TomHoward

If we were to install permanent anchor points, like a Linadapter with an eye, is there a method to attach to this out of reach? Like a pole op that could be used to attach/detach with a hook with latch to drop a steel of the right length down from this?

Another problem is with this being a sports hall is it is used for ball games for the rest of the year. Whilst a shackle on a round sling shouldn't have  a problem if it gets whacked with a ball, it swinging around could be enough to concern some people. (You'd think they shouldn't be smashing balls into an 8m+ ceiling, but we remove basketballs jammed above the RSJs all the time)

The rope loop sounds like a good idea but I'd be a little worried other users might think a loop of rope with a karabiner on was a lifting point in itself? I could mark it as such but it might still pose a risk of someone hanging something on it? I could probably come up with a heath Robinson system of passing a rope over the beam each time to pull the round sling over through, as I did just pass the round sling in the first instance today, hook it up & over and let the weight of the shackle bring it down the other side.

I have a semi-regular need to rig a couple of small 250kg manual chain blocks in a sports hall that has huge (24" x 10") RSJs. (About 4 times a year)
Off this goes about 6m of truss, without about 6 LED cans and 4 conventional PAR cans or fresnels.

The ceiling in there is pretty high, it's just out of reach for a 14-rung Zarges so getting the round slings over the RSJ is always a bit of an effort. Once a round sling is over, the bottom shackle is reachable to put the chain block on.

Every time I say I should just leave the round slings up there, but how would this work in terms of inspection? Can I leave some up permanently or any other kind of sling and it not require 6 month/annual inspection?

Or does anyone have any success with any kind of telescopic pole like window cleaners might use to pass a sling over a beam that's out of reach, and pick it up from the bottom?

Depending on how many people are handling, we build Steeldeck on multi leg adaptors by having 3 people, two lift on the diagonal corners and the third pushes down on the far corner furthest away from the 3 leg adaptor so the hard to reach corner pops into the air.
It's a unusual manoeuvre but avoids going underneath, not likely to be professional enough to be a fix to your problem really but just how we do it.

If one supplier quote of 3 is higher it'll make your other two look more affordable.... don't need 3 just the same otherwise you wouldn't be able to make a case for which to pick
I am a big fan of Viking but would also throw Batmink in for straight box-supplying distribution, if they stock what you're after they can be really competitive.

What’s the licensing scheme, is it subscription now? Do you reckon you can still buy 3 seats outright?

will have to buy an M1 Mac mini to go with it…

Finally... we retired the Bullfrog but good to see there's a sensible way for users to be able to access fixtures without having to install software at their end edit a fixture table themselves.

On 4/28/2018 at 1:46 AM, UKTheatreTech said:

I trawled through this useful thread (chortling at Tom Howard's rants) and took the plunge in April 2018.

I've still not let it go, it still winds me up.

I always thought those USB emulators would only read and write at the size of floppy disks, so my guess is you may have to use another formatting tool to create many 1.44MB partitions. One of the main reasons I never did ours was as it didn't actually fix the problem of the partitions being too small to fit any files off the Zero88 website from.

Are the 6 DMX levels the same every year? Apologies for a basic question but could it just be done via 0-10V inputs on the dimmer if there are any and some resistors, or even more basic if they're all 100% just power the strip directly?

Do the peri's always teach in the same rooms, or so some teach between rooms? Although the text ID shown is the same, most equipment handles different physical speakers differently as far as I am aware as I have a huge list of duplicates in my phone from multiple of the same devices.

However pairing would be a pain as you wouldn't know which room you were pairing with initially.

(Our peri's all teach in the same rooms, week in, week out, year in, year out)

Handystraps.co.uk seem to sell all the bits for what you need, and have made me up ratchet straps in custom lengths & colours before so seem to be able to make them up themselves too

I'd use 41mm strut across the top of the joists as you could just screw it down and wouldn't need the clamps.

Then boom down the studding off that, use a channel nut, a square plate washer on the outside and a lock nut tightened up against the square plate to clamp if back to the channel nut.

