Sample BOM for a Big T-Slot Adapto

This bill of materials is for a pretty big Adapto with a 310x220x270mm (18.4L) print volume that uses T-slot extrusions for its frame. The Adapto is a very flexible design that can easily be adapted to your need. Details on how to do that are discussed in some of the "Comment" fields and below the actual BOM.

BOM Listing

Note: this BOM is a work in progress and still needs to be verified. Use it, but use it with care!

The Sample Source field aims to give one or several sample shop links for each item. It is currently biased towards Europe and especially Germany since that's where the initial BOM author lives. Feel free add additional suitable sources if you know them! For little hardware items that are required in small quanitites (screws used in the extruder etc.) it's often most cost-efficient to get them in a local hardware store. If larger quantities are required, it's often cheaper to order a bag of e.g. 50 screws online even if you won't need all of them (the rest may still be useful for further projects).

Quantity	Part Name	Part Type	Used Where	Comment	Sample Source
5	NEMA 17 stepper motor	Electronics	Axes, extruder	1.5A or less, 8mH inductance or less, 44Ncm (4.4kg.cm) or more of torque, 1.8 or 0.9 degrees per step (200/400 steps/rev respectively), ca. 47mm long.	[1] (BEL),[2] (NL), [3] (US/UK)
1	J-Head hotend	Electronics		Preferably with 0.4mm nozzle, for 3mm filament. Includes thermistor and resistor. Alternatives: e.g. Makergear or Budaschnozzle.	[4]
1	Silicone or kapton heater, 300x200mm, suitable for 24V	Electronics		Must be able to reach 100 °C above room temperature when run from 24V	[5] (UK), [6] (DE)
1	RAMBo electronics	Electronics		Alternatives: e.g. 4pi, RAMPS, Sanguinololu	[7] (US/UK), [8] (DE)
1	100k thermistor	Electronics		To measure the heatbed temperature; not necessary if your bed heater already includes one	[9] (BEL), [10] (US/UK), [11] (NL)
1	24V 15A power supply	Electronics		12V 20A is a more conventional choice and sufficient for a regular-sized printbed (200x200mm), but for a large printbed more power seems desirable.	[12] (CN), [13] (CN), [14] (CN/de)
1	Device connection cable, 3 1.5mm² wires, mains plug at other end, length 1.5m or as desired	Electronics		Get one that fits your type of mains sockets	[15] (UK), [16] (DE)
1	Switchable socket outlet	Electronics		Get one that fits your type of mains sockets. This is the easiest solution, you can also wire a switch between the PSU and mount it to the printer frame.	[17] (UK), [18] (DE)
1	Speaker cable, 2 x 2.5mm², length ca. 1m	Electronics		To connect PSU to RAMBo	[19] (DE)
1	Speaker cable, 2 x 1.5mm², 1.5m or longer	Electronics		To connect heatbed and hotend	[20] (DE)
4	Heatshrink, ca. 1.6mm/0.8mm diameter before/after shrinking	Electronics		To insolate thermistor wires	[21] (NL)
1	Kapton tape, ca. 6mm wide	Electronics			[22]
4	20x20mm T-slot extrusion, aluminum, 360mm long	Extrusions	Bottom frame		[23] (DE)
3	20x20mm T-slot extrusion, aluminum, 420mm long	Extrusions	Top frame
1	T-slot nuts for M5 screws, bag of 50+	Extrusions	Frame		[24] (DE)
2	M8x30mm bolt	Hardware	Idlers
4	M8 nut	Hardware	Idlers	Do not use zinc-coated, either plain steel or stainless is fine	[25] (DE)
1	M8 washers, bag of 20+	Hardware	Idlers, extruder		[26] (DE)
2	M8 nyloc nut	Hardware	Extruder		[27] (DE)
1	M5x10mm socket head cap screws, bag of 50+	Hardware	Frame assembly etc.		[28] (DE)
1	M5x20mm socket head cap screws, bag of 20+	Hardware			[29] (DE)
1	M5 washers, bag of 50+	Hardware			[30] (DE)
1	M5 nuts, bag of 50+	Hardware		Thin nuts preferred	[31] (DE)
2	M4x55mm socket head cap scew	Hardware	Extruder	Length can vary a bit; other head types are OK as well	[32] (DE)
2	M4 nut	Hardware	Extruder		[33] (DE)
1	M3x10mm socket head cap screws, bag of 50+	Hardware	Motor mounts, extruder etc.		[34] (DE)
1	M3x20mm socket head cap screws, bag of 10+	Hardware	Print table etc.		[35] (DE)
1	M3x35mm socket head cap screw	Hardware	Extruder
1	M3x10mm grub screw	Hardware	Extruder	Used in small gear
1	M3 washers, bag of 50+	Hardware			[36] (DE)
1	8mm hobbed bolt (ca. 60mm long)	Hardware	Extruder		[37] (US/UK)
2	Spring, ca. 8mm OD (outer dia.), ca. 16mm long	Hardware	Extruder
6	Binder clips, 19mm wide	Hardware	Print table		[38] (UK), [39] (DE), [40] (DE)
1	Zip ties, bag of 50+, 100mm long (or shorter)	Hardware		To secure wires	[41] (UK), [42] (DE)
1	Zip ties, bag of 20+, at least 140mm long	Hardware		To secure wires to the frame	[43] (DE)
1	PVC aquarium tubing, OD 6mm, ID 4mm	Hardware	Z axis	Typically sold in pieces of 1m or longer (though you won't need more than ca. 2x 16mm or so)	[44] (DE)
7	608ZZ bearing	Mechanical	Idlers, extruder		[45] (BEL), [46] (US/UK)
10	LM8UU bushing	Mechanical	Axes		[47] (BEL), [48] (CN), [49] (DE)
2	GT2 belt, 6mm wide, at least 900mm long	Mechanical	X & Y axis	Alternative: T2.5 belts and pulleys	[50] (US/UK)
2	GT2 pulley	Mechanical	X & Y axis		[51] (US/UK)
4	8mm drill rod, 435mm long	Mechanical	X & Z axis	Called "Silver Steel" in some parts of the world; type O1 or W1 works fine and is usually cheapest. Plain steel rods from a hardware store are not recommended; zinc-coated rods are not suitable.	[52] (DE), [53] (AT)
2	8mm drill rod, 400mm long	Mechanical	Y axis
2	5mm threaded rod, 400mm long	Mechanical	Z axis	Plain steel or stainless will work, but stainless is recommended. Do not use zinc-coated rod, as the zinc can lead to binding.
1	Glass plate 310x220x2mm	Mechanical	Print table	Top-most part of print table. Don't try to order glass online; better ask in some local glazier's shops to get a custom-cut piece of the desired size.
2	Aluminum sheet, 310x235x1.5mm	Mechanical	Print table	Middle and lower part of print table. Upper one serves as heat spreader, the flexible heater is taped below it. 15mm deeper than the glass plate to leave place for M3 screws.	[54] (DE/Berlin)
1	M8x20mm grub screw or threaded rod	Mechanical	Extruder

