Solved Need advice on new heated bed aluminium plate

[TLeTourneau]

Jumping in on this. I'm thinking about moving to a cast aluminium plate, I'm stuck on what thickness to get. The plate would be 500x500mm (19.6875"2 square) and the options seem to be 1/4", 5/16", or 3/8". In that size the 1/4" and 3/8" are the same price and the 5/16" is $10 more. I'm just not sure which way to go. Any advice would be truly appreciated. My machine is a CoreXY with dual Z axis using single start T8 leadscrews that have a 2mm lead. On the plus side I live about 90 minutes away from Midwest Metal Supply.

Thanks,

Tom

[crynool]

Anyone experience with them?

https://www.metalsupermarkets.com/phoenix-southwest/

[mrehorstdmd]

@tletourneau When it comes to thickness, you're balancing rigidity against heat-up time. You can get an idea of heat-up time from this site: https://jscalc.io/calc/uS8JYjYISgIvzJ1x 1/4" plate may be a little thin for that size depending on how thin you want to print your first layer, or whether or not you're going to use mesh compensation.

A 500x500 plate will expand about 1mm when heated to 100C. Make sure the mounting system can deal with that- the mount is usually not heated, so the screw locations don't move by 1 mm. I have used a kinematic mount on 2 printers (so far) and it works well.

[TLeTourneau]

@mrehorstdmd thanks for the reply, I'll keep the mount in mind. I guess I have to decide between the 5/16 (12.22lbs, 7.9375mm) or 3/8" (14Lbs, 9.525mm). It's a fairly large build area (at least in my mind) and I'm concerned about rigidity. I have a 3mm heat bed now and it is not the most rigid thing in the universe.

I also can't seem to get a good automatic bed level (my dual Z's are independently driven) or a good mesh. I'm using dc42's mini differential IR sensor but I can start another thread for that. I do have a 1/4" glass top on the bed.

[wilriker]

@ricky_grade10 said in Need advice on new heated bed aluminium plate:

I know some of you are aware of these plates...

https://clever3d.de/epages/7a4290fc-7c7f-46cc-9b99-eadef22228e2.sf/seca129485ade/?ObjectPath=/Shops/7a4290fc-7c7f-46cc-9b99-eadef22228e2/Products/c3d-DDP-PEI-natur

I am actually really aware of exactly this shop and plate. I was considering to buy one of these but: the price compared to an uncoated plate is insane. 220mm² uncoated (different shop, same plate) cost 15 €. The coated one you linked 55 €. That's 40 € for PEI on both(!) sides - who needs PEI on the side where the heater is attached anyway?

Only real advantage of this plate would be to have the holes for mounting screws already drilled as compared to the other one and I don't have neither a drill press nor a milling machine, so drilling exact holes with only a cordless drill is a bit daunting.

[TLeTourneau]

Does anyone think the additional weight of going with a 14lb (3/8") plate over a 12.2lb (5/16") plate would have a detrimental effect on the Z axis?

[DeltaCon]

@wilriker said in Need advice on new heated bed aluminium plate:

who needs PEI on the side where the heater is attached anyway?

Lots of people use these plates on top of the heated alu bed (with clamps). It is nice to have a plate that you can turn over to choose between a glossy or a matte finish.

[deckingman]

@tletourneau said in Need advice on new heated bed aluminium plate:

Does anyone think the additional weight of going with a 14lb (3/8") plate over a 12.2lb (5/16") plate would have a detrimental effect on the Z axis?

Probably not.

BTW I've replied to the other thread that you've started with more or less the same topic.

[mingtaial]

@fcwilt [https://www.aluminum-alloy-supplier.com/aluminum-plate/](link https://www.aluminum-alloy-supplier.com/aluminum-plate/)

[jens55]

Pardon the slightly off thread question but I have tried PEI on glass with 486MP and had nothing but issues. Both items came from Amazon and maybe that was the problem but the PEI curled something fierce at higher temperatures (it's been a while but I am thinking it was ok to about 60C) and it also developed bubbles/areas where the 486MP let go.
Disappointed doesn't even get close to how I felt about that mess. The off topic question - how do you spread silicone RTV glue into a smooth consistent layer so your PEI stays smooth and flat ?

[Phaedrux]

@jens55 How thick was your PEI sheet? The 486MP shouldn't let go that easily, and the PEI should be thick enough to be stiff enough to resist and cupping.

[jens55]

@Phaedrux, I'd have to dig it out and measure it but it was substantial ... I am thinking in the order of 1 mm. I will see if I can find it in the morning and measure it.

[DeltaCon]

@Phaedrux Yes, but I think the difficulty is getting no air trapped in the glue-liner. It expands when heated and causes the issues like unevenness and will work areas loose eventually. I have a glass plate and a 6mm alu plate both with thick PEI glued on top. I am very happy with how it sticks, but absolutely NOT with how even it is. I am a trained signmaker so I know how to prevent airbubbles and I have none visually, but nevertheless it's uneven enough to spoil first layers.

[jens55]

@Phaedrux, confirmed 1 mm thickness ....
I did actually take great care with the installation of the glue sheet (seperate sheet so two chances of getting air trapped) and thought I did well but chances are it got mucked up first time I went too hot. Just for laughs, I can get the edges to curl up about an INCH !!!
This is going back a while so I might be off by a bit but it wasn't just a mm here or there
I still suspect that I got some kind of a clone product but have no way of finding out if it is the real thing and I was not about to spend another $20 on a new sheet of PEI. I went back to printing on straight glass (no glues, hairspray or other magic potion)