Highland Railway Drummond 0-4-4T Passenger Tank

Discussion in 'Kits, Kit bashes & Scratch builds' started by paul_l, Jan 11, 2019.

  1. Mossy

    Mossy A classic grump Yorkshire man Full Member

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    Hi Paul,

    £100 - £150 saving over a kit isn't to be sniffed and if you were building big tender engines 4-6-0 4-6-2 etc the savings must be substantially higher but are your costings also a palliative to swmbo? Don't worry I wont blow the whistle on you. Given a 3d printer costs £2000 - £3000 you would need to build a stable of 10-12 locos to cover its cost, and I don't need anywhere near that number for a small end of branch station. I have to admit your build looks superb and some of the little extra fiddly bits you created with the printer really push what's possible forward. Andy's signal box builds also look fantastic. Those handrail bending jogs you created looked serious useful, I wouldn't mind a couple of those.

    I look forward to reading more on your 3d adventures so keep up the good work.

    Mossy
     
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  2. paul_l

    paul_l Staff Member Administrator

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    Hi Mossy

    The printers I have fortunately cost quite a bit less, my 1st Photon cost me just shy of £400, and the boss allowed me to buy it as I had a bonus from work. The second Photon I got for £260 when Anycubic released the Photon S and discounted the original Photon. Both these printers still work and are used when I'm printing larger prints on the Mono X. And my final printer is the Mono X which set me back just over £500 (I was lucky enough to be on one of the early pre-orders).

    The Mono X's build plate is approx 8" x 5" with 11" build height, and the Photon's build plate is 5 1/4" x 3 3/16" with a 6" build height. Due to the use of a higher powered UV source and a less absorbant mono LCD screen the Mono X is about 3 times faster at curing the layer than the Photon.
    The Mono X is a 4K screen giving a Pixel resolution 0.05 x 0.05, whereas the Photon is a 2K screen with a pixel resolution of 0.047 x 0.047, giving a very similar quality of print. The larger capacity printers currently use 11 to 13 inch screens still with a 4K resolution, so the pixel size is larger, for example the Phrozen Transform the resolution is 0.076 x 0.076.
    So when I'm in full production mode, larger models are printed on the Mono, and the smaller parts are printed on the Photon's, with final print times being similar.

    I've not tried a full height print yet, as I try to pick models that will fit my build plate, so coaching stock above 4 wheelers (a 6 wheeler is just too big for the Mono X), but I have a few idea's for them in the future. I have managed to print an 4mm LNER Articulated coach I downloaded from the web. The chassis printed ok but the coach body was a little too thin, so will need tweaking for another go in the future.

    There are rumours of 13 to 15 inch 6K screens coming to market - the 3D market is now getting big enough for the screen manufacturers to make screen uniquely for the 3d market rather than repurposing Tablet screens. Ever noticed how the printer manufacturers offer printers with the same print capacities - they all buy in the screens probably from the same producer.

    A large printer is on the wish list, but as Mossy pointed out the list price is £2000 to £3000, and SWMBO reckons a divorce lawer is cheaper (but it must be close to the breakeven mark), so if any printer manufacturers are reading this there's the target price point, less than the cost of a divorce lawer. :avatar:

    Paul
     
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  3. Mossy

    Mossy A classic grump Yorkshire man Full Member

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    Paul,

    I didn't realise you could pick up printers for that kind of price and kind of assumed the £2-3K price tag.
    Equally I didn't realise the build plates were as small as that. So no big loco's until prices fall and bigger build plates come to the market,
    but, like all electronics it's just a volume game and therefore a matter of time.

    Do you remember the cost of the original "brick" mobile phones. My ex-boss got a very early one, we had great fun when he called us by making random hissing noises and complaining about the reception and claiming we couldn't understand a word he was saying. Happy days!

    Keep up the good work and give us all facinating threads to read.

