Archived posting to the Leica Users Group, 2002/05/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Tom, Sounds like a nice product you are working on. One thing that concerns me is that these cameras usually have a lot of wear on them, and their gears are brass. How much extra stress does the Rapidwinder put on these parts? Mike D - ----- Original Message ----- From: <TTAbrahams@aol.com> To: <leica-users@mejac.palo-alto.ca.us> Sent: Saturday, May 11, 2002 1:29 PM Subject: Re: [Leica] LTM vs. M > . . . > I now have lived with the prototype "Barnack" winder ( IIIf/IIIc/IIIg) for a > couple of weeks. This one is completely untreated with insides in gleaming > alloy and unpainted steel. So far so good! It works very well and except for > some minor redesigns, it should be ready to go into production this summer. > One of the reasons for building a prototype is to find out what can go wrong, > or what needs to be modified. The lever track needs to be slightly longer, > the lock needs a different disc and the current returns spring is a bit to > strong, but that's it. Not bad for a first try. The screw-mount Leicas has > some idiosyncrasies that are specific to them. One is that the shutter can be > released even when the camera is only cocked halfway. This means that you > have to pull the trigger until the camera's shutter mechanism stops the > advance. Or you can end up getting overlapping exposures (this is a function > of the camera, not of the winder, as you can induce the same effect by > advancing the film partially with the knob-advance). This is one reason for > extending the track in the winder slightly to give it a safety margin. The > lock needs to be redesigned to allow the disc to turn 180 degrees, rather > than the 90 degrees of the M-Rapidwinder. > I have also found out that the Rapidwinder for the LTM is far more sensitive > to the condition of the cameras advance mechanism than the M6/M7/M2 > Rapidwinders. If the LTM body is stiff or "balky" in the advance, this > translates into a stiffer leveraction of the winder. I have a small selection > of IIIf's and IIIc's that are used for testing, a couple are old and cranky, > and that is immediately noticed when you put the winder on it. > The "Barnack" winder has a tripod bushing, centered under the lens, rather > than the offset on the regular baseplate. Physically, it is the same height > as the top-plate of a IIIf although it looks a bit bigger, mainly due to the > fact that it is the same height across, whilst the top-plate has all kind of > different "levels" on it. It is amazing to watch all the stuff that has to > turn when you advance a IIIf, the shutterspeed dial, the rewind-knob, and > even the release button rotates. Gears galore inside! > The LTM really needs the baseplate winder, as it is virtually impossible to > advance the film without dropping the camera from the eye. Now, the loading > is another matter altogether! I am already at work designing a replacement > ABLON filmcutter template for the LTM users. The original ones are now > overpriced collectibles and I think I can improve upon that design anyway. > It will still take a couple of month to fine-tune the design of the Barnack > Rapidwinder, but at least it now exists in the "flesh" so to say and it works > well. > The sun is shining and I am now heading out for yet another test-shoot with > said prototype. Red Dial IIIf with a 25/4 Snap-Shot Skopar on it and Fuji > ACROS in the camera. The fact that we now can get modern, high-quality lenses > for our old LTM's is an added bonus too. The little 25/4 Skopar is one of the > sharpest lenses that I have encountered and it is a perfect match "tri-pack" > of portable equipment. A 15/4,5 Heliar, the Snap-Shot 25 or a 21/4 and then a > 50/2 Collapsible Summicron (or the 50/2,5 Color-Skopar) and possibly a 90/4 > or f3,5. The whole package can be carried in pockets rather than in a bag. > Not a bad way of whiling away a sunny Saturday! > All the best, > Tom A > > Tom Abrahamsson > Vancouver, BC > Canada > www.rapidwinder.com > -- > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html > - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html