View Full Version : Need Holes Drilled for Lens Flange
Hey all,
I bought a Commercial Ektar lens some months ago, ordered a properly bored lensboard from China to fit my Tachihara, but I'm having the darndest time finding somewhere locally to drill holes for the flange screws.
I took the screws to Home Depot to discover that they're #2 machine screws, though I couldn't determine the thread spacing. I can't justify sending everything to SK Grimes to have them drill me 5 holes for $65+s/h. I only have to make threaded holes in a thin Linhof board so I was thinking I might be able to do it myself with self-tapping screws.
The only problem is, I don't know what to search for to find #2 self-tapping machine screws. I don't mind buying a couple different thread sizes to try them in the flange to see if they'll work. Any info would be greatly appreciated!
Are you sure they're #2? Those are only 0.086" diameter... quite tiny.
#2 machine screws would be either #2-56 or #2-64. Those are the only standard sizes.
You can see what self-tapping screws are available at McMaster-Carr Supply at http://www.mcmaster.com
Click on the Screws and Bolts icon at upper left, then
on Tapping, Wood, and Drywall Screws on the 2nd line.
- Leigh
60 Pc SAE & Metric Tap and Die Set from Harbor Freight runs you under $40.00. Have tapped probably 100 holes in metal and plastic and have yet to break a tap. Of course I am very careful and work slowly (I realize that this Tap and Die Set would never hold up under commercial applications).
For screws I go to my local ACE Hardware store. They determine the thread spacing for me for free.
I wouldn't go the route of self tapping screws. I've had them fail going through thin metal, whereas never had a bolt screwed into a threaded hole fail. Now I back up the the bolt with a nut on the inside of the lens board.
Thanks, Leigh! I'm looking it over now. This is how I determined the size.
https://uploads.tapatalk-cdn.com/20170413/c8ba95e8c5378cc2b8f367336bcbb285.jpg
https://uploads.tapatalk-cdn.com/20170413/a51c9f2770508fce37c319c53a2a456a.jpg
Sent from my iPhone using Tapatalk
Thanks, Leigh! I'm looking it over now. This is how I determined the size.
Those gauges are reasonably accurate, more so for larger screws.
- Leigh
Now I back up the the bolt with a nut on the inside of the lens board.
Do you think making an unthreaded hole backed up with a nut might work? Perhaps with some thread locker on it to keep it secure?
Sent from my iPhone using Tapatalk
Alan Gales
13-Apr-2017, 16:05
You could just drill your own holes and then use bolts.
If you really want the holes tapped for screws you might check out your local machine shop. They may do it for you for a nominal fee. I don't know but it won't hurt to check.
You could just drill your own holes and then use bolts.
If you really want the holes tapped for screws you might check out your local machine shop. They may do it for you for a nominal fee. I don't know but it won't hurt to check.
Definitely considering it. I've contacted 4 shops. 2 of them don't have the right bit and 2 didn't respond unfortunately.
Sent from my iPhone using Tapatalk
Jac@stafford.net
13-Apr-2017, 16:11
What a simple issue. Go to Ace Hardware (if you have one). They have every screw you could want. Choose the correct one by fitting it into the flange holes. Then choose a matching nut. Drill the lens board with the appropriate drill or one slightly larger. Be happy.
You do not need holes to be tapped. It's a waste of effort.
.
Alan Gales
13-Apr-2017, 16:16
Definitely considering it. I've contacted 4 shops. 2 of them don't have the right bit and 2 didn't respond unfortunately.
Sent from my iPhone using Tapatalk
I mailed the flange for my 14" Commercial Ektar to Bruce Wehman so he could mount it to a new Wehman board. I took a pencil and marked the flange at top dead center. I then taped it to a card and marked TDC above my pencil mark so Bruce could easily see it. Bruce did a great job for me. My lens mounts to my camera exactly as I wanted it to.
Don't forget to mark your flange the way you want it if someone else is doing the job.
Good luck to you!
el french
13-Apr-2017, 16:28
A #50 drill bit and a 2-56 tap will set you back between $5 and $10. It's not a difficult task to tap 2-56 threads. Practice on a piece of scrap metal first.
http://www.shender4.com/thread_chart.htm
Keith Pitman
13-Apr-2017, 17:00
Where are you? If you were in the Denver area, I would do it for you. Otherwise someone else here might make the same offer.
