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Hi every one
Im new to this, so Im really hoping someone can help me.
I have recently treated myself to an elagoo mars, mainly because i do a lot of 54mm scale dioramas and liked the idea of being able to print the detail accessories that I cant seem to source anywhere.
So, the printer arrives and I run off the test print. Lovely detail, nicely finished, very impressive. Next, I get myself onto tinkercad and run off a couple of simple prints ( guttering, drains, buckets etc). Again, all is well and I'm pleased with the results.
I then get a bit adventurous and download an STL file of a composite figure, around 27 or so pieces which i would expected to be able to assemble easily.
The original size of the figure was a little small for my taste so I scaled all the parts to 200% in Chitubox, and here began the problem.
Either Chitubox or the Elagoo has a very elastic interpretation of the concept of scale. The smaller parts seemed fine, but the larger the parts were the more inaccurately they printed with quite noticeable differences in size to the smaller parts that it should join to.
I have double checked that I scaled all parts the same, and have even loaded two large parts into Chitubox ( a front and rear body piece, too large to fit on the print plate together when scaled so i have to print them seperately) to make certain that the pieces fit together before scaling and they do, perfectly.
So, is the problem with Chitubox and its scaling process, or is the Mars simply a cheap and inaccurate printer? For the small parts that I actually bought it for, its merely satisfactory and, I suppose, if I were simply printing miniatures then it wouldn't matter. I did expect a better level of accuracy for larger parts though, but I cant find any threads or videos that cover this problem as all the tutorials seem to be based around printing single part miniatures. Is my printer broken, or is this the best I can expect?
Sorry for such a long winded first post, but I really need some help here.
Any advice will be appreciated, so thanks in advance for any that I receive
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" ... is the Mars simply a cheap and inaccurate printer? ... " - i can not confirm this.
i am printing mechanical parts with the Mars, and they all fit perfect.
i think it's the scaling in Chitu. What about scaling in another program and doing no "editing" - just slicing - in Chitu?
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(05-10-2020, 10:50 PM)fromFDMtoSLA Wrote: " ... is the Mars simply a cheap and inaccurate printer? ... " - i can not confirm this.
i am printing mechanical parts with the Mars, and they all fit perfect.
i think it's the scaling in Chitu. What about scaling in another program and doing no "editing" - just slicing - in Chitu? Maybe, perhaps you could suggest a suitable application? Im really no whiz at this and am pretty much working straight out of the box. I didnt think that the printer would read anything other than a Chitubox generated print file?
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i scale my models as *.stl-files and than load in Chitubox. i use a CAD-prog. that can import and export *.stl.
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(05-11-2020, 08:37 AM)fromFDMtoSLA Wrote: i scale my models as *.stl-files and than load in Chitubox. i use a CAD-prog. that can import and export *.stl. The problem I have is that I'm working from a laptop and although I've tried to run a couple of CAD programmes I don't have a suitably powerful dedicated graphics card to run them. The only program I can successfully run is Tinkercad which requires no download. Anyway, although I thank you for your suggestions, it no longer matters as I got so cheesed off running reprint after reprint, watching my not inexpensive resin supply steadily deplete over four days of despair with nothing worthwhile to show for it, and having the super brittle resin parts break up when I try to assemble them that I've admitted defeat and thrown the whole project in the bin. For what it's cost me in wasted resin, it would almost have been cheaper to send the files off and get them printed properly and certainly less stressful. I'm more than a little disappointed about the whole thing really, I expected the complete set up to be plug and play. I chose the Mars not just on price but on all the reviews and expected the printer and elegoo supplied software to produce better results. In fact, I've just been trawling through the threads about inaccuracies on the Z axis and either having to hack the operating program to reset the zero, or strip the unit and replace or add spring washers. It all seem a bit too much really and not something I feel inclined to have to do. I realise its a £240 machine and not £2500, but its really taken the shine off of what at the outset had seemed like an interesting and satisfying pastime.
