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View Full Version : Small upgrade to 3D printer



BobL
10th Nov 2021, 09:09 AM
My printer came with a 4mm thick Al plate bed, covered by a ~300x300 mm plastic/carbon fibre, sticker cover, onto which the printing takes place. However the prints weren't adhering all that well to the cover and after seeking advice from my tech support guy (my son) he suggested applying a UHU glue stick to the cover (apparent hairspray also works) in the area where the print will be deposited.

This worked well. . . . too well . . . . now completed prints would not come of the cover all that easily. In most cases I had to resort to using a single sided razor blade to get in between the print and the cover and then use a sharp thin bladed spatula, and work my way around the edge of the print. After printing about 50 or so objects I invariably ended up making a number of small cuts in the surface of the cover and then ~20c size pieces of the cover started peeling off from the Al plate. Initially I was able to print around the holes but eventually there were too many.

My tech support guy said - "the cover is considered a consumable, peel the old one off, and let the moths out of your wallet and buy a new one". Which I did, but peeling the old one off was more difficult that it appeared. Strange that bits of the cover would peel off when removing prints! The new cover cost $20 and the adhesive is a "peel backing off and you get one shot at applying the cover", and it narked me that I did not apply it straight and it looked awful.

This cover lasted about 2 prints before it got a nick in it when removing a particularly stubborn print. Removing the next print tore a 50c size hole in the cover !!!

Back to tech support and this time he says, "you should get yourself a tempered glass plate for the cover". They adhere well at higher bed temperatures and "let go" more readily at room temperature. I bought one for my machine ($40) but it was 7.6mm short on one side - apparently that's how they come. Not a problem, but this means the built in clips that hold the plate down onto that side of the printer cannot be used.

Tech support says, "use bulldog clips, my latest printer came with 4 bulldog clips as the bed holding mechanism". I did this and it works well, but the bulldog clips really looked ugly so I came up with the following solution.

It's a Al strip that acts as long Z-clip to hold the glass plate in position.
The long clip was milled out of a piece of 6 x 12 mm Al strip sliced using a table saw from a 6mm sheet of Al

Now the original plate holding clips can be used to hold it down
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Here's a side on view so you can see the profile.
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Then I transferred it to the back edge of the glass so you hardly even notice it
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Jekyll and Hyde
11th Nov 2021, 08:45 AM
Glue stick and hairspray work quite well, as does 'abs slurry'.

However what I now use for almost everything on my glass bed is a product called 'Dimafix'. Not sure of the chemistry behind it, but the hotter you get it, the higher its holding power - to the extent it will even hold straight polycarbonate down for about an hour and a half at 140 degrees bed temperature on my unenclosed printer before the print finally pulls away from the warping. The best I ever managed with many different surface experiments previous was about 40 mins.

For ABS/ASA it's just brilliant, holds the print perfectly. If you try to remove the print just after completion, you'll pick the entire printer up. The trick is that when it cools back down, it lets go again, usually when the bed drops to between 35-40 degrees, at which point for ABS or PC you'll hear a loud crack that sounds like your glass plate just split in half, and the print will just be sitting there.... PLA doesn't release as spectacularly, and of course at typical PLA bed temperatures, the Dimafix doesn't have a huge amount of holding power, but the flip side is that PLA doesn't usually NEED much holding power.

The other advantage is that Dimafix is so grabby you can lift your initial Z height up slightly, as it will hold even when the first layer is basically just being dribbled onto it, whereas many other surfaces tend to reward squishing that first layer down for fear of lifting partway through...

If you try it out, you can figure out what's actually in it for me, as it is kind of expensive. Fortunately you use very little of it, and can just touch up the spots where the previous print was if needed. It's water soluble, so complete removal from the bed is simple if desired.

On which last note - if you've got something stuck to the buildplate with UHU stick, dripping a bit of water around the edges of the print (on a cool build plate) can help to dissolve the bond. From memory IPA also works?

BobL
11th Nov 2021, 10:50 AM
Thanks for the info J&H - very useful.
I've seen Dimafix used on Youtube clips and various comments, some claiming it was no better than glue sticks.
I've now printed about half a dozen PLA things on the glass plate and they would still not hold unless I used the glue stick but they released easily once the bed had cooled down.

