Im just starting to build some kind of re-usable "stage" for my upcoming stop motion masterpieces. Im probably going to get into the whole Moco question, with stepper motors and arduinos and sliders etc.
Right now I have a slider, mounted on tripods, a few good lights... and...
An old table that I think would make the basis for a good "stage".
Before I jump right in Id like to ask a fw very simple questions to save me the heartache of finding out the long way. Hope you guys can oblige with your experience.
1) What is a good working height? Currently the table is just 40cms high and I was thing to increase it to about 1m, or 90cms. Assuming I will be sitting here for many hours leaning in and out, what would be a good ergonomic hight?
2)I have variable colour on my lights, and I may get arty (probably actually) with gels etc, but would you normally shoot tungsten or daylight colour?
3)Assuming I only have a regular slider for left/right moves, Are there any cool ways to track in and out (In the old days I used to move the whole scene (on squared paper to time to moves) towards the camera, but that was completely wrong really as the lights didnt move, so shadows would move... I didn't notice it much then, but I do now. Im think of making sliders on each side of my table that the camera slider can move on... Is this a known way? How DO you do tracks?
Im sure there will be many more questions... but maybe...
Can I ask?
Can you guys share pics of your stages, if they seem relevant to what IM try to achieve.
Maybe I can make a "build series" ? so here's my starting place...
Thanks for the clarification Simon.
After further looking, I must say that's probably a bit expensive for what it is too. Yah I just googled Black Box stepper motor and up that came...
Im waiting to see if I win a cheap EBay... if I do thats kind of defining some part of my route... Im glad I have limitations, would never make up my mind. Yes, I dont think either the electronics cabling or any programing will be an issue, Not sure about having to fabricates stuff though I dont have the tools for metalworking, and no 3D printing (yet) So its those bits I need to source really... the motors and drivers Ill just figure out, but you have pretty much shown me the right way now.
cheers again and Happy Corona Easter
Hopefully we can continue the discussion sometime.
The idea of having a bunch of 3D printable parts that can be assembled with stock extrusions and bearings etc into a working rig would, I think, be attractive to quite a number of people. Even without a printer, it is possible to get stuff made. So that's what I aim to be working towards with Luke Bosshard, who designed the DIYnder that I reviewed recently and have been beta testing for him.
Happy Easter to you too!
One question for folks who have actually DONE this before.
In DF, can you connect one movement axis thingy (sorry dont know what its called) spline(?) to TWO motors? or wire them up so ONE axix in DF sends exactly the same to two motors?
You see what IM wondering, if I used these linear actuators from open builds on either end of my slider, I could do a controlled rise? They look like they might be strong enough, but only if I can control the left and right motors precisely.
(Or if I had an extremely precise pulley weigh thing on one side?)
I made a drawing...
The green is the track and dolly slider, the red is the rise and lower actuators?
I realise this seems very specific and not very flexible, but Im working with very specific type of models, very theatrical, like a toy theatre, so this works perfectly for me... (Note the proposed rig for set hangings...might not be totally like this, but... maybe)
These are lines that I have also been thinking along. Let me say first up that I have not made anything with two steppers, but cannot see why it should not work.
The Arduino sends a message to the driver, which translates it into stepper-speak, i.e. direction (only two options for rotation) and steps, i.e. the number of steps to take. Each step describes 1.8 degrees of arc, or a fraction of this with micro stepping. So if you use the same driver for both steppers and those steppers are identical, they should move the same, assuming you have wired it all up the right way round! Hence the need for those enclosed drivers that can handle up to 4 amps...
A comment on your diagram. The moveable arm on which the camera rests is very susceptible to twisting and letting the camera droop especially when extended. Instead of having an arm like that in mid air, why not have two motors driving the vertical supports along tracks at the base, then the camera support just needs to travel laterally along one axis and is never far from the attachment point?
Going a step further, it is possibly to turn all this upside down and have the camera rig supported from the ceiling, giving lots of space for animating.... Very like the Ditogear Animators cube solution.
You have identified the reason why a jib arm can be so useful, because it can be balanced with weights on the back, but as you say not cause the whole rig to move in towards the playing area. Except that a jib arm still requires a moving dolly truck...
If you are going down the linear route, then try to make the width of the X axis plate as generous as you can to resist the torsional loads better. A wide right angle aluminium bracket on each vertical actuator?
