Custom Heat Pad and thermistor question
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@phaedrux
The deploy and retract is working via the macros but not by the direct M401 and 402 in the console. Is that normal? What should i test next or have as a macro? -
The macros must be in the system folder for M401 and M402 to work. If you have them in the macros folder only, they won't.
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@phaedrux So what directory should the two macro's go in? At the moment i have them directly in the macro directory. I do have a BL Touch folder/directory created within the macro directory but havent placed those two files in there yet.
Nevermind i see your last message says in the main directory... but then what is the point of being able to make other directories and keeping things less cluttered?
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@wingtip said in Custom Heat Pad and thermistor question:
but then what is the point of being able to make other directories and keeping things less cluttered?
You still can do that, but the firmware is looking in the /sys folder for the probe deploy and retract macros. That's just the way it is.
In other words, the macros folder is your to do with as you wish, but the sys folder is for the firmware and you must play by it's rules.
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@phaedrux
Ok, so if the macros are working now from the macro directory then i can leave it that way right? So what should i test or add next to the directory... Thank you for all the help! -
You can leave a COPY of those deploy and retract macros in the macros folder, but if you want the probe to deploy and retract when you send G30, a copy of those macros must also be in the /sys folder.
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Now working from the console with the m401 and m402. I had to remove a space in the name of the files and now they work. Ok what now?
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@wingtip said in Custom Heat Pad and thermistor question:
Ok what now?
If that works, you can do the tests described here and measure your XYZ probe offsets as well.
https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe
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Custom heat pad just arrived. 752mm x 522mm, 110vac, 1500 watt.
45c-110c with safety cut at 120c.
In this pic you can just see the heating element pattern
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Looks really good. Not sure if they included instructions for mounting it, but here's what Keenovo recommends. High temp silicone is the way to go. You don't want that thing coming off mid print.
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@phaedrux
Trust me, it will not come off. I never use self adhesive on my heat pads. There will be the aluminum base, a layer of cork, the heat pad, then the glass layer, the possibly some buildtak or printbite or pei or something all held down by the good ol binder clips. It's always worked for me in the past. -
@wingtip said in Custom Heat Pad and thermistor question:
There will be the aluminum base, a layer of cork, the heat pad, then the glass layer,
Wait, so you're putting the aluminum on the bottom and then cork and then the heater and then the glass on top? That's a very bizarre heated bed sandwich.
The heater should be attached to the bottom of the aluminum so that it can act as a heat spreader. The glass then goes on top of the aluminum. Use the cork to insulated the bottom of the heater pad if you like.
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@phaedrux Thats the way i setup my FT5 R1 and has been flawless for years. the cork is only a spacer due to having to cut a slot for the thick area of the heat pad where the cables connect and thermistor are installed etc... Why heat up a whole sheet of alum and still have to heat the glass up beyond that? If i had put the heat pad under the alum the heat pad would have to be smaller than the alum to allow room for the mounting screws and nuts/adjustment screws.
I just got the cork and heat pad and glass layed down... about to try to finish the setup steps in the document you listed last night. Still have to wire up the heat pad and the SSR and thermistor. After that i need to print a spool holder. Then decide if i want to print on the plain glass or install pei, buildtak, printbite, or some other printing surface. Havent decided yet.
I did lose some 20mm print area in X axis with the large clips i used to hold the sandwich down lol...
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There's more than one way to crack an egg.
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Here is the big mac sandwich
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That bed is thicc.
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@phaedrux
Has to be as big as it is... if it were a skinny bitch it would flex -
I am going to stick my head out here and comment on your heated bed configuration ....
Sorry to be a downer and all that but there is a good reason why everybody else uses the heat bed configuration that they use. The heat pad has, as you pointed out, individual wires that generate the heat. This has to be evened out which is done by the aluminum build plate.
The cork has two functions - one is to insulate the bottom of the heat pad so you don't radiate a good portion of all that heat into space and it is also used to apply pressure to the heatpad to keep it in touch with the build plate. Of course this only works if you have some sort of mechanism under the cork to press it against the heat pad. This is usually done with another aluminum plate.
The glass on the very top is your actual build plate but it could be a myriad of other solutions. You do NOT want to print directly on the aluminum build plate.
The arrangement that you are using makes zero sense! -
@jens55 I think you're looking at his picture upside down. The glass is the build surface. The aluminum is the support base underneath.
Definitely not traditional and I would worry a bit about the heater not having a large sink source to smooth out the heat, but that glass is very thick so maybe won't be so bad.
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@phaedrux, I think the op has explained it sufficiently .... from bottom to top, it is aluminum plate, cork, heater, glass.
IHO nothing good can come from that and I wanted to express my thoughts rather than be quiet and politely not say anything. OP can do with my opinion what he wants (I expect the opinion will be dismissed) but at least I know I tried to warn him ....
