MadModder
Gallery, Projects and General => How do I?? => Topic started by: rvt on March 28, 2010, 06:45:44 AM
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Hi
Are there any UK members on here with machining experience who could possibly help me out?
I specialise in converting old film lenses to digital cameras. It's very low demand and I do them all by hand. However, I'd like to make a kit of sorts to sell instead, to improve turn over time and labour time.
I am based in Shropshire and need assistance of a home shop with a lathe to machine 4-5mm (roughly) off a camera lens adapter, as it is to thick. Not being a machinist myself, I am told it could be faced off in the lathe, the outside diameter (one example, they vary slightly) is (62 mm) and is (49 mm) inside and they are generally made out of quite soft metals, often brass. The adapter, excluding the mounting ring, is 10mm thick. There is also drilling (1.5mm bit) of 4-8 holes, which need to be countersinked as well, I can do that myself but if it could be done at the same time that would be great. I looked into getting a metal lathe, but they are too costly at this time, as I really don't make much money off this.
(http://www.warehouseexpress.com/webcontent/product_images/large/127/1009853.jpg)
Does anyone know somewhere i can get this done or could anyone here possibly help?
Thanks for your time.
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It sounds simple enough, do you need any threading done on this part :scratch:
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It sounds simple enough, do you need any threading done on this part :scratch:
Hi Darren,
Yep, it is pretty simple I think, I just don't have the tools :-). No threading needed. It's basically just shaving a chunk of the bottom (hope I didn't confuse you with my technical knowledge there ;-) )
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OK, I'm pretty sure just about anyone here could help you out with that ... Hopefully someone close to you will pipe up. :thumbup:
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Thanks Darren, that's good to know. To be honest, they don't have to be in Shropshire, I have no problem with sending parts in the post.
When I do the conversions by hand I use a much thinner adapter piece, in combination with other parts that already inside the lens. So as I've never done it this way before I'm not 100% sure of the exact thickness it would need to be, but that would be worked out and once one is done it would be easy to use that as a 'model'.
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Drop me a line.
john [at] stevenson-engineers.co.uk.
John S.
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Drop me a line.
john [at] stevenson-engineers.co.uk.
John S.
Hi John,
Message sent.
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I should also say that I'm not ruling out the possibility of buying a lathe myself yet, or finding a friend/family member who has one. Mini lathes seem to start at around £350 new. That's a lot of money to me, as I don't make a lot per lens conversion and it's low demand. So I'm still trying to weight things up, that's all i wanted to say...
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Just thought of a significant issue :(
The actual adapters I'll use will have a pcb chip in them so the camera knows what is mounted, like this:
(http://www.rocksphoto.com/web_data/product_img/7e383b0e89b13145025e0d12c79662ea.jpg)
However, that chip 'sticks out' into the inner diameter of the adapter. The opposite end of what needs to be ground off. So it would surely be in the way of the chuck? You can't put any pressure on the chip or it will break, it's very delicate.
Anyone think of a way around this?
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An adapter can be secured in the chuck with the ring mounted to that.
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The chip should not present any problems with mounting :thumbup:
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Ah, thanks! I didn't look at the picture carefully enough. I now see that a three jaw chuck would fit in fine :)
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I presume this needs to be machined very true/square, that would suggest a dedicated holder or at least soft jaws on a three jaw chuck.
I would consider one of these, esp if you had a few to do. For that matter if my turret lathe was set up I suppose many could be done in an hour.
http://cgi.ebay.co.uk/5C-Step-Collet-Style-123-to-Suit-Boxford-Lathe-3_W0QQitemZ290418771864QQcmdZViewItemQQptZUK_Home_Garden_PowerTools_SM?hash=item439e4ec798
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I have done a few little jobs like that, adapting old lenses, telescope, etc to my camera. (No chips though, I am a "Pentaxian" :med:)
The method I used was to buy to an old camera and adapt the camera body flange to fit a piece I could hold in the lathe then when I need to machine an adapter in any way it is firmly held by the camera body flange and is easy to remove.
I found when trying to hold in the 3 jaw that there is a fine line between too little force which causes slippage and severe cosmetic damage and too much force which produced a tri-cornered adapter!
Another thing you could use would be an unwanted macro tube which you could maybe fill with resin to get something solid the chuck would not distort.
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Some nice ideas there John, :clap:
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Darren, thank you. The one I'm looking at buying comes with a soft jaw chuck of sorts, but if it's not appropriate I will order that one. Things do have to be aligned perfectly, yep. WIll getting it centered/flat be an major problem? (again, excuse my ignorance I know nothing about lathes...)
John, thank you! I had never thought of that. An extension tube might just be the trick! If I can attach the adapters securely to one, it will mean I won't have to physically mount the adapter on the chuck. Hope you're enjoying your Pentax ;). My friend just switched to a K7 and a couple of limited lenses... must admit, they look like wonderful tools.
I will keep the 3 jar chuck in mind regarding potential damage. A soft jaw chuck of sorts looks like the best option. Don't have an extension tube with me for the required mounts, so can't say about the build or thickness of the metal... I'm hopeful it will hold it's shape well enough w/o resin though (as it will be perfectly circular on the chuck-mounting side, so I could hopefully use a circular chuck or one with more jaws... which i assume makes distorting the metal less likely)
Thank you everyone! You're a very friendly and helpful bunch, glad I (eventually) found this site! Alas, I can't share any experience myself for others, but if anyone every wants some photo-related tips or a canvas print you know where to come :D
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Alas, I can't share any experience myself for others
Don't worry about that. I joined here a few months back, with almost zilch machining experience. And now look at how they're egging me on....
As far as I can tell, there's two important things to remember about this forum:
1) Everyone & anyone with any kind of interest in machining is welcome, no matter what their level of experience as a machinist, and
2) :worthless:
You'll have the second one covered easily, I'm sure... and if you do buy a lathe & maybe a small milling machine (or even a big second hand one!), you'll find lots of stuff you can make. And, of course, share...
Just remember: :proj: is a pernicious and very contagious disease....