    Mossy
     
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  4. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    Thanks for the kind words re my buildings. I wouldn’t say they are any more difficult that your Loco Paul? Not when you look at the gearbox you mocked up.. and it more or less worked first time and you made your own gears to boot! That is some accolade! (Maybe I should have a go? )

    I must admit I’m finding some things easier to make now, as you learn as you go on.. this is only 6 years of self taught. If you saw the first efforts compared to now, you can see the progress..!! And all with the same obsolete program (as Paul).

    having the resin printer has helped as before it was send your file off to Holland and wait 10 days for a model to turn up. With the printer, we have it in a few hours..

    Incase your interested, the signal boxes are around 7-8hrs printing time, so it would be one a day. (I can’t print at night as it’s under the bedroom! :oops::oops:
     
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  5. paul_l

    paul_l Staff Member Administrator

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    Hi Mossy

    It gets better - Currently from Anycubic's site

    The Original Photon is going for $169 ( approx £120), the Mono (not the Mono X) $199 (approx £140), the Mono is worth the extra £20 as it has a Mono screen so has a faster cure - approx 2 sec per layer against 8 sec per layer for the Photon, and the Mono screen will last longer - screens are counted as consumables.
    So far I haven't had to replace a screen, replacement costs Photon £40, Mono £50 and Mono X £106
    The Mono X currently is available for $609 (£430)
    All prices do not include P&P.

    And no I'm not sponsored by Anycubic, just a happy customer (most of the time :hammer:)

    Paul
     
  6. Mossy

    Mossy A classic grump Yorkshire man Full Member

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    Paul,

    Why is the screen "consumable", if it needs replacing what is the cause?
    I presume the wash and cure machines are also needed to set the resin after printing?

    Sorry about the questions, just curious as to the process involved.

    Mossy
     
  7. paul_l

    paul_l Staff Member Administrator

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    Hi Mossy

    Wash n Cure machines are handy, but not an necessity. I do have the smaller Wash n Cure, but to prolong the life of the IPA, I use two pre-wash baths, both of these are from the sistema range (Tesco's stock them) the first is the dirty bath, here I use a brush to wash down the build plate, models and resin vat, as they come from the printer. Next up is a Pickle container, the parts are removed from the build plate placed in the pickle bath and agitated. If there a lot of small parts and printed on the Photons, then the the Pickle bath step can be missed and the build plate used in the Wash n Cure.

    The LCD screen, will due to heat from the UV light will eventually get pixels burning out. Standard screens are rated with an average life of 200 hours - note the word average, some will fail way before that. Mono screens have an average life of 400 hours. Life can be extended by increasing the power-off setting between layers allowing the heat from the UV light source to dissipate before the next exposure. This will of course extend the print times, for example, if we have a model 20mm high, and we print at 0.05 layer height, then our print job will have 400 layers. If the print cycle is 10 sec (2 sec to raise, 2 sec to lower and a 6 sec exposure) then our exposure time would be 4000 sec or 1h 6m 40s. If we add a 2 second delay - power off, then the print time will be 13m 20s longer. The Mono screens only have a monochrome layer, instead of Red+Green+Blue layers so allow more light through, so have a shorter exposure time, and therefore less heat buildup.
    The other main cause of screen failure, is from the FEP film of the tank leaking (normally caused by physical damage from bits of failed print or dings from cleaning) this resin will then cure to the screen, and boy is that a *** to remove without damaging the screen.
    And the final cause of damage is from dropping something directly on the screen.

    So far I have not needed to replace a screen (touch wood), and both of my photons have well exceeded 200 hours. But the photon is a low powered printer (approx 25W), whereas the Photon S is a 40W printer. The Mono X is a 120W printer, but doesn't run at full power - if the user wants to bump up the power setting they can, but it will be at the detriment of the panel - my Mono X was factory calibrated and set to 50%.

    Hope that helps, and just keep asking.

