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Permalink Reply by Simon Tytherleigh on February 10, 2019 at 1:48pm

Hi Cameron
I have designed and built a couple of moco rigs, and there are some threads on this site with pics and some details.
Also there are some good videos on YouTube by Edu Puertas about his own rigs.
Something you need to bear in mind is that you require slow speeds and high torque for the stepper motors. I am using the high precision geared steppers from stepperonline, and they seem pretty good - acceptable backlash. But these steppers need to run off something like 24V and 1.6A. I don't think the motor illustrated in the Amazon ad would be strong enough.
Also consider if you need more than one axis. Track is relatively easy to achieve using a commerically available slider - there are good and bad ones of these as well. For a small moco rig Edu's method of using a belt works well. For pan and tilt you need to construct an arm that can support the motors, the camera and accommodate the gear train or belt. Then for the focus you just need some of those plastic focus rings to fit the lens and a small stepper to align alongside.
It is of course possible to buy a professionally made unit, but these are expensive. Have a look for other threads about moco rigs on this site, and consider if you have the necessary skills/equipment to construct one.

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Permalink Reply by Simon Tytherleigh on February 10, 2019 at 1:52pm

BY the way, the Arduino kit you linked to would be capable of being controlled by Arcmoco in Dragonframe. You need a 12V power Supply to run the stepper motor.
This set-up would be able to operate a simple movement of something fairly light - I recently used a motor to give the rise and fall of a sleeping person.

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Permalink Reply by Simon Tytherleigh on February 10, 2019 at 1:53pm

BY the way, the Arduino kit you linked to would be capable of being controlled by Arcmoco in Dragonframe. You need a 12V power Supply to run the stepper motor.
This set-up would be able to operate a simple movement of something fairly light - I recently used a motor to give the rise and fall of a sleeping person.

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Permalink Reply by Cameron Grant on February 20, 2019 at 6:57am

Thanks Simon,

I will look into those. I'm familiar with Edu's amazing work. I was unsure weather the board would work with Dragonframe or not but know I know I'll just have to worry about the motors. Could you recommend any motor's that are strong enough? If it helps the camera I use is a Canon EOS 1300d.

Thanks.

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Permalink Reply by Cameron Grant on February 20, 2019 at 6:57am

Thanks Simon,

I will look into those. I'm familiar with Edu's amazing work. I was unsure weather the board would work with Dragonframe or not but know I know I'll just have to worry about the motors. Could you recommend any motor's that are strong enough? If it helps the camera I use is a Canon EOS 1300d.

Thanks.

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Permalink Reply by Simon Tytherleigh on February 22, 2019 at 3:07am

Dragonframe's Arcmoco can use several types of board. The Arduino Uno gives 4 axes and the Mega up to 8. So you need to decide how many motors you want to control.

The shield that fits on top of the Uno has drivers for 4 motors, and you need to do some bridging of connections to get micro-stepping. Otherwise it is ready to go once you have a power supply for drivers and motors. (The drivers are the units on the shield). 

If you use a Mega then you will need separate drivers. I use the black box type, as I discovered the Big Easy Drivers would only handle 1A, and the geared motors were all 1.6 to 2A. The black box drivers can be bought for about £6 each, and they have switches for microsteps and different amperages.

I recommend going to OMC stepperonline, who do a wide range of motors and have been very efficient in dealings with me. Have a look at their high-precision steppers, something like a 30:1 would be good. https://www.omc-stepperonline.com/precision-planetary-gearbox/

This will give you plenty of torque and not too much backlash. Run it off 24V power supply. If you go for a track and belt like Edu, then you can get away with the ordinary geared motor, which is a bit cheaper, as the backlash is not amplified. But for the tilt and pan, where you need a further gear reduction or belt system, the backlash becomes unacceptable with the basic motors. And this is where you need the torque that a gearbox provides.

Edu's solution was to go up to the NEMA 23 size of motor and use them without a gearbox but using a worm gear. This is also a good way to go, but the motors are bigger and heavier than the NEMA 17s. 

One final thing about the high precision motors. The brackets to mount them have to be slightly different to the normal motors, and I have not been able to find any online. So I bought some alloy angle brackets suitable for the normal motors and filed them out. Just another little nuisance!

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