PDA

View Full Version : Screw Source for C-403



Steven Pituch
18-Apr-2017, 15:45
Hi All,
I am looking for a source for the thick headed machine screw that acts as a pivot for the slider levers for the standards. Not sure if I described it correctly, but included is a photo. I think the camera is a very nice Calumet C-403. I thought it was 100% complete until I noted the one lever was not working and discovered the bolt was missing. Thanks.

Steve Pituch
Corpus Christi, Texas, USA

163977163978

Keith Pitman
18-Apr-2017, 15:59
Unless it's a standard fastener, it will be hard or impossible to find. It's not really clear from your pictures where this is and how a screw fits in there. It looks like there is a screw in there but that a longer screw with a larger head is needed--correct? If so, a socket head cap screw and a washer might take care of it. Take the existing screw out and take it to Home Depot or an Ace where you can size the screw and buy the right length. It might help to take the camera with you. You may be able to find these screws in stainless which will look better on your camera.

Leigh
18-Apr-2017, 17:03
If you can post a picture of the screw itself, that would help.

McMaster-Carr Supply carries a huge assortment of screws of many different types.
http://www.mcmaster.com
and click on the "Screws and Bolts" icon at upper left.

- Leigh

Keith Pitman
18-Apr-2017, 17:23
If you can post a picture of the screw itself, that would help.

McMaster-Carr Supply carries a huge assortment of screws of many different types.
http://www.mcmaster.com
and click on the "Screws and Bolts" icon at upper left.

Does Leigh get paid every time he recommends McMaster Carr? If not, he should. :-)


- Leigh

Leigh
18-Apr-2017, 17:32
Hi Keith,

No. I'm just a satisfied customer. I place one or two orders every week.
They have everything I've ever needed, in stock.

McMaster-Carr has been a major US-based industrial supplier for over 100 years.
I think they deserve our full support.

- Leigh

Mark Sampson
18-Apr-2017, 17:40
These CC-400 cameras are the VW Beetles of the LF world. Rugged, functional, and found everywhere. Calumet sold them by the thousand, for decades, and I can't imagine that there are any exotic parts in what is a very simple design.
(Of course when we used them at Kodak, Calumet was still in business and parts, if needed, were a phone call away.)
Perhaps someone rescued the drawings and parts inventory from the wreckage of Calumet? Even if not, should not be too difficult to repair.

Steven Pituch
19-Apr-2017, 16:35
Hi All,
Thanks for the advice. I will take out one of the screws this weekend and take a macro photo of it, and also take some measurements with a micrometer. For those of you that don't know, and I should have included another photo, it is under the rail and when you squeeze the lever you can slide the standard along the rail quickly without needing to turn the knob. Once you get the standard in roughly the correct position one can use the knob to fine tune the focus. Having the lever function is not really needed as I use the knobs to move the standards and focus most of the time anyway. But I would like to have the camera complete. I noticed the three remaining screws are loose and I will put some Loctite on them.
Also wondering if someone might have a junker that I can buy a screw from.

Keith Pitman
19-Apr-2017, 17:25
. . . the three remaining screws are loose and I will put some Loctite on them...

Those screws may be loose for a reason. Proceed cautiously. Also, a picture of a screw isn't going to do much good. An actual screw can be measured and replaced.

Jac@stafford.net
19-Apr-2017, 18:51
Bring your screws to Ace Hardware, 15326 S Padre Island Drive, Corpus Christi. They have gauges on display to size your fasteners. You might have to shorten them. They also carry the economical Dremel kits.
.