    Paul
     
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  8. Mossy

    Mossy A classic grump Yorkshire man Full Member

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    Paul

    Thanks for the explanations, I like to understand the why's and where fors of a process even if I am not going to use it.

    Mossy
     
  9. paul_l

    paul_l Staff Member Administrator

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    Hi Mossy

    Not a problem, I must admit, when I discovered the screens were a consumable, it was after I had bought the printer, and with a quoted average life expectancy of 200 hours, combined with my average print times for the Photon being 6 to 8 hours, I was looking at replacing the screen after 30 prints :eek:. I have lost track of how many prints I have done, and find the whole process relatively straight forward - although often frustraiting, especially it can be over 3 hours before you can actually see if anything is printing.

    Paul
     
  10. Mossy

    Mossy A classic grump Yorkshire man Full Member

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    Paul

    Two more questions, both tla's what do IPA (not Indian Pale Ale I presume) and FEP stand for in English!

    Mossy
     
  11. paul_l

    paul_l Staff Member Administrator

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    Hi Mossy

    IPA - Iso Propyl Alcohol, used to wash the Prints.

    FEP - Fluorinated ethylene propylene (FEP) is a copolymer of hexafluoropropylene and tetrafluoroethylene - a non-english version may be better :avatar:.
    Invented by Dupont and is usually known by the trade name Teflon FEP.
    It is used in sheet form to give a clear non-stick base to the resin vat. The resin is exposed to the ultraviolet light via the LCD mask through the FEP sheet and should then cure to the build plate, or the previous layer of resin. Sometimes that is the hardest part of the process, getting the resin to stick to the buld plate rather than the FEP.

    Paul
     
  12. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    Tried the 0.025 again, but had a mixed result. Items in the middle of the FEP failed but another two items (slightly larger) were successful.

    need to empty the vat tomorrow and clean the FEP again as it’s stuck to the bottom :(
     
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  13. Rob Pulham

    Rob Pulham Happily making models Staff Member Administrator Feature Contributor

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    And I thought 1:1 mix resin casting was complicated and messy :rolleyes:
     
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  14. paul_l

    paul_l Staff Member Administrator

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    And Rob - we need to be careful we don't drink the wrong IPA :cheers:

    Hi Andy

    Do you use a raft ? - I found it helped with adhesion to the plate, gives a larger area for the supports to stick to.

    Try using the same exposure setting for the base layers as you do at 0.05

    I've also bumped up the amount of supports to between 50% & 80% in Chitubox, high in Lychee, for the auto supports

    Paul
     
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  15. Mossy

    Mossy A classic grump Yorkshire man Full Member

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    Rob,

    If I could figure out what Paul and Andy are discussing I might be able to appreciate the difficulties.

    Perhaps we should hold a straw pole, using a raft to help adhesion, 1:1 mix resin casting and my cross to bare NER Days kits. I think my cross would come last!

    Mossy
     
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  16. paul_l

    paul_l Staff Member Administrator

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    Hi Mossy

    After we have created the 3D model, we then need to export the model into a slicing program, that will cut the model into "slices" just like a bacon slicer at the meat counter.
    The filament printers (FDM) normally use 0.2mm or greater slices, the resin printers are capable of far finer (thinner) slices, 0.05mm being the norm. However they are capable of printing down to 0.01, but being capable and actually able to do so and combined with a print time 5x that of the 0.05mm sliced models makes this layer height probably un-realistic -; although I will probably give it a go sometime :whatever:.
    Andy and I are trying a layer height of 0.025mm, even running my finger nail accross the surface I can't feel the layers. This does increase the print time, but the increase in print quality may well be worth it.

    The issue Andy has is that the model has not stuck to the build plate in the center, but has towards the outside and has stuck to the FEP (teflon) base of the resin vat instead.

