Can I Wire The Heated Bed This Way?

I am finding it a challenge to line up the cables for soldering to the heated bed the way the manual shows. Can I do it another way? I would do it as per the other end of the cable. I.e. join a wire to each group of 12 (and one to extend each thermister wire). Then these would get wired to the heated bed. I mocked it up with scraps like this because I need practice anyway :

Separate wires and bundle with zip-tie. Strip them:
Twist and tin:
Solder to a new wire (what size to use?):
Apply smallest heat-shrink:
Apply larger heat-shrink:
Remove zip-tie and apply largest heat-shrink:
Orient to heated bed like this:

I would lead them out from the inside. (Example) Would this be OK as long as I don't intend to solder to the center holes?

This way would mean the wires are likely too stiff to mount as the manual shows (looped around and under the bed for a while). In that case I would run them out the back and then under the Y carriage. Should I expect this would be fine as long as I'm careful not to knock them ever? Or maybe I could still orient them as the manual shows.

I would try to fix the wires to the heated bead with Kapton tape for strain relief if needed. I think I should be able to apply Kapton to the heated bed anywhere without worry of it getting too hot or otherwise bothering the leveling of the glass.

I would appreciate comments. Thank you!

I don't understand why when you get to your 03 picture you can just solder that tinned section to the PCB? How is that any harder than soldering a single thick wire?

The piece of wire you show looks too thin to carry the current. It would need to be the same as red and black supplied.

If you put the wires through the holes in the PCB you may not get the glass on. You might get away with it, the glass is cut to quite a poor tolerance so it depends on the particular piece you received.

I don't think there is enough clearance over the Y motor to allow the wires to be routed under the Y carriage.

You can stick Kapton to the underside of the bed but you don't want the insulation of the wire to touch it as it is only rated for 105C and you might want more than that if you print ABS. It would need to be PTFE insulation if it was in contact with the bed. You shouldn't need strain relief between the wires and the bed because there is no movement there. The ribbon clamp provided the strain relief.

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[www.hydraraptor.blogspot.com]

nophead Wrote:
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> I don't understand why when you get to your 03
> picture you can just solder that tinned section to
> the PCB? How is that any harder than soldering a
> single thick wire?

I am having trouble bending the group of wires as shown in the manual. I think I could do it more easily if the wires lead to the outside rather than the inside. Could I do that or is there a reason they must lead in? I assume the reason would be so as not to obstruct the middle connections.

> The piece of wire you show looks too thin to carry
> the current. It would need to be the same as red
> and black supplied.

Yes, I was just using a scrap piece of wire.

> If you put the wires through the holes in the PCB
> you may not get the glass on. You might get away
> with it, the glass is cut to quite a poor
> tolerance so it depends on the particular piece
> you received.

Yes, thank you. I was showing that picture because they had the leads pointing out like I am wondering if I can do. I would not put the wires through like they do.

> You can stick Kapton to the underside of the bed
> but you don't want the insulation of the wire to
> touch it as it is only rated for 105C and you
> might want more than that if you print ABS. It
> would need to be PTFE insulation if it was in
> contact with the bed. You shouldn't need strain
> relief between the wires and the bed because there
> is no movement there. The ribbon clamp provided
> the strain relief.

More good information above.

If I can lead off the wires to the outside I think this step will be easier for us. But if they must lead in we will do that.

Thanks again!

Yes the wires can lead inwards from the pads. Perhaps that is better anyway. The current arrangement stems from a previous revision of the PCB which had smaller pads.

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[www.hydraraptor.blogspot.com]

nophead Wrote:
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> Yes the wires can lead inwards from the pads.
> Perhaps that is better anyway. The current
> arrangement stems from a previous revision of the
> PCB which had smaller pads.

Hi, I am sorry to bother you again but am I correct to read 'inward' above as 'outward' as the subsequent sentences suggest to me? I just don't want to make a mistake. Thank you.

I mean't inwards but I think we are talking at crossed purposes.

To be honest I can't see how it is a problem to do it exactly like the manual shows. I have done it like that many times. If you want the stripped wires to point the other way. I.e. the wires pointing outwards along the pads and the insulated cable leading inwards from the pad it will be fine, possibly neater.

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[www.hydraraptor.blogspot.com]

Thank you for clarifying. Sometimes it takes a lot to get through my rather thick skull .