Jim Jones
20-Apr-2017, 07:47
The screw appears to be complete and functional. That screw on my similar camera has a 4-40 thread and about a 0.140 diameter head. Perhaps a socket head 4-40 screw cut to the correct length and the head turned down to the correct diameter would be a quick Ace Hardware substitute. However, the problem may well be the lever is sprung so it slips over the screw head instead of pivoting around it. If you do remove the screw, use Locktite when replacing it so it doesn't unscrew with use.

tonyowen
20-Apr-2017, 08:06
For what it is worth the screws on my CC400 are all imperial sizes (inch based) albeit some metric screws thread are very close to imperial and if you are lucky interchangeable
.
regards

Tony

Harold_4074
20-Apr-2017, 17:21
Jim Jones probably has the best answer. I just took a look at one of my CC-400 cameras, and it looks just like yours---except that the head of the screw is close to flush with the face of the lever. If you are careful not to lose anything and take note of what goes where, you should be able to disassemble the faulty release lever and inspect it to see if the part which engages the screw head is bent outward. If necessary, you can also disassemble the other release mechanism and compare the parts. A guess would be that the screws are original, but the lever has been bent.

Jon Shiu
21-Apr-2017, 08:55
He is missing a bolt. He has only 3 out of the 4 total.

Jon

Harold_4074
21-Apr-2017, 12:25
Yup. Its right there in the first line. Seeing the picture I had understood that he was looking for a replacement for a replaced, but non-functional, screw. Darn.

But the head of a 4-40 fillister head or socket head screw should be about 0.183 diameter, so chucking one in an electric drill and taking a file to it should solve the problem fairly easily.

Steven Pituch
22-Apr-2017, 09:37
Thanks everyone for the advice. Yes, I've been to the Ace Hardware store and Home Depot, but I really didn't know what to look for. I will go back to Ace and look at their 4-40 screws. I have the following info now:
Top of threads: .108"
Unthreaded part of shaft: .076"
Height of head: .070"
Diameter of head: .143"
Approx pitch: 40 th/"

I was afraid I would need a lathe but using a drill and file is a good idea. I will post a progress report soon. If Ace doesn't have a decent cap head screw I will check out McMaster-Carr Supply.

Steve
164130

Leigh
22-Apr-2017, 09:48
I was afraid I would need a lathe but using a drill and file is a good idea.
Your dimensions look good. The nominal thread diameter for #4 is 0.112", so your 0.106" is fine.

Socket-head capscrews are made from the hardest steel in common use, almost a hard as a file.
Turning down the head diameter would probably require a grinding process of some sort.

Of course, screws from certain Asian countries may not meet normal specs.

- Leigh

tonyowen
22-Apr-2017, 10:32
I took one of the relevant screws off my CC400 and found that a 2mm or 2.5mm or 3mm screw fitted the tapped hole. (I do not have a micrometer hence I'm not certain as to what sized screw I used). The original screw has either a shoulder or a plain portion to its shaft so that it does not clamp the lever tight when fully tightened. The metric screw I used had a nylok fitted so it could be screwed in, but not clamp the lever nor vibrate out.
regards
Tony

Harold_4074
25-Apr-2017, 08:40
I just went out to the garage and tried filing a couple of black-oxide finish socket head cap screws (a 2-56 and a 6-32) and a smooth mill file cut them just beautifully. However, YMMV.

With due regard for personal safety (eye protection, particularly, and no personal appendages in contact with sharp, hot, or moving objects) you should be able make a replacement screw yourself.

The procedure than I have used a number of times on screws this small or even smaller: run nuts onto a fairly long screw (at least half a inch or even more if possible) to give drill chuck jaws something to bear on other than the threads. Lock at least two nuts together, flats aligned; this may damage the threads, but will keep the screw from rotating and will be cut off later anyway. In decreasing order of preference, use a bench grinder, file, or belt sander to reduce the head diameter while the drill is spinning the screw. It takes a certain "touch" to keep the head round, but screws and nuts are cheap compared to cameras...

To cut the finished screw to length, the obvious tool (a hacksaw) is almost worthless unless you use something like a coupling nut (see McMaster-Carr, stock number 90264A410) and saw through both the screw and nut at the same time. My personal preference is a Dremel tool or the equivalent with a cutoff wheel; you can probably buy one at a Harbor Freight-type store for less than Calumet would have sold an authentic replacement screw. (If you go this route, use nuts run onto the screw and a vise or pair of locking pliers; the little thing will get pretty warm as you cut.)

