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1/24/2015 UPDATE: If you are coming here for the first time, it can be a bit arduous to wade through the 27 pages of discussion here. I've summarized the final materials and process in a new sticky thread. If you just want to learn one tried and true way of installing and using PEI, go to that thread. There are many other comments, suggestions, installation techniques here if you choose to wade through!

I'll start a new topic for us to discuss the PEI (Polyetherimide aka Ultem) print bed surface.

Firstly, this seems to have originated from discovering that SpiderBot is offering a bed with this surface for their delta machine in Europe although there are earlier discussions on various 3D Printing forums.

In the case of SpiderBot, they have laminated a thin ("close to 1mm") sheet of PEI to aluminum to use as a print surface. The material is supposed to be great for PLA and ABS.

I ordered a 12" x 12" sheet of .03" from Amazon and it came in today. This is .76mm so technically "close to 1mm".

The material is flexible at this thickness and looks like light colored honey - very transparent. I clipped it to my borosilicate glass just to see what it would look like:

[img]http://mhackney.zenfolio.com/img/s10/v1 ... 8874-4.jpg[/img]

As you can see, it is shiny and transparent. Clipping this thin sheet on the perimeter will not remove all of the waves. Even thicker sheets are likely to be flexible enough to lift from the center of the large Rostock build surface. Ideally, the thin sheet should be adhered to a flat substrate.

Just for grins, I decided to position a print close to the edge where the material is clipped reasonably well and see what happens. The print - PLA - is in progress now with a 60°C bed. I cleaned the surface with isopropyl alcohol, adjusted my X, Y and Z lengths by subtracting .76mm from them and fired off the print. It was amazing to watch how well PLA sticks to this stuff. I'm printing one of my "open weave" fly fishing reel parts that is very challenging to stick to a bed. The PEI is sticking nicely. I'll post updates when the print is complete.

To remove the part, you are supposed to run the plate under cold water. If this is the case, it would be good to have 2 of these so I can print and remove parts without interruption. I'm going to try to find some thin, flat aluminum to glue the PEI to. Short term I might just stick it to one side of my borosilicate to get going quickly.

I am dying to see what happens with ABS and it's tendency to curl. I know you will test it next so I will be patient.

The PLA parts came out fantastic. The surface is smooth and glassy. I allowed the plate to cool for 30 seconds and the parts popped right off.

[img]http://mhackney.zenfolio.com/img/s10/v1 ... 4695-3.jpg[/img]

I will try ABS sometime as soon as possible.

Michael, I think I am having one of my slow brain days. I understand why you subtracted from the Z axis to be at Z zero but I have having a tough time getting my mind around
the subtraction from the X and Y.

I meant the X, Y and Z length - the tower length adjustments that combine to get the Cartesian Z.

If you're going to glue the PEI to a metal or glass plate, you might want to vacuum bag it.

g.

Possibly. I need to investigate adhesives and substrates too.

mhackney wrote:I meant the X, Y and Z length - the tower length adjustments that combine to get the Cartesian Z.

Still confused, on the Orion with .091 repetier you just use the LCD to create a new zero height for Z or is the calculations for the X and Y also taking place and is
transparent to the user?

I set X Max Length, Y Max Length and Z Max Length to the same value to set my "Z=0". I suspect the calculation is taking place behind the scenes. I haven't checked if the Rostock LCD menu does the same, it probably does. It's easier for me to do it from the host though.

Ok, the Rostock LCD menu has a section for Z setting but it does't seem to work as I would expect. There is a page with 3 options:

Home Towers
Z Position->
Set new Z=0.00

---

Home Towers does what's expected. Z Position goes to a sub screen which has a line labeled "Z: 0.00 mm". I can rotate the knob and move the effector up and down (Z). Then, with a new Z position (say moving down 2mm) I click the knob and go back to the parent screen that shows Set new Z=0.00. If I click on that, I would expect it to set the current Z position to 0. However, it subtracts the delta (2mm in this case) from the original Z Max Length and then sets the Z Max Length in the EEPROM to this value. It does not set the X Max Length or Y Max Length.

mhackney wrote:I set X Max Length, Y Max Length and Z Max Length to the same value to set my "Z=0". I suspect the calculation is taking place behind the scenes. I haven't checked if the Rostock LCD menu does the same, it probably does. It's easier for me to do it from the host though.