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just my 2 cents:
basicly 3D-printing is NEVER plug&play - i started 5 years ago with my first FDM-printer, lot of prints failed and i have to learn a lot; and still learning every day about 3D-printing.
if you look at the expensive printers: they are also NOT plug&play, because there are so many settings/dependences to get a perfect print.
forums and the www are the best teachers for this learning process.
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05-12-2020, 01:05 AM
(This post was last modified: 05-12-2020, 01:48 AM by reg.)
(05-11-2020, 11:51 PM)fromFDMtoSLA Wrote: just my 2 cents:
basicly 3D-printing is NEVER plug&play - i started 5 years ago with my first FDM-printer, lot of prints failed and i have to learn a lot; and still learning every day about 3D-printing.
if you look at the expensive printers: they are also NOT plug&play, because there are so many settings/dependences to get a perfect print.
forums and the www are the best teachers for this learning process. I fully understand where you're coming from, and completely take on board what you're saying. Different resin types and their properties, curing parameters and exposure times, how to correctly set up and use supports; the list is endless. I have no problem in applying myself to learn new skills. I had a few failed smaller prints that I designed on Tinkercad that were caused by me not setting up correctly ( mainly orientation and incorrect support placement and type) and from these fails I learned and corrected my errors. Its not these things that I have an issue with, its the apparent inability of the machine and the supplied software to accurately reproduce what you input. If the composite figure prints I attempted had failed due to an incorrect curing time that I had set, or not been adequately supported, or any one of the number of other things that I had been responsible for then I would keep researching the problem until I knew what I was doing wrong and could rectify it. But the issue isn't with my lack of experience, its with the unit and the supplied splicing software. If I were to scratch design a composite object, I know that its down to me to make sure that all the tessellating faces are dimensionally correct. If not, it wont go together and that's my fault. However, if I download a tried and tested model that has been printed and built at many different scale sizes then I expect to have a modicum of success. My only input to the print is scaling, orientation and support. None of the prints failed on anything other than scaling issues, and other than telling Chitubox what size to print I have no control over this. I expect Chitubox to scale accurately, and the Mars to interpret the file and reproduce it equally accurately. That's what I mean when I say plug and play.
The test print that came on the usb stick printed well (although I can't know if it is an accurate representation in size of its original design). Thats plug and play. And in the same way, a downloaded model with no design editing by me should be reproduced accurately at whatever scale I choose, should it not? The issues that I have had with this print are not anything that I can learn my way out of. At the least, as you have suggested, I use Chitubox for nothing other than producing a sliced file that the printer will accept. Its a fair enough suggestion, I just don't feel that I should have to do that in order to get any level of satisfactory print result. Outside of the things that I can alter such as exposure times and layer depths, I should be able to rely on the printer and slicing program for a faithful representation.
Right or wrong, I compare it to this:
I buy a new car, i drive it home and it runs like a watch. The next day I take the family out for a drive and it wont run properly, coughing and spluttering and smoking, no power.
I ring the dealer to complain and he asks where I was and how many were in the car. I tell him four including me, and we were on the motorway.
He says " Ah, thats your problem. The cars CPU isn't set up for going over 30 mph with passengers. It needs different fuel pump and valve timing to compensate for the speed and load, and all the engine sensors need different parameters. You'll have to go on the internet and find the correct software for your engine with those increased speeds and upload that into the CPU. It should run ok then. Just use the original CPU settings that came with the car when your on your own at 30 mph, they're only of any use for that".
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"which i would expected to be able to assemble easily."
It's hard to say your exact issue, but this sounds like it could be the source. This is absolutely NOT how resin printing works.
Shrinkage, light bleed, reflections, over and under curing, translucency, part shape...all of these come together in complex ways to change the dimensions of your parts.
We're using light to cure a resin which changes as it cures. Light is complex, curing is complex.
When making pieces that need to go together, you have to put in quite a bit of effort to tweak the parts.
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