Wallace Pro Printer Build

Started January 2017

After initially building the Mr. Wallace 3D printer I continue to improve things on it and was interested in building something for our son to play with. Interestingly he brought it up before I could when talking about his Mechanical Engineering Tech degree studies. Of course I wasn't going to say no to building another 3d printer so this will follow along the build of his Wallace.

We decided to keep it simple and just build another Wallace based device but use all the small improvements I used on Mr. Wallace and more. The build uses the basic parts from the 8mm ++ version, the original bases as I like them better, a heated 200x300 print bed, and likley a bowden feed to lower the wobble effect.

I'm pretty sold on the simplicity of the Wallace design as it is so easy to extend the Y and Z axis areas without having to rethink the design. For the Y Axis you just using longer rods and a larger bed. For the Z axis you just use longer Z rods and lead screws. You could even make it with a wider X and a 200x300mm bed turned sideways if you really wanted to and just use longer threaded rod and X smooth rods.

Below are the steps to assemble a Wallace Pro based on the parts we've used. Things can be changed as you go if you want but you should get either a 200x200x200+ build area or a 200x300x200+ area if you use the larger hot bed.

Assembling the Base

The Wallace used two core base pieces to anchor the Z rods, connect the X together and allow for some Y feet extensions to keep it upright. This image shows a few things already assembled but the base includes the three stepper motors, two for each Z rod and one for the Y Axis. For a standard 200mm wide hot bed you should space your Z rods 300mm apart. If you are using the Wallace G1 hooked ends as shown, you're threaded rods holding these together should be 450mm long. This allows enough rod to hold it together and attach the base ends but not too long with things sticking out.

You will need to install the Y Rod LM8 bearings and the bearing retainers on the base ends. This can be done in conjuction with mounting the steppers are 3mm x 10mm screws can be used to mount these. For the Y bearing retainers not going into a stepper motor, 3mm x 5mm scres and nuts can be used. Space out your Z rods with a centerline of 300mm as mentioned above and shown here and tighten the M8 or 5/16" nuts around the base blocks keeping that distance.

 

 

Y Motor Mount and Y Idler

Next you can mount the extra Y motor mount and Y Idler. Technically you may not need the extra Y motor mount but it's cheap insurance against any flexing in the existing base mount. Install the zip ties into the Y motor mount and line up the stepper motor screw holes and used 3mm x 5mm screws to attach the mount to the motor. You can then tighten up the zip ties to hold the mount to the threaded rod. I prefer to install zip ties so they loop from the bottom through the top and back down but it should work anywhere.

The Y Idler can then be attached to the threaded rod in a similar fashion. It is recommended to center the outside of the smooth pulleys in between the Z rods so you are pulling the Y axis centered. It will work in any position but you may have better results with it being centered avoiding any binding or side pull.

The Y belt routing is shown here. It loops around the stepper pulley with the back side against the smooth idler pulleys. Check the stepper motor pulley to make sure it's aligned with the idler pulleys to avoid the belt riding against a pulley edge somewhere. You will not be attaching this belt until the Y bed is completed and installed but it's best to align now to avoid forgetting in the future.

You can install the end caps if you want to at this point in most cases. This close up shows the various parts of the base ends and how it is assembled. Be sure and line up the stepper motor 3mm screws and tighten them before lining up the threaded rod bolts and tightening them down.

Tips and Tricks and Other Lies

X Carriage Wiring Bundled with HotEnd

For a Wallace setup, it's easier to actually put the X Limit switch ON the carriage and run the wire run back up with the hotend and other wiring. The wiring will be longer but you won't have to run a separate run that follows the X carriage up and down that way. I've always mounted the switches on the frame but this works out better the other way around.