RepRap Mendel i2
RepRap Mendel i2

RepRap Prusa Mendel (Taken from Wikimedia user Julianh72)
Contents
Printed Parts
(Iteration 2)
Frame and motors
Quantity | Description | STL model | Status |
---|---|---|---|
4 | frame corner with foot | [1] | to be printed |
2 | frame corner | [2] | to be printed |
8 | bar clamp | [3] | to be printed |
2 | rod clamp | [4] | to be printed |
4 | belt clamp | [5] | to be printed |
2 | belt clamp nut holder | [6] | to be printed |
1 | X-axis carriage | [7] | to be printed |
1 | X-axis idler holder | [8] | to be printed |
1 | X-axis motor holder | [9] | to be printed |
1 | Y-axis motor holder | [10] | to be printed |
4 | Y-axis bearing holders | [11] | to be printed |
3 | pair of bearing belt guides (2 parts) | [12] | to be printed |
2 | Z-axis motor holder | [13] | to be printed |
2 | Z-axis coupling (2 parts) | [14] | to be printed |
2 | belt gear pulley | [15] | to be printed |
3 | endstop switch holder | [16] | to be printed |
Extruder (print head)
Quantity | Description | STL model | Status |
---|---|---|---|
1 | Wade's extruder body (2 parts) | [17] | to be printed |
1 | large gear | [18] | to be printed |
1 | swall gear | [19] | to be printed |
Non-printed parts:
Frame and motors
Quantity | Description | Comments | Available |
---|---|---|---|
83 | M8 nut | Buy a 100-pack to be on the safe side. | have |
93 | M8 washer | Buy a 100-pack to be on the safe side. (Grade 2 works fine.) | have |
6 | M8×30 mudguard / fender washer | These have a much larger outer diameter | have ø32mm |
2 | M4×20 bolt | To mount the extruder | have |
2 | M4 nut | To mount the extruder | have |
2 | M4 washer | To mount the extruder | have |
2 | M3x8 grub screw | Anything 6mm or longer should do. Even M3×10 bolts will do the job. | have |
22 | M3×10 bolt | have | |
8 | M3×20 bolt | The M3×25 bolts are too long for the recent Prusa z-motor-holder, rod-clamp, and couplings. | have |
8 | M3×25 bolt | have | |
4 | M3×40 bolt | have | |
70 | M3 washer | have | |
40 | M3 nut | 8 optionally locknut / stop nut / nyloc | have (also locknuts) |
3 | 608 ball bearing | Standard wheel roller/inline skateboard bearings. | have |
12 | LM8UU bearing | Linear bearings to slide over 8mm rods. | miss |
4 | ballpoint pen springs | To fit over M3 bolts. About 25mm long and compress to about 10mm. | have maybe |
6 | M8×370mm Threaded rod | 3 per side - Can be cut from larger 6x1m pieces (see Threaded Rod Cut Order below). | to be cut |
4 | M8×294mm Threaded rod | front / rear | to be cut |
3 | M8×440mm Threaded rod | top / bottom | to be cut |
2 | M8×210mm Threaded rod | Z-leadscrew | to be cut |
1 | M8×50mm Threaded rod | or M8x30 or longer fully threaded bolt for X idler. | to be cut |
2 | 8mm×420mm Smooth rod | X-bar - 304 Stainless Steel, A2 Tool Steel, or O1 Tool Steel are recommended. | have stainless |
2 | 8mm×406mm Smooth rod | Y-bar | have stainless |
2 | 8mm×350mm Smooth rod | Z-bar | have stainless |
1 | 225mm×225mm Thick Sheet | Print top plate | have probably |
1 | 140mm×225mm Thick Sheet | Print bottom plate (Prusa Iteration 2 design does not use a print bottom plate?) | miss |
1 | 840mm×5mm T5 pitch timing belt | Y axis | miss |
1 | 900mm×5mm T5 pitch timing belt | X axis | miss |
5 | NEMA 17 bipolar stepper motor | At least 20mm of shaft length. One should have a torque of > 40Ncm. | miss (maybe have 2) |
50 | small cable binder / ziptie | have |
Extruder (Print-head)

Wade's extruder design (Taken from the RepRap wiki)
Quantity | Description | Comments | Available |
---|---|---|---|
2 | 608 bearings, skateboard bearings | miss | |