If the hex nuts are wider than the screw head (they usually are, but there are exceptions) you can use the drill chuck as a vise: file, grind or sand the screw to length. Removing the nuts will straighten any burr on the threads but you will want to bevel the first thread (Dremel tool again, or an oilstone) so that it will start easily when you put it into the rail clamp.

tonyowen's comment about not clamping down the lever suggests that there may be variations out there, but my CC400 looks just like yours.Only the head is used for the pivot, so the screw should be short enough seat on the underside of the head.

Good luck!

tonyowen
25-Apr-2017, 10:07
[QUOTE=Harold_4074;1388665]To cut the finished screw to length, the obvious tool (a hacksaw) is almost worthless unless you use something like a coupling nut (see McMaster-Carr, stock number 90264A410) and saw through both the screw and nut at the same time./QUOTE]
Curiosity only, why cut through the screw and nut? The way I was taught (half a century ago) was to cut a slot through one of the flat faces of the nut. This means the nut can be clamped onto the screw thread when held in a vise OR use two nuts and lock them together. Then adjust the nut(s) so that the desired screw length is defined by the 'outside face' of the nut (or second nut). Cut against the face of this nut and file away burrs. Then undo the nut(s) which remedies any screw thread damage caused by the saw and file.

regards
Tony

Harold_4074
25-Apr-2017, 11:41
tonyowen:

Your question might appear to be afield from the original question but it is not, really; there is a matter of scale involved.

The screw in question is a 4-40, with a minor diameter of only about 0.080 inches. The reciprocal of this about 12, and to work well a saw blade should have at least three teeth engaged, so in theory a 36 teeth-per-inch sawblade would work unassisted. In practice, getting the blade down to the minor diameter in the first place is a challenge, because the corners of the teeth tend to hang up on the sides of the threads. Cutting through a wider piece of metal gets around this problem, and one or more nuts (typically 1/4 or 5/16 inch wide) is a simple solution.

Holding a 1/4 inch nut to slot it into a clamp requires a pretty decent vise, but if it can be held firmly a jeweler's saw with a fine pitch blade will cut both the clamp nut and the screw itself. But you can also run one nut all the way onto the screw, put a pair locked together with the inside face one saw kerf away from the intended length, and hold the locked nuts in order to cut along the inside face. One cut and you are done, and the first nut will de-burr the threads when you take it off.

I have a jeweler's saw and blades, but find that the fragility of the blades favors the electric drill technique unless I am cutting a brass screw and am willing to take the time to switch out the knurled vise jaws for smooth ones just to hold a 4-40 nut. When I "bolted" a lens retaining ring to a wooden lensboard with a Packard shutter on the backside, I did saw them off---there were (oddly) seven 2-56 brass screws to shorten, plus a couple of spares in case I lost one.

For larger screws and bolts (1/4 inch and up) I do exactly what you describe; keeping a few long screws on hand, shortening them as needed, saves having to drive to town every time something falls off of a piece of farm machinery!

Leigh
25-Apr-2017, 15:20
I stock black oxide SHCS in all diameters from #2 through 1/2"

Available lengths vary by diameter, with longer ones available only in larger sizes.
I stock all available lengths because I'm unable to cut longer ones off.

This will likely vary considerably depending on where the screws were made.
Mine are all from reputable American manufacturers.

- Leigh

Steven Pituch
25-Apr-2017, 18:50
Harold and All,
Very good advice. I do appreciate it. It seems I will have to take very little off of the head to made it the right diameter. It should look stock. I thought of reaming out the holes in the lever. It would be easier but would not look stock.

One question. Steel could rust once it is filed. I know Ace carries some stainless. Should I try to use a stainless steel bolt instead? I will probably go to Ace sometime tomorrow. I don't know if stainless would be more difficult to file.