    Normally caused by

    1. Print bed not correctly level - but as its not sticking in the center, but is towards the outside is unlikely to be the cause. Still for the tme it takes to re-level, is still worth checking / setting.
    2. FEP sheet not tensioned enough - as the print bed rises, the model has to peel off the FEP sheet, as the sheet will flex, the center has to move more than the edges.
    3. Raise height is set too low - related to the above cause, if the FEP tension is OK, then the build plate may need to raise further to allow the model to peel off. The default is 8mm I have mine set to 10mm - as my raise / lowerspeed is set to 3mm/sec, it adds an extra 0.6 sec to each layers print time.
    4. By using a raft, you provide a larger area incontact with the printer plate.
    5. Cure time for the base layers is insufficient. I have set my base layer cure time to the same as my 0.05mm layer height prints.

    The above model has a raft at the base, and all the supports grow from the base


    Whereas this model has individual supports with thier own base, giving a smaller contact area, increasing the chance of a support not sticking.
    Also look at the right hand side, the supports have broken away from the model, or failed to print correctly - three possible causes / cures, increase the size of the supports, increase the number of supports (putting them closer together and / or increase the cure time, but as the rest of the model looks OK this would be a last resort.

    Hope that helps

    Paul
     
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  17. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    What Paul said!! :avatar:

    although I think mine was down to the raft - the two parts that worked are on a large one.

    the ones that stuck I’d made as 5 individuals.

    worked perfect back at 0.05mm again:facepalm:
     
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  18. paul_l

    paul_l Staff Member Administrator

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    Hi Andy

    Can you post up your resin cure settings for both the 0.05 and 0.025.

    My adhesion problems in the center were solved by tensioning the FEP, increasing the lift height and combining multiple models into 1 raft in the center areas. The issues with the 0.025 models not sticking were resolved by uping the base layer cure times to be the same as 0.05 models (40 sec).

    Paul
     
  19. Mossy

    Mossy A classic grump Yorkshire man Full Member

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    Paul,

    I like your bacon slicing analogy. We used to use the phrase Salami slices when discussion how to chop up an IT development into suitable mouth fulls.
    I can understand how the reduced layering produces a better quality finish with a corresponding run time.

    Possibly a final question, what software do you use to produce the 3d model in the first place and how do you get the detailed plans to develop it from?

    Mossy
     
  20. paul_l

    paul_l Staff Member Administrator

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    Ah .........

    Andy and I are using Autodesk 123D, a free program that is no longer available, and to be honest has a reduced feature set compared to other software, but it works.

    I have downloaded and registered for Autodesk Fusion 360, being a hobbyist I get the free licence - I have to renew it each year, and if I end up with a turnover of over $100K, then I need to purchase a licence.
    Blender is a a very good and fully featured open source offering available for Windows, Apple and Linux, and is used by a lot of commercial modellers.
    I also have access to Solidworks, another very capable piece of software, but expensive.

    All three operate in a similar manner, but all have steep learning curves - hence Andy and I are still using 123D. I'm not sure which software to migrate too, thier are lots of tutorials on the net, and the ideal way would be to pick a project and stick with one of the pieces of software.

    For the Highland Railway Passenger tank, I've used Peter Tatlow's book Highland Locomotives (OPC Press), which has 4mm scale drawings for each locomotive. I used my scanner to copy the drawing, and then scale it up to 7mm, and print to A3.
    My next model I will try and import the scan into the 3D software, and trace around the parts to create the sketches used to produce the 3D assembies.

    I am a self taught novice at this, the last formal drawing training I had was during my apprenticeship, and that was drawing reading not actual design, before that was my O level in Technical Drawing over 40 years ago, and computers were housed in high rise buildings, for computer studies, we hand coded punched cards and sent them to Keele University for the programs to be run - ah those were the days...........
    My journey during this project has been enlightening, especially the assembly side, not a supported feature of 123D, but you can import 3D models, so once I discovered how to do this has made life easier. The newer software has all this and more built in so will allow the management a lot easier (so I'm told).

    Paul
     

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