1 | M8×50 half-threaded bolt | to be hobbed, M8×60 has a longer smooth part, allows a second lock-nut, and may be easier to find | miss |
1 | (M)8×20 Threaded rod | have | |
1 | M8 nut | Nyloc works better, but a pair of nuts will also work | have a pair of nuts |
4-5 | M8 washers | to space the large gear clear of the motor retaining bolt heads | have |
1 | 608 bearing, skateboard bearing | have | |
4 | M4×60 or M4×45 hex head bolts | Hex head will work best (they won't turn), and longer than 45 mm will be easier to assemble if you can find them. | miss |
2 | M4×20 bolts | have | |
2 | M4 nuts | have | |
4 | M4 wing nuts | normal hex nuts will do also. | have hex nuts |
10 | M4 washers | have | |
(16) | M4 washers | optional; 4 washers on each M4X45 idler bolt between the main block and the idler block will limit the idler travel and make reloading filament easier. | have |
4 | ~4mm ID springs | Sized to fit over an M4 bolt, unsprung length of 10-12mm, each spring providing 25-35N load. For a given filament drive force, you'll need about twice the spring force - i.e., if you want 100N of filament drive, your springs need to push with about 50N each. | have maybe |
NOTE: Some users have their extruders working without springs, but springs are recommended. A good source for these springs is in the cloth-cabinet on spring loaded skirt-hangers or trouser-hangers. Just cut the right length off the springs. | |||
2 | M3×35 bolts | have maybe | |
3 | M3×10 bolts | Low profile bolt heads might work better here | have |
7 | M3 washers | have | |
3 | M3 nuts | have | |
1 | M3 grub screw | To secure the pulley, ideally 8mm long, but anything 6mm+ should be fine | have |
1 | 2.5mm drill | RepRap Hot End]] | miss |
1 | NEMA 17 bipolar stepper motors | 49 Ncm (70 oz*in) works well; at very least 40Ncm (57 oz*in) | miss |
Electronics

Almost fully assembled Gen7 board. (Made by Traumflug)
The Generation 7 Board is easily self-made and extensible. It uses no SMD devices, needs only one layer of copper so it can be etched or possibly milled.
This list is ordered to match the order of assembly.
Electronic Components
Name | Count | Designations | Vendors | Available | |||||
---|---|---|---|---|---|---|---|---|---|
0.6 mm Wire | 50 cm | Völkner | Digi-Key | Mouser | have | ||||
Resistor 10 Ohms | 2 | R11, R12 | Reichelt | RS | have | ||||
Resistor 560 Ohms | 2 | R14, R22 | Reichelt | Völkner | Farnell | RS | Digi-Key | Mouser | have maybe |
Resistor 1 kOhms | 6 | R2, R6, R8, R10, R16, R18 | Reichelt | Völkner | Farnell | RS | Digi-Key | Mouser | have |
Resistor 4.7 kOhms | 2 | RT1, RT2 | Reichelt | Völkner | Farnell | RS | Digi-Key | Mouser | have |
Resistor 10 kOhms | 1 | R30 | Reichelt | Völkner | Farnell | RS | Digi-Key | Mouser | have |
Diode 1N4004 | 2 | D1, D2 | Reichelt | Völkner | Farnell | Digi-Key | Mouser | have | |
Coil 100 uH | 1 | L1 | Reichelt | Völkner | Farnell | Digi-Key | Mouser | have | |
Crystal 16 MHz or 20 MHz | 1 | U6 | Reichelt | Völkner | Farnell | Digi-Key | Mouser | have | |
Reset Switch | 1 | RESET | Reichelt | Völkner | Farnell | Digi-Key | Mouser | have | |
Ceramic Capacitor 100 nF | 12 | C5, C8, C9, C10, C11, C12, C13, C14, C16, C17, C18, C19 | Reichelt | Völkner | Farnell | RS | Digi-Key | Mouser | have |
LED 3 mm Green | 3 | LED2, LED5, +5V | Reichelt | Völkner | Farnell | Digi-Key | Mouser | have | |
LED 3 mm Yellow | 1 | Standby | Reichelt | Völkner | Farnell | Digi-key | Mouser | have | |
Ceramic Capacitor 22 pF | 2 | C3, C4 | Reichelt | Völkner | Farnell | RS | Digi-Key | Mouser | have |
Electrolytic Capacitor 10 uF | 2 | CT1, CT2 | Reichelt | Völkner | Farnell | Digi-key | Mouser | have | |
