Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?
 
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Matt
 Matt
(@matt-2)
Estimable Member
Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

I'm trying to cram my MK3S into the V2 Lack enclosure. Now I know there's the problem with the heatbed clearance at the back - With the heatbed at its furthest backwards limit, the distance from heatbed cable to LCD screen is too long to fit in the enclosure. My heatbed has the screw-0n wires rather than the soldered-on ones, so I downloaded and printed the 45 degree cover modified specifically for the models with screws. The trouble is, even following the guide the maker of that part gave, I can't cram the wires in no matter how hard I try. So I wondered about another way to make it shorter - Reduce the length of the arms holding the LCD screen.

The arms hold the LCD screen body 15mm away from the aluminium base frame. When the heatbed is as far forwards as it can go, the LCD screen body sticks out past the two thumb tabs on the heatbed by 11mm. If the arms were 11mm shorter, the screen would be exactly in line with the heatbed at its furthest forwards limit (so pushed up close to the doors it would still not obstruct heatbed movement) while still leaving a good 4mm between the LCD screen case and the aluminium frame for the screws behind it.

I can edit the STL files so the functional parts are 11mm closer together, which I think might be enough to give clearance to the cable at the back without the 45 degree modification (or at least then allow me to make my own 45 degree heatbed cable cover that has a more generous curve for the cable to turn in). It would mean that you'd have to crouch to see the screen when it's printing at the furthest rear extent, but that's a small price to pay.

Am I overlooking anything? I'm asking here specifically because I don't have the MMU2 upgrade so I'd like to know how this might affect it as well.

Posted : 30/09/2019 7:06 pm
Bunny Science
(@bunny-science)
Noble Member
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

This 60 degree heat bed cover gives you just enough clearance to use inside LACK enclosure for either the stock Prusa MK3S or Bear frames. Usual LCD mounting arms can be used.

https://www.thingiverse.com/thing:2964580

Posted : 30/09/2019 8:13 pm
Matt
 Matt
(@matt-2)
Estimable Member
Topic starter answered:
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

Ah you're quite right, it is 60 degrees not 45 degrees. Yes, that's the exact one I'm using. I simply cannot get the cable to fit like in the picture. There's not enough bend in the cables for my printer.

I've tested the stock LCD arms model in Lightwave and shifting the back face and the associated holes 11mm further in doesn't create any impossible geometry in Prusa Slicer. So it just comes down to how practical it is, I think.

I'll run a set off in the next couple of days and see what happens.

Posted : 30/09/2019 8:55 pm
Bunny Science
(@bunny-science)
Noble Member
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

Odd. I have it working in two LACK cases.

Posted : 30/09/2019 10:11 pm
bobstro
(@bobstro)
Illustrious Member
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?
Posted by: @matthewmeek

Ah you're quite right, it is 60 degrees not 45 degrees. Yes, that's the exact one I'm using. I simply cannot get the cable to fit like in the picture. There's not enough bend in the cables for my printer.

Could it be that you have the soldered bed connections and are using the screw STL or vice-versa?

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and miscellaneous other tech projects
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Posted : 01/10/2019 1:38 am
Matt
 Matt
(@matt-2)
Estimable Member
Topic starter answered:
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

This is the connection that I have (image - top) and the cover that I'm trying to use (image - middle with comparison to straight cover). When I try to cram the cables into the 60 degree cover, the positive terminal's wire starts to buckle outwards. The only position I can put the cables in and have that buckled wire remain flat enough to fit into the interior space with the covers screwed together has the cables coming out a full centimetre further out (image - bottom left). If I force the cables into the conduit hole, the bulge in the positive terminal's wire becomes so large that it prevents the cover screwing down properly (image - bottom right). The only solutions I see to this are:

  • I could crop the wire off and buy some more crimped-on terminal ends to fit the smaller curve, or take both off and solder them on directly, but I'm not comfortable irreversibly modifying the electrics.
  • I could modify the lower cover to have a larger cavity that will accomodate the bulging wire. This should be fairly simple - Just a case of moving the right vertices out a little bit to make the cavity larger while keeping the screw holes in the same place. Moving the cable hole outwards to fit where the cables want to be when flat would be more effort and wouldn't give enough space-saving to fit in the enclosure anyway.
  • I could shorten the arms of the LCD display to make the printer shorter at the other end (which I'm currently printing; I switched to orange PETG this morning anyway).

