MAC 600 shutter problem

[fireball40k]

I've discovered a problem with one of our Mac 600s that is required for setup on Sunday morning.

 

The shutter was stuck open and when I opened the unit, it was clear that the blade had deformed due to the heat and had been scraping on the chassis metalwork below. After removing, straightening and refitting the blade, the stepper is still only moving the blade a fraction of the distance that it should move. Even with the blade removed again, the stepper shaft barely moves. I'm wondering whether the stepper has cooked some of its windings as a result of the blade making contact - the stepper shaft does also seem stiff.

 

The Mac is not showing any errors but I wondered whether there are any tests I can run or whether it's just a case of fitting a new shutter stepper (in which case does anyone have one spare in the south midlands area?)

 

Any help or advice gratefully received. Cheers.

[DrV]

I've discovered a problem with one of our Mac 600s that is required for setup on Sunday morning.

 

The shutter was stuck open and when I opened the unit, it was clear that the blade had deformed due to the heat and had been scraping on the chassis metalwork below. After removing, straightening and refitting the blade, the stepper is still only moving the blade a fraction of the distance that it should move. Even with the blade removed again, the stepper shaft barely moves. I'm wondering whether the stepper has cooked some of its windings as a result of the blade making contact - the stepper shaft does also seem stiff.

 

The Mac is not showing any errors

 

It won't, as there is no position sensing on the shutter.

 

but I wondered whether there are any tests I can run or whether it's just a case of fitting a new shutter stepper (in which case does anyone have one spare in the south midlands area?)

 

Any help or advice gratefully received. Cheers.

 

You might get away with dismantling and cleaning up the innards of the motor as a stop-gap. Before bothering to do so though, check that the windings are both intact and not shorted to the casing. I think it's pins 1 and 3 for one winding and 2 and 4 for the other but just compare with the good motor. It is sometimes possible to repair these too but you need to be good with fine soldering!

 

E2A: Just thought, can't remember whether the 600 has one or two shutter blades - if it's only one the comment about comparing with the good motor is nonsense.

 

Dave

[fireball40k]

...You might get away with dismantling and cleaning up the innards of the motor as a stop-gap. Before bothering to do so though, check that the windings are both intact and not shorted to the casing. I think it's pins 1 and 3 for one winding and 2 and 4 for the other but just compare with the good motor. It is sometimes possible to repair these too but you need to be good with fine soldering!

 

E2A: Just thought, can't remember whether the 600 has one or two shutter blades - if it's only one the comment about comparing with the good motor is nonsense.

 

Dave

 

Thanks Dave, the stepper spindle is very tight, so it looks like it's been boiled - I don't suppose there's any way to revive them for the short term? WD-40, axle grease or not?

 

I will meter the windings tomorrow.

 

Steve

[gyro_gearloose]

I don't suppose there's any way to revive them for the short term?

No, or if there is its a waste of time really. Bin it and fit a replacement. Are there any part numbers on your motor? I've got a few Mac 250 shutter assemblies, and while they have two blades the motors might be the same as those on the 600s. Something else to be aware of is that since the motor got jammed, its driver chip may be damaged as well.

[DrV]

I don't suppose there's any way to revive them for the short term?

No, or if there is its a waste of time really. Bin it and fit a replacement. Are there any part numbers on your motor? I've got a few Mac 250 shutter assemblies, and while they have two blades the motors might be the same as those on the 600s. Something else to be aware of is that since the motor got jammed, its driver chip may be damaged as well.

 

You've got nothing to lose by trying some WD40 etc. It may well be totally shot but if you can't get one in time then as I said - as a stop gap - it might get you out of trouble.

 

Dave

[gyro_gearloose]

...as I said - as a stop gap - it might get you out of trouble.

True it may work as a temporary stop gap, but you could end up with the shutter sticking open mid-show. If it were me I wouldn't use the unit until it is properly sorted, otherwise you'll end up doing the same job (getting the motor out to either hose it down with WD40 or replace it) twice.

[fireball40k]

...as I said - as a stop gap - it might get you out of trouble.

True it may work as a temporary stop gap, but you could end up with the shutter sticking open mid-show. If it were me I wouldn't use the unit until it is properly sorted, otherwise you'll end up doing the same job (getting the motor out to either hose it down with WD40 or replace it) twice.

 

I had the same thought and redesigned the rig without it.

[WiLL]

if the motor is really stiff to turn (when the power is off) then the motor has probably burnt out or been damaged. It should feel firm but easy to turn and when you turn it you should be able to 'feel' the steps. If you can't then replace it. The good thing about it being a mac is that parts are easy to order, your local lighting hire supplier should be able to get one, or even order directly from martin. Swap out the motor and Bob is your Mother's Brother.

[Jof2375]

Hi,

 

There is no way of cleaning the motor's used in our fixtures, you will need to order a new one the p/n is 05701607, E-lite Technology Services will be able to supply, give price, their number is 01622 675576.

[Richard CSL]

Hi,

 

There is no way of cleaning the motor's used in our fixtures, you will need to order a new one the p/n is 05701607, E-lite Technology Services will be able to supply, give price, their number is 01622 675576.

 

 

If as you claim" there is no way of cleaning the motors in Martin fixtures", why do they have 4 screws to undo the casings,

 

and due to experience of these matters, the bearings are not sealed (god only knows why) therefore subject to ingress of dust and other particles, which in my experience is the main cause of a "stiff" motor shaft,

 

removal of the armature and a good dose of alcahol 96 or even wd40 releases the bearings instantly, then cleaning the laminations carefully with a dremelwire brush to remove any carbon deposit works a treat. I am aware you can only do this a couple of times in the life of the motor as the magnetic field degrades slightly on opening of the motor and removal of the armature.

 

but to claim the motors are not servicable is typical of a company which only wishes to sell spare parts. and make a profit, and not really support the customer in his best interests, which in this case seems to be a temporary fix to get him out of trouble rather than make him wait a week for spares to arrive.

[fireball40k]

Thanks for all your replies.

 

I have been in touch with E-Lite and they have the stuff in stock. The owner of the Mac is sorting out the replacement bits.

 

Once I have replaced the old stepper, I will take it apart and do what Richard suggests and see how far I get with rejuvenating it for possible use as a future emergency spare.

[timsabre]

If as you claim" there is no way of cleaning the motors in Martin fixtures", why do they have 4 screws to undo the casings,

and due to experience of these matters, the bearings are not sealed (god only knows why) therefore subject to ingress of dust and other particles, which in my experience is the main cause of a "stiff" motor shaft,

removal of the armature and a good dose of alcahol 96 or even wd40 releases the bearings instantly, then cleaning the laminations carefully with a dremelwire brush to remove any carbon deposit works a treat. I am aware you can only do this a couple of times in the life of the motor as the magnetic field degrades slightly on opening of the motor and removal of the armature.

but to claim the motors are not servicable is typical of a company which only wishes to sell spare parts. and make a profit, and not really support the customer in his best interests, which in this case seems to be a temporary fix to get him out of trouble rather than make him wait a week for spares to arrive.

 

Too harsh!

Stepper manufacturers say you should not take stepper motors apart like this as it creates misalignment problems, so his advice is correct. The fact they have 4 screws does not mean that they are designed to be serviceable.

 

It is of course possible in an emergency to do as you suggest, but it is not recommended.

[Jof2375]

We do not manufacturer the motor's used in our fixtures, but like timsabre says they do not recommend that you clean them as it can cause more issues. I was offering my experience on the issue, which is to replace rather than clean, the client can either use the info or not.