Mendel frame
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Mechanical: Overview | Mendel solid model files | Procurement | Preparation of materials | Assembly notes | Extruder | X-axis | Z-axis | Y-axis | Circuit boards | Frame | Squaring the axes
You may find the Mendel assembly data sheet useful during assembly.
Contents |
Frame sides
BOM
Total # of assemblies: 2
| Frame-vertex_6off | 3 | 6 | RP |
| Stud-frame-side | 3 | 6 | Studding |
| M8 washer | 14 | 28 | Fastener |
| M8 nut | 14 | 28 | Fastener |
| z-leadscrew-base | 1 | 2 | Assembly |
Printed part
Assembly
Triangles are equilateral (J1 applies to all sides).
In addition: each assembly needs either a Z-motor or Z-tensioner bracket, as shown in the diagram. Tensioner should pair with the leadscrew base which has the opto installed.
Check the Mendel assembly data sheet for bar/stud lengths and jig/inspection distances.
Frame ends
BOM
Total # of assemblies: 1
| Name | Qty/assembly | Total Qty | Type |
| z-bar-top-clamp_4off | 4 | 4 | RP |
| M4x40 bolt | 4 | 4 | Fastener |
| M4 nylock | 4 | 4 | Fastener |
| M4 washer | 8 | 8 | Fastener |
| Stud frame end top | 2 | 2 | Studding |
| Stud frame end | 4 | 4 | Studding |
| Stud z base beam short | 2 | 2 | Studding |
| Stud z base beam long | 2 | 2 | Studding |
| M8 nut | 68 | 60 | Fastener |
| M8 washer | 64 | 56 | Fastener |
| Y motor bracket | 1 | 1 | Assembly |
| Y idler bracket | 1 | 1 | Assembly |
RP parts
Assembly
Note extra nuts and washers on the upper two studs of the bottom frame ends. Check the Mendel assembly data sheet for bar/stud lengths and jig/inspection distances.
It's a good idea to put some soft feet on the bottom vertex parts. This lifts the machine off the ground a bit, and also reduces the transmission of the vibrations from the machine when it's working to the surface on which it's standing, hence reducing noise. The simplest way to make such feet is with some pieces of thick (about 1mm) foam double-sided sticky tape. Simply cut squares from the end of the tape reel and stack them to form a soft foot. Leave the tape-cover strip on the bottom-most one.
Installation of X-axis
BOM
Total # of assemblies: 1
| Name | Qty/assembly | Total Qty | Type |
| z-bar | 2 | 2 | Bar |
| x-axis | 1 | 1 | Assembly |
| z-leadscrew | 2 | 2 | Assembly |
| M4x12 bolt | 6 | 6 | Fastener |
| M4 nylock | 6 | 6 | Fastener |
| M4 washer | 12 | 12 | Fastener |
| z-belt | 1 | 1 | Belt |
Assembly
Roll the frame onto its back, and position the x-axis into the top end. Thread the z-bars through the leadscrew base, x-axis and top-clamp. Fasten z-bars.
With the frame still on its back, slide the partly assembled z-leadscrew through the leadscrew base and screw into the M8 trapped nut on the x-axis. Screw in until bearing sits flush in leadscrew base. Fasten with caps.
Complete the leadscrew assembly with the parts which were temporarily removed in the initial assembly. Repeat for other side.
Keep frame on its back. Whilst still keeping the x-axis at the top end of the leadscrews, rotate the leadscrews until the x-axis is approximately square. Better calibration will be achieved later, however, both leadscrews should turn fairly freely. Attach the z-belt. How taught should it be? The answer is: as loose as possible without backlash. Tighten it too tight, and turn the Z stepping motor by hand. You should see both Z screws rotate, even when you turn the motor by a single stepper step (you can feel the detent). Now gradually slacken the belt so that you are at the limit where it still behaves like this: as you turn it one detent, then back again, both Z screws turn forwards and backwards.