A #50 drill bit and a 2-56 tap will set you back between $5 and $10. It's not a difficult task to tap 2-56 threads. Practice on a piece of scrap metal first.
http://www.shender4.com/thread_chart.htm
This is great! Thank you!
Where are you? If you were in the Denver area, I would do it for you. Otherwise someone else here might make the same offer.
Thanks, Keith! Unfortunately, I'm in Los Angeles. But hopefully another generous soul may make that offer. Regards.
The meaning of "nominal charge" varies quite a bit.
Its meaning for a photographer is very different from its meaning to a machinist.
I have a commercial machine shop.
My lowest rate, for really simple stuff, is $100/hour with a 1 hour minimum.
At that rate I'm just breaking even, not making any profit.
- Leigh
You can back the screws with nuts IF the bolt circle on the flange (with rear nuts) is smaller than the FS inner opening diameter, or a no/go, because it will not fit inside the FS...
Tapping such a thin board is tricky, as the tap must not wiggle it's angle while tapping, or it can damage the newly cut threads... Then you will have to cut the 2-56 screws so they will screw flush on the rear (and not interfere with the light trap on rear)...
Also, Linhof boards hole height is staggered, so you will have to see where the flange/lens will fit, but you can use the front rise to center the lens on the axis... And make sure the lens/shutter will fit on front of camera and operate the controls clearly...
Worst case, you can epoxy the flange to the board... Done well, it will NOT come off...
Steve K
Nodda Duma
13-Apr-2017, 19:50
Take this is an opportunity to learn to tap threads.
Learn now and you'll save your future self a ton of money, not to mention the self-confidence boost you'll get from DIY! :)
Just google how to tap threads, read a bunch, and then give it a go on some scrap.
Take this is an opportunity to learn to tap threads.
Learn now and you'll save your future self a ton of money, not to mention the self-confidence boost you'll get from DIY! :)
Just google how to tap threads, read a bunch, and then give it a go on some scrap.
I agree, but this really should be done on a drill press or mill, so the drill is perpendicular to the surface (with no run-out), and the tap has to be started at least in the chuck with such small threaded holes, so there are tools and processes involved...
But DIY is very empowering, and can solve many detail issues!!!
Steve K
Duolab123
13-Apr-2017, 20:28
What a simple issue. Go to Ace Hardware (if you have one). They have every screw you could want. Choose the correct one by fitting it into the flange holes. Then choose a matching nut. Drill the lens board with the appropriate drill or one slightly larger. Be happy.
You do not need holes to be tapped. It's a waste of effort.
.
Absolutely agree. I go to a local Ace Hardware. Twice in the last month I mounted flanges onto Zone VI aluminum enlarger boards. Nice older fellow helped me. He had to use SS #2 machine screws, I got some teeny weenie lock washers and SS nuts as well. Brass would have been my first choice but they stopped at #4. If the flange has nice counter sunk holes get flat or oval head. If it's just a hole get a pan head machine screw. Tapping aluminum boards can be vexing. I love the work from SK Grimes, it would be perfect and threaded etc. If cheap and easy is what you seek, just find a nice guy at a hardware store.
Mike
The trick to tapping is to keep the tap absolutely perpendicular to the material being tapped.
If the tap skews off at any angle, it will break.
The simple way to accomplish this is to use a supported tap handle.
These have an axle sticking out the top and a hollow sleeve in which it rotates.
The sleeve is held in a chuck in a drill press, supporting the tap.
Here's one that's commercially available: http://www.atwaterkent.info/Images/img_tap%20handle%20lg_DS8_1823t.png
Here's the product page at McMaster-Carr: https://www.mcmaster.com/#2550a64/=176sab5
And here's one that was made in a shop: http://www.atwaterkent.info/Images/Img_tap%20handle%20sm_DS8_1824t.png
To use these, you first clamp the work on the drill press table, properly positioned.
Then you drill the pilot hole for the tap.
Then without moving the work you raise the quill and grip the guide in the chuck.
Install the tap and holder, and tap the hole.
- Leigh
Nodda Duma
14-Apr-2017, 05:59
I've only ever tapped by hand. Use speed taps. By design they tend to self-align with the pre-drilled hole.
What's a speed tap? Pictures and catalog reference please.
