Just finished my kit build - First impressions  

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Hobsie
(@hobsie)
New Member

Just finished my kit build yesterday.

First impressions are great - parts feel seriously well made/machined and solid and the whole thing just speaks quality. The touch screen is _very_ good - hope that makes it on an MK4 along with built in storage and WiFi!

Couple of janky construction choices (looking at you carbon filter holder mounting thing) and some cable clearances could be improved (cables under the PCB are easy to slice on the metal edge if you need to rearrange)

Mentioned on the instructions page that you guys should mention not taking off the red tape earlier from the PCB battery (it's not present in an image _before_ the message about not taking it off)

Right now though I could do with an extra print debugging option - first test print I tried (the prusa model hexagon test print) failed to stick to the build plate - which you can't detect until about 2 hours in - Van den Waal welded itself to the FEP (took a while to get that unstuck!). Would be very helpful to have some sort of _peek_ function during a print (pause, plate lift, continue button) that way we could check for plate adhesion early on troubleshooting that issue.

 

Posted : 15/09/2019 9:38 am
paul.m27
(@paul-m27)
Honorable Member

 

I bought some 1"x1" mirrors on Amazon ($3 for 20).  I'm going to print a mount that will fit on the side of the tank and hold the mirror at an angle.  The hope would be to be able to see whether the print is sticking as soon as the platform clears the liquid.  The trick will be keeping the mirror out of the goo.  We'll see how it goes.

 

Posted : 16/09/2019 7:13 pm
Henry Casson
(@henry-casson)
Trusted Member

Having just achieved my first successful print, I can say that you should be able to hear a different sound when the platform dips, sort of like "Flump". I figured it was working, because that did not occur in any unsuccessful print.

Retired doc, should have been an engineer....
Posted : 20/09/2019 5:42 am
Henry Casson
(@henry-casson)
Trusted Member

 

Although I had one of the first kits delivered, I have only now achieved a print. This is just the demo print of Josef so I will not show it. The print is awesome, and even though not at the finest resolution available , it takes work and a good magnifier to discern any lines at all.

 First there was a self-test failure of the rear fan, and after perhaps 5 days of testing Prusa’s  responsive help decided to send me a replacement. This worked. Part of the further delay was just other things in life, but I also did about five prints which did not adhere to the platform. I solved that by doing all the things mentioned in the forum. I screwed down the screws holding the FEP, some of which may have been high, redid the setup, raising the platform until it was definitely too high, and then lowering it until it was level or maybe still a hairline high. I obsessively cleaned the platform. I also lengthened the exposure times, first layer to 45 sec, and the rest to 8 sec. When I first hear the “flump” sound on separation, I knew that I had arrived.

I have some thoughts on the kit. It must have taken a lot of time to produce the assembly manual, as good or better than any I have ever seen. Also the packing must have taken design time, and be expensive to produce. I ordered the kit because that was what was available at announcement time, and I enjoyed the Mk3 kit. I think making the Mk3 was worthwhile in knowledge to help troubleshooting. The SL1 however is a totally different level of technology, beautifully made, but assembling it will not educate you to cope with any problems that come along. However one also saves $300, I think. Assembling it at the factory should not take more than maybe 4 or 5 man hours, and packing the completed machine will be much cheaper than the kit. So I am not sure why the kit is so much cheaper, unless there is a matter of principle related to the RepRap ideology.

Washing up after each print is not such a chore as I expected, as I can walk to a utility sink with a plastic bowl.  The gloves are a must, the resin leaves things sticky and unpleasant, and I suspect it may eventually produce contact sensitivity. The smell is not that bad, although maybe my nose is going the way my ears are. I have an easy run to a vent, and shall be printing parts on the Mk3S to join some hose to it.

Retired doc, should have been an engineer....
Posted : 20/09/2019 5:54 am
paul.m27
(@paul-m27)
Honorable Member
Posted by: @henry-c

Having just achieved my first successful print, I can say that you should be able to hear a different sound when the platform dips, sort of like "Flump". I figured it was working, because that did not occur in any unsuccessful print.

I definitely hear the sound of the layer peeling off.  However, only sometimes (even on a successful print).  I think I less dense layers the peel is quieter or silent.

Fortunately, the initial layers tend to be dense, so you can at least tell you are starting correctly.

 

Posted : 20/09/2019 12:25 pm
Hobsie
(@hobsie)
New Member

Update: I've had several excellent prints since my initial post. I have built an MSLA in the past and I think I had the same issue there as the SL1 - the FEP is so damn smooth to begin with the Van Der Waal force is just too crazy on a first print. Cleaning up then trying again the next day with the exact same print had zero issues. The "flump" sound is also far quieter than the first print I tried which sound more like the loud bang of a drum.

A couple of other take aways now that i've been using the printer for a week.

  • I'm currently getting the most perfect prints I think I've ever seen - detail on the medium setting is incredible
  • Sending prints from Prusa Slicer directly to the Printer is super useful/convenient - add this to an MK4!
  • Updating the firmware on the printer itself over wifi is also super useful/convenient - again, add this to an MK4!
  • I have been doing a full wash of the vat at the end of each printing day and then calibrating before my first print of the day
    • I have noticed that the step offset for the VAT tilt is different every time with ~100 step value variance in value - is that expected?
  • It seems to hint at having a directory structure when sending prints from Prusa Slicer but doesn't look like it has that in the menu on the printer itself
  • The print plate/bed is actually very tricky to hold when getting the resin and part off as there's not a whole lot to hold onto that isn't covered in resin
  • I bought a £40 ultrasonic bath from Amazon and it does an incredible job cleaning the finished prints in IPA - I don't seem to have issues with tiny parts breaking as Prusa mentioned when talking about the CW1 - i've just been using a UV Nail thing to post cure but I'm going to cannibalise the UV lamps from my old self built SLA for that purpose
Posted : 20/09/2019 1:23 pm
Milhooz
(@milhooz)
Trusted Member

Thanks to you Hobsie, I just understood why they are telling not to print the vat with IPA.

...
Posted : 21/09/2019 12:00 am
islander29
(@islander29)
New Member

I'm been printing with SLA for the past 4 years. I don't own a SL1 but my experience should apply here as well. Here are some tips for consistent results:

1- figure out what the shrinkage is on your resin and compensate for it in CAD
2- don't touch the film with anything but a silicon spatula - don't use IPA there's no need for that. Mixing resins works fine.
3- scratch your buildplate in X directions with a coarse sandpaper for the prints to stick better.
4- some resins are more sticky than others and lower the z-lift speed when printing bigger models.
5- no two light sources are the same; play with the exposure to find the sweet spot - you don't want to overcure the resin when printing as it'll harden and stick to the film causing a failed print.

Posted : 21/09/2019 4:54 pm
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