IMPLEMENTATION... WAR IS BEGINNING !

3D MODELISATION

STRICTLY OBSERVE ALL MEASUREMENTS  ! 

ALL MEASUREMENTS ARE MADE FOR A MK2A HEATBED WITH 314 x 214 mm TOTAL SIZE, 300 x 200 mm  HOT AREA SIZE, 300,8 mm HOLES DISTANCE LENGTH AND 200,8 mm HOLES DISTANCE WIDTH.

VERYFY YOUR HAVE EXACTLY THE SAME SIZE ! OTHERWISE YOU MUST ADAPT ALL MEASUREMENTS !!! 

ALSO VERIFY YOUR SHATFTS ARE 400 mm (3 mm less or more)

Items List:

Angles:

- 2 x      20x20 aluminium angles  400,5 mm length

- 2 x      30x20 aluminium angles  220,1 mm length

Plates:

- 6 x  Aluminium Plate 20 x  2 mm (thickness) 47,3 mm length (47 should be ok)

Screws:

- 20 x    M3 screws (preferabley hexa head) 10 or 12 mm length

- 6 x       M3 screws 16 mm length preferabely flat head (these are for heatbed,)

- 6 x       M3 screws 20 to 25 mm length

- 1 x        M3 screw  25 mm length

- 12 x      M4 screws 10 to 16 mm 

- 2 x       M4 screws 16 mm length

- (of course same nb of nuts)

Printed Parts:

- A1_Heatbed_Carriage_FRONT_BRACKET.stl

- A1_Heatbed_Carriage_REAR_BRACKET.stl

- A2_Heatbed_Carriage_3rd_Bracket_Front.stl

- A2_Heatbed_Carriage_3rd_Bracket_Rear.stl   (for this one rear & front are the same)

- A2_Heatbed_Carriage_3rd_Bracket_Rear_GAUGE (Only one gauge, it's for brand hole to drill)

- A3_Wheel_Bracket_GAUGE.stl

- 6x A3_Wheel_Bracket_v4.stl

- 6x A4_Wheel_Version2_M3_Normal_Nut_Hole.stl

 There is 3 versions of "Wheel", version 1 is for insert hot insert nuts, but you'll need 3mm thin nuts, v 2 is for normal nut insertion with some glue, v3 is for normal nut also but hole is smaller than nut,  to insert with soldering iron, like hot insert nuts (push slowly nut into hole with soldering iron). Choose better solution for you.

- A5_Belt_Tensionner_Part_A.stl

- A5_Belt_Tensionner_Part_B.stl

The two 220,1 mm aluminium angles must have  exactly the same length, if not then equalize with a file,  equalize is most important than loose 1 millimeter. Same thing for 400,5 mm angles

You must position it like animation below, shorter 200,1 mm are under 400,5 mm

- Measure and drill at ⊘3 mm (or a bit more, 3.2 to 3.5) at indicated locations, if you drill the two layers alu once, make sure you have a perfect 90° angles with the frame squarre.

- Then try to mount, tight the 8x M3 10mm to 16mm screws, and check angles.

You must have a perfect 90° parrallelepipede,  check and recheck the four angles, otherwise, carriage will not slide correctly.

If you are unable to have good result, try to enlarge holes with bigger drill, to have more loose.

- When angles are ok, then  disassemble all, glue the parts in direct contact on the corners (after a bit sandpapering), reassemble all, tightening screws, checking angles with frame squarre, moving parts until you refind perfect angles postition,  then securily tighten, recheck angles, and wait 24 h, whatever glue you use don't touch it during 24 h.

(I used a Bi-component Epoxy glue for metal, but i assume that neoprene or even cyanolit should work).

Before mouting Brackets, check Shafts hole by trying 8 mm shafts insertion, if there is to much resistance then roll a piece of sand paper on a 6 mm drill and equalize holes with it.

Place Heatbed carriage front bracket inside, along  front angle at exactly 7 mm of inside aluminium left angle, Paying attention to right direction (place parts as indicated on picture), then brand holes and drill at ⊘ 4 or 4,5, do same thing with rear bracket.

Then mount them with M4 Screws 10-16 mm and nuts.

tight all screws and verify that there is still 7 mm (6 mm or  8 mm will be ok, but only if rear/front have same value), otherwise enlarge holes a bit to get some loose, to rectify offset , then place Heatbed carriage third bracket_Gauge (red) following yellow, and do the same thing to mount it.

VERYFY YOUR HAVE EXACTLY THE SAME HEATBED SIZE ! 

