How to change the heat bed to spring leveled by Andy Cohen

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John@Raise3D
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How to change the heat bed to spring leveled by Andy Cohen

Postby John@Raise3D » Mon Mar 21, 2016 7:36 am

Originally posted by Andy Cohen

I finally got all the HW I wanted so I could change my build plate to a user adjustable leveled bed. So I cleaned off the hot glue from connectors for the heater and disconnected them, removed the 5 M3 bolts/nuts, then lifted the plate off.
The springs i used; Midwest fastener #M159… I tested each from the batch I got with a digital scale. At mid compression each handles ~8lbs of pressure. 8x5=40… that’s 40lbs of pressure before the 5 springs are compressed further… that’s 18 spools of filament! You could easily add 4 more springs using shorter stabilizers bolted to the holes from the other 4 bolts I removed which would bring it up to 72 lbs of downward pressure needed to compress the springs further.
http://www.thingiverse.com/thing:1409412

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JohnSays
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby JohnSays » Fri Aug 26, 2016 2:27 am

Of note on this thread: The insulator is no longer "fish paper" but a heavy duty composite so there is no worry about the binder clips wearing through and shorting out the heater nor of screws doing the same. In fact, the whole spring replacement can now be done without the need for printing and using any plastic parts whatsoever. You can reuse the supplied nuts and lock washers with some Locktite. All you will need to buy are the springs and 3mm thumb nuts. I could not find the springs Andy used anywhere. And no, not even Ace hardware.

You also will not need to Kapton tape the whole bottom of the heater plate as it is protected now. I did tape around the center hole however. In fact, now that I think about it, I would use a PET-G standoff on that center screw to protect the heater plate.

You can use these springs from mcmasters.com: http://www.mcmaster.com/#catalog/122/1271/=13vwu8a

springs.jpg


Thumb nuts: https://www.amazon.com/gp/product/B016CLFCZI
- John
2 Raise3D N2 Duals, V2 nozzles, Bondtech BMGs, adjustable table, Panucatt SD2224 drivers, run-out sensor, thermal overload protection resistors on motion controller board, Firmware 1.1.8ABH - with Lin_Advance, Palette+

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Vicky@Raise3D
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby Vicky@Raise3D » Fri Aug 26, 2016 8:22 am

Thanks for updating.

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walshlg
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby walshlg » Fri Aug 26, 2016 2:22 pm

FWIW- My thoughts:
1) I use 9 screws instead of 5 because I think it makes the bed more stable. Yes it is a bit of an added pain to level.
2) I like the use of the printed spring holders as they keep the springs centered around the screw. I have modified other bed systems without them and the springs always got all misshapen , sideways, and having the edge jammed up against the screw -> this , in turn, causes the spring to catch on the thread and leveling the bed is unstable because the catching will suddenly release at random during your prints.
3) use longer springs and screws. I will be replacing my screws with 55mm to get more room for adjustment.
4) I am getting some differential thermal expansion of the build plate -> the bondtack side bows up in the center by 150 um when hot, not much but makes use of the entire print area difficult when using the edges -> so I flipped the plate over, since you can pull down the edges but not the middle, printing with hairspray and it is better for using the whole print area.
5) use the original lock washer with another flat washer to keep the screws in the build plate tight.

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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby JohnSays » Fri Aug 26, 2016 2:50 pm

I agree with the printed spring holders. I went with them today. I printed them with a lip that the spring OD fits into and I made the center of the stabilizer holder a little less than the height of the spring fully compressed. I have attached the stl's as they work with the Mcmasters springs. Ideally the center washer would be thicker because it sits under the surface of the insulation piece.

Wow, I will say that leveling the bed could hardly be easier now and is the first time I have had a level build plate since I got the machine.
Attachments
Washer.stl
(101.35 KiB) Downloaded 91 times
Stabalizer.stl
(379.67 KiB) Downloaded 95 times
- John
2 Raise3D N2 Duals, V2 nozzles, Bondtech BMGs, adjustable table, Panucatt SD2224 drivers, run-out sensor, thermal overload protection resistors on motion controller board, Firmware 1.1.8ABH - with Lin_Advance, Palette+

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walshlg
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby walshlg » Fri Aug 26, 2016 2:57 pm

One trick: getting the spring loaded bed screws into the holes is HARD. I put a 10 pound thermal brick on top (any weight will do) and its much easier to reach up and maneuver the screws into the z plate.

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rlballard
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby rlballard » Sat Aug 27, 2016 3:08 am

This is one mod you will never regret, I did this a while ago and there is no turning back...
BB

DreamForge
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby DreamForge » Sat Aug 27, 2016 3:32 am

Thank you for the file John! just ordered the springs, knobs and bolts...

"Ideally the center washer would be thicker because it sits under the surface of the insulation piece." Any idea how much I should thicken up that center washer over the current washer thickness from the file you provided?

Cheers,
Mark

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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby JohnSays » Sat Aug 27, 2016 4:54 pm

You are welcome Mark. Thanks for asking that question. And now I can feel a little silly because... It is just one PET-G washer thick at 2.5mm. So just make one extra washer and stack two of them.
- John
2 Raise3D N2 Duals, V2 nozzles, Bondtech BMGs, adjustable table, Panucatt SD2224 drivers, run-out sensor, thermal overload protection resistors on motion controller board, Firmware 1.1.8ABH - with Lin_Advance, Palette+

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walshlg
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby walshlg » Sat Aug 27, 2016 8:13 pm

fwiw I just used a smaller diameter washer over the lockwasher for the center hole, it avoids the thermister sensor fine.