RE: DIMAX
You didn't say if you used the Dimax aerosol or the pen. I'm not keen on using aerosols inside my printer enclosure as they eventually just coat everything thing including inside the electronics and even though it's water soluble i don't want to be washing mother boards even on an occasional basis.

[QUOTE=Jekyll and Hyde;1991286] . . . . .If you try it out, you can figure out what's actually in it for me, as it is kind of expensive. Fortunately you use very little of it, and can just touch up the spots where the previous print was if needed. It's water soluble, so complete removal from the bed is simple if desired.

according to the MSDS for Dimafix it contains
1 < 2 % Isopropyl alcohol
2,5 < 5 % 1-vinyl-2-pyrrolidone-vinyl acetate polymer
30 < 40 % Ethyl alcohol
60 < 70 % Dimethyl ether
The 1-vinyl-2-pyrrolidone-vinyl acetate polymer appears to be binder which BTW is widely used in agriculture as a binder for seed coatings and slow release fertilisers so its probably not too bad.

The MSDS does not say whether it's for the aerosol or the pen but I suspect that they are similar, the aerosol probably just has a propellant added.
I also stumbled across this which seems to be useful.
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RE: Water/IPA tip for letting go of prints
Thanks for that.

Jekyll and Hyde
11th Nov 2021, 12:13 PM
Thanks for the info J&H - very useful.
I've seen Dimafix used on Youtube clips and various comments, some claiming it was no better than glue sticks.
I've now printed about half a dozen PLA things on the glass plate and they would still not hold unless I used the glue stick and they released easily once the bed had cooled down.

RE: DIMAX
You didn't say if you used the Dimax aerosol or the pen. I'm not keen on using aerosols inside my printer enclosure as they eventually just coat everything thing including inside the electronics and even though its water soluble i don't want to be washing mother boards even on an occasional basis.


I have the pen. Not sure if the aerosol is even available anymore, I think that may have been the original product and they may have replaced it with the pen?

If you're only printing in PLA all the time, most of the time glue stick on glass should be perfectly sufficient, and release nicely, and there shouldn't normally be any significant gain with Dimafix, as the bed temperature isn't high enough to really make it grip hard (as shown in the graph).

For anything else requiring a higher bed temperature, it certainly works far better than glue sticks for me (and a mate who does more commercial scale printing of ABS), but from much reading over the years, different brands and colours of glue stick can vary wildly in their effectiveness.

I also wonder whether the gluesticks we get here are quite the same composition as the US gets, as my results haven't quite matched up in the past...

I tend to chop and change between different filaments (rarely PLA these days!), which is why I mentioned Dimafix works with PLA - I don't have to clean it all off the bed and change to something else when I change filament, I just touch up whatever bits need it, and hit go.

Is it likely that the "1-vinyl-2-pyrrolidone-vinyl acetate polymer" is the active ingredient, and the rest is just carrier solvents? I was wondering whether there is a way to make your own, or use a more garden variety product. Although I'm not even 20% of the way through the one I bought, so it's not that relevant I guess.

BobL
11th Nov 2021, 02:44 PM
I have the pen. Not sure if the aerosol is even available anymore, I think that may have been the original product and they may have replaced it with the pen?

Aerosol is still available thru Element14.


If you're only printing in PLA all the time, most of the time glue stick on glass should be perfectly sufficient, and release nicely, and there shouldn't normally be any significant gain with Dimafix, as the bed temperature isn't high enough to really make it grip hard (as shown in the graph).

Maybe its my glass plate but the PLA I have doesn't stick that well to it - about the same as the plastic/carbon fibre sticker I have on the Al plate - unless I use UHU.


For anything else requiring a higher bed temperature, it certainly works far better than glue sticks for me (and a mate who does more commercial scale printing of ABS), but from much reading over the years, different brands and colours of glue stick can vary wildly in their effectiveness. Tha 's what my son says as well. We're both using the BIC brand at the moment. The kling-on factor for PLA on the standard plastic/carbon fibre plate cover using BIC glue is very high.

I've also used the BIC glue stick with PETG, TPU and a "PLA wood fibre mix" filaments on the old Al with plastic/carboin fibre sticker and found it works well - Haven't tried an other stuff yet.


