Convert a Frustrating 'Toy' into a Business 'Tool'

[smartrail 0]

I am seriously struggling with ANY prints with my UM2 - I would reckon my success rate is below 10% and this is with both PLA and ABS.

I am typically wanting to print parts with a relatively large footprint (about 50-75% bed plate size) and I predominantly want to work with ABS due to the intended usage of the parts. I have tried every possible combination of glues, including the 'Staples' PVA stick supplied, photo-mount spray, a specialist fabric bonding spray, liquid PVA in various concentrations and have even considered putting a double-sided adhesive sheet on the glass to print onto that. I am currently trying the Acetone & ABS puck method - we'll see what happens. I've tried so many different combinations of bed plate temperature, nozzle temperature, fan speed etc that I need to use Taguchi Methods to evaluate which are the most significant factors. I currently have the printer working with an external cover, which I made from 5mm modelling foam board to provide an internal temperature within the printer of approx 40-45^oC. I've tried brims of varying sizes, adjusting fill percentage, increasing wall thickness, etc, etc I've looked at the science of glass temperatures for various plastics to try to assess what's going on and why shrinkage occurs

I have referred to the forum many times and have searched on 'prints warping', 'prints lifting' and numerous other terms and it seems that these are pretty much universal experiences. However what I have yet to find anywhere is a description of what each of the printer variables means in terms of the effect on the print. I have seen people say that the fans shouldn't be used on ABS prints, that the bed plate temperature should be 110^oC and that the external cover should be used to avoid over-rapid cooling of the print as it builds-up. Then again I've also seen people saying that after the first few layers the fans should be switched on and the bed temperature reduced to 90^oC and the cover removed to prevent warping.....! Which is correct???? All of these methods are contrary to the Ultimaker 'default' settings....... I have tried contacting the Ultimaker help desk and had extended e-mail exchanges with them but even they don't seem to have a full grip on all the variables to make a print successful.

I know that 3D printing via material deposition is still an emerging technology but I need to hit on a 'foolproof' solution for my prints that gives me at least 80% success rate. I'm trying to make parts for clients or for actual applications and I don't have time to man-mark the printer every minute it's working! At the moment I cannot classify the UM2 as a 'tool' because it isn't, it's a frustrating 'toy' that needs constant management and even then when something goes wrong at hour 11 in a 12 hour print there's nothing to do but scrap it, waste the material that's gone into it and try again. I'm at the point where I've got no option but to scrap the printer, suck-up the £2k waste of money and disappoint clients, or spend yet more money on another printer that might be more successful.

So I guess this is a 'last gasp' appeal - what can I do that will turn this 'toy' into a true business 'tool'?

 

[IRobertI 521]

What would you say is the major issue you're having? I see you mentioning warp, is that the only problem? Pictures of the failures will help in figuring out what's happening as well as examples of objects you're trying to print.

 

[gizmo999 11]

I have the best results using garnier fructis ultra strong hold en flex no.5 hairspray all the other hairspra etc sucks .( just one coat on the bed ,not to much)

Fo big objects to print in abs i use also mouse ears or brim ,and ofcourse the heathed bed atleast 100c.

And maybe colorfabb xt is the answer for you its alot easyer to print with

[skint 62]

No other printers within this price range will perform better than what the UM2 can IMHO. Agree with Robert, can you post some pics of some of the failures that you have had and some of the models that your are printing? Hopefully you can get that % a bit higher!

 

[Anders Olsson 136]

Your enemy is basically temperature gradients in the printed object.

Professional printers solve that problem with a heated chamber.

I have like 95% success rate printing ABS on the UM2, but I generally print small things and/or things which are suitably designed for printing in ABS. I just wrote a rather long reply about that in another thread: http://umforum.ultimaker.com/index.php?/topic/8157-percentage-of-prints-completed/?p=81116

If you insist on printing difficult objects, like large thin walled cubes, in ABS, you should try to mimic the heated chamber concept.

That means:

- Hot buildplate (To stay above Tg and to heat the "chamber"

- Fans off

- Front of the printer covered

- No open windows or fans next to the printer.

A top cover should improve it further, but I have not tried that myself yet.

 

[zoev89 73]

Please note that heating the build chamber might cause problems with the stepper motors, they get very hot.

For large objects I would also consider XT material since shrinkage is less of a problem compared to ABS. I have printed large area ABS objects but they were not high so the shrinkage problem was reduced. I also saw a video of somebody printing large arm like structures and he designed holes in the vertical wall. The holes effectively reduce the shrinkage problem. Just a thought for designing parts for ABS.

If you go for high temperature heated build room you might bump into other problems with the extruder or the hotend, the ptfe tube will not like it.

Optimizing the printer for large ABS parts is not a simple task.

 

[smartrail 0]

Guys,

Thanks for your feedback and comments to far - I will happily post photos of failed and completed prints when I've worked out how to....

Needless to say I finally got a completed ABS part from my latest attempt, using:

 

• Bed plate temperature - 110^oC
  
• Extruder nozzle temperature - 260^oC
  
• Acetone and ABS puck method for creating adhesive layer on glass
  
• Using a cover created in foam-board to block front and to create a 'box' over the open top. This was giving me an internal temperature of approx 45^oC inside the build chamber
  

I'm still not confident that my success will be replicated every time - BUT at least I've achieved something.

 

[highlea 2]

I have a UM1 and have recently installed the heated bed upgrade.

PLA prints are brilliant and come away so easily one the bed has cooled fully. (not sure what temp it has to get below)

I tried ABS, using the Pritt stick supplied, but it still warped and came away from the bed.

I then saw 'Wolfbite' advertised, made for the Airwolf printer. I managed to get hold of some and have to say that it is brilliant. One application is supposed to last for about 10 prints. Haven't fully tested this, but still working after several PLA and ABS prints.

No sign of lifting from the bed and easy removal when cool.

Wolfbite is available in the UK via Cutwell Ltd.

I am printing parts based on cylinders around 60mm dia and using the Cura quickprint settings (normal quality - 0.1mm) I get good prints, but the outer wall has de-lamination cracks. Have upped the temp to between 250 and 255.

Cracking got noticably less over the last 20mm of the print, having started 5mm from the bottom. (35mm total)

I also want to try enclosing the build area and turning off the fan. I notice that the bed cannot maintain 100C once the fan starts. Drops to around 90C, then gradually recovers as the head moves furter from the bed.