MiniMAC help

[DMXBandit]

I recently acquired a pair or Martin MiniMacs as a kind of restoration project and as an introduction for myself into moving heads (having previously only used and repaired moving mirror scanners). I admit that I was a bit out of my depth at first, but I now have everything working apart from the tilt. The problem here is that whatever was used to tension the belt is missing, no pulleys or anything. Would it be possible for someone who has repaired Minimacs (or, I’m guessing, similar moving heads) to show/tell me what’s meant to go here, as everything I come up with results in the belt working its way off the main toothed wheel?

I hope someone out there can help!

Thanks,

John

[dave singleton]

This is why Martin's very friendly Technical Support (service) centre exsist.

 

If you give them a call they'll be able to advise you on the exact part and proberly even send you one out. Failing that tell you where you may be able to source one. Just give them a call.

[jayselway]

Have you got a photo of the arm, without the covers on? That might be handy so we can say "there's something meant to be "there"! :o

[DMXBandit]

Have you got a photo of the arm, without the covers on? That might be handy so we can say "there's something meant to be "there"! ;)

 

Yeah:

Picture 1 : You might have to squint, but you can see there’s nothing there.

Picture 2 : From the other side.

Picture 3 : Not so useful against the black.

Picture 4 : The second fixture. It has something the other doesn’t.

Picture 5 : You can see a slight bend in the arm. Is that meant to be there?

 

I will ring Martin at some point, but I thought that as I have the resources necessary to make nearly any missing parts I’d give it a go first.

Thanks,

John.

 

EDIT: They should be working now.

[jayselway]

On Picture 4, the belt should be on the other side of that little pulley that's there. The beck of the belt (no teeth side) will be in contact with the pulley. There's a little screw that goes into the pulley and if you turn it slowly, the pulley will tension the belt more or less. If it's too tight, then it will work off, and wear the belt more. If it's loose, it'll work off even more!

 

As for the bend in the arm, I have serviced some where the bend wasn't there at all, and some where it has been so prominent that it stopped the head from tilting at some points of its rotation. On these ones, it was a case of splitting the two plates apart, and fitting new plates to it, as the rivet holes had split, possibly through abuse whilst in use, and that caused the arm to bend more, hence stopping the rotation. That was a late night repair to get it done in time! If I remember rightly, the bend should not be there at all.

 

Are they all working right now then? ;)

[hippocrocaphant]

In picture 4 you can see the part that is not present of the other fixture, this is the tension bearing, the timing wheel runs round this and it is adjusted with the screw from the other side of the yoke to get the right tension. As for the bend, no that is not supposed to be there

[DMXBandit]

Ah-ha! Many thanks!

 

I didn't think that bend was meant to be there, but I thought I'd ask before hammering out a precision engineered curve ;)