I also wonder whether the gluesticks we get here are quite the same composition as the US gets, as my results haven't quite matched up in the past...
Could be.


I tend to chop and change between different filaments (rarely PLA these days!), which is why I mentioned Dimafix works with PLA - I don't have to clean it all off the bed and change to something else when I change filament, I just touch up whatever bits need it, and hit go.
I would certainly like that.


Is it likely that the "1-vinyl-2-pyrrolidone-vinyl acetate polymer" is the active ingredient, and the rest is just carrier solvents? I was wondering whether there is a way to make your own, or use a more garden variety product. Although I'm not even 20% of the way through the one I bought, so it's not that relevant I guess.

Just after I sent the last post I realised the dimethyl ether in the brew will be the propellant, so that is not needed
The vinyl-2-pyrrolidone-vinyl acetate compound is widely used in hair and skin care products but buying small amounts looks tricky.
A web site in China sells it but minimum buy is 25kgs.

moorebrm
18th Jan 2022, 01:47 PM
The best mod I have done is to move to a magnetic bed on my 3d Printer.
In 2019 I used magnets under the heater plate and a thin 1mm thick flat sheet on top.
I plastic laminated the steel sheet with a3 laminate sheet (yes it will go through the laminator) Sand (scratch up) the surface with about 120 grit paper, wash it with acetone then use a very thinned light coating of abs slurry on top of the sheet.
The abs slurry acts like a super large thin brim and works for abs pla and petg. Flexing the top sheet allows the print to pop off.
I have tried the bed surface stickers but still use scratched up plastic film as a preference.

You can now buy spring steel mag beds from 3d parts stores they are cheap and work fine and are a great mod.

If you are having problems with first layer stick check your FIRST LAYER EXTRUSION MULTIPLIER - Slicr uses 250% extrusion on the first layer as the default setting but other slicers don't.
This puts out lots of plastic pushes it hard on the plate and gives you an excellent bottom layer surface finish.
I never print without at least a 200% bottom layer extrusion.

Regards moorebrm

Grahame Collins
19th Jan 2022, 11:23 PM
The best mod I have done is to move to a magnetic bed on my 3d Printer.
In 2019 I used magnets under the heater plate and a thin 1mm thick flat sheet on top.
I plastic laminated the steel sheet with a3 laminate sheet (yes it will go through the laminator) Sand (scratch up) the surface with about 120 grit paper, wash it with acetone then use a very thinned light coating of abs slurry on top of the sheet.
The abs slurry acts like a super large thin brim and works for abs pla and petg. Flexing the top sheet allows the print to pop off.
I have tried the bed surface stickers but still use scratched up plastic film as a preference.

You can now buy spring steel mag beds from 3d parts stores they are cheap and work fine and are a great mod.

If you are having problems with first layer stick check your FIRST LAYER EXTRUSION MULTIPLIER - Slicr uses 250% extrusion on the first layer as the default setting but other slicers don't.
This puts out lots of plastic pushes it hard on the plate and gives you an excellent bottom layer surface finish.
I never print without at least a 200% bottom layer extrusion.

Regards moorebrm

Hi moorebrm

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BobL
29th Jan 2022, 08:00 PM
The best mod I have done is to move to a magnetic bed on my 3d Printer.
In 2019 I used magnets under the heater plate and a thin 1mm thick flat sheet on top.
I plastic laminated the steel sheet with a3 laminate sheet (yes it will go through the laminator) Sand (scratch up) the surface with about 120 grit paper, wash it with acetone then use a very thinned light coating of abs slurry on top of the sheet.
The abs slurry acts like a super large thin brim and works for abs pla and petg. Flexing the top sheet allows the print to pop off.
I have tried the bed surface stickers but still use scratched up plastic film as a preference.

Thanks for that info - very interesting - have sort of headed this way to some extent.

I now have 3 heated bed cover plates.
- the original with the black PC bed cover.
- the glass one as before
- a home made 3.5mm Al plate covered with a thin magnetic sticker, on top of that is a thin flexible magnetically backed Black PC cover - this should work like your metal plate.
all of these fit the original heated bed plate which has a claimed max Temp of a 110ºC but is in practice only about 100ºC

I also have made another slightly longer home made 3.5mm Al heated bed plate that can hold any 3 of the bed cover plates listed above. I was going to use bull dog clips but I don't like the way they can get in the way of the auto leveling device so I made a different hold down mechanism that is able to hold the slightly smaller glass plate and the other bigger plates without interfering with the auto level. Will post this soon.

