Tobbens Folgertech Kit Unboxing Log

This page describes Tobben's observations while unpacking a Folgertech 2020 Prusa i3 kit

Packed Kit

Observations

Design is the type of parts used, how the printer is planned to be when assembled. Packaging is how I receive the parts. Are they the correct ones? Are they intact? Are bags good and separation of parts logical? Kit is the type of and quality of parts (after they have been properly unpackaged).

Time order	Observation Regards	Comment	Image
0	Tool needed:	Knife for opening packaging
1	Tool needed:	Trashcan for packaging paper
2	Packaging:	Bag of screws is sealed with packaging list. Gets ruined by opening
3	Packaging:	Bags have messages on them regarding assembly process. "You need to upload firmware". This is untidy information noise.
4	Packaging:	Bags have messages on them regarding part specs. It says "2.1 kg/cm, 4.8 kg/cm" on motors, but it doesn't say what these numbers mean (probably stepper holding torque). Information noise.
5	Packaging:	Bags have messages on them regarding what motors are used on which axes in other kits. Information noise.	See above picture
6	Kit:	Print quality is usable. First layer squashed, walls not perfectly smooth, but still ok.
7	Design:	Use printed endstop/smooth rod- connectors that easily moves around, tempting users to over tighten so they break. Bad design.
8	Packaging:	They sent me an American power plug and not a European one. Sloppy.
9	Tool needed:	Scissors for opening glued electronics bag and taped motor packaging
10	Kit:	They included a cheramic screwdriver. Nice, but not needed since we're not going to adjust stepper driver trimpots.
11	Kit:	They use a stronger motor for the moving Y-axis. Increases unique part count and risks misplacement but economically sane.
12	Kit:	Motors have round shafts, not flat as I expected. Might be a problem.
13	Kit:	Small (XZ) motors have very high driving voltage (12 V).
14	Kit:	Stepper Motors are not marked with model number, current rating, inductance or winding resistance! No current rating makes torque output rating useless.
15	Kit:	Small stepper motor has 6 pins where 2 are unconnected (inf resistance). Resistance of windings are 28.9 and 29.3 ohms. This gives a current rating of ~0.41 A. (I = U/R). Two soldering points are left unsoldered and the soldered points seems to have been done too cold and in a hurry. The used wire is winded very many turns per spool (since it is very thin). This results in high inductance since inductance is proportional to number of turns squared.
16	Kit:	Datasheet on Folgertech drive says inductance of small motor is 37 mH+-20%. This is very high, and limits speed dramatically. 20 percent of 37 mH is more than the total inductance of most stepper motors. See [1]
17	Kit:	Datasheet on Folgertech drive has awful precisions (0.1 mm on screw hole separation, 10% on resistance). This is where they saved money.
18	Kit:	Big stepper motor has 6 pins where 2 are unconnected. Resistance of windings are 2 ohm. This gives a current rating of 1.7 A.
19	Kit:	Big stepper motor inductance unknown, but probably an order of magnitude better than small motor.
20	Kit:	Power supply was pre-set to 110 V even though it was sent to Europe.
21	Tool needed:	Screw driver to change power supply configuration.
22	Kit:	Z-couplings and belt pulleys both use grub screws for fixation and require flat area on motor shaft.
23	Kit:	Roll of kapton tape is extremely narrow. Not intended or suitable to cover print bed.
24	Packaging:	M5 threaded rods packaged in a way that effectively avoids bending too much.
25	Kit:	MK2 heat bed has thermistor already soldered, and thermistor connector already crimped.
26	Design:	No glass bed included. Design relies on very thin alu sheet or PCB flatness. This is very wishful thinking. Can be mitigated with grid Z-probing and firmware compensation.
27	Kit:	Spring loaded direct drive extruder with early Reprappro style hot end comes pre-assembled with thermistor and connectors ready.
28	Design:	Spring loaded direct drive and very weak X-motor will limit this printer to very low print speeds.
29	Packaging:	Extruder needs knife or scissors to unpack, and fragile wires are easily cut by mistake while cutting open packaging.
30	Kit:	No information about nozzle diameter found on nozzle.
31	Kit:	2020's have sharp edges.
32	Kit:	Smooth rods have phased ends.

Complete Unpacked Kit