Scans and scrollers

[londonjim]

Hello all what would you reccomend out of the HES Trackspot and the CP Miniscan?

 

And do all scrollers have to be looped back, or is it just the Chroma Q ones?

[peter]

I can't answer your question about the scans, but hopefully I can shed some light on the scroller issue. The recommendation for loop-backs is to decrease the 'seen' cable length. If the cable is looped back, the power supply sees the cable as half the length, and thus the signal can be sent via the shortest route to each scroller. (this is basic physics, not some clever electronics). Common practice is to loop back any scrollers which are on a long chain (20m+). The precise requirements depend on the quality of the cable used. So, the real answer is to do it where possible, but don't bother too much if you can't. Remember of course to take into account the maximum distance allwoed by the PSU. With a loop backed system, I think (IIRC) this distance effectively doubles, but don't quote me on that.

[MarcT]

As Peter says, if you add a return line to a ChromaQ scroller circuit, power can then flow either way around the ring. This helps reduce voltage drop to the scrollers which otherwise would have been at the end of a chain.

 

However, the control signal (DMX) is only transmitted from the "out" socket on the PSU, and is actually terminated at the "return" plug. Therefore DMX only flows one way around the ring.

 

As a consequence, if there's a break in the ring (cable comes unplugged / cable fault) - some scrollers may receive power and signal, and some might only receive power (from the return socket). Therefore when troubleshooting, its sometimes useful to disconnect the return line at the PSU, as it will show up problems more easily.

 

Having said all that, with 6 scrollers per circuit and short cable runs (Peter's 20m suggestion sounds good), you probably don't need the return line at all.

 

With 8 scrollers per circuit and/or a long run, it would be wise to use a return.

 

From the ChromaQ manual:

Note: Do not connect more than 8 units per Chroma-Q circuit on any DMX / Splitterbox, as this may overload the output. Total cable length per circuit must not exceed 60M / 200' on the 8 unit PSU / Splitterbox and 105M / 350' on the 18 unit PSU / Splitterbox.

 

...and remember that's a 60M loop.

 

Marc

[ianl]

Hello all what would you reccomend out of the HES Trackspot and the CP Miniscan?

 

<{POST_SNAPBACK}>

 

 

kind of depends which model of miniscan,

 

miniscan 150 and miniscan 300 have fixed gobos, miniscan hpe and hp3 have rotating gobos and prisms

 

I havn't used a trackspot in about 10 years so I cant remember whether they havre fixed or rotating gobos, I woulkd asume fixed from the age (asuming it is the same version)

 

I do remember having lots of problems with the trackspots with lots of them having blown the DMX output stage so they wouldn't link on

 

personally I would go cp cos afaik they are more modern and in my experience more reliable, if it is miniscan HPE then definatly cp

 

guess it also depends what your using for control and whether you want 5 pin or 3 pin DMX, cost and useage,

[mac500]

The HES Trackspot 2 would be more similar to the CP Miniscan. I'm a fan of the miniscan. It depends what you things they'd be used for.

[johnhuson]

As mentioned above it depends on the model of Miniscan (150, 300, HPE, HP3) and Trackspot (Original or 2).

 

However one thing to bear in mind, if it is an original Trackspot, they only have a tungsten halogen lamp (Phillips M33 24v 250w) which is going to produce lower light output than any of the Miniscan models as they all feature discharge lamps, lamp life is shorter in the Trackspot but then the lamps cost significantly less than the Miniscan lamps.

 

As mentioned above the Trackspot 2 is a closer comparison to the Miniscan models due to it's discharge lamp, prisms etc. One other thing to note is that there is only one replaceable gobo slot in a Trackspot, the rest are etched to the disk and they don't rotate. Where as all of the Miniscans have replaceable gobos, can't remember is the 150 & 300 have rotating gobos though. The HPE & HP3 both have rotating gobos.

[Tom Baldwin]

can't remember is the 150 & 300 have rotating gobos though. The HPE & HP3 both have rotating gobos.

<{POST_SNAPBACK}>

 

Only the HPE & HP3 have rotating gobos.

 

As an aside, there was/ is a Miniscan variant with a 250W halogen lamp, but it was badged as a "Silverado", and was indeed silver, rather than black.

 

Tom

[ianl]

the miniscan 150 and 300 had 2 diferent types of gobo wheel,

 

one was a single disc punched with 5 gobos and a hole (for no gobo)

 

the second had the same disc but punched with 3 gobos and 3 holes, 2 of which would accept standard (e size?) gobos

[johnhuson]

the miniscan 150 and 300 had 2 diferent types of gobo wheel,

 

one was a single disc punched with 5 gobos and a hole (for no gobo)

 

the second had the same disc but punched with 3 gobos and 3 holes, 2 of which would accept standard (e size?) gobos

<{POST_SNAPBACK}>

 

I stand corrected Ian, for some reason I thought that all the slots in the Miniscans were replaceable.

[Jamtastic3]

I can't tell you much about the Trackspot but CP Miniscan's are just little gems.

 

I've been using 4 Miniscan HPE's for the past year and they are really effective and effeciant. Easy to maintain, easy to rig and have a whole range of opportunities. The only thing I notice when using them is that they have pretty slow gobo and coour wheels when say changing from gobo 1 to gobo 7 in an instant. Though I spose I can't complain much cos its the rotation devices on them that make it slower than the speed of cheaper gobo/colour sharing wheels. But I'm a fan of the Miniscans (HPE in particular) and look brill as group fixtures on stage.