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Greetings from Santa Cruz, and a question!

Posted: Thu Jul 14, 2016 5:54 pm
by kevnmeek
Hello!

I purchased a Rostock Max kit at the Maker Faire a few months ago (thanks again to the SeeMeCNC staff for patiently answering my questions), and finally got time to assemble it over the 4th of July weekend. To my pleasant surprise it actually worked straight away...up to a point. With the exception of a E3D v6 hot end, I built the whole thing exactly per the excellent instructions scripted by Gene Buckle. My question pertains to printing the two fans shrouds in ABS as per those instructions. I sense this may be one of those questions that may annoy those who've heard it asked a bajillion times before, but please bear with me ;-)

Finished printer

I'm using 1.75 black ABS from Matter Hackers, and though the bottom edges of the 1st shroud peeled up a bit at the ends of the longest axis, the print completed. I've tried to print the 2nd shroud six times now and each time it gets to about he same height before coming loose from the glass bed. The bed is set to 80° C (except where noted below) and I verified that temperature to be within +/- 5° C using one of those no-contact thermometers. The hot end is set at 228° C.
  • A little bit of glue per the instructions
  • A moderate amount of glue
  • Far too much glue
  • Setting the bed to 100° C
No success with any of that, so I ordered a PEI disk with adhesive and applied it to the glass bed and also printed a dial indicator mount which helped get my tower cal figures zeroed. Tried once more last night without glue and it came loose at a similar height to the others, even with this presumably miraculous PEI surface:

Bottom view
Side view

What would you recommend at this point? I can keep casting about (as I have) but if there is anything obvious I should try then I would certainly appreciate your input. Thanks for looking!

-Kevin

Re: Greetings from Santa Cruz, and a question!

Posted: Thu Jul 14, 2016 6:18 pm
by CodonExe
Adjust your z height a little lower so the nozzle extrudes a wider bead on the first layer.
Is your first layer 50% slower then the others?
Are you applying the glue on a room temp build surface?
Have you tried increasing the hotend temp?
Are your temps stable when printing? +/- .5 degrees
Is your printer in an area where there is air flow(under ac vent or near a fan)?

These are just a couple of things to start with :D

Re: Greetings from Santa Cruz, and a question!

Posted: Thu Jul 14, 2016 6:21 pm
by CodonExe
You do not want air currents near your printer when using abs, your part will warp if you do.

Re: Greetings from Santa Cruz, and a question!

Posted: Thu Jul 14, 2016 9:26 pm
by Windshadow
Give some consideration to using the SeeMeCNC hot end and you learn the ins and outs of the printer I am still learning to print ABS and I have yet to Assemble the E3D hot end... once i do the PLA printing this summer also on the Stock hot end then I will build the E3D for printing with the high temperature filaments it was designed for

Re: Greetings from Santa Cruz, and a question!

Posted: Thu Jul 14, 2016 10:13 pm
by mhackney
Might I recommend you read the documents in my signature? In particular, print the single layer test object to make sure you are getting perfect first layers.

On your PEI - did you clean it with an alcohol wipe or IPA? Grease is the kiss of death for any print surface.

Re: Greetings from Santa Cruz, and a question!

Posted: Thu Jul 14, 2016 10:31 pm
by Tincho85
Hi Kevin, try with natural ABS (not pure white). It's the easiest one to print as it doesn't have pigments that can modify it's properties.
I find 225ºc for this particular color a good value, but it's very relative to each configuration.

For Black I would try a range between 230ºc and 245ºc

Are you using glue on top of the PEI? if so, you shouldn't. Clean it with some isopropyl alcohol before every print.
Also, for ABS an enclosure is recommended. Cover your printer with some cardboard and see how it goes.
Try with a bed of 110ºc

Re: Greetings from Santa Cruz, and a question!

Posted: Sat Jul 16, 2016 11:33 am
by kevnmeek
Thank you all for your kind responses, I will be experimenting with the things you've suggested!

-Kevin

Re: Greetings from Santa Cruz, and a question!

Posted: Tue Aug 02, 2016 1:17 am
by rehabmax
I can speak from personal experience going from the stock hot end to the E3D hot end. After 9 months of use, my original hot end would not reach proper heating temperature as one of the resistors failed. This is a weak point of the design. Replacement resistors are cheap but you have to go through all the copper silicone, bending the ends like a dog's leg, etc., just like you do in the initial assembly. The worst part is the thermister just getting pushed in with a gob of copper silicone. After I did the replacement i inadvertently damaged the thermister and fried the whole hot end. I was fed up. The E3D hot end has a much simpler design, no copper silicone or tons of Kapton tape. The thermister is held in by a nice little screw. The latest version of the E3D has an even easier thermister connection. I am just made the transition over to the new hot end and I think it is going to be very good. One tricky part is making sure the filament feeds smoothly from the bowden tube into the heat break (melting area) . I think SeemeCNC should offer the E3D as an option from the start. Matter hackers sells the E3D for around $85 and it is well worth it.