RepRap Mendel i2

RepRap Prusa Mendel

Printed Parts

(Iteration 2)

Sponsored by I.T.E. / FoRTH

First out of three sets of printed parts.

Collection of all printed plastic parts.

Frame and motors

Quantity	Description	STL model	Status
4	frame corner with foot	[1]	printed
2	frame corner	[2]	printed
8	bar clamp	[3]	printed
2	rod clamp	[4]	printed
4	belt clamp	[5]	printed
2	belt clamp nut holder	[6]	printed
1	X-axis carriage	[7]	printed
1	X-axis idler holder	[8]	to be re-printed for lm8uu bearing
1	X-axis motor holder	[9]	to be re-printed for lm8uu bearing
1	Y-axis motor holder	[10]	printed
4	Y-axis bearing holders	[11]	printed
3	pair of bearing belt guides (2 parts)	[12]	printed
2	Z-axis motor holder	[13]	printed
2	Z-axis coupling (2 parts)	[14]	printed
2	5mm pitch timing-belt pulley gear	[15]	printed also a 2,5mm pitch pulley
3	endstop switch holder	[16]	printed

Extruder (print head)

Quantity	Description	STL model	Status
1	(Tom's guided, Greg's accessible, hinged) Wade's extruder body (2 parts)	[17]	printed
1	large gear	[18]	printed
1	small gear	[19]	printed

Non-printed parts:

Thanks to the sponsors:

• Michalis K.
• Dimitris K.
• AnKostis
• Dimitris Ch.
• ggalan
• sque
• z☽

Frame and motors

Collection of metal parts for the RepRap

Print platform made form glass and MDF wood.

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.	ordered (have only 6)
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
1	140mm×225mm Thick Sheet	Print bottom plate (Prusa Iteration 2 design does not use a print bottom plate?)	probably have (in scrap wood)
1	840mm×5mm T5 pitch timing belt	Y axis	probably have T2.5mm pitch
1	900mm×5mm T5 pitch timing belt	X axis	probably have T2.5mm pitch
4	NEMA 17 bipolar stepper motor	At least 20mm of shaft length. One should have a torque of > 40Ncm.	ordered (maybe have 2)
50	small cable binder / ziptie		have

Extruder (Print-head)

Wade's extruder design

Filament transport mechanics

Quantity	Description	Comments	Available
2	608 bearings, skateboard bearings		ordered
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	have (to be hobbed)
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 (maybe also nyloc)
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.	have round (allen) head
2	M4×20 bolts		have
2	M4 nuts		have
4	M4 wing nuts	normal hex nuts will do also.	have
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 (will be cut otherwise)
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	See RepRap Hot End	missing
1	NEMA 17 bipolar stepper motors	49 Ncm (70 oz*in) works well; at very least 40Ncm (57 oz*in)	ordered

Hot end nozzle

missing

Electronics

Fully assembled Gen7 board.

have (flashed with Teacup firmware)

The Generation 7 Board by Traumflug 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

Taken from available parts sponsored by various donations and from recycling.

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 470 Ω
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	have
Molex KK100 2 Pin Header	2	TEMP1, TEMP2	Reichelt			RS	DigiKey	Mouser	have
Cable Connector for the above	2		Reichelt			RS	DigiKey	Mouser	have
Crimp Contact for the above	4		Reichelt			RS	DigiKey	Mouser	have
Molex KK100 3 Pin Header	3	X_MIN, Y_MIN, Z_MIN	Reichelt			RS	DigiKey	Mouser	have
Cable Connector for the above	3		Reichelt			RS	DigiKey	Mouser	have
Crimp Contact for the above	9		Reichelt			RS	DigiKey	Mouser	have
Molex KK100 4 Pin Header	4	X_MOT, Y_MOT, Z_MOT, E_MOT	Reichelt			RS			have
Cable Connector for the above	4		Reichelt			RS			have
Crimp Contact for the above	16		Reichelt			RS	DigiKey	Mouser	have
Molex KK100 6 Pin Header	1	SERIAL				RS	DigiKey	Mouser	have
Optional: Cable Header for the above	1					RS	DigiKey	Mouser	have
Optional: Crimp Contact for the above	6					RS	DigiKey	Mouser	have
Heater Header Molex 26-48-1045 (2 Pin)	2	HEATER1, HEATER2				RS	DigiKey	Mouser	have
Cable Connector for the above	2					RS	DigiKey	Mouser	have
Crimp Contact for the above	4					RS	DigiKey	Mouser	have
Disk Power Header	2	CONN2, CONN3	Reichelt			RS	DigiKey	Mouser	have
ATX24 Power Connector	1	CONN1				RS	DigiKey	Mouser	have ATX20 (okay!)
Heatsink for the MOSFETs	2		Reichelt			RS	DigiKey	Mouser	have (cut from old heat sink)
Bolt M3 x 8 mm for mounting the MOSFET heatsink	2								have
Washer M3 for mounting the MOSFET heatsink	2								missing (nevermind...)
Nut M3 for mounting the MOSFET heatsink	2								Unnecessary! Heat sink has thread.
Heatsink for the Pololus	4		Reichelt	Völkner		RS			have (from "north bridge" - to be cut)
Heatsink Glue	1		Reichelt	Völkner					ordered online (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	using StepSticks
Open Source Alternative	StepStick	ordered