Note: the required RP ("rapid prototype" or reprapped-printed) parts are listed on the main Adapto page and not repeated here.

Suitable print settings

The recommended infill amount for each part is documented in the RP parts list. Line infill is fine; using 3 perimeters and 3 solid layers results in very strong parts. Use the layer height you prefer, e.g. 0.2mm or 0.3mm.

Generally, you can print in ABS or PLA, as you prefer. For parts that get hot (especially the Extruder_X_Carriage_Combo), ABS might be advantageous.

Optional parts

The following parts are not strictly required but may be advantageous to make building the printer easier or to enhance its capabilities.

Quantity	Part Name	Part Type	Used Where	Comment	Sample Source
1	Post-install T-slot nuts, bag of 20+	Extrusions	Frame	You don't strictly need those, but they are extremely useful for mounting additional stuff to the frame after initial assembly. Usually require M4 screws since larger sizes won't fit.	[55] (DE)
1	M4x10mm socket head cap screws, bag of 20+	Hardware		To fit the post-install nuts.	[56] (DE)
1	M4 washers, bag of 20+	Hardware		To fit the post-install nuts.	[57] (DE)

Additional comments

RAMBo electronics

RAMBo packages usually already include 3 mechanical endstop switches, 3 cables with 2x2.54mm plugs for the endstops, wires for 2 thermistors, 4 terminal plugs for the motor cables, and an USB A/B Cable. If your electronics kit doesn't include them, you'll need to get them separately.

Power supply

If you run everything from 24V, you must take care that electronics, hotend etc. can handle it! RAMBo and 4pi accept 24V; RAMPS does too, but you MUST remove the diode that feeds the Arduino or it will be grilled!

You can run a 12V hotend (such as the J-Head) from 24V by setting the maximum PWM to e.g. 88 in the firmware; then recompile and re-upload the firmware. Actually, this will feed 14V (sqrt(88/255)*24) to the hotend, but that should be OK.

General size calculations

The Adapto requires 7 T-slot extrusions:

• 2 in X direction that form the front and the back of the lower frame ("X extrusion" or Xe)
• 2 in Y direction that form the left and right sides of the lower frame ("Y extrusion" or Ye)
• 2 in Z direction that form the vertical part of the upper frame ("Z extrusion" or Ze)
• 1 that forms the top part of the upper frame ("top extrusion" or Te)

To determine the necessary extrusion lengths based on the desired print volume, the following rules of thumb can be used:

