Looking at the parameters of the Nema 17 Stepper Motor, I can't see the max RPM characteristic. I'm looking to offer three speed settings for a continuous camera track slide over 1.5m and need to work out what those speeds would be. Not being a mathematician I wouldn't know how to start about this issue but having access to the RPM would allow me to take into consideration the pitch of the threaded drive shaft on which the camera sled, with a payload variance of between just 750gr and 3kg is sitting. This motor may be overkill though as i want to have the unit as portable as possible with the power source being incorporated into the control panel and to be able to be simply recharged in situ. Given my tack will be the max 1.5m long, and the sled payload differing between .75kg and max 3kg sitting on a 5mm threaded steel drive shaft what motor meeting the criteria above would be suitable and the big question being what kind of rechargeable power solution should I look at bearing in mind there is a microcontroller within the system that doesn't like north of 5v solutions. Cheers, Mark. PS If I'm overlooking the obvious just kick me.
Hi Mark, A lot depends on the quality of your motors and their drivers but basically, you can drive 200 step per revolution motors at any desired speed up to about 900 rpm using a 24volt supply but at that speed the available torque is reduced considerably and relates to the motor’s maximum current rating. At 12volts the maximum rpm you could expect is about 400 and at 48volts it would be about 2,000 rpm. (If you want to operate everything at 5volts then I think you need to consider servo motors rather than stepper motors). Hope this helps. Tweakie.
Hey there, Thanks for the response. Is it not possible to have a solution that 'leaks' the required power to a segment of the circuit which requires less than the remaining elements? Would the torque of such a servo motor be suitable to move the camera sled? Mark.
Certainly is - A simple IC voltage regulator will do the trick. Perhaps if you describe your specific requirements and the constraints in a bit more detail it would help. Basically anything is possible it is just the degree of difficulty that varies. Tweakie.
My constraint is lack of engineering understanding in all aspects, software, CAD, CAM and all the issues to do with Electrical stuff, this is why this community is a blessing in disguise for me. My project is to make a slider as light and portable as possible that can stand alone and operate in a field, forest, beach or wherever I'm shooting without the need for mains power supply. The max payload on the sled is around 3Kg, the lightest around .75Kg.
I didn't mean your constraints rather the constraints of your intended build Perhaps look at the camera sliders that have been built so far and their associated discussions and see if there is anything there you can copy / emulate to suit your needs. http://www.openbuilds.com/builds/time-lapse-camera-rail.1307/ http://www.openbuilds.com/builds/camera-slider-for-stacking-focus.224/ Tweakie.
I have the design sorted, the wish list done and will be making the order later today or tomorrow. Just looking around for the dimensions of the V-Slot Gantry Plate? This will dictate the V-Slot track I need etc. It's just an esthetics thing, personally I don't want to have a lot of plate hanging out over the edge of my track. Cheers for the suggestions and pointers, much appreciated. Mark.
