Ray H

The picture or Mavis?

I have managed to do a little more to the layout now that I seem to have gotten over at least some of my initial teething problems with the 3D printer. The first of the two (new) drop in sections (DISs) was held in place with very crude home made bolts and some locating pins. Following the success with the up-market home made bolts fitted to the 2nd (larger) DIS, I upgraded the bolts on the first DIS yesterday and have removed the now redundant locating pins. Some trial running with a light engine showed a slight "hump" at one end of the rejuvenated DIS. Some judicious packing under the track on the DIS in that area has solved that problem. As previously mentioned, the DISs will sit on the trackbed when not in use. This has an upside and a down side. The upside is that in this position the DIS prevent any runaways taking a dive to the floor off the end of the baseboard. The downside (?) is that whatever (minimal) scenery there is in those areas would have to stay below rail height. Whilst my dislike for undertaking scenic related tasks is well known (by mean at least), limiting the height to such a low profile is probably unrealistic. As a result I plan to fit some blocks to the underside of each DIS. These blocks will be in-line with the track upon which the DIS sits when not in use. It is easier to fit the blocks before I ballast the DIS as the securing screw can be be buried under said ballast. I think it is now safe to dismantle the old lifting access flap, which will be one of the next tasks.

I believe there is a Zimo decoder CV that determines how long a loco/motor should run on for if track power is lost. This may be set to a (very) low value on 7800 and may account for the difference. Are the two capacitors of a similar rating? You should be looking for a number followed by µF or uF. The higher the better (within reason).

I had seen the auto arrange option in Chitubox but hadn't understood its purpose, so thanks for that. And to continue the saga . . . . The computer has indeed arrived. It came with a power lead and what looks like a wireless Internet dongle but the monitor was absent as were the keyboard and mouse. Unfortunately my present monitor has a 15 pin VGA style connector whereas the new box of tricks has a connector - USB? HDMI? - that I've not aware of seeing before. I have been promised delivery of the remainder of the kit by Friday. I do have myself partly to blame because I ordered the various items over three days but I'm told the monitor I was to have had failed during testing hence the delay. Anyway, back to the Mars 3 Pro. I thought I'd nailed it with the more flexible build plate but No! Probably my fault because in my hurry to try it, I overlooked to give the flexiplate a clean, just using it straight from the packet. I did get three out of the ten models printed but the bottom layers (and little else) for the remaining seven were stuck to the FEP. I cleaned the flexiplate - which I've just discovered has some fairly sharp edges that I need to attend to - and increased the bottom layer exposure time back up to 30 seconds. Just under two hours later I had ten models, all of which look to be complete prints. They've just been removed - quite easily - from the flexiplate and have been through the wash machine. They'll go through the curer in the morning. Fingers crossed, I think I might now have a better understanding of this 3D printing lark. Thanks for all the responses & suggestions. Can I suggest for those who don't know about it, search YouTube for videos on the use of the Tank Cleaner facility. It's saved me having to keep draining the tank. I've got some work I want to do on the layout over the next day or so, so I'll probably give the printer a rest until after I get the new computer up and running.

The Modelu .stl file does come with a raft. I think I just got carried away yesterday for some reason. I'm fairly certain that I saved the finished item (all ten models) using Save Project before I started the print but I can't find that file now so I'll recreate it without the extra supports and try reprinting. The mirrored version of yesterday's half model printed OK so maybe the half model struck unlucky. I think that might have been the one near the marks under the FEP. Thanks for the tip about the right mouse button. I've just tried it but it seemed to take a while for the display to respond. The replacement PC is due later today, thank goodness. The flexiplate is a story in itself. Intent on taking full advantage of my month's free Prime membership which I got when buying the Mars 3, I looked for the flexiplate thereon and found what I thought was a complete set. When I opened it I somehow thought the metal plate I found was the magnetic part with the adhesive "stuff" on the other side so I went shopping again elsewhere and bought what I thought was just the magnetic flexiplate. Imagine my surprise when I eventually discovered that the second purchase wasn't actually needed - the metal plate that I found in what I'd bought originally was the flexiplate and the adhesive side incorporated the required metal plate to affix to the build plate. Doh! The removable plate that I'm currently using doesn't seem too flexible - it does bend with some force but so far its only managed to cast a few models off. Your post has just encouraged me to check all the other plates that I bought. Lo and behold, the plates of two of the unused three sets are a lot more flexible so I've changed over to one of them. All good "clean" fun. Expect a pause in developments whilst I sort the computers out.