The new heated bed plate uses a 700W 240V silicone covered heat pad so it gets up to temp in double quick time and although the silicone is rated to 200ºC, it's limited to 130ºC by its own PID - this works really well. It also has a replaceable 150ºC thermal fuse under the bed and is fully earthed - I will post details when I have finished it - just waiting on couple of parts. The higher temps are only intended for use with the glass plate.


You can now buy spring steel mag beds from 3d parts stores they are cheap and work fine and are a great mod.
If you are having problems with first layer stick check your FIRST LAYER EXTRUSION MULTIPLIER - Slicr uses 250% extrusion on the first layer as the default setting but other slicers don't.
This puts out lots of plastic pushes it hard on the plate and gives you an excellent bottom layer surface finish.
I never print without at least a 200% bottom layer extrusion.


I don't really have a holding problem with ABS/PET on the black PC bed cover and bit of glue stick. If anything, it sticks too hard but recently I have bee using a bit of water around the print edges and seems to work wonders.

Bit hot to print stuff in Perth lately. We have refrigerated AC but I'm happy to wait till it cools off a bit.

Thanks again for all the info.

BobL
2nd Apr 2022, 09:54 PM
Finally got my 3D printer "independently PID heated bed" up and running.

The reasons I'm doing this are
- printer bed that came with the printer is supposed to go to 110ºC but it only gets up to 99ºC.
At first I thought this could be caused by the thickish plastic printer bed cover and/or lack of insulation underneath the heater but nope, the heater itself barely gets to 100.
- I was also hoping to try printing some plastics that require 120-130 bed temps.

Below shows the PID box with 3 plug/socket outlets, and two switches.
The box is printed in black PLA plastic.
The wrinkled finish is a result of bed levelling issues which I subsequently fixed before printing the lower half of the box.

The audio plug is from the heat sensor located under the heater element
The orange gland is for mains input power (also printed using 3D printer)
The silver plug is a HD mains 3 pin plug for the heater
397822

The two switches are for
- mains power generally
- the second one allows for the mains power to the heater to be turned off, but the PID can still continuer to run and measure temperature.

Below shows the underside of teh heater bed with the orange silicone covered heater element stuck onto a custom made oversize Al bed.
The heater element came with a built in Negative coefficient sensor (coiled up red cable)
BUT
The Basic Inkbird PID I'm using requires a sensor with a positive coefficient sensor, so that is the silver slug double kapton taped to the centre of the heater element.
Also embedded alongside the sensor is a 150ºC rated thermal fuse as the orange silicone material covering the heater element doesn't like to go much above 200º
The heater is rated at 700W so it heats up much faster than the regular printer heater which is only 24V DC powered about 200W.
397823

Below is what it looks like from on top.
The slightly smaller than standard glass plate bed cover is held in place by some thin SS strips and socket screws.
There are several threaded holes in the Al under the SS strips to suit a standard Al bed cover.
397824

I haven't tried it on the printer yet - I hope it fits!

No auto switching on the PID yet (I will have manual turn the heater on and off) but its coming in phase two of this mod.

BobL
3rd Apr 2022, 07:19 PM
After much mucking about and running around in circles like a headless chook I finally have the PID 3D printer heated bed up and running. I started collecting the bobs and bobs for this project in Nov last year so 4.5 months - not too nbad I suppose.

The issues included
- working out a way to leave the old bead plugged in (but turned off in software) so I can easily do a quick switch back if needed
- the glass bed is slight smaller than the stock Al plate but the Al support plate is longer so making sure there was enough clearance when the support plate and bed moved back and forth and making sure the bed levelling attachment didn't touch anything it was not supposed took a lot longer than expected.
- rigging up am elasticised cable suspension system so the flying leads to the heater dont get tangles up in the Y-axis movement was solved with 4 elastic bands forming a long elastic connection to keep the leads up and clear with any Y movement.

Not really much to show except that there's enough room to fit the PID box inside the printer enclosure like this.

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Now for some form of automation - might be a while, especially given I can easily print as it is.