Put a drop of loctite on everything as a secondary safety (inc the two nuts at the fixture) and it's not going to come apart without some big spanners or heat

You can add an L bracket with a eye bolt on at the top and bottom of the studding if you really wanted or another method of attaching a safety between fixture and studding so secondary the fixings and just rely on the main length of studding once, but with loctite and bolts it's going nowhere anyway and is probably more heavily installed than any AC or false ceilings 

On 1/25/2022 at 11:52 AM, Dave m said:

I am intrigued to know how much lift a Henry can generate. I force an experiment with a plastic bucket and Henry.

Is there an easy modification to make Henry blow or is it connected to the exhaust?

Are there any plans for this hovercrafts, do they tend to have a skirt or just plywood & 2x1 round the edge?

4 hours ago, sunray said:

I'd rather not use SWA for site temporaries but as far as I'm concerned there is nothing else out there for such situations.

BS7909 specifies H07-RNF, not sure what's the specific situation that would require armoured, doesn't sound too flexible. Do you use the sheath as earth conductor or have an additional core and earth the sheath too?

Sorry to resurrect an old topic for a wayward point but back when I used to tech a well known northern nightclub the fire exits were usually a bit suspect, there was often a high entry fee and what used to happen was that some punter would crash open a fire door to let all his mates who were waiting on the steps outside to rush in before anyone could get to it. They'd get in without being vetted / searched as well so it was a security nightmare, which probably could be avoided be some other means but it may explain why sometimes crash bars may have locks from the inside or there may be some resistance to fire exits being able to be repeatedly easily opened & closed at a moment's notice, obviously this isn't ideal but at least there sometimes could be some reasoning behind something rather than just plain ignorance

Firing the triacs is working fine direct from the ESP GPIO pin into the Darlington pair IC.... I have the firing working it's just the timing for the zero crossing I need. I tried something out of that transistor but it wasn't a clean trigger so I might try add my own zero crossing circuit and try that 

Thanks I did think about that too as there's some spare pads down on the bottom left behind the pin headers and I assume I could run it from the low voltage side of the transformer too. I might just add my own zero crossing as I know it'll be reliable but be interesting to know if it is already on there 

Thanks, I'll see about driving the op amp from the ESP32. I'm not planning to connect into the high voltage side of the circuit, do it all from signal side. The ESP32 is WIFI in so hopefully not too much risk to a wider data circuit, although being in the box is a problem but I'll get it working with a cheap one first before I buy one with an external antenna.

I think the way the original circuit is working is with a saw tooth wave maybe ramping up or down, and an op amp comparator. My thought is that transistor at the bottom right may switch with the AC frequency so I might just try borrow a scope and have a look. This would make sense as I couldn't work out how the original circuitry changed from a voltage to a timing.

I appreciate the thought about not modifying too much but the alternative is throwing it in the bin, there is zero chance I will ever want to run it on 0-10V again. I'm more playing with it and if it ends up useful so be it.

Hi

Apologies if this isn't the right area and should be in Workshop or similar.

I've got two old Eltec 3-channel Alphapack style dimmers that run on 0-10V. Partly to see if I can, and partly because they would be of use, I'm trying to bypass DMX entirely and see if I can modify them with an ESP32 to run directly on ArtNet. (I've got the ArtNet reception working on an ESP32 before so that isn't really the issue.)

Rather than trying to replicate 0-10V out of a ESP32, I was going to try tap into the circuitry to trigger the triac directly. It has 3x BTA16 triacs for the 3 channels.The dimmer has a ULN2004 transistor array that seems to do the Triac triggers an attaching an IO pin to this seems to open the triac. As I don't have the timing for dimming I just hit it every 1ms and it seems to open fully. The spec sheet says it needs 6V to trigger but it seems to work at 3.3V.

In order to do the timing for dimming I'd need to find a zero crossing trigger to do the timing from. Would there seem to be one on this board? Is it the transistor down on the bottom right by the earthing to the case and the finger? That seems to be connected between earth and an AC voltage which I guess would cause it to square wave maybe?
I haven't got a scope to have a look at it.

