First, you're going to have to drill out all the holes for the parts to go into. I've included a LibreCAD document with the measurements of where the holes need to go.
Throughout this whole section, I will be referring to the piece of wood the tracker is on as 'the board' or 'the main board.'
For this part, you'll need:
- A drill or drill press
- A 3/8" drill bit
- A 11/64" drill bit
- A 1/4" drill bit
- A 1" spade bit
- A 3/4" (1" nominal) thick piece of wood. I used a piece of 1x12 pine that was around 18 inches long that I had left over from something else. As long as the wood has a length and width of at least 6 inches each, you should be fine, just keep in mind you will need a bit more to cut a riser for the stepper motor.
- A saw. I used a jigsaw, but if my table saw was set up, I probably would have used that. You don't have to cut anything super straight, which is one of the reasons I was okay using the jigsaw. If you want the exercise, you can also use a hand saw, but it will just take way longer.
Here's the design I drew up in LibreCAD. This file can be downloaded by clicking the 'download project zip' button in the 'Code' section. For some reason, it doesn't play very well with Illustrator, but if you need to, you can always open the dxf in LibreCAD. Keep in mind this is only really intended as a guide for doing it by hand. I have no idea if this will work were you to get it laser cut.
I purposefully did not label the distances between the 1" diameter hole, the holes for the tripod plate, and the rest of the design because the location of those three holes will really depend on your setup.
1.1 - Drill two holes for 8mm rods. I used a 3/8" drill bit for this. Yes, that is a brick holding the platform up; My drill press is really old and the clamp no longer holds the platform in place.
1.2 - Drill four holes for mounting the pillow block bearings using an 11/64" bit.
1.3 - Now, you're going to want to drill four holes for the bolts that hold the stepper motor on using the 11/64" bit. It is very important to make sure these are aligned properly. After I did the first two, I dry-fit the motor mount to make sure it was ok before continuing on to the last two.
1.4 - Cut the riser for the stepper. Mine was about 55x50mm. I cut mine out of another piece of 1x12, so it was 3/4" thick.
1.5 - Now, clamp the riser to the board and drill through it to copy the holes in the main board to the riser. You should still be using the 11/64" bit. I used two clamps and put a bolt in the newly-created hole to keep everything in place before I removed a clamp. Make sure to make a mark on the main board and riser so you remember the orientation it was in.
1.6 - Drill the hole for the polar alignment scope. I first drilled a pilot hole with the 1/4" bit and then drilled the hole with the 1" spade bit. Take extra care in making sure this one is pointing straight up and down. For spade bits, it's very helpful to have a second piece of wood under the one you're drilling into so you don't accidentally drill into whatever platform you're drilling on. Also, drill very slowly to prevent cracking the wood. This isn't the same piece of wood you've seen in the other gifs since I forgot to film it the first time around, but the idea is the same.
1.7 - Drill the holes for your tripod plate. You want to make the holes close to the left/right center of mass to avoid unnecessary stress on the mounting hardware. In my case, my camera with counterweights weighs around 10 pounds, so I drilled the holes pretty near where the camera itself is mounted. The tripod plate I am using has a hole for a 3/8" bolt and a hole for a 1/4" 20 bolt. Use the same size drill bits, so a 3/8" bit for the 3/8" 16 bolt and a 1/4" bit for the 1/4" 20 bolt.
In this section, you will assemble the board, attaching all of the parts except for the electronics. You will need all of the parts you purchased and you will also need all the hand tools mentioned in the 'Parts & Tools" section.
2.1 - The first thing you're going to want to do is to attach the pillow block bearings. Using four M4x40mm bolts and 4 M4 nuts, tighten them up. Make sure the heads of the bolts are on the opposite side from the stepper motor so the 2gt pulleys will have enough clearance.
2.2 - Use the 5mm to 8mm shaft coupler to attach the 5mm rod to the 8mmm rod. You may want to use a Dremel to shorten these rods as I've done here, but that is not necessary. I cut the 5mm rod down to about 34mm, although you could go a bit shorter, and I cut the 8mm rod to about 90mm.
Then, insert this rod into the set of pillow block bearings nearest to where the stepper motor will go. You want the 5mm rod on the same side as the stepper motor. The bearings are self-aligning, so they may be a bit skewed. I had to put a lot of lateral pressure on the rod to get the bearing to align how I wanted it to, and even then, it wasn't very easy to fit in. If you're having trouble, you can always try the age-old technique of whacking it with a mallet until it works.
2.3 - After that, attach the 100 tooth belt drive pulley to a different 8mm rod. Mine was a very tight fit, I actually had to hammer it on with a rubber mallet. I pushed it on so there was about 12mm (0.46 inches) in-between the top of the pulley and the end of the rod. Don't put this into the pillow block bearings just yet.
