8mm Forum: GS1200 PUZZLE

»	8mm Forum » 8mm Forum » GS1200 PUZZLE

UBBFriend: Email this page to someone!

Author

Topic: GS1200 PUZZLE

Paul Adsett
Film God

Posts: 5003
From: USA
Registered: Jun 2003

posted November 25, 2003 07:53 AM

I am puzzled by a feature of one of my GS1200 projectors. It is the late model with the improved film path and the rear facing loop restorer lever. The puzzle is this: the film roller next to the red arrow where you insert the film for threading, slides back and fore and activates a microswitch. I had assumed that the function of this switch was to somehow pulse the motor on the supply spool , in order to ease the film transport to the top sprocket. Well I ran some tests, activating the roller microswitch in both forward and reverse play, and it does'nt appear to do anything at all. Is this a fault on my machine, and what exactly is the purpose of this sliding roller/switch assembly anyway? My other GS1200 (early model) simply has a fixed roller and runs quite happily without this sliding roller arrangement.

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

| IP: Logged

Paul Adsett
Film God

Posts: 5003
From: USA
Registered: Jun 2003

posted November 26, 2003 08:19 AM

Thanks to Kevin Faulkner ("Mr. Elmo UK") for e-mailing me the following explanation: [Wink]

:
Ok Paul, now for an explanation. If you put a 50-200ft spool of film on your early GS and then run the machine in reverse its possible that the feed spool will pull the film too hard and cause damage. What Elmo did on the ver2 series is put a speed control board in the machine for control of both take up motors. They also incorporated that little switch so that in reverse mode if the film torque with a small spool is too high it will lift that switch and lower the torque.
If you look in your later machine you will see this board attached to the side of the feed spool motor whereas you early machine is void of this board. The early motors were connected straight to the transformer and if you think about it the torques required between say a 50ft and 1200ft spool are quite different. You have to also remember that the 2 motors are wired together so that when one is going in one direction the other is working as a brake. The early arrangement was too sipmle and did cause probs. When they introduced this mod they also changed the spec of the motors. The newer ones are a different voltage so shouldnt be interchanged with the older ones. Not a lot of people are aware of this fact and can have all sorts of problems when the interchange the motors.
Hope that all helps. Try running the machine with say a 1200ft spool on the feed arm and run the machine in reverse. You should be able to feel the torque reduce on the reel when you lift that roller.

Kevin.

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

| IP: Logged

Alan Rik
Film God

Posts: 2211
From: New York City, NY, USA
Registered: Jun 2003

posted November 26, 2003 09:47 AM

All I can say is....Damn he's good!

| IP: Logged

Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

posted November 26, 2003 05:28 PM

Well thanks guys you have just made me blush. [Cool]

Seriously I have had Elmo's all my life and its'probably due to working for Ilford Films here in the UK and getting to know the service guys etc when Ilfords were the UK European Distributor. Kept in touch with one of the guys for many years and leanrt quite a lot about the internals of the Elmo's.
Anyway feel free to chuck questions at me I love it really. [Smile]

Kev.
PS That gave me the idea for my new email address: mrelmouk@tesco.net [Wink]

[ November 27, 2003, 04:57 PM: Message edited by: Kevin Faulkner ]

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

| IP: Logged

All times are Central

Printer-friendly view of this topic

UBB.classic^TM 6.3.1.2