Posted : 01/10/2019 9:06 am
Bunny Science
(@bunny-science)
Noble Member
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

Don't solder the wires. They will mechanically fail after a couple hundred hours. 

I think you need to angle the connectors away from the opening to have enough space for the loom. It should fit. I have thicker than stock, 16 g silicone wires in mine and it still works. https://www.amazon.com/gp/product/B07D3N6722/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Posted : 01/10/2019 9:43 am
Matt
 Matt
(@matt-2)
Estimable Member
Topic starter answered:
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

That worked, thanks. It was a very, very tight fit, but it's on now. I've also tried the shorter arms and they seem to do the trick as well (picture below), so I've got the best of both worlds.

Posted : 01/10/2019 11:18 am
Bunny Science
(@bunny-science)
Noble Member
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

Please post your shortened arms. I think they would be useful too.

Posted : 01/10/2019 11:26 am
cwbullet
(@cwbullet)
Member
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?
Posted by: @guy-k2

Please post your shortened arms. I think they would be useful too.

I am also interested.  

--------------------
Chuck H
3D Printer Review Blog

Posted : 01/10/2019 11:44 am
Matt
 Matt
(@matt-2)
Estimable Member
Topic starter answered:
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

Done.

https://www.prusaprinters.org/prints/5922-prusa-i3-mk3s-lcd-supports-short

Posted : 01/10/2019 12:06 pm
bobstro liked
KevinK
(@kevink)
Trusted Member
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

Just as another alternative, I mount the LCD outside the hot area of the enclosure for easier access but make it easy to reattach the LCD if I want to take the printer out for service or the like.  Here's a link to that option:

https://www.prusaprinters.org/prints/5925-removable-frame-or-enclosure-lcd-mount-system

Posted : 01/10/2019 5:47 pm
cwbullet
(@cwbullet)
Member
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?

Now I have find one for my Bear Prusa that is slimmer.  

--------------------
Chuck H
3D Printer Review Blog

Posted : 01/10/2019 5:53 pm
Matt
 Matt
(@matt-2)
Estimable Member
Topic starter answered:
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?
Posted by: @kevin-k49

Just as another alternative, I mount the LCD outside the hot area of the enclosure for easier access but make it easy to reattach the LCD if I want to take the printer out for service or the like.

I might try that if I find ABS or ASA prints are warping because I'm opening the door to start the print. At the moment the ribbon cables are all neatly curled up in the EINSY case and fixed to the frame, so I'm taking the path of least resistance 😀

 

Posted by: @charles-h13

Now I have find one for my Bear Prusa that is slimmer.  

I'm not familiar with the Bear Prusa, other than it's a modification that makes the i3 sturdier, I think. But my edit to the original Prusa LCD supports took all of 3 minutes to open in Lightwave, edit, export and then re-import back to PrusaSlicer. I can't imagine it's going to be much different for the Bear ones. Let me know exactly where to find the LCD support model files for your Bear frame, and how far the front of your LCD casing needs to go backwards for it to be in line with the front tabs on your heatbed when fully forward, and I'll have a stab at it.

Posted : 01/10/2019 6:16 pm
cwbullet
(@cwbullet)
Member
RE: Alternative for 45 degree heatbed cable cover - Shorter LCD screen arms?
Posted by: @kevin-k49

Just as another alternative, I mount the LCD outside the hot area of the enclosure for easier access but make it easy to reattach the LCD if I want to take the printer out for service or the like.  Here's a link to that option:

https://www.prusaprinters.org/prints/5925-removable-frame-or-enclosure-lcd-mount-system

That on is interesting.  I might need a longer LCD screen.  

--------------------
Chuck H
3D Printer Review Blog

Posted : 01/10/2019 6:19 pm
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