- Leigh
jim10219
14-Apr-2017, 07:02
https://www.speedtaps.com/
It's just a brand of taps that is specialized for impact wrenches.
Jac@stafford.net
14-Apr-2017, 07:06
What's a speed tap? Pictures and catalog reference please.
They might be good for very large work, but just scare me for the delicate sizes we use in camera fabrication.
https://www.speedtaps.com/
It's just a brand of taps that is specialized for impact wrenches.
The smallest thread available is 1/4"-20.
We're talking about tapping #2-56 threads.
That's a very big difference.
And those speedtaps are designed for use with an impact wrench, not hand-driven.
- Leigh
Nodda Duma
14-Apr-2017, 08:05
Erg.. I should have said high speed gun taps. Always said speed tap for short
Don't get distracted by some company's variation of the basic principle.
The key feature of high speed gun taps are the tapered starting threads and flute design which help self-center in a pre-tapped hole. Historically there were used in milling machines and drill presses. Now they are used in CNC mills for high speed tapping. But every machinist I know uses them to tap by hand as well because of how they work. Hand taps are similar but I prefer these.
Surely I'm not the only person here who has spent time in a machine shop?
https://jet.com/product/detail/5a63ba284a204bfc8eee934eaf1e9680?jcmp=pla:ggl:NJ_dur_Gen_Tools__Home_Improvement_a3:Tools__Home_Improvement_Power__Hand_Tools_Taps__Dies_a3:na:PLA_784744692_42602135033_pla-293429972383:na:na:na:2&code=PLA15
Surely I'm not the only person here who has spent time in a machine shop?
I'm a journeyman Tool & Die Maker. I've owned a commercial machine shop for over 30 years.
- Leigh
Nodda Duma
14-Apr-2017, 09:17
Ah, excellent! I yield to your greater experience.
I'm an optical designer who has been around machine shops for 10-15 years in support of that work (think prototype lens barrels and other small parts), and was trained by a Navy machinist with >30 years' experience.
Alan Gales
14-Apr-2017, 10:31
The meaning of "nominal charge" varies quite a bit.
Its meaning for a photographer is very different from its meaning to a machinist.
I have a commercial machine shop.
My lowest rate, for really simple stuff, is $100/hour with a 1 hour minimum.
At that rate I'm just breaking even, not making any profit.
- Leigh
Thanks, Leigh. That sure puts it in perspective.
BrianShaw
14-Apr-2017, 13:50
Why not use the flange as a retaining ring from behind? Sure beats all of the effort to drill, tap and hope its all aligned. That how my CE was mounted to a Cambo board and it works just fine.
BTW, punker... that was the solution implemented by Steve's Camera Repair in Culver City.
Colin Graham
14-Apr-2017, 14:09
Why not use the flange as a retaining ring from behind? Sure beats all of the effort to drill, tap and hope its all aligned. That how my CE was mounted to a Cambo board and it works just fine.
This does work sometimes, but some shutters just don't have enough mounting thread to reach through thick lensboards and engage the flange on the other side, and some flanges have a raised bearing surface that's needed to allow clearance for aperture rotation. Also the rear element on some lenses won't screw all the way back in when the flange is mounted behind the board.
Why not use the flange as a retaining ring from behind? Sure beats all of the effort to drill, tap and hope its all aligned. That how my CE was mounted to a Cambo board and it works just fine.
Wow that never even crossed my mind! I'll give it a shot and see if it fits like that.
Sent from my iPhone using Tapatalk
A gun tap is also called a spiral point tap. It is not intended to adjust itself more perpendicular to the object than an ordinary tap. The advantage of the spiral point is to push out the cut material ahead of the tap. It works best on an open hole through a thin piece of metal, just like a lens board. It tends to survive longer because the cuttings don't jam it as much as ordinary taps do.
Best wishes --- Allen
A gun tap is also called a spiral point tap. It is not intended to adjust itself more perpendicular to the object than an ordinary tap. The advantage of the spiral point is to push out the cut material ahead of the tap. It works best on an open hole through a thin piece of metal, just like a lens board. It tends to survive longer because the cuttings don't jam it as much as ordinary taps do.
Correct a mundo.
- Leigh
goamules
14-Apr-2017, 18:36
This sort of question always amazes me. I can't believe the knowledge of drilling a hole and attaching two parts by a machine screw and nut is that complicated today. Tapping a metal hole for this job is way overkill.
