View Full Version : Slipping focus on Arcas Swiss telescopic rail

Jeff Keller
17-Jan-2015, 14:41
I recently bought a used Arcas Swiss camera with the telescopic rail. The geared track in half of the rail sometimes slides within the groove when trying to focus the camera. I could probably put a little lock-tite on it and not have any problems but what is the best way to keep the geared track from sliding? I don't see any locking screws so is glue the typical solution?
Thank you,

neil poulsen
18-Jan-2015, 01:59
I would call precisioncameraworks.com; they're the Arca authorized US service center. Using glue could make the camera worse, or worse, make it more expensive or impossible to repair.

Are the slats on the rail stripped? If not, it could be that the function carrier's gear is stripped.

Emmanuel BIGLER
18-Jan-2015, 02:57
HI Jeff !
Are you speaking about an Oschwald-type rail or an F-line?
I mention this because apparently, from the user's point of view, the rail and geared track look similar from 1960 to 2015; although the manufacturing process has obviously changed in half of a century, hence the proper repair procedure might be different for an Oschwald rail or a F-line, or even between a 1985, F-line transition rail type-1 model, to a current rail type-2.
Many modern glues were unknown in Zurich in 1960, and many glues known in 2015 did not exist in 1985 ;)

Jeff Keller
18-Jan-2015, 10:04
The camera is an F-line metric. No gears are stripped nor do I think the problem is wear related. I don't know if the geared track is intended to be press fitted into the rail, glued, or some unknown method used.

The track in one of the two extensions is fine. I've seen no sign of it slipping. The track in the other extension will nearly always slip if the focus is moved very much. It takes a fair amount of effort to move it back into place but not nearly as much as I would expect from a loose press fit. The camera shows almost no signs of wear. It was advertised as mint, never used. From its looks that could be true. The faint marks I've seen could be due to shipping. It makes me wonder if the track is normally glued but the glue failed. I suppose there could be shims used to lock it into place but I see no signs of that.

HI Jeff !
Are you speaking about an Oschwald-type rail or an F-line?

Jeff Keller
18-Jan-2015, 10:14
I don't know the difference between a type-1 and a type-2. The rails are black with a 5mm wide silver colored toothed track fitted into a slot in the top of each extension rail. The tooth track appears to be designed to slid into the slot at the top of the rail but I can't see anything that would lock it into place. The camera has 171 size frame carriers.

Emmanuel BIGLER
18-Jan-2015, 12:42
Thanks, Jeff.
So if it is a F-line, it is very close to the current model, you should send the faulty rail to Precision Camera works together with both function carriers in order to check that they slide properly. Not necessary to send the format frames except if you have doubts concerning the parallelism at zero tilt.

F-line rails type 1 are similar to pre-1984 Oschwald models except for their blask finish (Oschwald = white aluminum finish). The hole inside a rail type 1 is thin and rectangular. On the telescopic rail they are locked by a series of screws on the sides.
F-line rails type 2 are thicker than type 1 and the hole in the middle is perfectly circular. On the telescopic rail, rails type 2 are locked by a system underneath sliding through a thin slot as long the rail itself.
Most probably since you have an extension rail, your rail is a type 2 i.e. the current model.
Hence : to be repaired or changed.
Since I've never experienced this problem with my 12 years old F-metric, I cannot say much.

18-Jan-2015, 13:27
The rack (-> 'geared track') is pressed into the bed. Mine went loose, I took some two component glue to fasten it. It's fine now for a long time. But clean the rack and the bed with alcohol before you apply only a very thin film of glue to it, otherwise it might stick a bit too high out of the bed and ruin the gearwheel.

Jeff Keller
18-Jan-2015, 21:25
Thank you everyone for sharing your thoughts. I visited the precsioncameraworks.com website but didn't find any relevant information but it is good to know where "America’s only authorized service center for ARCA-SWISS" is.

I took a thin piece of plastic (actually a straw) to clean out the slot and found it removed some thin streaks of transparent material (probably a small amount of glue). The rack now slides easily in the slot of the rail. I don't think mine was ever pressed in. The fit feels perfect for it to slide without wobbling around. Knowing toyotadesigner had success with glue makes it an easy decision to try that approach ... although years ago my daughter went through a "goth phase" and I discovered black nail polish has many uses for photography equipment repair... Nail polish remover or Acetone removes it when desired.

I did a little searching and found some good pictures of a type-1 rail. I guess I've stared at the cameras and been oblivious to the rails until now other than the obvious folding vs. telescoping and the very early rails.

Again thanks for sharing your thoughts.