I decided to have another go late yesterday afternoon, this time with some of Modelu's seated people. Five as supplied and five as mirrors of the supplied five to give ten in total. There were no other changes other than the mirroring so if one model printed and its mirror didn't I could tell whether or not there might be a problem with the model's supports. I'd let Chitubox add supports below the Modelu base and also add a few other supports that it felt needed. The Bottom Exposure was set to 25 seconds and the normal exposure set at 3 seconds One of the ten models was nowhere to be seen once the print had finished and another was only printed from the waist down and ended up waist down stuck to the FEP. The other eight look OK although I haven't inspected them too closely yet. The (Chitubox added) bottoms were a swine to remove from the build plate. Luckily, I was able to remove the models themselves from the Chitubox supports so the models escaped damage. I'm going to try a slightly shorted bottom exposure, perhaps 22 seconds next time. I did notice that I could see a mark on the underside of the FEP/top of the screen when I was removing the half model. My guess is that the IPA hadn't completely dried when I refitted the tank. That may account for the problem with one of the models. The missing model maybe attributable to it not being sat on Chitubox's "build" mat which I'll check later. Trying to squeeze all ten models onto the "build" mat wasn't the easiest thing and I may well have lifted the missing model when I meant to move it sideways, but that's just a guess. I plan to rotate the print horizontally through 180º prior to the next print as another means of checking that I'm heading in the right direction. An advantage of seated passenger models is they aren't so tall, so the print finishes quicker🙂

It does look as though the straight blade isn't sitting snuggly against the curved stock rail when the point is set for the straight - the apparent step where the other end of the straight blade meets the closure rail - the rail leading towards the frog - isn't smooth has already been mentioned. Is there any chance that you make a slight revision to the layout? Could you replace the left hand point with a right hand point that takes the place of half(?) of the last curved section? Alternately, could you move the point towards the point at the other end of the loop and insert a straight length between the end of the curve and the point's new position. You would lose some of the length of the loop but it might go a long way towards eliminating the derailments.

Are all the derailments at the same place on the point. Can you locate/identify that position.

Check one of the wires hasn't come out of the ferrule.

Did you discover what was ailing the Class 37 yesterday?

The bottom one is 35 seconds and the ordinary is 2.5 seconds.

Thanks for the latest responses. I believe that I have now set a new printer profile or, at least, changed from the Default printer to the Elegoo Mars 3 (and deleted the Default printer). I can't remember whether I've always used the Default printer or whether it got changed at some stage although I don't recall ever changing it. As yet, I haven't had time to do a test print but intend to do that later this morning and report back.

Other commitments have had priority this morning which was probably a good job because no matter what I tried to do earlier, the machine wouldn't recognise the files that I was trying to print. That said, I've just noticed from the icons on the machine's screen that either the computer itself, Chitubox or the memory sticks I'm using - not the one that came with the printer - are misbehaving. Something must be amiss as the file I produced with multiple scaled down rooks is only showing with a file size of 1,211KB. The memory stick to which the file has been written still has over 13.5GB space so it isn't a disk space problem. I'm half inclined to see either if my Chitubox program itself offers an update (for the free version) option or whether their website has an updated version available. This PC has only a few days left to live (hopefully) but it might be worth uninstalling the program and then trying again. Heaven knows how the program arrived at the .cbddlp file extension.

Thanks for all the ongoing suggestions and comments. I was wondering whether trying to test print something that is spread reasonably evenly across the build plate - something like numerous rings of "plastic" of say an 15mm diameter and perhaps 10mm high might be worth the effort. I haven't tried printing the Elegoo rook so multiples of that reduced in scale could be a better test. The printer hasn't been moved since I first used it and several of my initial prints came out fine but I'll try a spirit level on the machine before the next print. The printer is in a spare bedroom. The ambient indoor temperature currently is a little over 21ºC. Is that high enough & how do you keep the resin's temperature up once it is in the tank. Is simply having the machine on for a (continuous) period OK? Can you get/do I need a tank heater? I've given the resin a good shake each time before putting it in the tank. This generates a number of small air bubbles in the top of the resin once it is in the tank. I've tried to push them aside before I start printing. Do they matter? Your reference to resin calibration tests and print speed are new terms to me. I've just googled "resin calibration test" and will give that a go. Would it be necessary each time you change resin or should resins from the same supplier where only the colour varies be the same? Another dumb question - how do you set the print speed? Is that the same as the lift speed?

