(New Updates below! – 23 Januray 2012)
I bought a bunch of DSLR equipment lately and one of them is a Indian made IGUS styled slider. Though it worked very well manually, I still can’t get it to slide at a constant rate. Motorizing the slider came to mind but I didn’t know how to go about doing it.
Thanks to DSLR filming enthusiast websites like Cheesycam.com I saw a post which featured a DIY solution. http://cheesycam.com/diy-camera-stabilizer-motorized-igus-slider/
I was inspired by this video and figured that, hey I can do this too!
The first thing I did was I bought a really cheap electric hand drill and used the spooling method to drive the slider. The torque from the geared hand drill worked pretty well, unfortunately, it was noisy as hell and I had no way of securing the hand drill and the slider moved in fits and starts. The RPM was also way too high and inserting a potentiometer between the motor and power supply is not the best way to control the speed which I quickly found out. I gave up the idea of using the hand drill motor as the slider drive unit.
From my research and consulting my electronics expert older brother, I found the best way to control the speed of the motor is to use a PWM unit. http://en.wikipedia.org/wiki/Pulse-width_modulation
Using a PWM controller will deliver power effectively to the Geared motor. So I went on Ebay and ordered a 60rpm 12V DC high torque geared motor and a PWM controller. ****update**** I realized that the PWM board comes printed in Chinese so for anyone who doesn’t read chinese characters, here’s an image to show you how I connected the board.
I got these in about 2 weeks and 3 days ago started putting them together. 2 weeks prior, I went to buy parts like steel brackets and hose clamps to secure the motor. I also bought sliding door roller bearings to act as a pulley for the nylon cord. I initially used cheap plastic nylon rope but these were too slippery and changed to 2mm braided nylon cord instead. I also bought a plastic box to protect the electronics. Along the way I bought a heavy vice to secure steel brackets for drilling. I used these modified steel brackets to secure my Indian follow focus unit on my DSLR and it worked very well.
My motor came with a 6mm shaft and I have a hard time trying to attach it to a suitable pulley. Initially I used a coupler to convert the 6mm to a 4mm shaft attached to worm gear which I hoped could be used to drive the nylon cord, it worked well but only for one direction. I gave up the coupler and worm gear idea and decided that I needed a faster motor and also a way to securely attach a pulley onto the motor. A quick trip to the local Electronics dealership, I bought a new, faster and more powerful motor at 130rpm. And I was very lucky to find a rubberized Pulley that was originally used in Factory automation.
This Rubberized pulley created a lot of grip even on a single cord. As my later experiments showed me, a single cord is not enough, I even wrap it once around the pulley and it gave a lot of grip but the cord kept entangle on itself and caused a slight shake during the slider travel. The pulley is extremely well made but it had a drawback, it had a 9mm diameter hole whereas my motor shaft is only 6mm, in a flash of inspiration, I took a small 8mm aluminum tube section, saw it in half and placed it between the pulley hole wall and the motor drive shaft. The grub screw on the pulley steel section is screwed in tight. Though the pulley did not spin perfectly center, it is good enough for me.
Underneath the slider I attached a steel brace which was meant for mending wooden furniture. I drilled a hole right at the center and attached it below the slider. The 2 ends sticking out will serve as anchor points for the nylon drive cord. An aluminum tubing section was used to secure the nylon cord end. The cord is strung through the door slider roller pulley on one end and pulled very tightly to ensure grip on the other end on the rubber pulley.
The motor with the pulley is secured with a 90 degree steel bracket and hose clamp. Washers are used to lower the height of the pulley. The gearbox casing is very strong and I’m able to tighten the hose clamp around it to the steel bracket. Holes on the steel bracket had to be widened for the screws.
Its a good thing I have a lot of washers, nuts and bolts with the same thread size for securing photo devices, and I used them a lot in this project.
Here is what the whole thing looked like.
I bought a black plastic box from the Electronics parts store to keep my PWM controller safe and easy to handle. I had to drill holes and cut a slot for the power cables and switches. A gelatin based plastic optic fibre is used to stream light out from the power LED.
Other Images of my motorized slider
Action Videos! And yes you can control the speed on the fly!
I am quite surprised myself how successful this went, but the motor slider is not perfect. It still stutters a little on the return slide, but I attribute it to cord vibration due to slippage. I will be experimenting with 2 cords to act as a drive belt for the slider and see whether it gives me better results.
I hope my experience here will inspire you to try motorizing your IGUS sliders!
Happy DSLR film making!
I have just concluded some R&D tests and found out that the jitter movement is caused by an improperly aligned pulley and lack of grip using only 1 nylon cord. After re-adjusting the motor and pulley and using double the length of the cord as a drive belt, most if not all of the jitter is eliminated. It is also noted that for proper function the slider must be secured properly. I am able to traverse the slider at very slow speeds and get very smooth shots.
Below are some of the modifications.
New motors are bought, a 5RPM motor and a 65 RPM motor. Result, the 65 RPM motor gives a slower and smoother slide. The 5RPM motor is great for time lapse photography.
I’ll let the pictures do the talking.
Time Lapse Madness!
Here’s me making a fool of myself! Enjoy!