Dr Virago Pete's
Bray Magi Trak Restoration

I am not affiliated with Bray in any way. This webpage is a way to chronicle my restoration of my own equipment purchased missing parts and non-working.



The previous owner/owners lost a couple of the black plastic "roller chain sprockets" so I will either have to buy replacements or make my own.

Notes:
Chain roller diameter of .195"
Sprocket teeth = 17
Sprocket pitch = .305" approx
Hole dia .238"

Gear thickness = .108"
Hub thickness = .048"
Hub thickness = .228"
    taper largest = .915"dia
    taper narrowest = .385" dia
    (note curved taper)
============
Overall thickness .384"

Most likely the original was a black nylon gear. It may be a glass filled nylon as it seems to be very hard and rigid.

Update 2/15/17
My options are to draw it in CAD or scan it using my Roland Picza scanners Pix-3 or Pix-4. I tried using an online sprocket generator and entered the dimensions- I was able to import it in CAD software "Solvespace" but the dimensions are all wrong and creates a very tiny/miniature gear- so the gear generator doesnt output a proper DXF file. Also I see that the gear drawing is very rudimentary with a very sharp tip - where it is not a real-world ready-to-go drawing. I have to keep looking for another online sprocket generator.




Update 2/16/18
I have used CAD software and my old Dell Inspiron 2650 laptop running Windows XP to model this elusive
hard-to-find-a-replacement-for sprocket. I have been searching for parts for years unsuccessfully. Here are 2 screenshots of my DIY gear which I feel is ready to be test 3d printed and will probably take several attempts to get a good print from ABS plastic as I will have to try various settings for supports and temps etc so I get the best end result. Also since the actual cutout was modeled using 3 beziers. I may have to tweak the shape of the tooth for best fit. So far so good. I own 2ea 3d printers (heavily modified Alunar R100 and factory stock Stratasys Genisys Xs) and I will decide which one to use for creating this gear. My Stratasys printer uses a very hard brittle Polyester. The Alunar Ive only used ABS in the 1-1/2 years Ive been modifying it. So it comes down to those 2 materials as my choices. I think I need to make 3ea gears to complete the chain drive system. This gear is never imersed in chemicals - so the plastic doesnt need to be chemical-proof.

Later I will need to make the pin that goes in the yellow drive belt to make the length of yellow "rope" into a circle and connect both ends together. My full-size Magi Trak didnt come with this- the previous owner(s) lost those parts And I have been unable to find any parts or closeup photos of it.

Later I will  need to make a magnetic dogbone (which actually pulls the film through the machine's chemistry) as that part was lost by the previous owner(s) also. I did have 2 emailers years ago but they didnt provide all of the photos I needed to understand the inner workings. I will need to invent my own version based on the limited photos I have of the dogbone.

Here was a link regarding a Bray Magitrak but this video is no longer active (not my video and I got no response from author who is somehow affiliated/employed by/with Raspberry Pi prototyping company) I suspect this machine was dumped as the autoe was showing it running outside and had dirt and debris from being outside. You cant leave a machine outside- even though its made of PVC and chemical proof. I hope it didnt get trashed and dumped- it was a half-size e-6 processor and a female owner asking for people who would like to partner with her to process e-6 film. I suspect that idea fizzled and the machine was junked and trashed. I never did get any response to my inquiries. What a waste of a machine left outside. That horrible jumpy video is the only time Ive ever seen a working Magitrak.
http://www.youtube.com/watch?v=ni5FX884Zqg

Thankyou to Paul Kra____ (2016 emails) and Ole Henri____ (2014-215 emails) for their emails several years ago and some snapshots of their own unit- these units were not the same model as mine - but it helps me to understand what my missing parts may look similar to.




Somewhere on old flashdrives or CDROM/DVDs or a failed computer hard drive I have photos from Ole Henri___ 2014-2015 but at this moment I dont know exactly where it is. He had a C-41 unit (mine is E-6) and he had offered to sell me some parts but I didnt have the funds at the time and that deal for his spare parts fizzled. Later when I contacted him to try and buy again - he had sold all of the extra parts and his entire machine. Dont you hate it when computer and hard drives fail?

Nowadays I only store information on USB flashdrives. Hard drives are great when they work and a great loss of information when they fail.

I retrieved these old photos from my Yahoo/Att mailbox as who knows when they will delete my old messages and photos. These were photo attachments to emails which I put in zip files.

Unfortuately some emails were from a drop box which no longer is retrievable. So hopefully I have those somewhere.

The magic of 3d printers is something I could only dream of a few years ago. Now I actually have 2ea 3d printers (and one more that I havent gotten around to fully restoring - and doesnt work yet) and Im enjoying every minute of restoring my previously impossible to fix machines. Because I WANT TO PROCESS FILM in my very very rare Magitrak from approximately 1980 year. Im juggling the restoration of several machines.

see my webpages about my 3d printers
http://www.drviragopete.com/3d-printed-parts-gears.php
http://www.drviragopete.com/stratasys-genisys-restoration.php






Here is my CAD drawing of this gear of which Im missing 3ea. I used Solvespace version 2.3tilde7c1ca460 (files created on February 16, 2018) to model this and is hand drawn. The gear is made with beziers for the notch and may need to be tweaked to fit perfect. I have also included the STL file which was generated by Solvespace. The more I use this software - the more I like it. I learned this software in January 2018 and my skill level is growing exponentially. It should be just fine for use as an idler with the miniature chain rollers. The mfg chose this oddball miniature chain size rather than standard bicycle chain. My only option is to make my own replacement part.


Bray Magitrak Sprocket Bezier Notched.stl Bray Magitrak Sprocket Bezier Notched.stl
Size : 65.316 Kb
Type : stl
Update 2/17/18
After a failed attempt at support material 3d print, I stopped the print as the Cura software created gcode running on my Alunar was causing the printhead to collide with the uneven support structure. There is something not right with support function either in my settings or a bug in the software?

I have decided to rework my drawing so it prints an incomplete part that I will need to CNC mill on my rotary axis to complete or possibly on my lathe. When this print completes I will check to see which machine can hold it better. I added some surface area for this 2nd operation.

Here is the reworked "latheable" drawing which now has a totally flat back so it will lay flat on the 3d printbed. And protrusion at front for lathe to hold. Backside of teeth been removed for 3d print- lathe will cut that later. The leftover remnant will be the front protrusion - which shouldnt interfere with its function.

I can see a need to upgrade my Alunar printer still further by adding a 2nd printhead - for soluble support material - which renders all of this sort of thing a moot point in the future- but I want to proceed and accomplish this.





Dr Virago Pete (847) 454-7858 between 11am and 7pm daily
drviragopete@att.net
Illinois USA

(C) Copyright Dr Virago Pete All Rights Reserved 2018