I'm sorry for all the questions, but I am the type that if I don't understand I have to learn.
The calculations are being done but are transparent to the user. All the user knows is that he is zeroing the z axis.
You do the manual stuff because of your years of experience and your love of confusing the hell out of me. (just kidding)
After doing further research I finally understand and won't be bothering you any more. (you don't have to be THAT happy)
I am fascinated by the PEI material and from what I have read it also works great with ABS at 100c bed.
Thank you for being the trail blazer for the rest of us.

Well, now I don't understand the LCD Z setting! It does not work as I would expect. So, here's the question for you - take a look at the EEPROM window in Repetier Host and note the values of X Max Length, Y Max Length and Z Max Length. Then go to the LCD and tweak it like you were going to set a new Z=0, say to compensate for a 1mm thick surface on top of your bed. Now, look at the EEPROM in RH again and those 3 values. What did you see before and after?

For me, only the Z Max Length is getting set and that screws up my printer.

mhackney wrote:Well, now I don't understand the LCD Z setting! It does not work as I would expect. So, here's the question for you - take a look at the EEPROM window in Repetier Host and note the values of X Max Length, Y Max Length and Z Max Length. Then go to the LCD and tweak it like you were going to set a new Z=0, say to compensate for a 1mm thick surface on top of your bed. Now, look at the EEPROM in RH again and those 3 values. What did you see before and after?

For me, only the Z Max Length is getting set and that screws up my printer.

I see the same results you do. Confusing to say the least.

I used the LCD process with both my Orion and Orange Menace after the 0.91 upgrade and I haven't noticed any issues with the Z being different from X and Y.

g.

Gene, I posted over in the Manual topic about this. Even your screenshot of the EEPROM window shows the Z is different than the X and Y Max Lengths. I don't get it!

Sorry to throw you so far off topic, can we get back to the PEI?

Yes! I've printed 15 PLA things today on it and it has been really nice. The surface on the parts is glass shiny. I don't actually like that but it is interesting. I am going to print something special in ABS to show you tomorrow Eagle! It should be impressive if it works.

mhackney wrote:Yes! I've printed 15 PLA things today on it and it has been really nice. The surface on the parts is glass shiny. I don't actually like that but it is interesting. I am going to print something special in ABS to show you tomorrow Eagle! It should be impressive if it works.

If it works without curling my order goes in for the PEI.

Believe it or not, today I just used the spray adhesive I got for attaching paper (it's in my printing on paper thread) and simply attached the PEI to the glass bed. I haven't even cut it round yet. It doesn't take a lot of adhesive to hold it down and the spray puts on a very thin even coat.

Here's something I did not realize - one side of the sheet of PEI is glass slick, the other side has a matte look to it. I just flipped the sheet over to try printing on the matte side to see if that finish transfers to the part and if the parts stick as well to this side. That would be very cool if it does both, then you can control what the parts look like!

You're killing me with anticipation! Clone yourself 3 times so you can work faster!

Eaglezsoar wrote:You're killing me with anticipation! Clone yourself 3 times so you can work faster!

Therein lies the problem Eagle, I've already cloned myself 3 times; one for my "real" job, one for my "reel" job and one for everything else. I should have cloned 10 of me!

Live and learn, I thought your reel job was full time, I didn't realize that you had a real job. Sorry for rushing you.
Now get busy!

Ok, ABS sticks to PEI at 80°C fantastically. And, the matte surface of the PEI is transferred to the part so you can get a matte finish if you want!

Unfortunately, the spray adhesive I used lets go at 80°C so the parts are not flat. I've been looking for a better bonding solution. The guys on the delta printer google group use a 3M tape but it's hard to find in 12" x 12" and expensive. I'm leaning towards this Permatex spray gasket adhesive with copper. It is good to 280°C, has copper for better thermal conductivity and is cheap and readily available. Worth an experiment!

mhackney wrote:Ok, ABS sticks to PEI at 80°C fantastically. And, the matte surface of the PEI is transferred to the part so you can get a matte finish if you want!

Unfortunately, the spray adhesive I used lets go at 80°C so the parts are not flat. I've been looking for a better bonding solution. The guys on the delta printer google group use a 3M tape but it's hard to find in 12" x 12" and expensive. I'm leaning towards this Permatex spray gasket adhesive with copper. It is good to 280°C, has copper for better thermal conductivity and is cheap and readily available. Worth an experiment!

THANK YOU, THANK YOU, THANK YOU!!!! You have just made my day! Hell, my whole month! A solution to ABS curling. YOU'RE DA MAN!
My order is going in today for the PEI and I am going to use the gasket adhesive also. If you haven't noticed I usually stick with what you find out works. Why?
YOU DA MAN!