RB67 SD 120 Back Screws

Trail Images · Nov 15, 2016

Hello all, looking for guidance on repairing one of my SD 120 Backs. It is my primary back and it has worked well for years. Today while in the field the rear swing door would not lock. Upon review the rear swing door plates that lock into the forward roller body lost all 3 retaining screws. I saw the last screw drop directly into the soft sand and was never to be found. I was able to retrieve the 2 brackets that align with the front roller assembly that guide the rear swinging door directly into place and it has 2 rivets that are used for the lock-down.
Where might I find these size screws and what would their designation be if you know? I would categorize them as black micro screws and obviously very fine threads.
Thank you for any thoughts you might share on locating these items on line.

Kirks518 · Nov 15, 2016

I have had good luck getting tiny screws at hobby shops, particularly shops that sell trains and RC cars/planes. There is also McMaster, they have every screw under the sun, but you may have to buy 100+ to get them from there.

darkroommike · Nov 15, 2016

You might try the parts department at MAC (Mamiya America Corporation) they used to be very good and had no problem selling parts to end users. Either that or look for a donor piece. http://www.macgroupus.com

Trail Images · Nov 15, 2016

Thank you for these ideas. I'm sure MAC will know the exact size needed. A scrape product would be another thought too. Without knowing the exact size these ideas mentioned would be a safe bet also.

MattKing · Nov 15, 2016

Trail Images said:
Thank you for these ideas. I'm sure MAC will know the exact size needed. A scrape product would be another thought too. Without knowing the exact size these ideas mentioned would be a safe bet also.

Does MAC have anything to do with Mamiya any more?

Leigh B · Nov 15, 2016

Kirks518 said:
There is also McMaster, they have every screw under the sun, but you may have to buy 100+ to get them from there.

I was going to suggest McMaster-Carr, as a source of information rather than a source of screws.
http://www.mcmaster.com
That brings up the introductory page, and the very first link is Screws and Bolts.

They have a very good descriptive page that lists all of the thread sizes and dimensions for machine screws, both US and metric.

Are these screws cylindrical (straight sides) or tapered? Do they thread into metal fittings or wood?

- Leigh

Trail Images · Nov 15, 2016

MattKing said:
Does MAC have anything to do with Mamiya any more?

A valid point now that I think about this approach. As I recall a few years back now I had a Prism issue I asked MAC for help on, not sure exact issue now, but they never answered. I eventually had KEH help me on that item. So, I'm not sure MAC has much support on the legacy hardware any longer.

Part of my issue is not having any of the 3 screws to do research with at this time for size and thread count.....etc. As I finished out my trip using my very old Pro back I'm not pressed for an immediate resolution. So it may require looking for a "parts-only" SD back to scavenge the necessary exact 3 screws to resolve the issue.

Thank you each for your ideas and it has helped me by bringing to light some avenues to review going forward.

shutterfinger · Nov 15, 2016

Which screw(s)?

I guarantee you they are metric and the part numbers appear to be the size and length in millimeters.
PD1.7x2 is a 1.7mm diameter x 2mm long screw and PD 1.7x2.5 is a 1.7mm diameter x 2.5mm screw.
I do not know if these will work or not.
http://www.metricscrews.us/index.php?main_page=index&cPath=98_298_299

You may find some screws that work in an eyeglass repair kit.
https://www.amazon.com/s/ref=nb_sb_...t&sprefix=eyeglass,aps,414&crid=2ETX0IGQ2HHM4

Trail Images · Nov 15, 2016

shutterfinger said:
Which screw(s)?
View attachment 167358 View attachment 167359

I guarantee you they are metric and the part numbers appear to be the size and length in millimeters.
PD1.7x2 is a 1.7mm diameter x 2mm long screw and PD 1.7x2.5 is a 1.7mm diameter x 2.5mm screw.
I do not know if these will work or not.
http://www.metricscrews.us/index.php?main_page=index&cPath=98_298_299

Thank you kindly Shutterfinger for taking the time to post this information. This should help me in the quest to find the right screws one way or another.

ryushinkan · Nov 16, 2016

Trail Images said:
Thank you kindly Shutterfinger for taking the time to post this information. This should help me in the quest to find the right screws one way or another.

Having spent some time replacing a screen on my laptop I have found that they use similar small screws - try your local computer repair man....

Trail Images · Nov 16, 2016

ryushinkan said:
try your local computer repair man

Thank you, now that I have the size information from the exploded diagram and the itemized screw listing I will able to resolve this very quickly.......

tedr1 · Nov 16, 2016

This is a good place to find miniature metric screws http://www.metricscrews.us/

Trail Images · Nov 16, 2016

tedr1 said:
This is a good place to find miniature metric screws http://www.metricscrews.us/

Thank you, that is the same link that Shutterfinger listed and you're correct, looks like the best outlet I've seen so far.

darkroommike · Nov 16, 2016

Trail Images said:
A valid point now that I think about this approach. As I recall a few years back now I had a Prism issue I asked MAC for help on, not sure exact issue now, but they never answered. I eventually had KEH help me on that item. So, I'm not sure MAC has much support on the legacy hardware any longer.

Part of my issue is not having any of the 3 screws to do research with at this time for size and thread count.....etc. As I finished out my trip using my very old Pro back I'm not pressed for an immediate resolution. So it may require looking for a "parts-only" SD back to scavenge the necessary exact 3 screws to resolve the issue.

Thank you each for your ideas and it has helped me by bringing to light some avenues to review going forward.

Not my experience with MAC, always was able to talk to a real live person when I called (and I was willing to call even though the number is not toll free). I've also had them fax exploded views to me in the past. Just curious, did you email or call? Email can fall into spam filters.

Trail Images · Nov 16, 2016

darkroommike said:
Not my experience with MAC, always was able to talk to a real live person when I called (and I was willing to call even though the number is not toll free). I've also had them fax exploded views to me in the past. Just curious, did you email or call? Email can fall into spam filters.

Very possible that was what happened with my email. I've never had issues with MAC on previous encounters. In fact, they sent me info on a 140mm Macro lens I needed immediately after my email around the same time. So, not sure about the Prism support at the time. It was not a big issue in the end as KEH took care of my needs easily also.

HiHoSilver · Nov 16, 2016

Trail, should other sources not come through -
http://www.microfasteners.com/home.php?cat=734
If you have to get a longer length than ideal, get a couple of the mating nuts, thread them to desired cut-off length, cut, file & unscrewing the nuts will chase most burrs back into alignment for use. You may already know that or have other or better methods, but it has worked well so far.

Trail Images · Nov 16, 2016

HiHo, thank you for your input and providing the link too.

Trail Images · Nov 30, 2016

Sorry it took a bit of time to give a positive and final update here. I tried various avenues once I had your solid input and especially the exploded diagram that Shutterfinger provided. In the end it was KEH to the rescue. A special thank you goes out to those folks. They asked for a photo of my pieces and what I was trying to accomplish and once they had that information they immediately shipped me the 3 micro screws. I received the screws in postal not more then 1/2 hour ago and the repair was made without any issue beyond my horrible eyesight and trying to see well enough......

To all who responded with ideas and words of support on this issue I wanted to thank each of you.......

RB67 SD 120 Back Screws

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