2.4 - Attach your stepper motor mount with the 4 M4X50mm bolts and the four M4 nuts. I only used 3 since I slightly messed up the alignment of the fourth bolt, but that was more than enough to hold it in place very securely. Don't make this super tight as you may have to move it around a little bit to get the stepper motor properly aligned.
2.5 - Attach the stepper motor with the included mounting hardware. I know, I know, there are only 3 bolts on my stepper motor. It is possible that one of the bolts may have fallen into the black hole known as the underside of my workbench from which no hardware has returned alive.
This is also a good time to attach the worm gear. You want to attach the longer end to the 5mm shaft on the stepper motor and the one that looks more like a 'normal' gear to the 5mm rod already on the mount. Attach the gear close to the coupler, tighten it down, and then tighten the bolts on the pillow block bearings so the rod stays in place. At this point, you'll want to make sure that the motor is making good contact with the worm gear through a whole rotation. Do this by spinning the shaft the long gear is on. If it is not, remove the stepper motor and try to move or rotate the mount slightly. Do this until the worm gear is properly aligned.
2.6 - Next, attach the belt drive. Put the belt on the pulleys and then attach both of them to their respective rods, pushing them to the bottom and tightening them. My 100 tooth pulley was a very tight fit, so I actually had to attach it to the rod first, and then insert both of them into the pillow block bearings.
2.7 - Take the 3/8" male to male bolt and insert one end into the 3/8" end of the 3/8" to 8mm coupler. Tighten the 3/8" side and put it on the 8mm rod. Push it in until it won't go any further, then back out a millimeter or two. Now, loosen the 3/8" bolt and re-tighten it, making sure that it is flush with the coupler. If it is not flush with the coupler, rotate it a bit and try again. This will probably take a few tries to get right.
If you're worried that this will not hold, I would recommend putting some super glue on the threads of one side of the 3/8" bolt.
2.8 - Screw the quick release clamp into the exposed side of the 3/8" bolt. If you want, you can hold the 3/8" to 8mm coupler with vice-grips while tightening to make sure it's pretty tight.
2.9 - Attach the tripod plate. You want to screw the bolts into the threaded part of the tripod plate you normally use to insert the 1/4" 20 or 3/8" bolt when you're mounting a camera.
2.10 - Now, you're going to want to attach the alignment scope. Note that I didn't drill the hole in the same place as you probably have. That was due to poor planning on my end causing me to run out of space. I've included a .stl in the project zip that will adapt the scope to a 1" hole. Sadly, my 3D printer is currently being a little iffy, so I wasn't able to test this. If you don't have a 3D printer, I'd recommend putting some electrical tape around the threaded portion of the alignment scope and press-fitting it. It isn't perfectly aligned in this picture. When you're taking photos, make sure it is perpendicular to the board.
First, you're going to want to solder headers to the TMC2226 breakout board. Solder them so that the top of the PCB (the side with the SMD components on it) is facing down.
Next, connect all the wires. I like using alligator clips to connect the stepper motor to the breadboard because they're really easy to attach and detach. Make sure that the 100uf capacitor is facing the right way. You want the side with the "-" to ground. That side often has a white stripe as an indicator. It'll be pretty obvious if you put the capacitor on backward because it will explode as soon as you apply power. Note that the Feather board in the Fritzing image is a Feather M0, however, you should be using a Feather M4. I just couldn't get the Feather M4 Fritzing part to work right. Also, the TMC2226 I've got in the Fritzing image is just a modified TSSOP-20 breakout. The pinout is the same, it's just not as wide as the TMC2226-BOB.
- Feather pin 6 to TMC2226 STEP
- Feather pin 5 to TMC2226 DIR
- TMC2226 pin +Vcc IO to Feather 3V
- TMC2226 pin MS1 to common GND
- TMC2226 pin MS2 to Feather 3V
- TMC2226 pin +VM to 12V
- All TMC2226 GND pins to GND
- TMC2226 pin B2 goes to stepper wire B (gray)
- TMC2226 pin B1 goes to stepper wire D (green)
- TMC2226 pin A1 goes to stepper wire A (red)
- TMC2226 pin A2 goes to stepper wire C (yellow)
You can power the Feather through the USB port or through the JST port. I prefer the JST port as the power banks I tried using shut off after a few minutes of powering the Feather. I've used LiPos and AAA battery enclosures and they both worked great.
To attach the breadboard, I'd recommend peeling off the piece on the bottom that covers the adhesive and then sticking it to the board.
You're going to want to attach a ball head to one end of the plate, and attach the weights to the other end. To balance the camera plate, attach the camera and try balancing it on top of a pencil to find the center of mass. You'll have to re-do this when framing your shot, but it's good to get a general idea how to do it when there's light.
Additionally, only use the weights you have to. It's much better for the mount to use one weight, even if you have to attach the tripod plate at the very end as I did in the time lapse gif of it moving.