Putting it all together questions

I’m about to start my build and was just test fitting my printed parts with the new hardware I just received from the store. I have a couple questions that might be obvious once I actually start putting it together but I thought I would ask just in case:

[ol][li]How do I secure the smooth rods onto the XZ_END & XZ_Motor part? During test fitting the rod are snug but not snug enough for them to not move. [/li]
[li]How do I secure the MK_MOUNT_3 part onto the X part? [/li]


the motor side is stopped by the motor screws, the other side gets snugged up by the bearing screw, or a drop of superglue your choice.

The mount should clip on so damn tight it can’t move.

I added some thin double sided scotch tape to the 2).

The mount 3 Shouldn’t need tape, but it won’t hurt anything either. The mount 2 would relax over a few months, so far so good with #3. Kinda cool now I have a good thickness gauge for structural stuff in Printed parts because of it.

Oh, maybe I have mount 2… Will mount 4 have a spot for the autolevel sensor? :slight_smile:

There isn’t room after I stick the parts polisher on there.

Am i missing something? Mount 2 and 3?

Nah your good, mount 3 is the right one.

I use a single layer of blue tape to snug up the snap fit of the mount. Without it I see drift on the X axis. No idea what version number though.

So, I’ve completed all the milling for the MP3DP. I’m using 1/4" MDF (couldn’t find 3/8"). I also milled a 1/2" MDF base(Jeffeb3’s design…thanks for fixing the dxf on TV Jeff).
I’ve cut two sets of the XY_Frame, one set in 1/4" and the other in 1/2". I’m thinking of trying another approach for stiffening up the XY frame. I have some 3/4" 90 degree aluminum angle material, and I was going use it to secure the XY plates to the base. I’m wondering if this will also help stiffening up the front and back plates and prevent any bowing. I know I would need to cut the aluminum to fit around the Y stepper and belt printed parts, but I think it will make it stronger.
Any thoughts on whether this would work instead of using the 1/2" XY_Frame plates, or am I out to lunch?


Use the 1/2 inch. You shouldn’t habe your belt so tight that you bend it. If youre still worried then you could run screws from the base into the 1/2.

The belts should be looser than that, Like I said I am using 1/4" and it barely shows any bowing after many months of continuous 24/7 use.

It’s easy to forget nothing is permanent. You can print really well as it was designed, and then improve it based on your results.

You don’t really need 3/4" right angle, just a small piece of plastic to dampen the vibration.

If you put a little right-angled piece of plastic and screwed it into the XY frame and the base, then it would stiffen it right up. Here’s a pic of what I’m talking about, replace that little square with a piece of plastic (it could even be the “Brace.STL” from the MP3DP). Do the same on the back. (((BTW, I think Ryan suggested this first when I showed him the base)))

[attachment file=36036]

Another thing I was thinking about if you want that extra few mm in the Y direction, you could move the XY Frame to the outside, instead of the inside of the corners. It wouldn’t look as good, but it would give you a tad more stretch.

So in this pic, Just leave everything else where it is, and move the board to the left side.

[attachment file=36037]

And thanks for trying my base. AFAIK, no one else has done it. I keep meaning to build a box underneath it for my CPU and RAMPS, but everything is fine just floating around, and I’m otherwise still pretty busy.

Do I use the 6-32 .75 screws to attach the lead screw nut to the printed parts?

M3x10 same as the steppers screws.


I purchased a SPST illuminated rocker switch and a 3 wire ac chassis receptacle for the psu. The receptacle wiring is pretty straight forward, but Im not sure about the switch. It has 4 prongs. Two larger ones labeled 1&2, and their other two labeled 3 with + & - (pic attached). Does anyone know what the wiring should look like? The switch is rated 6A-125VAC, 3A-250VAC.

[attachment file=36701]

The two small ones are probably for an LED, is it a lit switch?

The big ones are where you would connect you load wire, Generally the Black, but a double pole is a bit more safe.

Yes it has a LED. So I should not use thus switch?

It’s fine. You don’t have to use the light, but if you do it probably only takes a 5V or maybe a 12V power source.

Quick question regarding the driver for the extruder. I already have one installed with the current already set for the extruder stepper motor on my ramps board that is connected to my MPCNC. Is there any reason why I could not swap that one and install it on my new ramps for my MP3DP? Im using a Titan aero with a stepper that has the following specs and based on the calculation found on the Ramps Stack page on this site the current for the driver should be 0.63V.

Property Value
Manufacturer Motech
Model No. 1701HSM140
Holding Torque 14.7 N-cm
Resistance/Phase 1.9
Inductance/Phase 2.0
Stepping Angle 0.9°
Rated Current 1.4A