There is a scissors type knurling tool. This type tool squeezes the part between two knurls. It places very little load on the machine. Your 7x10 mini lathes can handle knurling just fine with one of these gizmos.
So, how did they do it before CNC?
There were several posts in this thread regarding how challenging it is to make duplicate parts using conventional (non CNC) machines. Not at all true. It just takes skill in machining instead of skill in programming. It is fairly simple when you know how and have the correct equipment. Take a knurled knob for instance. chuck an oversize bar in the three jaw with enough hanging out to make a part. Place your right hand turning tool against the end and use a travel indicator with a magnetic back placed on the ways. This is your zero and it will repeat within .0005 every single time. Face the bar and note the indicator reading. Turn the O.D. Note the reading on the crossfeed hand wheel and use that number on all of the parts. Every one will be the same. Turn the hub noting the handwheel number and the dial indicator number. All the hubs will be the same now. Knurl the OD until the diamonds shape up and you are done turning. Another number for the parting tool (It is mounted in a back toolpost right?) and they will all be exactly the same length. Do the same thing when you reverse the run of knobs to face the other end. Simple, yes? Trust me, many subhuman working machine operators (not machinists) are living proof that this aint rocket science. If some of the guys I have worked with over the years can do it, any of you can too.
A 7X10 minilathe is capable of doing all of the machining you will EVER need to do including milling slots with a milling attachment you can make on the lathe itself. Harbor Freight currently has their minilathe available for $440, add to that $50 for a four jaw chuck (it comes with a 3 jaw which if you had to choose, you would want the four jaw not the three), $14 for a faceplate and maybe you would want the follower rest for $19. So yes they are expensive to get initially, but you could pay for one really quick making knobs for camera builders. The 9X20 from Grizzly comes with everything and it is $750. It is way more than twice as much lathe too. You can do real serious work on it. I know what you are thinking, "that is the price of a Super Angulon on Ebay". True. Only you can decide. My lathe has paid me back more than 30 times what it cost me so far and it will last me the rest of my lifetime and my kids lifetimes too. I wish I could say the same for any camera lens.
If anyone has any machining questions, I would be more than happy to answer them.
Thanks for the explaination, Barry. Now we have to schedule time for you to show how in person and we can make lots of knobs for our cameras.
The soul never thinks without an image.
What he said!
Originally Posted by magic823
while not part of the current topic, but related to the thread...have a question for you guys. Does anyone have a source for the GG springs that hold the GG on the frame? Have an older Korona that is begging for a new GG from SatinSnow, but hate to remove the petrified tape that is holding one side of the GG on the frame.
Thanks in advance for any input...had been following a source on ebay, someone was selling a set of 4 for a Dorff, but have not seen these in a while.
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
maybe the GG springs photomc needs must be exact, but I had been considering whether picture framing spring clips for aluminum frames could be used for back springs. They're dirt cheap.
Machining question: How hard is threading things with weird camera threads, like retaining nuts for shutters, etc. I have another weird one, a lens with 95 mm thread but coarse pitch, so available accessories only go on one thread...it's visibly different. (Custom lens so not gonna find another source probably).
I finished my 5x7 and will post some pictures as soon as I figure out how. I used stainless steel so I was able to find useable parts at Mcmaster. There is an online machine shop where you download drawing software, draw your parts and send them in and get a quote. I don't remember the site name though. I had my parts made by a retired tool and die maker. One more thing if you think you are going to save money making your own camera I think you are mistaken. I spent a lot of time doing drawings and making parts and I didn't get everything right.
Some of the genius of Canham was to see what was possible from CNC shops, and design his camera around it. The end of the line for Deardorff was effectively when the vendors that supplied it no longer worked with 1920 technology. In the case of replacing worn metal parts on a Deardorff, the cost is heart-stoppingly high using contemporary methods. That Gandolfi has continued and Wisner has survived is remarkable. Look at a Crown Graphic, and marvel how it was made. Build my own camera ? You guys are brave !
You might contact Steve Grimes' succesors if you get stuck.
"One of the painful things about our time is that those who feel certainty are stupid,
and those with any imagination and understanding are filled with doubt and indecision"
Knurled washer-face 1/4-20 thumb screws:
Purchasing springs or having them made for LF is pretty expensive. I inquired about having some made from stainless steel for 11x14 and larger cameras and it was over $100 for one pair. You can make springs from carbon steel hacksaw blades or better bandsaw blades. You can build a jig for bending and heat with a propane torch. You need a nozzle that a plumber would use to produce an optimum flame. Use a pair of blades, one shorter then the other to make one spring.
There have been other posts recently. I usually heat to a dull red, perform the bend and then let the piece air cool or quench in air temperature water. Then reheat to a straw color and then let cool again. The cameras I have been working on do not use springs on the back, but I have been experimenting for making some 8x10s down the road with springs.
"Fundamentally I think we need to rediscover a non-ironic world"