Update of 8-July-2017
Sanding your build plate is a lot of work. There is a leveling technique that you should try with yours before deciding to pursue the atomic solution described here. This technique has been described by Aaron Widmer on the Facebook group for the D7 printer and it follows here:
Take a piece of plain copy paper and lay it over your LCD screen (VAT removed) and push the screw posts through it so the paper lays flat on the screen. Loosen the 4 screws on the plate bracket so it is free to move (Do not install build plate assembly yet!). Home Z axis. When Z is finished homing, move the build plate to its highest adjustment position and attach build plate assembly and tighten to arm (While holding the plate so it does not lower and crash into LCD!). Gently lower the plate against the paper and apply slight pressure to make sure it is snug against paper and then tighten while applying the pressure. Move z axis up so you can install vat and start your first print.
If the above works for you then great! If it does not and you still want to sand your build plate then read on. If you do sand your build plate you will not need to follow the above procedure and can, in fact, level your build plate following the process that Wanhao advocates in their documentation for the printer. Your build plate will also look a lot like the one used on a Form 2. Maybe the Wanhao R&D team has one over on Formlabs ... but I kinda doubt it.
Original Post Follows
The good news is that Wanhao has made some great strides in reacting to feedback on the version 1.1 and 1.2 printers. Cooling and packaging in particular but a host of other things as well. The bad news is that they seem to be sending at least some customers build plates that are concave and painted with something slippery.
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| This is when I knew that I had a problem. Build plate should have had stuff on it! 100% casualty rate. |
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| So I did a little bit of sanding. Clearly something is wrong here as only the corners and edges are being touched. |
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| So I did a lot of sanding...by hand...with 80 grit paper. This is where I realized that getting rid of my 240 to 120 volt power supply and my yankee sander was going to be an issue. So I ordered a Black & Decker Mouse Sander. |
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| See anything funny about this print? Since I had some down time I printed a build plate just to see if it would work. Extrusion lines! |
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| Mine was printed using PET and it actually worked pretty well. Prints stayed on until I wanted to take them off. |
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| Finally got the sander and a pack of papers from 60 grit to 800 grit and I walked through each one, a couple in come cases. |
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| After hand sanding with wet emery paper from 1000 to 7000 we had 100% stickage. There is a problem on the left side but not a build plate issue. Update of August 2017 - I did a second plate and stopped sanding at 800. This last bit is overkill! |
Thank you for your suggestion. We are trying to do some more machining on building plate. Hopefully we would put into mass production in short time.
ReplyDeleteThank you!
WANHAO TEAM
Manlo, I have the older steel plate and the new aluminum one. All of the changes you made between versions have been good other than this one. The steel plate was perfect. It was flat, it is a hard surface and does not scratch like aluminum, and it even cleans up better. I am sure you saved some money with the aluminum one but I would go back to the steel and pay more for it. Cheers, Will
DeleteThanks for the suggestions. Received my D7 on the weekend- without any included resin (thanks Aliepress Wanhao store!!) So had to wait till I could get some Monocure Rapid delivered. It arrived and I set up last night for my first print. Took a while to connect (had to install drivers) to the laptop but eventually got it sorted. Tested the LCD and saw the first layer of the print so was feeling confident. Imported my print, added raft and supports, tweaked cure settings (50um layer, 90 sec for 5 layers than 8 sec for addt'l layers) with Monocure Grey. Sliced, homed, etc, added the resin, kicked off the print. Two and a bit hours later I removed the lid to find an empty build plate and a vat of uncured resin that seems devoid of loose parts or fragments of model. Frustrating to say the least. Not sure now if it's a problem with the LCD not projecting properly or the build plate not sticking. I've got a Rasberry Pi on the way to try NanoDLP, but it'll be weeks till that gets here. Going to check out Aarons suggestion for leveling, and then maybe try sanding the plate as you suggest. Seems to be relatively common for prints to fail like this?
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DeleteAre you sure there is not a thin pad of resin cured on the bottom of the vat in the shape of your print???
ReplyDeleteFollowing on to the above. If there is a small pad of resin on your fep sheet then you did have a first layers stickage issue. If this is the case, IMHO, just sand the build plate down to how it should have been designed in the first place! If there really is nothing on your FEP sheet, and another dry run shows that the LCD and UV are working, well, I dont know what to say!
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