I was looking around for a solution for a couple of lighting projects where I want to have position control of effect wheels, either DMX control or by timer stepping between positions. I was thinking the cheapest way to do this would probably be to strip the stepper and control board from a simple second hand DMX lighting effect. Then I came across these £35 moving heads on ebay ;

https://www.ebay.co.uk/itm/70W-Moving-Head-Stage-Lighting-RGBW-7LED-Light-DMX-Remote-Color-Mixing-Party-KTV/153775454728?hash=item23cdbb3a08:g:nuUAAOSwQjxdLvyC" rel="nofollow - https://www.ebay.co.uk/itm/70W-Moving-Head-Stage-Lighting-RGBW-7LED-Light-DMX-Remote-Color-Mixing-Party-KTV/153775454728?hash=item23cdbb3a08:g:nuUAAOSwQjxdLvyC

Now, these must be awful some how, I mean they have to be, but could the pan motor turn and reliably position an effect wheel? has any one had one in their hand? do they even have stepper motors in them?

Alternatively If anyone has something that can do the job cheaply I'd be interested.  I'm wanting a control board and single stepper motor that is set up to allow any position / step to be selected (so not a gobo wheel system which only allows the selection of set positions for example, or a gobo rotator drive which runs at diferent speeds but doesn't index).

James Tengo wrote: Do you need continuous travel in one / both directions?

No, although it would be nice.

One project is to utilise the oil wheel from a Coemar 'Graffiti'. This is a plastic wheel with chambers moulded into it (ten positions IIRC Edit; it has 8 positions), with different coloured oils in (blue and pink in one, red and yellow in the next etc.) so you can select the chamber with the coloured oil of your choice.

http://vintagenightclublighting.blogspot.com/2010/10/coemar-catalogues.html" rel="nofollow - http://vintagenightclublighting.blogspot.com/2010/10/coemar-catalogues.html

I'd be happy to step through the positions on a timer with this, without the ability to select specific colours, so I could use limit switches  on cams and dc motors (exact positioning is not critical) but I've not got around to doing this in the 20+ years I've owned this wheel, and a stepper would do a better job of it.

The other project is to run a 5 position rotating gobo wheel in a big projector I have repeatedly failed to repair on numerous occasions. With this one I need to hit positions accurately but it never gets used for scrolling. This one needs to be a Nema type 17 stepper size in order to fit next to the rotation motor. (I have plenty of these I can use for either project)

https://elmario80.blogspot.com/2012/06/coemar-graffiti.html" rel="nofollow - https://elmario80.blogspot.com/2012/06/coemar-graffiti.html

Found a better picture of the Graffiti for anyone interested.

Might be cheaper to source a martin 218. these boards and steppermotors are almost indestructible and dirtcheap and does all the tricks and more, and you get an extra shutter included. 

If you do a led-conversion, remember that oilwheels need the heat of the lamp to really get going. Led's dont'always work. 

Not sure I'll find one cheaper than £35 including delivery though? It would certainly be prudent to use something common so I can drop in a replacement board if required.

Bams wrote: If you do a led-conversion, remember that oil wheels need the heat of the lamp to really get going. Led's dont'always work.

It will be used with a standard halogen Solar 250 unless the output proves to be too poor, in which case I'll try it in my 575w K4 and see how the plastic holds up. The original unit ran a 1000w halogen lamp

One of the sections contains brown oil, an uncommonly used colour in modern projection effects! (I think this is original too rather than discoloured from heat)

I think I've found the one, although its cost more than I imagined to start with.

I've ordered a slighty damaged futurelight RT240 (mirror barrel effect) from the bay, It has a 16 position colour wheel which should let me snap to positions (or split positions) on the oil wheel easily and it also does a rainbow effect on this channel which could look good if it will go slow enough to allow the oils to move and mix, rather than just centrifuging them all to the edge.

The gobo system (also 16 positions) from the donor unit gives me the option of either adding another effect wheel, or using it for strobing as it has this function on this channel.

The mirror barrel drive is available too, although I'm trying not to get too carried away with this project. I'll try using this with the 5 position gobo wheel in the other unit and see if it solves the issues I've had with it and if it does I'll maybe buy another of these RT240s.

(Slightly off-topic but), I know those U'King units are cheap, but I do worry about safety when they manufacture and sell these...

https://www.uking-online.com/product/1-5m-3pin-power-cable-for-stage-light-3port/" rel="nofollow - If you can't see what's wrong, then, oh dear!

Hmm, yes, glad I avoided them.

Floating earth is great!!