Regards,
Steve

Harold_4074
25-Apr-2017, 21:46
Steven,

The screw that you illustrated is slotted; socket-head cap screws were suggested because it is the side of the screw that forms the bearing surface in the camera situation, and the cap screws have tall, vertical sides. If you want something which looks resonably original, get a fillister head screw; the head shape is cylindrical at the sides and gently domed on top. This should give you plenty of bearing surface and you can file the head flat without losing all of the driver slot. For some reason, McMaster-Carr calls these fillister heads when they are Philips drive, and high-profile when slotted (which is what you would want.) The originals are either stainless or nickel on my cameras, so here

https://www.mcmaster.com/#91794a108/=17cyjde

is an example in type 316 stainless. All of the common stainless steels except for type 303 are tougher (not necessarily harder) than carbon steels. They will be a little, but not much, more difficult to cut and anyway the amount of metal that you need to take off is really small.

Good luck; I don't expect that you will have much trouble, and in any case that's a nice camera so it will be worth it. :)

Harold

Steven Pituch
4-May-2017, 08:25
Harold,
I did order those screws from McMaster-Carr and have received them. I think I am going to replace all 4 screws so they match and then ream out the holes a tiny bit if they need it. At least they will all match. Harbor freight sells a reamer that is a minimum 1/8 inch so I think it will do the job. I am going to try this on the weekend so I will let everyone know how it goes. Again, thanks all.

Steve Pituch

Steven Pituch
4-May-2017, 16:29
I reamed out the hole in the lever with a Harbor Freight step drill. The step I reamed it to read "3/16" , which is just over the .183 of the screw head.
It looks like the hole is bigger though. There is a little more slop in this arrangement than the one for the original screw. But it works fine.
I did it for both sides of the rear release lever. I think I will buy the $2.99 reamer from Harbor Freight when I do the two screws for the front standard.
That way I should get a tighter fit.

164410

164411

Leigh
4-May-2017, 16:36
HF cutting tools have zero tolerance.

That does NOT mean they're precise.

- Leigh

Jim Jones
4-May-2017, 17:41
HF cutting tools have zero tolerance.

That does NOT mean they're precise.

- Leigh

I buy Harbor Freight tools that will get only non-critical occasional use. They are usually good enough for that.

Leigh
4-May-2017, 17:56
I buy Harbor Freight tools that will get only non-critical occasional use.
They are usually good enough for that.
Barely.

- Leigh

Harold_4074
8-May-2017, 11:32
Steven,

I'm glad that it worked out.

If I had thought you might ream out the hole, I would have suggested not a step drill, but a #15 twist drill (0.180 nominal diameter) followed by a #13 (0.185, giving you a couple of thousandths clearance). The reason for two drills is that these tools are not meant to make precise diameter openings (that's what reamers are for) but usually are pretty accurate in their own diameters. Taking all but a trace of metal away with the first drill means that the second one will have very little work to do, and probably cut close to the nominal diameter.

Fortunately, if you look at the geometry of the lever, when you press on it the load is on the side of the hole where the metal is widest. The narrrow side would probably have been OK anyway, but before removing metal from something stressed it is always a good idea to figure out the load situation. Some designers don't mind letting the rest of us live dangerously :)

Your pictures show a nice bit of work. Unless the bevel left by the step drill exposes unpainted steel which then rusts, it is unlikely that anyone will ever recognize the modification.

Harold

Steven Pituch
8-May-2017, 17:15
I think this would have been perfect if I had had the patience to wait until I was near a Harbor Freight store.

https://www.harborfreight.com/t-handle-reamer-66936.html

Harold_4074
11-May-2017, 13:41
Yes, patience is often useful. With enough of it, good hand-eye coordination and either a round Swiss-pattern file or a Dremel tool, you could have opened up the hole to the head diameter of whatever screw you first acquired--without needing to know the actual diameter!

Or you could have used that tapered repair reamer to very precisely open out the hole. In metal that thin, the difference between a cylindrical hole and one that tapers slightly would be meaningless.

(Mantra: it's good to know a way of doing whatever is needed, but it is much better to know five different ways, because then you can choose the best one for the situation at hand.)