{"id":413,"date":"2011-11-06T19:27:02","date_gmt":"2011-11-06T09:57:02","guid":{"rendered":"http:\/\/www.l8ter.com\/?p=413"},"modified":"2011-11-06T19:27:02","modified_gmt":"2011-11-06T09:57:02","slug":"diy-timelapse-dolly-rig-powered-by-arduino-and-openmoco-part-2","status":"publish","type":"post","link":"http:\/\/www.l8ter.com\/?p=413","title":{"rendered":"DIY Timelapse Dolly rig powered by Arduino and OpenMoco Part 2."},"content":{"rendered":"

This is a continuation of my previous post\u00a0http:\/\/www.l8ter.com\/?p=390<\/a>\u00a0. This post will basically focus on the building of the dolly and getting it ready for the miniE controller.<\/p>\n

So here was my\u00a0initial\u00a0brain storm;<\/p>\n

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After thinking about it for a while longer it looked more like;<\/p>\n

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I\u00a0didn’t\u00a0see any need to design it fully rather I went and built it off the cuff.<\/p>\n

I grabbed;<\/p>\n

\"\"<\/a>\u00a02m of Aluminum C channel, I was wanting 40x40mm at 3mm thick but\u00a0unfortunately\u00a0they\u00a0didn’t\u00a0have any so i settled with 25mm * 40mm @ 3mm thick. I think if i were to do it again i would try and get 50mm \u00a0high in the center, 25mm is fin for the top and\u00a0bottom\u00a0however. The C channel is for the runners either side, it should be cut into 2 x 1m lengths (Or longer if your going longer)<\/p>\n

\"\"<\/a>1.5m of Aluminum flat bar 50mm width by 3mm thick. the 50mm flat bar is used for braces to keep the C channel from moving.<\/p>\n

1m of Aluminum flat bar 25mm wide by 3mm thick (any where from 15mm \u00a0onward\u00a0will work.). This is used in several places e.g to hold the dolly platform to the nut on the screw drive, to securing the bearing.<\/p>\n

3mm aluminum plate 160mm*140mm this is for the platform, this will be what you attach the tripod head will mount to.<\/p>\n

I got all the above metal for about $56<\/p>\n

\"\"<\/a>\u00a01m 3\/16″ (Or whatever size you want to use) threaded rod to work as the screw drive system (Bunnings has this)<\/p>\n

\"\"<\/a>1x bolt for the above threaded rod<\/p>\n

Additional Hardware;<\/p>\n

Optional: Drill press (But it makes life a hell of a lot easier)<\/p>\n

\"\"<\/a>4x Roller wheels (used in kitchen drawers, sliding doors etc, These ones are rolltrak wheels 4060, easy to get a Bunnings hardware stores but they are a tad hexy at $9 each.<\/p>\n

Pack of 10 short (~10mm) 1\/4″ bolts and nuts<\/p>\n

Pack of 10 long (~30mm) 1\/4″ bolts and nuts<\/p>\n

Pack of 30 1\/4″ flat washers<\/p>\n

Pack of 10 1\/4″ wing nuts (to help with tightening or loosening parts in the field.<\/p>\n

Pack of 100 rivets \u00a01\/8″ width and 3\/6″ grip (enough grip to do 6mm – 9 mm thickness)<\/p>\n

Drill bit to suit rivets<\/p>\n

Pack of small cable ties<\/p>\n

Optional: 4 rubber feet<\/p>\n

Hose clamps (smallest)<\/p>\n

\"\"<\/a>Bearing 3\/16″ flanged (lawn mower shop, skateboard shop etc), friend Chucky hooked me up with this one, a tad expensive at 20 odd\u00a0dollars\u00a0but great quality, and local pickup).<\/p>\n

\"\"<\/a>\u00a02x Parallel (Or in my case I used DB9 Serial port as i only needed 9 cables as i didnt want to use the focus line and i already had the parts)<\/p>\n

So lets start some light\u00a0walk through\u00a0of what I did (If you need more detail just leave a comment and i will get back to you)<\/p>\n

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Using a jigsaw and an aluminium blade I cut the 2m C Chanel in half, I then cut the 1.5m of 55mm flatbar into 8 sections of 180mm. One one piece of that 180mm into 2 pieces of 90mm.<\/p>\n

