Heated Bed updated information?

[jhertzberg 19]

A few things you could try first:

 

• Rotate your design to not be at 45 deg to the bed, to change the fill pattern orientation in relationship to the corners of your design. This will alter the direction of shrink forces.
  
• Turn on brim (in the Platform adhesion type dropdown). You can make the brim as wide as you need by increasing the Brim line amount in the expert settings. Brim trims away easily.
  
• Clean your blue tape with Isopropyl Alcohol.
  
• Rub a thin layer of glue stick onto the bed (UHU brand is frequently mentioned.)
  

 

[gr5 2,005]

jhertzberg has very good advice.

Why brim? Because sharp corners lift too easily. So much force is all on that one tiny spot at the corner of your part. Enough to lift it. Once the corner lifts the force is spread a little more but now there is leverage to pull more and twist it up. So a brim makes the corner round. Also the brim doesn't have any higher layers so it can concentrate on holding your part down. An ideal brim would get a little thicker where it meets the model.

Why isopropyl alcohol? It works! It increases the stickiness to the blue tape by 10X. Why? Because blue tape has a wax on it to allow it to be unwound. This wax needs to be removed with isopropyl alcohol. You can buy this at any store that sells bandages such as a pharmacy, supermarket, convenience store.

The next problem you may have is that the part sticks to the blue tape but the blue tape lifts from the bed. This is fixed with wider blue tape. I use 2 inch. Some people use 6 inch blue tape.

 

[stephan 0]

 

Thank you jhertzberg

Actually, I positioned the model specifically like this because of the strength of the infill that, alined like this, would benefit the models necessary strength. But I should try it anyways.

Normally I have the brim turned on but I didn't think it would have any effect on the models warping because it's not even touching the model. Is the brim not just to get the flow going? And the model was to big for a Brim.

As you can see on the first photo, the blue tape came loose of the build platform but was still sticking to the model. So the model sticks well to the blue tape but the force of the warping is so big that it pulls the tape right of.

And if I enter "glue stick" in the search engine it gives no result, can you mention it one more time, please ;-)

thanks again...

 

[gr5 2,005]

Don't get "brim" confused with "skirt". They are similar but "brim" touches the model and skirt doesn't. Skirt's purpose is to both get the flow started and also it gives you a chance to manually grab the z screw and turn it a little for a minor adjustment in height.

 

[stephan 0]

Thank you both,

I'm still a Newbie, and thats why my answers are so slow... somebody reads them first...

I did confuse brim with skirt and I thought that the alcohol would only weaken the clue.

Why would I want to adjust the z screw manually?

thanks

 

[gr5 2,005]

somebody reads them first

 

I think after 5 posts you don't need to be moderated so you can get past that by just replying to this one saying "cool.".

 

Why would I want to adjust the z screw manually?

 

Some people are lazy about levelling. It only takes a minute but it's a pain in the neck. So instead they just start printing without levelling first and if it's off by a bit they just grab the zscrew and twist while it's printing the skirt.

 

[stephan 0]

 

 

Quote

 

somebody reads them first

 

I think after 5 posts you don't need to be moderated so you can get past that by just replying to this one saying "cool.".

 

Coool...

 

[stephan 0]

I'm lazy guy where I can but I didn't think of this one or I'm not doing enough to be lazy.

Still that question of the glue stick please, what was that brand?

And now stretching my luck, going al the way back, what would happen if I stick my UM in a 70 degree environment?

thanks

 

[jhertzberg 19]

If your tape is lifting off, you may have to strip your old tape off, and clean the acrylic bed with isopropyl alcohol before putting fresh tape down. You do this in order to clean any old adhesive and bits of dust off the acrylic, to ensure maximum adhesion. Make sure that the isopropyl alcohol has evaporated off of the acrylic bed before putting down the new tape, and as gr5 said, use the widest tape you can find. I use 48mm wide 3M Scotch-Blue Painters Tape for Delicate Surfaces since it has a smoother surface for smooth bottoms. Make sure that the tape is down firmly. Eliminate all bubbles. I use an Exacto knife to lightly score the tape to let the air out of any remaining bubbles, because you don't want to give lifting a place to start.

 

I mentioned UHU brand glue stick, but other polystyrene glue sticks would probably work as well. You can try a thin coat where the corners will be later printed. I have not used this for PLA prints, but have done so when printing Nylon directly on my acrylic bed (no tape). Other people have used a light brushing of cyanoacrylate glue (super glue) where the corners will print, but I am a little nervous about that.

Regarding putting the UM in a heated chamber, I can't say for sure, but in addition to the control electronics underneath, in the long run you may also need to cool the motors, and the amplifier board at the hot end. You will also need to replace any PLA printed add-on parts such as belt tensioners and fancy fan cowls with versions printed in ABS or Nylon. If you are keen on doing this (and I would not be), then look into the kinds of water cooling kits that PC overclockers use.

 

[stephan 0]

Thanks again both of you, so helpful.

I print on 5 cm wide blue 3M tape and tried to attach it as firm as I could of course but the alcohol, glue stick, and skirt I'm trying now.

And about putting the UM in a heated chamber, you're probably right, and I have some alternatives now to at least try first.

BUT I too can't wait until UM comes with a HB upgrade for my 3 month old UM1. If I only knew I had to wait 3 months for a UM2 with HB.

 

 

[jhertzberg 19]

Glad we could help. The topic of bed adhesion is inexact and evolving. I just saw the following thread http://umforum.ultimaker.com/index.php?/topic/3016-while-waiting-for-the-heated-bed-printing-on-glass/

 

[matengi 0]

Hey guys, I wan't to share my progress in adding a Heated Bed to my Ultimaker. I find it hard to find the right information for adding a HB and it seems that everyone has his/her own approach. There are many options like the kind of heater (silicon, kapton, PCB), powersupply (12, 24, 230 V) etc. etc. My solution probably doesn't make the choice for a HB more easy but maybe it has some useful information for you.

 

 

Just want to say thanks, works great. I like to tweak around with temperatures during prints, so I can do without the printer controlling the HB. Printed some really nice ABS parts recently for a GPS car mount where PLA failed because of creep at higher temperatures, I'm really happy with it.

 

[kristen 0]

Just a quick question, does anyone know what the bolt pattern for the mounts is supposed to be exactly? I was just writing some code to cut a new heated bed from some MIC-6 and I left the original at home.

 

[gr5 2,005]

https://github.com/Ultimaker/UltimakerOriginal/tree/master/1114_Build_Platform_Acryllic

The pdf doesn't have hole dimensions and I wouldn't trust reading the dimensions off the image. But the STEP file will have all that.

I didn't bother adding slotted holes - insted I just blind drilled from the bottom and took the existing screws out of the bed and put them in pointing up from the bottom. It works pretty well.

 

[matengi 0]

I used just holes too, drilled to the diameter of the screw heads. To fix them I used washers where I cut out a slot with a side cutting, I slide them below the screw head.

The holes are in a plywood sheet. The alu plate is cut to fit between the screws front and back sides, with overlap to the left and right to provide space for the clamps which hold the sandwich together; the heating mat sticks to the alu plate.