Tapping a metal hole for this job is way overkill.
Not necessarily.
I've encountered many situations where the hole was too close to an obstruction to allow proper fitting of a nut, or where there was no way to place the nut from the rear, or to hold it while tightening.
- Leigh
BrianShaw's simple idea seems to work like a charm. I took the flange off the original board and screwed it into the back of the new board. Haven't tested for light leaks yet but I don't expect any. I still might go to ACE and look into having the screws properly tapped etc. But this may just work. I also had a generous offer from a forum member to drill them for me as well.
Thanks, all!
https://uploads.tapatalk-cdn.com/20170415/36d37367cdb57b1d5ece4158a8f82d74.jpg
https://uploads.tapatalk-cdn.com/20170415/7dad9f05600c6160391a3d256252490d.jpg
Sent from my iPhone using Tapatalk
goamules
15-Apr-2017, 05:46
Not necessarily.
I've encountered many situations where the hole was too close to an obstruction to allow proper fitting of a nut, or where there was no way to place the nut from the rear, or to hold it while tightening.
- Leigh
I say again: Tapping a hole for this job is way overkill....
BrianShaw
15-Apr-2017, 06:20
Yay... good for you! Now you can shoot some pics instead of discussing machine shop techniques on the internet! I'd like to take credit but not only did I see a pro mount that lens that way, but I also verified that in the old Kodak literature that someone here kindly made available at one time in the past. The CE is my favorite lens; enjoy!
B.S.Kumar
15-Apr-2017, 08:42
One more thing you might want to do: The flange-now retaining ring is a bright chrome. Put some matte black paint on it.
Kumar
One more thing you might want to do: The flange-now retaining ring is a bright chrome. Put some matte black paint on it.
Kumar
Good looking out. Will do!
Sent from my iPhone using Tapatalk
BrianShaw
15-Apr-2017, 09:57
Good idea but as a piece of additional info: I have not and haven't (yet) had any reflections.... or any other detrimental imaging effects.
B.S.Kumar
15-Apr-2017, 16:09
Maybe no reflections, but perhaps there might be some loss of contrast?
Maybe no reflections, but perhaps there might be some loss of contrast?
If you shoot into a VERY bright white overall area, you can sometimes see a round flare on film from internal reflections, reflecting from film to ring...
Steve K
Duolab123
16-Apr-2017, 18:38
BrianShaw's simple idea seems to work like a charm. I took the flange off the original board and screwed it into the back of the new board. Haven't tested for light leaks yet but I don't expect any. I still might go to ACE and look into having the screws properly tapped etc. But this may just work. I also had a generous offer from a forum member to drill them for me as well.
Thanks, all!
https://uploads.tapatalk-cdn.com/20170415/36d37367cdb57b1d5ece4158a8f82d74.jpg
https://uploads.tapatalk-cdn.com/20170415/7dad9f05600c6160391a3d256252490d.jpg
Sent from my iPhone using Tapatalk
You are set, if it slips put a piece of good tape on the ring and board. If it works leave it. Then you still have a virgin board.
Looks good, Mike
Thanks, everyone! Finally got to use this lens on a camping trip this weekend.
https://c1.staticflickr.com/5/4168/34093278472_5061506e99.jpg (https://flic.kr/p/TWGXU5)
Sherwyn (https://flic.kr/p/TWGXU5) by Blurmageddon (https://www.flickr.com/photos/analoguefilm/), on Flickr
https://c1.staticflickr.com/5/4163/34093277792_ce0a04a4cc.jpg (https://flic.kr/p/TWGXGm)
Erik (https://flic.kr/p/TWGXGm) by Blurmageddon (https://www.flickr.com/photos/analoguefilm/), on Flickr
Duolab123
25-Apr-2017, 18:53
Very good work. People that shoot digital won't get pictures like that. Looks like you are set
Mike
Jim Noel
27-Apr-2017, 19:57
Do you think making an unthreaded hole backed up with a nut might work? Perhaps with some thread locker on it to keep it secure?
I have mounted ass many rings with bolt & nut as with bot and threaded hole.It is fast and secure. If concerned, add Loctite to the bolt threads before putting on the nut.
Sent from my iPhone using Tapatalk
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions Inc. All rights reserved.