• The X extrusions should be 50mm longer than the width of the print volume (to leave room for the Y extrusions and for extruder movement): Xe = Xp + 50
• To calculate the length of the Y extrusions, add 55% to the depth of the print volume (to leave room for the bearing holders below the printbed and for the endstop) plus 15mm extra (for the screws that connect the 2 aluminum plates to each other): Ye = Yp * 1.55 + 15
• The Z extrusions should be 150mm longer than the height of the print volume (to leave room for extruder assembly and printbed): Ze = Zp + 150
• The top extrusion should be 60mm longer than the X extrusions to exactly fit the printed parts: Te = Xe + 60

For the sample BOM above, the chosen print volume is:

• Xp = 310mm
• Yp = 220mm
• Zp = 270mm

The resulting extrusion lengths are:

• Xe = 360mm
• Ye = 360mm (rounded)
• Ze = 420mm
• Te = 420mm

Lower frame size (assuming that the X extrusions cover the whole front/back and the Y extrusions are mounted between them):

• The width of the frame is equal to the length of the X extrusions: Xf = Xe
• The depth of the frame is 40mm more than the length of the Y extrusions: Yf = Ye + 40

For the sample BOM above:

• Xf = 360mm
• Yf = 400mm

Maximum outer dimensions of the printer:

• The X/Z assembly is ca. 145mm wider than the lower frame: Xo = Xf + 145
• The printer is 10mm deeper than the lower frame due due the thickness of printed parts around the frame: Yo = Yf + 10
• The printer is 100mm higher than the length of the Z extrusions: Zo = Ze + 100

For the sample BOM above:

• Xo = 505mm
• Yo = 410mm
• Zo = 520mm

The printer requires 6 smooth rods (drill rods), 2 for each axis. Their length should be approximately:

• X rods: ca. 70mm longer than the X extrusions: Xs = Xe + 70
• Y rods: as long as the lower frame is deep: Ys = Yf
• Z rods: ca. 15mm longer than the Z extrusions: Zs = Ze + 15

For the sample BOM above, the chosen lengths are:

• Xs = 435mm (rounded up a bit so the same rod length can be used for X and Z)
• Ys = 400mm
• Zs = 435mm

The printer requires 2 threaded rods for the Z axis. They should be approximately 20mm shorter than the Z extrusions: Zt = Ze - 20

For the sample BOM above:

• Zt = 400mm

Alternative sizes

Smaller, Prusa-sized Adapto

If you want to use a Prusa PCB Heatbed (214x200mm build area) with your Adapto and aim for a build height of, say, 250mm, the preceding size calculations can be applied as follows:

• Length of X extrusions: Xe = 214 + 50 = ca. 265mm (rounded)
• Length of Y extrusions: Ye = 200 * 1.55 + 15 = 325mm
• Length of Z extrusions: Ze = 250 + 150 = 400mm
• Length of top extrusion: Te = 265 + 60 = 325mm (same as Y extrusions)

• Length of X smooth rods: Xs = 265 + 70 = 335mm
• Length of Y smooth rods: Ys = 325 + 40 = 365mm
• Length of Z smooth rods: Zs = 400 + 15 = 415mm

• Length of Z threaded rods: Zt = 400 - 20 = 380mm

• Dimensions of glass plate: 214x200x2mm
• Dimensions of aluminum sheet: 214x214x1.5mm (same area as the PCB heatbed; only 1 aluminum sheet is needed in this setup since the PCB is stable and doesn't require a separate heat spreader)

Big Mendelmax 2 sized Adapto

The upcoming Mendelmax 2 will have a huge 250x320mm heatbed. Maker's Tool Works, the Mendelmax makers, already sell a 240x310mm kapton heater suitable for that huge size. The following size calculations are for a large Adapto with a 320x250x280mm print volume that integrates that (or a similar) heater.

• Length of X extrusions: Xe = 320 + 50 = 370mm
• Length of Y extrusions: Ye = 250 * 1.55 + 15 = ca. 400mm (rounded)
• Length of Z extrusions: Ze = 280 + 150 = 430mm
• Length of top extrusion: Te = 370 + 60 = 430mm

• Length of X smooth rods: Xs = 370 + 70 = 440mm
• Length of Y smooth rods: Ys = 400 + 40 = 440mm
• Length of Z smooth rods: Zs = 430 + 15 = 445mm

• Length of Z threaded rods: Zt = 430 - 20 = 410mm

• Dimensions of glass plate: 320x250x2mm
• Dimensions of aluminum sheets: 320x265x1.5mm (either order the kapton heater without a heat spreader or order just 1 additional aluminum sheet instead of 2)

Note: the mentioned kapton heater already comes with a thermistor so you don't need to order another one if you choose this solution.

Even bigger?

If you want to go even bigger than that, you should consider using 10mm smooth rods instead of 8mm. 10mm is recommended if the length of the rod surpasses 450mm. Printed parts that fit 10mm rods and LM10UUs can be found in the RP_Parts/STLs/10mm directory in the Github repo. (But note that some of them may missing or they may be be outdated compared to the 8mm STLs. If that's the case, you'll have to create your own 10mm version from the parametric files in RP_Parts/SCADs or from the 8mm variants.)