RMweb Premium ianmaccormac Posted April 11, 2019 RMweb Premium Share Posted April 11, 2019 No, if anything this smells hardly at all! Just used the black as well and same. I am finding I need two different lots of IPA, one for an initial rinse that I filter to get rid of most f the muck to use it again, and then a newer batch to give a final wash. Seems to clear all the remaining resin much better, and then under the UV for setting. Cheers Ian 1 1 Link to post Share on other sites More sharing options...
Skinnylinny Posted April 12, 2019 Share Posted April 12, 2019 (edited) A quick question to owners of the Photon: Has anyone attempted to print interlocking parts on it, and had any success? I'm considering buying one, but unless I can solve the problem below, it's looking unlikely. I ask because I recently had two test prints of a design made - one on an industrial SLA printer (but only at 100 micron layer height) and one on a Photon. While the Photon gave extremely impressively crisp prints, I found that none of the parts fitted together, whereas those printed on the SLA printer fitted first time. Am I missing something? For reference, what I'm trying to print is this set of parts: Which should assemble to give The seats came out too wide on the Photon print, and didn't fit between the sides. The roof was too tight on the inside (or perhaps the ends and compartment dividers were too big?). Meanwhile on the SLA print, I got everything fitting perfectly with no fettling short of removing supports. What am I doing wrong please? Edited April 12, 2019 by Skinnylinny Link to post Share on other sites More sharing options...
MikeTrice Posted April 12, 2019 Author Share Posted April 12, 2019 Possibly nothing you have done. I have found that prints tended to be rounded up or down presumably to suit the resolution of the LED screen and Z axis travel. If you want to ensure parts fit then you will probably have to provide test prints and then adjust individual parts to ensure they fit and reprint. Fortunately the cost of producing a print is pretty small. Does that help? 1 Link to post Share on other sites More sharing options...
Nimbus Posted April 12, 2019 Share Posted April 12, 2019 There's also the behaviour of the exposure light in the Photon and similar. As it penetrates the resin, it is scattered and becomes de-focussed. Thus some resin outside the boundaries of the target voxel becomes part-cured. This problem will remain although the higher-resolution LCDs which are in the offing will reduce the pixellation rounding errors. The Nim. Link to post Share on other sites More sharing options...
MikeTrice Posted April 16, 2019 Author Share Posted April 16, 2019 I have just obtained the results of an experiment carried out on my Photon regarding print size accuracy in conjunction with the Anycubic grey resin.. A general rule of thumb appears to be that the Photon prints 0.1mm larger at an edge such that a projection 5mm wide actually prints 5.2mm and a recess 5mm wide prints 4.8mm wide. This confirms Linny's observations above so his seats need to be 0.4mm narrower than the body interior to fit. Forewarned is forearmed. 1 2 Link to post Share on other sites More sharing options...
Skinnylinny Posted April 17, 2019 Share Posted April 17, 2019 Thanks, Mike. That should be easy enough to adjust on the seats, although the elliptical roof might take some work to correct! This also explains why my 0.1mm wide and deep door edges didn't print very well on my first test print - they were present but only just discernible. Food for thought! Link to post Share on other sites More sharing options...
MikeTrice Posted April 25, 2019 Author Share Posted April 25, 2019 I mentioned earlier that I carried out an experiment to determine print size accuracy. This is the test piece I used: Having produced a wheel insert for the old style Romford wheels I wanted to produce one for the Mansell Wheel. Armed with the information obtained from the experiment a model was drawn up and printed: Well they went well so I am very happy with those. For anyone wanting to print their own inserts for the Romford Wheels I have attached the stl files. disc wheel v03.stl mansell wheel v02.stl 10 Link to post Share on other sites More sharing options...
dpgibbons Posted April 25, 2019 Share Posted April 25, 2019 Mike - very useful data thanks. Presumably the sizing error is a % rather than a constant? So eg a 10mm width would print at 10.4mm? Link to post Share on other sites More sharing options...
MikeTrice Posted April 25, 2019 Author Share Posted April 25, 2019 No it is generally always +0.2 so 10mm prints at 10.2mm and 40mm prints at 40.2mm based on experiments to date. 3 1 1 Link to post Share on other sites More sharing options...
Atso Posted April 25, 2019 Share Posted April 25, 2019 The issue is UV light bleed which over cures the edges of the print by around 0.1mm on each edge (depending on how long you expose each layer). Reducing the exposure time to around 5 seconds largely removes this but at the expense of having a very soft and fragile print. In most cases it would be better to account for this in the design stage but reducing the width and length accordingly (hight seems unaffected) - a bit like accounting for shrinkage in castings but in reverse. 4 1 1 Link to post Share on other sites More sharing options...
michl080 Posted April 26, 2019 Share Posted April 26, 2019 14 hours ago, MikeTrice said: No it is generally always +0.2 so 10mm prints at 10.2mm and 40mm prints at 40.2mm based on experiments to date. Mike, I can confirm this 0.2mm deviation with my Formlabs Form2. Michael Link to post Share on other sites More sharing options...
