vibedisco Posted May 11, 2010 Share Posted May 11, 2010 Ive got a robe 160xt moving head that is causing me problems at the moment. The shutter sometimes sticks in the closed position for 20 minutes or so and then operates as normal. The stepper motor is not stiff and it moves with ease and the fan is a 2.2w sunon so there should be enough airflow. I have a sneeking suspicion the shutter is at its worst on a slow program which would suggest its overheating and then cooling down slightly on a faster program. I wonder if anyone has some thoughts on what else it could be? I really dont want to replace the motor because its a b**ch of a job. Link to comment Share on other sites More sharing options...
Ashley R Posted May 11, 2010 Share Posted May 11, 2010 I'm no pro but worked on a few Chinese movers which have had jamming shutters similar to what you are describing. No I do not think you will have to replace the motor. passably it is actually Jamming and when it is on the slow program it simply does not have enough momentum to get it self unstuck. but when is on the fast program is has enough momentum to free it self every time. and when it stays shut for an extended period of time the small amount of heat on the blades slightly expands the metal enough to let the shutters free. But I emphasise I'm no expert. just a guy who knows how to tinker with alot of things and usually gets them to work after said tinkering. Link to comment Share on other sites More sharing options...
KevinE Posted May 11, 2010 Share Posted May 11, 2010 The best thing you can do is whip the shutter motor out and stick a new one in and give that a go. The shutter mechanism on a 160XT isnt like a camera iris as on more 'pro' fixtures; it's just a scimitar-style flag, and is unlikely to foul on anything unless its seriously bent ; you'd hear it 'tinging' as it strobed if it was catching on anything. The shutter motor is often the first to fail on many moving heads because its the closest (thermally) to the heat. On the 150 and 160XT, the internal temperature is very dependent on the way the head points on static or very slow chases, the factory fitted main Sunon fan (and aux motor cooler where fitted) barely keep the head cool enough (IMHO) especially if the head spends a great deal of time with the fan on top. I've explored this problem in detail including attaching thermocouples internally (to the light) and noting temperatures under various conditions. As a result, older units can suffer from the heat and motors prematurely fail. A greatly overheated stepper motor will lose magnetism over time and the torque will suffer. Check the base fan while you've got the fixture down, these fail as well! Link to comment Share on other sites More sharing options...
Richard CSL Posted May 12, 2010 Share Posted May 12, 2010 The shutter motor is often the first to fail on many moving heads because its the closest (thermally) to the heat. units can suffer from the heat and motors prematurely fail. A greatly overheated stepper motor will lose magnetism over time and the torque will suffer. Is there a method of re magnetising steppermotors?, as I have aquired a collection of weak stepper motors over the years. the other favorite is the bearings, why do they use unsealed bearings? I have now bought an ultrasonic cleaner from Maplin to solve this problem. Link to comment Share on other sites More sharing options...
KevinE Posted May 12, 2010 Share Posted May 12, 2010 Is there a method of re magnetising steppermotors I have no idea, at £12 to £20 a shot its hardly worth it! Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.