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Using the stepper motor (Same one from part 1 of this tutorial), I cut out a section of \u00a0one of the 180mm 55mm flat bars to help the motor sit flush (This is only needed with the 40mm height C channel, So the motor sits flush).<\/strong><\/p>\n

THE BEARING END OF THE DOLLY:<\/p>\n

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I clamped together one of the 55mm flat bar and the parts of C channel , and drilled 4 holes at 25mm from each edge FOR THE TOP SIDE, BEARING END. Each time I would get one hole drilled I would insert the rivets to help stop the dolly moving.\u00a0On the\u00a0UNDER SIDE OF THE BEARING END I put 2x 180mm pieces of the flat bar to give a mounting point for 2x tripods in future (one each end).<\/p>\n

NOTE: when one side is complete measure the gap EXACTY, then ensure when drilling the other end that the gap remains constant (+\/- 1mm), Otherwise the platform may have un wanted movement when sliding down the frame. Once those both ends are done then drill the center underside mount, again ensuring the gap doesnt change.<\/strong><\/p>\n

THE MOTOR END OF THE DOLLY:<\/p>\n

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Pardon the recent image, i\u00a0didn’t\u00a0take an early image of this part) Again the underside is made of 2x 180mm *55mm flat bar (1x piece with the motor cut out if required as per instructions a few images above), Again for the underside I drilled 4 times, once in each corner 25mm from each side. The top however for this end will be\u00a0removable\u00a0to help fix and replace parts in the field, So it is drilled on opposite corners using a 1\/4″ drill bit and secured using one of the 1\/4″ short nuts and wing nuts. I also drilled and cut out a hole for my DB9 connection or in most peoples cases the parallel port, then secured using some small screws and nuts i had\u00a0lying around the shed.<\/p>\n

THE PLATFORM THAT TRAVELS ON THE DOLLY RAILS:<\/p>\n

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This bit is a bit fiddly and this is where you could do a little bit of maths to work out where the wheels should go to fit snuggle between the rails. I\u00a0didn’t\u00a0go the maths route as such but this is how i did it: I put one wheel on it\u00a0approximately\u00a0where i thought it should go, marked that spot, then using a set square I marked where the second wheel should go (on the same side) and drilled the first 2 1\/4″ holes for the wheels, i then mounted using two of the longer 1\/4″ bolts and wind nuts. I then sat the two wheels on one track (lets say for example the left track) then upside down i put the 3rd and 4th wheel on, and marked their position. I then drilled about 1-2mm closer to the edge than my markings to ensure a tight fit eliminating any vertical movement. (I actually had an issue where somehow my square of aluminum wasnt square so my 2nd initial wheel wasnt in the right place (so the dolly was loose). I fixed it by expanding the hole drilled on the aluminum platform so the wheel can be where it needs to be, then cutting a piece of the smaller flat bar (about 40mm long) and drilling a 1\/4″ hole then moving the wheel to where it needed to be. Then drilling 2 holes for rivets to hold the fix in place. (This is why people use plans :P)<\/p>\n

MOUNTING THE MOTOR TO THE END OF THE DOLLY:<\/p>\n

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This bit is fairly confusing and\u00a0difficult\u00a0to explain. This stepper motor mount sits on top of the end piece of the dolly like…<\/p>\n

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I bent one of the 90mm long 55mm wide flatbar in a little less then half (55mm * 35mm) just by putting it in a vice and\u00a0hammering\u00a0it into a right angle. Using a piece of scrap\u00a0cardboard\u00a0i built a\u00a0rough\u00a0template for the stepper motor. I put the motor into the dolly and screwed the top down, then I marked where the center of the motor is using a pen. I then trilled a 1\/4″ hole into the center of this marking (the shorter side), The hole is bigger so we can move the motor to the spot needed.. I also drilled 2 1\/4″ holes in the top half (the longer bit), and the top of the dolly. I then bolted it together and used the cardboard template i marked the two screw holes that needed to be drilled out for the motor to mount to, then using some screws i mounted the motor on.<\/p>\n

CONNECTING THE MOTOR TO THE SCREW\/THREADED ROD:<\/p>\n

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With the threaded rod I ground flat\u00a0about\u00a02cm of the rod, This is to help the hose and clamps to grab.<\/p>\n

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(yes i did show this picture before, but this is for a different reason) I also ground down the motor drive pin so it had a flat spot on it, again to help the clamps lock on to the pin.<\/p>\n\n\n

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