The reason the droop might be a problem is if you need to do a second pass and it should line up. This is where the engineering starts to get more challenging!
Looking forward to seeing your progress!
Ill just have to try the droop... Im expecting a pan tilt head in the post soon, so I suspect the answer comes shortly after that. Having to do a second pass (wire/rig removal, I suppose you mean) is not a technique I have used much. I routinely use AE in my day job, so "doing it" is not an issue, but my stuff, has a tendency to be just so damn blurry, Ive never had to remove a rig. My things look a bit like puppetry too, so the odd wire in shot doesnt matter. plus I can just avoid a dolly shot if Im gonna remove stuff later.
One small technical question.
In regards to motors, when you mention "1.8 degrees of arc" IM kind of assuming that smaller is better, so for my macro stuff would it be best to pay a little axtra fot these that have 0.8?
I don't think this matters, as you will be using 1/32 microsteps, which can be dialled in on the boxed drivers I showed you. The steps are so tiny that it is pretty much impossible to see the movement if it is one step. My DF Arcmoco usually has a movement translating into thousands if not tens of thousands of steps. bearing in mind that you are using geared down motors and the 1.8 degrees refers to the bare motor shaft. If you gear down 1:6, that becomes 0.6 degrees per step/32 microsteps = 0.018875 degrees. Small enough for you?!
Much more important is backlash, as this is not controlled so easily. So everything has to have really close fitting gears and bearings etc. No sloppiness acceptable!
Hi, It's been awhile since I posted. I've been busy though. I have scrapped the original table I showed at the start of this thread and gotten myself an AMAZING find.
In a farm barn (Norwegian readers PM me for the location and phone of the farmer) I found a stage. Literally a many part stage (photos soon, it currently dismantled for some engineering, Im shortening the legs by 10cm, its 110cm bit too high for me) I bought 2 parts of the stage. Basically they are huge sturdy (heavy) 1m x 1m tables on thick aluminium legs.
So my plan now is basically to use the legs from one table as pillars at the four corners of the other table. The moco rig will therefore be hanging between them. I have totally fallen in love with the lead screw version of an actuator, as opposed to pulleys, I feel they must be more accurate with less error. Am I right? especially in the vertical central (Is it Y axis?). And possibly less fiddly to build.
Now, on a (roughly) 1 meter square table I want it to be 1.5 meters in Z depth, therefore hanging over at the front by half a meter.
I bought a Xslider from Rat Rig, and unfortunately it's not gonna work for me. way too bendy with the pan/tilt head I got cheap off EBay. Possibly not the best and motors and electronics just getting chucked (A Sevenoaks.. I see various version of the same thing with different logos...) A bit heavy, but its what Ive got and I got it for £70 so... beggars cant be choosers.)
Im tempted to just SELL the Rat Rig slider, but am wondering if it could be used as the cross gantry (shown in the pic in green).
So to the questions:
1) The picture shows all the axis but one powered by lead screws. (Blue motors) But the aforementioned cross gantry cant fit like that as the motors need to be on the end. So I'm contemplating using the pulley method here only, to motorise the movement of the central Y pole. The images shows red boxes for 2 possible places to connect a motor (oops one box looks white) ... using pulleys.
2)The only problem with a X slider of 1.5m is that I cant find any lead screws for more than 1 meter. Is this for a reason? like ha ha ha... are you Bloody mad,. you cant possibly screw 1.5 meters...think of the torque /stresses/power requirements... idiot ... or does anyone know a source ...scandinavia preferably)
3)This looks remarkable like the dito moco... heh heh... which looks lovely... and theoretically could be also connected to the ceiling (I do have a concrete ceiling) But...I dunno.. it feels a bit... er... permanent. But out of your experience am I gonna seriously regret those 2 pillars at the back...getting in the background of sets... I mostly use a green screen background so the poles could be painted green. anyway tis the only design flaw I can see.
Comments before I start slowly buying it (bit by bit as my finances allow).
OK No comments... figures.. I always post huge long essays... not sensible.
Ill keep it simple
What's the difference between a NEMA 17 (that appears to be the norm) and a NEMA 23 (That is super popular on EBay "packages"...
Is there a question of torque I need to consider, (I dont understand Torque)
Whats a good number?
Justin Rasch has some good point in his latest video