(I know there's all sorts of other problems like whether I can do the timings for the triac whilst also receiving ArtNet on the esp, how it'll get wifi within an earthed box etc, but it's more of a playing around to be honest to see if I can)

With a generator hire company, if a unit is hired out for backup generation for a church it can use red? But for filming it would require clear diesel / DERV?

I'm not begrudging the use of red diesel for funfairs, but it seems out of line with the main theme of blanket ban for commercial use. We are a school, and I guess they'll have to stop using red diesel for groundskeeping as it looks like it counts as a commercial use.

It's hard to tell who it's aimed at as it penalises construction industry but allows agricultural and forestry an exemption. The arguments that it's to drive a greener switch and more accurately reflect the emissions from these red diesel construction vehicles could apply to agricultural too?

Is it a rural vs urban split to reduce emissions in cities as most of the exemptions seem to be rural uses?

On 1/17/2022 at 2:38 PM, timsabre said:

Serial control seems to be gradually being overtaken by ethernet/IP. Every manufacturer has their own version, but the ones I have got involved with you just send an http request with some attached parameters to move the camera to an absolute position (there are also relative up/down/left/right commands for manual control). e.g. for the Panasonic cameras you send "http://192.168.x.x/cgi-bin/aw_ptz?cmd=APCxxxxyyyy" where x=8000, y=8000 is "in the middle"

Thanks for this. I'll be honest I've found one someone will lend me one but I haven't actually tried it out yet. That could be really helpful (and if we end up buying one we can but Ethernet control instead) as presumably this could be easier to do a network request from Qlab even if it's via Script than RS232/485 control. 

Thanks. We've been reviewing what we need to do and it's likely if we use the ATEM we can pair one PTZ cam up with 3 fixed cameras to make it slightly more palatable to watch. It's a production of Around the world in 80 days and there's some animations for the transitions (the boat moving across the map, etc) that the cast are going to re-create live in miniature on a map and relay to projection. What I'd thought at first was going to be one large map worked across is more likely to be 2-3 set up on different tables and moving across localised continent maps etc.

I've found the loan of a PTZ camera but programming absolute moves directly from Qlab doesn't sound like it's going to be easy, and if they're relative I'd rather not stack a whole show up based on relative moves in case they are run out of sequence.... I'll have a look at using some controller software with absolute presets and seeing if I can automate triggering that from Qlab, or use a hardware controller and maybe try control the controller presents from Qlab rather than the camera directly. (This would also give easy driving if the preset / action ended up off the mark...)

Ta. I've found a PTZ camera to borrow (event I think not CCTV) and will have a play. I'm not sure if the focus will need moving too, so I might revisit doing it with servos and control the servos from DMX/Artnet out of Qlab maybe....

It needs live video, but it could be moving between presets. It would be nice to have control of speed of movement though and maybe zooming at the end.
It could be recalling many presets along the way depending how many were needed.

The 4K camera is an interesting idea, thanks for that - I have got an ATEM that may be used for capture and maybe switching but not 100% sure yet. It's possible I could use the camera on a 'right arm' / pair of servos for pan&tilt from QLab (see how much shake the servos have) and use zooming in qlab to pull in and out. I could also have a wide camera and the panning camera and maybe switch between them either in Qlab on the ATEM controlled from qlab.

Do you know if the control systems from PTZ over RS485 are absolute or relative? does it drive like a servo to a position according to value or drive "left / right / in / out" and would need tracking from the top of the show to repeat the same moves?

Has anyone got PTZ working on Qlab through some method or other?

We have a show coming up with some live video, where there is a map on a table and puppets / characters moving around the table, and live video of the map is relayed onto a screen.

Thinking of programming the zooms/areas and some moves on the map (items are left on it so live video is preferable) so they can be relayed via PTZ camera onto projector for the show.

I have some cameras available (canon HF G50) which could be mounted on a pan/tilt gimbal , I could hack the zoom with a servo but it'd be driven blind as I don't think the camera has data control of zoom. I am assuming though I'd be better buying a PTZ camera and using absolute values to drive it..