Yet another cast aluminum plate topic...

Wyvern

Got mine in!

It ended up being straight forward.

It's only 300W but I like that it warms slowly as to evenly heat for the first layer and there is less possibility for overshoot.

Literally the first print so I'm not sure how well the PEI will stick- I didn't realise when I ordered it, it was so thin, less than a mm- those are not bubbles, it is where I squeegeed the water out.

The SSR came with a chunky heat sink, with this low of power is it even necessary?

mrehorstdmd

@wyvern I use 0.7mm thick PEI and it lasts for years. It's very tough stuff.

Wyvern

Cool.

The test block popped off at 45C no problem, almost like glass with hairspray.

I lost 10mm Z build volume 390vs 400, I could shim the bearings even more, but I'ts not often I build that high anyway.

Next step is to route the wires so they are clean and out of the way- cable chain might be nice.

TLeTourneau

@wyvern said in Yet another cast aluminum plate topic...:

Got mine in!

It ended up being straight forward.

It's only 300W but I like that it warms slowly as to evenly heat for the first layer and there is less possibility for overshoot.

Literally the first print so I'm not sure how well the PEI will stick- I didn't realise when I ordered it, it was so thin, less than a mm- those are not bubbles, it is where I squeegeed the water out.

The SSR came with a chunky heat sink, with this low of power is it even necessary?

I am running a 1000 watt heater with my SSR, measured temp on the back of the SSR without a heatsink was around 35-40C which I think is reasonable so I am not going to install the big heatsink. 1000 watts at 120v is 8.333 amps, well under the 20 amp rating of the SSR.

taconite

Is there a possibility to set max bed temperature?

TLeTourneau

@taconite said in Yet another cast aluminum plate topic...:

Is there a possibility to set max bed temperature?

It should be in your config.g file already, it'll be under ; Heaters and look something like this:

M143 H0 S120                                       ; Set temperature limit for heater 0 to 120C
M143 H1 S280                                       ; Set temperature limit for heater 1 to 280C

H0 is my bed heater and H1 is my hot end.

I also use a 184C thermal fuse for redundancy.

Wyvern

Yeah, that is a concern of mine, there is always power available to the bed should the SSR short closed. A short circuit shouldn't be an issue since it's fused.

Phaedrux

@wyvern Something like this: https://www.be-electronics.com/product_p/ecg8149.htm

TLeTourneau

Here is the one I use: https://www.amazon.com/gp/product/B07DKD619C/ref=ppx_yo_dt_b_asin_title_o09__o00_s00?ie=UTF8&psc=1

Wyvern

Would taped to the mat suffice? I will probably source a lower temp one around 150C as I don't intend on heating it past 110C or so.

Phaedrux

@wyvern A blob of RTV silicone is a good way to stick it on.

Wyvern

Never thought of that! I'm an auto/machine technician so I have tons of that crap.

Wyvern

Hmm, before I start working on cad files for making my removable mechanical bed probe.

Is it possible to say, have the machine home X and Y and ignore Z and wait until you say, click the Z end-stop to start probing?
Does the probe always need to do a Z- offset on startup?

I really haven't dabbled in bed probing, only used the built in code on my Anycubic delta (and that thing is wonky)

I plan on using probing for a bed level map, as the level should almost never change.

Phaedrux

@wyvern said in Yet another cast aluminum plate topic...:

wait until you say, click the Z end-stop to start probing?

You could add a M291 pop-up prompt with a blocking wait until you click ok or cancel.

@wyvern said in Yet another cast aluminum plate topic...:

Does the probe always need to do a Z- offset on startup?

I don't understand what this means.

Wyvern

@phaedrux

The Anycubic had to probe Z and store that information before it would perform the bed compensation routine, but I imagine it is only for delta's.

There isn't any need to have this set up right?

Phaedrux

@wyvern I think I'm having a dense moment. I still don't really understand.

For Delta's you'd have to do an auto delta calibration before printing, but I don't understand that in the context of what you're asking.

Explain it like I'm 5.

Wyvern

Well with me we make 10!

The delta has a removable probe so it saves that data and applies it until it glitches out and forgets.

With that machine it has to probe Z and then it shuts off, you then have to probe and then save.

But that's a crap board, crap firmware.

I'm sure all I need to do is probe, save and apply the map every print.

Phaedrux

@wyvern said in Yet another cast aluminum plate topic...:

I'm sure all I need to do is probe, save and apply the map every print.

Yeah basically.

https://duet3d.dozuki.com/Wiki/Using_mesh_bed_compensation

percar

Just another tidbit of information
I have a 300mm x 600mm x12mm cast aluminum plate for my build platform, thinking that this would be quite level and also maintain level during heating...this was a big mistake....the thermal expansion of the aluminium is quite large being .5mm in the 300mm and 1mm on the 600mm. this cast plate was a tooling plate and surface ground initially. the mounting was fixed at one end and allowed to float in the other direction to prevent residual stresses. Even at that the plate warped and you could actually measure the warpage with an indicator during heating. The best level that i could maintain was .2mm. I change to a granite plate and this solved the issue of warping. If your build platform is small you will not run into this issue but if it is bigger than 300mm you will run into issues if you use aluminum.

Wyvern

@percar Wow! a full mm is pretty large, what type of plate did you use?