I think he means catenary although it might be after the next centenary before he starts - he's younger than me so might still be around by then 😄

The most recent print (after the aforementioned bolt tightening) was of four models (of people). One was successful, two had their supports on the build plate plus the lower parts of their bodies affixed to the FEP. The fourth only appears to have managed the supports - I have yet to drain the tank to check the FEP is clear. I've checked the settings that I'm currently using with those on the Chitubox website. The only significant difference that I've found is the exposure time 6s (Chitubox) above and 30s (mine) below. I've no idea where the 30 seconds exposure time has come from and if that is the time between each layer's print I'm certain that it is nowhere near that value when printing. I'll reset the 50s to the 6s suggested and have another go either tomorrow or Monday. Is my Lifting Distance setting of 6mm against the default setting of 5mm likely to make any difference?

The build plate securing bolts weren't fully tight. That's been corrected and I'm running another different print. I reverted to the black resin for the previous file I printed - the one that highlighted the loose bolts. There was a slight defect on one of the prints but the other two in the trio were fine. I have also been having trouble adding supports and despite watching a couple of YouTube videos to make sure that what I'm attempting to do should result in additional supports, I still can't do it. Thanks for the tip about using save project, rather than a plain save. I'll try to remember that. For reasons unknown to me, I have just managed to save a couple of files with .cpddpl extensions. I haven't tried printing one of those yet. I was only trying to open the .cbt to see if I could see anything obviously adrift that might have caused the print failures that I was having. The settings I have used have, to the best of my knowledge remained unchanged since one of the first files I printed several days ago and I have subsequently (almost) successfully printed the most recent file again with the same settings. That said, the file currently printing does seem to be, with one possible exception out of four, printing just the supports and not the bodies again.

Thanks for that. I'll wait for this print to finish and check they're tight (although I'm not sure why they've worked loose).

That dented your wallet 😃

Did that file look OK in UVTools? Could you open the file in Chitubox? I'm cleaning the bath after each print at the moment to make sure all the debris is removed. The build plate has a spindle. That spindle is connected to its carrier by two bolts that you set with the piece of paper scenario. Is that spindle supposed to move up and down in the carrier during printing once the bolts are tight? I may have found my printing problem if it isn't. I may not need to worry about reopening the .cbt files in the short term if I have found the cause of the print failures.

I've renamed this file to have an accepted extension of .stl. Reset the extension to .cbt and it should open in UVTools. _Buffer_Stop.stl I'm not too sure of what I should be seeing but I don't think it looks right. Although iI thought it was O gauge, what was left in the resin bath makes me think it is OO.

I hadn't thought of that so I've just taken a file I had open in Chitubox, closed it and opened it in UVtools with this result: I got a similar result with another file that I couldn't re-open in Chitubox.

Thanks Peter. Alas I tried that. The display looks normal on the right hand (black) window, The left hand window just shows a couple of small blobs for want of a better description. The message "Slice image import is complete, 3D preview is being generated" appears across the bottom of the screen. I've had a few successive print failures with either the same or different .ctb files. I'm currently trying several different things to see if I can pinpoint their cause. One idea I had was to re-open a .ctb file and play around with the supports as the failures that I'm having seem to relate to the model rather than the supports - the latter are generally printing out but the model itself isn't.

I created a file in Chitubox yesterday and saved it to a memory stick. The print failed so I want to review the file and possibly alter it. I've tried re-opening the file in Chitubox and can only see a very small portion of what I believe is the top of a couple of the items in the file although Chitubox shows the print time so it is presumably reading the (whole?) file. Is this a regular problem?

Have the H & S E been advised of the gap between loco and tender? 🙂 Why is it that I notice things like that but other just as viewable but more scenically related items seem to pass me by?