TUKI Build Notes:

Motors used.

I Figured I would give some account on some of the parts used. The motors before were labeled as NEMA17. They are, however the specifications vary greatly on NEMA17 stepper motors. I purchased these on e-bay from a source that had a huge stock of used motors. They came in a pack of 5. Here are the specs advertised. I used these to wire them and they have worked perfectly and have plenty of torque for my heavier than normal delta. Not only that, the direct drive extruder seems to work properly as well. I did not use the dampeners as I fear misalignment is possible with the dampeners; I will be experimenting with the dampeners in the coming days as I get my printer to print.

  • Current up to 1.2A
  • Voltage will work with power supply 12-36VDC
  • 1.8 deg / step
  • 6 wire connection uni-polar or 4 wire connection bi-polar
  • width 42mm x 42mm
  • total length of 44 mm with damper 50
  • 5 mm diameter shafts
  • shafts length 20mm
  • Weight 12 oz.
  • Connection wires provided from 2” to 6”
  • PIN1= B-
  • PIN3= B
  • PIN4= A
  • PIN6= A-

Tuning the stepper drivers

Please take your time and setup the proper miscrostepping. I set mine to 16 microsteps. And the drivers themselves were set to .425v. So far I am not experiencing any heat issues or problems.

Here is an image guide to microstepping. Notice the jumper location under each driver. Each driver must get 3 jumpers if you want to enable the full microstepping capability. I am only pointing to the Z driver.

Here is a chart on the microstepping.

Now the voltage. I borrowed the image from the reprap wiki. However you should note the position of the stepper driver as well as the adjustment pot. The top of the pot is a measuring point as well as an adjustment point. Keep in mind to move the pot in very fine increments. The adjustment necessary is usually less than 1/16th of a turn, don't go spinning this thing like a screw. With that being said here is where you should very carefully apply the multimeter leads. Please also note you should be sinking the main IC on the driver. Do not leave it bare.

Bed leveling.

I have to say that this seems to be a dark art that no one mentions at all. I would suggest before doing anything you ensure your bed is secured and level on its own. I do not suggest a spring loaded bed. I suggest you mount your bed on cork instead. Preferably 3 layers. This will give the bed enough give without having a mess on your hands.

With the above said, I have to give a big thanks to MINOW for creating an excellent guide.

Now I know people tend to implement auto bed leveling. I chose to manually level my machine. This way it will give me sanity to get the system running properly. The process is tedious. I suggest you use a caliper and a stack of business cards. This will give you some idea on how much to vary the variables. Once you get to the point of having a single business card under the hot end you can switch to A4 paper as most do. This will put you in the ballpark and give you absolute control of the device your building. 1/2 the fun of building a machine like this is to enjoy doing it yourself, knowing it better than anyone else. Go slowly and get it done right.


If your considering building one of these machines you must have tools. Here is the list of tools I found absolutely necessary.

  • Multimeter with a temperature probe
  • A set of calipers (I used a 250mm capable digital set)
  • Needle nose pliers (Set of two, fine tipped and coarse)
  • A drill press or hand drill.
  • X-Acto Knife.
  • a small socket set in either metric or standard. Both if you have mixed hardware like I do
  • PATIENCE. This last part is critical, think before you do.

Bruno M.

Engineer, Tinkerer, Technologist, Maker.

New York

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