.

What kind of bit is good for drilling through a metal board?

I have found it to be easily and quickly done on my old Southbend 10 inch lathe using the four jaw chuck. Reversing the chuck jaws take up more time than actually cutting the hole. I have found that a simple straight line drawn from corner to corner forming an X in the center of the board or alumninum blank is plenty accurate for mounting a lens to the board. I have also had good success using my bench mill and a standard flycutter. It is more difficult for me to set up than the lathe, so I prefer the lathe. I have also cut the hole with a coping saw, works, but slow and tireing.



Charlie....................................

kjsphoto said:

What kind of bit is good for drilling through a metal board?

Click to expand...

Assuming you don't have a metal working machine shop, for aluminum, a bi-metal hole saw would work. You would want to use it in drill press, or a lathe however.
I used a Forstner bit which is actually meant for wood with the board mounted in a 4 jaw chuck on a woodworking lathe. Using the bit on aluminum meant that the bit was more or less toast afterward. It's not something I'd recommend unless you have a lathe so that you can carefully control the feed rate, and rotation speed (SLOW!!!) and provide almost continuous lubrication during the cutting. I used it because I happened to have one on hand that was exactly the right size, and I didn't have to make a trip to the hardware store, or a machinist.

Twist drills large enough for a lens hole are quite expensive, say $30 U.S. and up, and probably more like $60+. For that sort of money, you can take it to a machinist and get it done "right". Asian forstners are around $10.00 and hole saws are about the same.
None of these methods gets you the accuracy that Barry Young was speaking of, but if you are careful you can get somewhat close.
I know many won't agree, but IMHO unless the coverage of the lens you are mounting is very close to the film diagonal, it won't matter very much of the hole is a few thousandths off center on a view camera. However, the size of the hole mating correctly with the mounting ring and lens is important, and it may be difficult to get a bit, hole saw or whatever which is just the right size (I was lucky), which is why an adjustable cutter or a boring bar is preferable, but those are more specialized tools than the ones I'm speaking of, and in the case of the boring bar, requires a metal working lathe. It might be a good excuse to get more tools though.

Barry Dial

Murray@uptowngallery said:

Jim Jones ~ Donald Qualls.

I wonder if it's the Ansel Adams beard thing...

there's a guy at work who does LF and he looks like them too.

But there are two other guys who do LF that do not...not a sound theory.

Click to expand...

Murray! You left me out! I've been bearded since 1970 and cut it only when my jacket zipper catches it. Thinking about buttons...

Whitey!

I left you out 'cuz your avatar looks more like Santa than Ansel. Good luck this weekend...hope you have good weather for flying!

I assume that's buttons on clothes, not like beads braided into the beard...

I haven't tried Forstners on aluminum yet. Apparently alcohol is a good aid for drilling aluminum...it doesn't seem like a lubricant, but maybe that's not what the purpose is.

With both the flycutter and ?bimetal? holesaw using a pilot bit, I like to start on one side, go partway in, then flip over and work on the other side. Seems to prevent ungraceful tearthrus and I seem to have fewer unexpected results.
Happy Holidays all

I like Ole's ancient hand drill method.

It has TWO levels of safety factor...the slow speed and the requirement to mount it because the drill requires two hands, thus you don't have it turn into your flesh if the bit grabs.

Now I am assuming one safely mounts the board to a safe work surface and doesn't hold it between ones knees!

If I didn't mention it previously, I measure the desired diameter with a digital caliper, visually set the flycutter bit to the caliper spacing, make a test drill partway thru a scrap piece of target lensboard material and recheck the measurement/adjust as desired.

This also gives me a preview of any blade cutting clearance (is that called kerf like wit a table saw blade?)...in other words, it reduces the number of surprises and vocal outbursts.

I mount the lensboard in a four jaw chuck in the metal lathe. Next cut a hole just under what you need with a hole saw. Finally finish with a boring bar. This is the correct way to do the job.