Tighten the sliding components of the X axis in position. Run the Z axis up and down by hand a few times. As long as you keep the two ends at the same hight (you can feel when one is going further that the other as the movement gets tight) it should move easily up and down. If it doesn't, slacken off the X clamps that set the X-axis length slightly and adjust them.
When you've got everything right, tighten the X belt. Again, get it as lose as it can be without backlash: when you turn the X motor forwards and backwards by a single step by hand, you should see the X acrriage move in both directions.
Leave assemblies in their current position for the next phase.
Fitting the bottom circuits
BOM
Total # of assemblies: 1
| Name | Qty/assembly | Total Qty | Type |
| circuit-board-spacer-m4_2off.par | 2 | 2 | RP |
| y-bar-clamp_10off.par | 2 | 2 | RP |
| m4-nylock.par | 4 | 4 | Fastener |
| m4-washer.par | 8 | 8 | Fastener |
| m4x40-cap.par | 4 | 4 | Fastener |
| Bottom-circuit-board | 1 | 1 | Assembly |
RP parts
Assembly
Position the board over the larger gap of the base, nearest the y-motor, with the XLR and USB sockets facing out (1). Use the spacer and clamp assembly attach to the frame (2).
Put the frame back in its upright position. Leave the x-axis at the top, out of the way for the next phase.
Installing the Y-axis
BOM
Total # of assemblies:1
| Name | Qty/assembly | Total Qty | Type |
| y-bar-clamp_10off | 8 | 8 | RP |
| m4x40-cap | 8 | 8 | Fastener |
| m4-washer | 16 | 16 | Fastener |
| m4-nylock | 8 | 8 | Fastener |
| y-belt | 1 | 1 | Belt |
RP parts
Assembly
Loosely install the y-bar clamps and y-bars. Set J3 so the bar clamps are in approximately the right place. (Bottom circuit boards hidden for clarity)
Now retract the y-bars. Position the y-chassis and thread bars back through the y-chassis. Re-confirm J3 and fasten the y-bar clamps fully.
Note that if you build the base etc from 4mm ply or MDF the rectangle that forms the tray for catching extrudate at the beginning of a build is held on with 15 mm M4 cap screws. But if you make the base etc from 6mm (which will give a better sturdier machine, and so is recommended) you will need 20 mm M4 cap screws for this.
Fit the y-belt. How taught should it be? As with Z, the answer is: as loose as possible without backlash. Tighten it too tight, and turn the Y stepping motor by hand. You should see the Y carriage move, even when you turn the motor by a single stepper step (you can feel the detent). Now gradually slacken the belt so that you are at the limit where it still behaves like this: as you turn it one detent, then back again, and the Y carriage moves both forwards and backwards.
Installing the bed
BOM
Total # of assemblies:1
| Name | Qty/assembly | Total Qty | Type |
| bed | 1 | 1 | Sheet Image |
| m4x40-cap | 4 | 4 | Fastener |
| m4-nylock | 4 | 4 | Fastener |
| m4-washer | 8 | 8 | Fastener |
| bed-spring | 4 | 4 | RP |
RP parts
RP spring design may vary
Assembly
Fit bed to chassis trapping the springs between the bed and the bearing brackets.
Fitting the top circuits
BOM
| Name | Qty/assembly | Total Qty | Type |
| circuit-board-bracket-m3_4off.par | 4 | 4 | RP |
| m3-capx20.par | 16 | 16 | Fastener |
| m3-nylock.par | 16 | 16 | Fastener |
| m3-washer.par | 32 | 32 | Fastener |
| Top-circuit-board | 1 | 1 | Assembly |
RP parts
Assembly
Wind x-axis down to the bed, as this will get in the way. Wind by lifting the frame up to pull the z-belt. Do not let nozzle closer than 1 cm to bed – if the bed slides around before calibration it may damage the nozzle by scraping against it. Position circuit board at the top of the front side, as high as possible (1). Use four bolts per clamp and fasten securely as this element improves chassis rigidity (2).
Finish
Congratulations! That's the assembly complete, we hope you enjoy your new 3D printer! Before printing anything don't forget to square the axes.
Back to Mendel mechanical construction root.