MikeTrice Posted May 3, 2019 Author Share Posted May 3, 2019 Well it had to happen some time! During an intensive printing session my FEP developed a small leak resulting in resin leaking onto the UV light screen and subsequently curing. The hardened resin was carefully removed by sliding the tip of a scalpal blade under the deposit resulting in it flaking off. It took a while as I was scared of scratching the glass but it did finally remove it all. Next job was replacing the FEP. Now all the best advice mentions using a bottle top 300mm wide by 13mm tall and specifically mentions Gaterade. Now I do have a few bottle tops I have been hanging onto but none that had those measurements. In the end I had one that was 15mm high and filed it down. Rather than continue in this state of affairs I decided to print a spacer to the recommended dimensions. There are a number out there for download but it was just as easy to knock up my own. Ideally I should have done this BEFORE needing to replace the FEP. So forewarned my stl file is attached. There are lots of videos available showing the FEP replacement sequence but I quite like videos produced by this guy: fep gauge.stl 2 4 Link to post Share on other sites More sharing options...
monkeysarefun Posted May 4, 2019 Share Posted May 4, 2019 My score so far..... 2 x FEP re[lacement 1 x LCD replacement 1 Link to post Share on other sites More sharing options...
MikeTrice Posted May 4, 2019 Author Share Posted May 4, 2019 Over what period of time? Link to post Share on other sites More sharing options...
Knuckles Posted May 4, 2019 Share Posted May 4, 2019 I've been so busy these past months I must of had my head in the RMweb sand as I didn't realize you had finally brought the printer. Great thread details. Good bit of kit init? Link to post Share on other sites More sharing options...
MikeTrice Posted May 4, 2019 Author Share Posted May 4, 2019 Yep. Thanks for the initial inspiration. 1 Link to post Share on other sites More sharing options...
Knuckles Posted May 5, 2019 Share Posted May 5, 2019 No probs. How are the cabs shaping up? Link to post Share on other sites More sharing options...
MikeTrice Posted May 5, 2019 Author Share Posted May 5, 2019 (edited) 7 hours ago, Knuckles said: No probs. How are the cabs shaping up? Sitting in a drawer as a "one-day" job So others know what we are talking about, Knuckles kindly supplied some of his A1/A3 cab mouldings so I could upgrade some early Hornby A1/3 models. Very nice mouldings they are too. Edited May 5, 2019 by MikeTrice Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted May 5, 2019 RMweb Gold Share Posted May 5, 2019 2 minutes ago, MikeTrice said: Sitting in a drawer as a "one-day" job Just how big is this drawer.. 3 Link to post Share on other sites More sharing options...
Knuckles Posted May 5, 2019 Share Posted May 5, 2019 Aha! It's the railway modellers infamous 'maturing cabinet,' I've got one too. Full of kits and bits waiting to be made. The longer you leave them the better they get, likely they mature not just due to time aging but also due to increased skill in building them by the time you get to them! 5 3 Link to post Share on other sites More sharing options...
MikeTrice Posted May 5, 2019 Author Share Posted May 5, 2019 3 hours ago, chris p bacon said: Just how big is this drawer.. To be honest it is 7 big Ikea units resulting in 28 large drawers. I always collected kits and bits "for my retirement" but now it has arrived don't have time to do any of them. It also explains why I can never find anything. 3 4 Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted May 5, 2019 RMweb Gold Share Posted May 5, 2019 I'm not far behind you then...and it will only get worse as I keep getting sidetracked.. Link to post Share on other sites More sharing options...
RMweb Premium ianmaccormac Posted May 5, 2019 RMweb Premium Share Posted May 5, 2019 I have jus been printing a Stroudley roof in 7mm at a new orientation as a discussion on the Facebook group. Placing the models at particular angles in accordance with the layer thickness makes the best smoothness. These two roofs were both printed at 0.035mm layer thickness. The left one flat and the right n at 36 degrees to the horizontal. The difference is quite astonishing! Rather difficult to photograph though! Hope you can see what I mean! Cheers Ian 2 5 Link to post Share on other sites More sharing options...
MikeTrice Posted May 6, 2019 Author Share Posted May 6, 2019 I found the same with coach sides. Link to post Share on other sites More sharing options...
Knuckles Posted May 6, 2019 Share Posted May 6, 2019 Main thing is to print most things at an angle. 10-35 degrees I find is fine for most things. Takes experimentation to find what is best. Still learning that. Link to post Share on other sites More sharing options...
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