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JohnSays
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby JohnSays » Sat Aug 27, 2016 9:29 pm

Yes, but the idea of the thicker washer is to keep spring tension the same at each point. At least, that is my idea of it.
- John
2 Raise3D N2 Duals, V2 nozzles, Bondtech BMGs, adjustable table, Panucatt SD2224 drivers, run-out sensor, thermal overload protection resistors on motion controller board, Firmware 1.1.8ABH - with Lin_Advance, Palette+

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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby JohnSays » Sun Aug 28, 2016 7:28 pm

I can only do the same as you and that is convert the specs on mcmasters. All the info you need is on that page. They are 1" in length, .420" OD and made with 0.47 piano wire (so subtract that from the OD to get the ID and convert to mm.
- John
2 Raise3D N2 Duals, V2 nozzles, Bondtech BMGs, adjustable table, Panucatt SD2224 drivers, run-out sensor, thermal overload protection resistors on motion controller board, Firmware 1.1.8ABH - with Lin_Advance, Palette+

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rhines44
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby rhines44 » Wed Aug 31, 2016 8:42 pm

I couldn't be happier as well. First time having a level bed. I've also been able to tune the bed while printing and keeping an eye on the first layer. I used all 9 areas as well, but have the extra 4 areas completely loose. I'm also looking into longer screws down the road for more adjusting. Once this mod is complete, does anyone know if there is a way to tell the machine that the build size is now an inch or so shorter? Wonderful modification! not sure why the sideways photo. :oops:
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20160816_155548.jpg

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Vicky@Raise3D
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby Vicky@Raise3D » Thu Sep 01, 2016 8:41 am

Once this mod is complete, does anyone know if there is a way to tell the machine that the build size is now an inch or so shorter?


3.png

And edit the global offsest as well if the zero point has moved.

5.png

DreamForge
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby DreamForge » Fri Sep 02, 2016 4:02 am

JohnSays wrote:You are welcome Mark. Thanks for asking that question. And now I can feel a little silly because... It is just one PET-G washer thick at 2.5mm. So just make one extra washer and stack two of them.


Strange but my N2 plus did not need the extra distance for the washer, it was the same measurement between the table and the heat bed in the center... Am I missing something?

Happy as hell I did the mod, first time the bed has been in zero with only a .05mm rise in the center due to some slight heat warping of the glass when the bed is on at 70 C.. Everywhere ells reads 100% level. I set my gap to .25 and ran a full bed test print without any issues.

I am using the silicone pads rather than the clips... seems to be working great, no X-Y movement of the glass and no more hitting the clips or having to re-level when I change the clip positions. I did need to up the bed temp an additional 15 C in order to reach the temps recommended for each filament... not a biggie, just have to remember to add 15C bed temp whenever I test a new product out.

Thank you Andy
Thank you John

DreamForge
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby DreamForge » Fri Sep 02, 2016 4:42 am

rhines44 wrote:I couldn't be happier as well. First time having a level bed. I've also been able to tune the bed while printing and keeping an eye on the first layer. I used all 9 areas as well, but have the extra 4 areas completely loose. I'm also looking into longer screws down the road for more adjusting. Once this mod is complete, does anyone know if there is a way to tell the machine that the build size is now an inch or so shorter? Wonderful modification! not sure why the sideways photo. :oops:


Looks great! I actually tightened all mine down to a tad over 50% compression before starting the leveling. It pre loads the table springs that way and gives a more rigid bed.

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rhines44
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby rhines44 » Fri Sep 02, 2016 11:32 am

DreamForge wrote:

I am using the silicone pads rather than the clips... seems to be working great


May I ask what silicon pads you refer to? Sounds like a good idea.
Thank you

Jetguy
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby Jetguy » Fri Sep 02, 2016 1:09 pm

https://www.amazon.com/400mm-205mm-Sili ... B007PPEW52
or
These are 1mm thick vs the previous 0.5mm thick pads https://www.amazon.com/400mm-205mm-Sili ... B007PPEW52
Thinner is better, but people have used both thicknesses in multiple 3D printing forums.

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rhines44
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby rhines44 » Fri Sep 02, 2016 1:11 pm

Jetguy wrote:https://www.amazon.com/400mm-205mm-Silicone-Thermal-Heatsink/dp/B007PPEW52
or
These are 1mm thick vs the previous 0.5mm thick pads https://www.amazon.com/400mm-205mm-Sili ... B007PPEW52
Thinner is better, but people have used both thicknesses in multiple 3D printing forums.

Great! Thank you.

Jetguy
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Re: How to change the heat bed to spring leveled by Andy Cohen

Postby Jetguy » Fri Sep 02, 2016 1:12 pm

Just cut into squares, I only put them in the 4 corners, but you'll hear a hundred different theories. I do only the corners so if the aluminum crowns in the center, the tiny air gap allows that to not lift the glass. The air gap also helps even out the temp. Yes, you need to preheat for 2-5 minutes before starting a print job to allow the heat to reach the glass, but not a big deal as a workflow.

Google search shows some pictures and thermal image links https://www.google.com/search?q=gino+pa ... gQ_AUIBygC


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