(314 x 314 mm, 300,8 mm HOLES DISTANCE LENGTH AND 200,8 mm HOLES DISTANCE WIDTH

If size is different but proximate, then you could adapt wheel brackets distances and perhaps middle hole (if different width).

a) PREPARE PLATES

Place 47,3 mm plate under Wheel_Bracket_Gauge, brand and drill at ⊘ 3,5 mm on edge holes and ⊘ 5 mm on the middle. same thing for 6 plates.

b) PREPARE HEATBED

- Drill sixth hole, same distances from sides than opposite.

PAY ATTENTION NOT TO DRILL RESISTIVE WIRE INSIDE HEATBED !

- Paste the buildtak, hot area has some mm left offset, verify your,  (see below and follow  resistive plate wires)

- Mount and tight 6x M3 Screws 16 mm length (& nuts), make sure there are straight.

c) Heatbed positionning

47 mm

- Now i give you a reference distance from wich you will have to positioning your Heatbed, brand all the Wheel brackets holes location and drill the frame. This reference is the distance between front heatbed screws and front angle edge, 47 mm. I advise you that heatbed is not exactly on the middle of the bed (lengthwise), this is normal and required (rear distance is 52mm).

Pic 1

Use this value to position fisrt Front Wheel brackets (right & left) with the center of middle  hole exactly at 47 mm of front angle edge, place little relief downside and on the inner side like on below pic 2, then brand and drill  alu angle on the two end fixation holes at ⊘ 3-3,5, and middle hole at ⊘ 4 or 5 mm (middle screws haven't  nuts). Mount Front Brackets and their plates with M3 Screws 10-12 mm Length and nut under angles, and tight them.

Pic 2

Now you've front brackets, it's easy to place followings, place the heatbed on the frame with all brackets, verify all is ok and it's well centered, then you can brand position of all brackets and fix them like in front.

Some pics if this can help, note that middle hole are bigger than screws (my middle supports are fixed with brass nuts, but take normals):

a) Drill 3 Shafts holes on rear side ⊘ 9-10 mm (try to mount them, but remove them after)

Pay attention not to damage brackets behind aluminium angle. (you can also remove it)

(my 3rd shaft exceed, i'will cut it one of these days)

b) make 2 squarre holes, 6 x 9 mm (width - height) for belt, front for attachement and rear for tensionner.

I made them by drilling and files, but you can do it round if you prefer.

c) Drill 4 holes to fix heatbed wires with plastic zip ties (size depends of your zip ties size)

d) Finalize by Rear belt tensionner mouting, it share one screw with Rear shaft bracket (left), Use 2 x 16 mm M4 screws.

So now that you have completed this part, you have a functional heatbed carriage.

If you haven't already done so, i advise you to test your heatbed.

Mount heatbed Sensor. put it in the middle hole with some silicon paste and high temp tape

These pictures are externals, i did not make the loops on power wires, i assume this is for not pulling on the welded part, but i would not did like that.

Connecting  heatbed/mofest/mainboard/PSU you can test all parts

Don't weld anything before next chapters, there is some measurements to do.

If all is working properly then you can attach insulation, i did mine myself but you can buy it for 2 €.

Some ideas for DIY:

• Cork plate.
• Cotton batting.
• Wool felt sheet.
• Rescue sheet, see e.g. Robert's Heated Bed ie the silver or gold rescue blanket used by hikers.
• Glass fibre soldering/plumbers/welding mat
• Silicon or teflon cooking sheet

You can attach it with some double-sided tape ro some glue.

Search on internet there is quite of tutorials.

Mount carriage on basement, to see if shafts have good alignement.

Remove the old one by cutting belt attachements, unscrewing shafts screws, and removing heatbed socket on mainboard.

Mount the new carriage without heatbed, openning a bit shafts like that:

Then insert them in bearings, slowly and without using force if something resist (you could loose bearing balls), and finally push shafts completely

Without tight screws, try to slide carriage forward/backward along the entire length, it must slide perfectly all over, without any undue mechanical resistance. Thus tight shafts screws (M3).

In case of resistance:

Try to identify cause and rectify.

If you don't find it, verify that your carriage has perfect 90° angles , or rectify.

Shafts brackets have been perfectly well sized but your printer could have a calibration defect and make smaller or bigger parts. If you think this is the problem, then reassemble genuine heatbed, calibrate printer, and re-print brackets.

SORRY, BUT SEQUEL WILL SOON COME,

STILL WORKING ON IT

...SOON

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