Bed chooses

  • hi completely off topic but bed chooses i currently have a 35x35cm 5mm mdf with silicon heated mat and topped by 2mm aluminum sheet on top (printing area)
    held at the corners buy the normal spring and screws the thing is the hole thing is not flat anymore its bowing so im thinking of going back to 4mm glass as my printed bed
    but ive had cracking problems in the past

    whats in your opinion is the best thing to print on and the best way to attach to printing area

  • 1/4" MIC6 AL plate with a silicon heater attached & insulated on the bottom. It can be mounted with mdf, plywood or a thinner aluminum sheet. I use 12"x12" BuildTak on one printer and 300mm x 400mm PEI on the other for the print surface. I used to use glue stick, but can be messy in maintaining it.

  • Everyone has their own favourite. You need something flat to start with so machined or cast aluminium tooling plate is a good option. It also serves a good heat spreader. Mine is 10mm thick but that was a bad choice (take too long to heat up and cool down), 6 to 8mm would be better. I use insulation underneath mine. It's not essential but will help the bed to warm up quicker. Some people print directly on to the aluminium but I prefer to have a removable print surface, so I use 6mm float glass (4mm would probably be OK). I have 3 sheets, one is covered with PrintBite, one has Blue tape and the third (which I use most of all) is just plain glass with 3DLAC.

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    Having removable print plates is the way forward. There are loads of options and much depends on what you are printing with. PEI is a good choice for ABS. Glass is a good choice for PLA, with glustick it also nice for EDGE or XT. I have heard a lot of good stuff about the clever3d pei coated aluminium plates but not tried them yet.

  • never thought of having a removal able print bed good idea i like it and as a removable plate i could use the 2mm ali plate has a heat distribution and go with glass and thicker ali plate
    on glass i use cheap non perfumed hair spray Salisbury cost 40p a tin works great with pla and abs slurry for abs but is messy ive tried glue stick but the pond shops ones just make a big black mess thanks for the ideas anyone tried a mirror kind of like the idea for pla would look good while printing

  • My vote is for 3DLAC on glass

    Here is a little video of something I made which I honestly thought would be impossible There is a bit in the middle of the clip where YouTube decided to cure the shakiness by making the hot end appear stationary and shaking the object about so ignore that part - it didn't really happen like that as the rest of the clip will show.

  • 3Dlac is your friend for PLA. Directly on glass and not heated bed needed.

  • that is impressive no glue are solvents to help whats it like with abs/nylons i want to print some tough parts in nylon

  • For ABS and PC I would use Dimafix with 100c bed heat.

  • Are you all using thick print plates I thought 5mm would be max are it would take to long to heat take it your using a 240v mains heater to get that to printing temp

  • Yes I'm using 10mm thick aluminium on a 400 x 400mm bed but it was a bad mistake. 8mm would be better, 6mm would probably be OK if it's well supported. Also, I have 6mm glass on top but 4mm would probably be better. Having said that, it works but t does take a while to heat up and cool down.

    Also, you have to be careful where you put the temperature sensor with a thick aluminium bed. The usual thing is to have the sensor in the centre of the bed between the silicone heater and the aluminium but that is a bad idea if you have thick aluminium because it takes a while for the heat to find it's way to the top of the plate. The electronics will turn off the heater when the thermistor (or PT100 in my case) reaches the set temperature but the top surface is still cool so it takes even longer to heat up. In the end, I drilled a hole in the edge of the aluminium so that I could fit the sensor close to the top surface and about 30mm in from the edge.

    For my size of build plate a 240V mains heater is pretty well a must have.

  • Thanks for the info there's a metal supermarket close to me so send them a email for some 6mm Ali sheets and and there's a glass shop on the way so when I get a day off ill round up the parts thanks for the info.

  • Make sure you get aluminium tooling plate because that will be guaranteed flat. Also, the glass needs to be float glass because that also is flat (horticultural glass my be rolled glass and isn't flat). Furthermore, don't be tempted to have the glass toughened - it may be safer but the toughening process can make the glass bow (I know from experience).

    If you build it right, with 3 point levelling you'll have no need for any sort of bed compensation. I've got to the stage where I can just power up the machine, select an object and hit print. No pre - print checks or setting up required (well maybe a quick squirt of 3DLac). The start gcode heats the bed, homes the axes, heats the hot end away we go.


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