Electrolytic Capacitor 100 uF | 4 | C1, C2, C6, C7 | Reichelt | Völkner | Farnell | Digi-Key | Mouser | have | |
Jumper Header 2 Pin Pairs | 4 pairs of 2x2 pins | J2/J3, J5/J6, J8/J9, J11/J12 | Reichelt | RS | Digi-Key | Mouser | have | ||
Jumper Header 2 Pin | 2 | J13, J14 | Reichelt | Völkner | RS | Digi-Key | Mouser | have | |
Jumper for the two above | 9 | Reichelt | RS | Digi-Key | Mouser | have | |||
ICSP Header | 1 | CONN6 | Reichelt | RS | Digi-Key | Mouser | have | ||
Pololu Header | U2, U3, U4, U5 | Reichelt | Völkner | Digi-Key | Mouser | have | |||
Socket for the ATmega | 1 | U1 | Reichelt | Völkner | Farnell | Digi-Key | Mouser | have | |
ATmega 644 (or 644P) | 1 | Reichelt | Farnell | Digi-Key | Mouser | have | |||
MOSFET IRFZ 44N | 2 | Q1, Q2 | Reichelt | Völkner | Farnell | RS | Digi-Key | Mouser | miss |
Molex KK100 2 Pin Header | 2 | TEMP1, TEMP2 | Reichelt | RS | DigiKey | Mouser | have jumper headers | ||
Cable Connector for the above | 2 | Reichelt | RS | DigiKey | Mouser | ||||
Crimp Contact for the above | 4 | Reichelt | RS | DigiKey | Mouser | ||||
Molex KK100 3 Pin Header | 3 | X_MIN, Y_MIN, Z_MIN | Reichelt | RS | DigiKey | Mouser | have jumper headers | ||
Cable Connector for the above | 3 | Reichelt | RS | DigiKey | Mouser | ||||
Crimp Contact for the above | 9 | Reichelt | RS | DigiKey | Mouser | same as for TEMP1, TEMP2 above | |||
Molex KK100 4 Pin Header | 4 | X_MOT, Y_MOT, Z_MOT, E_MOT | Reichelt | RS | have jumper headers | ||||
Cable Connector for the above | 4 | Reichelt | RS | ||||||
Crimp Contact for the above | 16 | Reichelt | RS | DigiKey | Mouser | ||||
Molex KK100 6 Pin Header | 1 | SERIAL | RS | DigiKey | Mouser | have jumper headers | |||
Optional: Cable Header for the above | 1 | RS | DigiKey | Mouser | only needed if you intend to solder your own USB-to-TTL cable | ||||
Optional: Crimp Contact for the above | 6 | RS | DigiKey | Mouser | only needed if you intend to solder your own USB-to-TTL cable | ||||
Heater Header Molex 26-48-1045 (2 Pin) | 2 | HEATER1, HEATER2 | RS | DigiKey | Mouser | have similar headers | |||
Cable Connector for the above | 2 | RS | DigiKey | Mouser | |||||
Crimp Contact for the above | 4 | RS | DigiKey | Mouser | |||||
Alternative to Heater Header: 2 Pin Screw Terminal | 2 | HEATER_1, HEATER2 | Reichelt | DigiKey | Mouser | ||||
Disk Power Header | 2 | CONN2, CONN3 | Reichelt | RS | DigiKey | Mouser | have (most probably in scrap electronics) | ||
ATX24 Power Connector | 1 | CONN1 | RS | DigiKey | Mouser | have (most probably in scrap electronics) | |||
Heatsink for the MOSFETs | 2 | Reichelt | RS | DigiKey | Mouser | have (most probably in scrap electronics) | |||
Bolt M3 x 8 mm for mounting the MOSFET heatsink | 2 | have (in scrap electronics) | |||||||
Washer M3 for mounting the MOSFET heatsink | 2 | have | |||||||
Nut M3 for mounting the MOSFET heatsink | 2 | have | |||||||
Heatsink for the Pololus | 4 | Reichelt | Völkner | RS | have (in scrap electronics - to be cut) | ||||
Heatsink Glue | 1 | Reichelt | Völkner | have thermal paste only |
Miscellaneous
Generation 7 Electronics uses a TTL header for serial communications to the host. As many modern PCs lack a serial port, these need an appropriate USB to TTL cable. An alternative to the USB to TTL cable is the same electronics in form of a small breakout board:
USB to TTL Breakout Board | Watterott | Sparkfun | have |
---|
Last not least, you need four stepper drivers, of course:
Stepper driver boards | Pololu] | |
---|---|---|
Open Source Alternative | StepStick] | miss |