Locosnstuff

Useful Bits

Small Diesel Coupling Boxes

By request I drew a copy of the coupling box used on Simplex locos, it is 4 slot and a 0.7mm pin goes through the hole to hold the coupling link in place.  For prototypical industrial use, fiddly and no auto coupling, but they do look right.

The two on the left show them straight from the printer, the one on the right has been filed flat to remove pips and the hole cleared with a drill.  They measure 12mm wide, 10mm high and 3mm thick, £1.00 a pair.  I can make other types if there is a need.

Dick Kerr PE axleboxes

Designed for use with the Worsley Works etches and 3D resin printed, available in 7mm scale or 1/35th.

Set of 4 for £2.00

Diesel parts

Taken from my Hudswell D29 kit, they are useful on any diesel and I have used several for detailing other diesels with no cab interior.  These are straight from the printer with attachment points still showing, they can be filed or sanded flat.  These are in 7mm but they can be made in any scale, I already have drawings for 16mm ones.  Prices are from £5.00 a set and vary with scale, you can have individual parts if you want from £2.00.

Garratt cylinders

I call these Garratt cylinders as they were drawn for a Garratt I am scratch building.  They suit large locos as they measure 14mm across the end covers, the cylinder part is 12mm diameter and height of the valve inspection cover is 15mm.  Location is with 2 pegs on the rear, just drill holes in your frames to suit.  The 3 pegs underneath are automatic drain cocks, quite common from the 1920s onward.  These were designed for a chassis with outside frames, I can make an extended version for inside frames by adding 1.5mm to the mounting face.

Garratt cylinders with brass tube for piston rod £6.00 a pair

I have suitable single slidebar crossheads to fit these at £4.00 apair

Wheel Fitting Jig

Like many others I always struggle to get wheels onto axles, plain axles are not so bad as they can be done in a vice, pinpoint axles being the worst as you have to not damage the points as well.  I often take 5 minutes per axle gently tweaking the wheels to get them square and to gauge so I thought about some kind of jig to do the hard work.

A one shot jig that assembled both wheels in one go would be nice but a different one would be needed for every gauge, and I deal with 7 or 8 gauges so this is the next best thing.  You get a base plate that mounts in a machine vice and a spacer for each gauge you use, the standard kit will come with 16.5, 14 and 12mm spacers.  To use it you will need a vetical drill, vertical mill or an attachment that fits a lathe, and a suitable machine vice to hold the base plate.  It works like this -

1 - Fit the axle in the chuck and lower towards the base plate, lining the point up with one of the drillings.  2 - Place the spacer with a wheel on top over the drilling and bring the axle back down pushing it throughthe wheel and spacer into the drilling until you feel it bottom out.  3 - remove the axle and refit the other way round and repeat step 2.

The wheels should now be fitted squarely and to gauge.  Note that this only works with standard 26mm pinpoint axles and wheels of 2.5mm thickness, which mine are.  For other axle lengths or wheel thicknesses different spacers will be needed which I can supply by calculating from the axle lengths, wheel thicknesses and gauge.  There are 3 drillings in the base plate, this is because they will wear in time and this gives you 3 times the length of use of the jig.  Also some might find it better to solder the spacers permanantly above a drilling, then you can have 3 gauges per jig.

From the 4 pictures you can see the first wheel lined up and ready, after fitting it, the second wheel being fitted and the wheelset shown being checked on a vernier gauge, fortunately it was a 14mm gauge set I was hoping for.  When you first try it, it might take a few minutes to do the first one, when you get the idea they can be done in less than 30 seconds each.

I can supply these for £12.00 each with extra spacers foc if ordered with the jig

General Advice for using a Kelant S400 printer

I looks like I am one of the few that have managed to get a Kelant S400 printer to behave itself and print properly.  I have posted details on a printing forum and have received several emails from people around the world for advice so I shall repeat it all here so its on record for good.

The Kelant is a good printer but it has requirements that are completely different from most other printers.  It took me around 30 prints to find the settings it liked, all failed for various reasons but it now prints well every time.  Chitubox is the best slicer to use for the Kelant, I found the slicer that came with it lacking in features and not reliable.  All the settings below are based on Chitubox, for other slicers the settings will be the same but the names of the settings may be a little different.

Machine Settings

Go into Settings in Chitubox and name the profile Kelant S400.  If you use other printers, the Kelant X and Y axis may not be the same way round, my Photons are the other way.  Set the resolution to X - 2560 and Y - 1600, set the size to X - 192, Y - 120 and Z - 200, ensure that the box for Lock Ratio is ticked, actually it is solid grey rather than white.

The main problem is that the separation forces when the film is pulled off the print are high and can pull the print apart or even pull it off the build plate.  To counter this you must use heavy supports for large items and medium supports for smaller parts.  The medium supports must be made thicker in the slicer as they will not work as they are preset, minimum thickness 1.2mm for the middle sections.  If you use Chitubox, a raft is generated when you go to add the supports, I found that the supports do not attach well to the raft and often fail, the solution is to click Remove All and the raft will disappear.  Now when supports are added they will all have their own bases which will all merge into one to form a raft, these will print well.  You can change the shape of the base in the settings, I use a cylinder 1mm thick, do not use thicker or the print will be very difficult to remove from the plate.

If the print has no flat faces it can be printed in any position but it is better to tilt it so that the amount being printed for each layer is kept to a minimum, particularly the first few layers of the actual print as these are most likely to fail.  If the print is a geometric shape, tilt it so that the base is at an angle of 30 to 50 degrees to the plate and then tilt it sideways by about 8 degrees, this means that the print will start in one corner and move out in all directions which is better for the printer, the film and the supports.  Apart from ease of printing, the base of the model which has the supports will never print well with this type of printing.  If positioned level it will need a lot of supports and will print very rough, as you tilt the print it will improve in finish but it will never be good and will need sanding afterwards.  If you tilt the print past 45 degrees you will need supports at the side or end as well which will then suffer from a poor finish.  I find that the best way is to decide which face can be easily sanded, make it 0.5mm deeper and sand it back after printing.  Some of my prints are assemblies and the poor face can be hidden by other parts, or if the part is hollow it can be supported from inside where the problem will not show.

Print Settings

- Layer Height - I use 0.1mm for most things as there is no real improvement in quality if you go smaller but the print takes a lot longer, the following settings are based on that.

- Bottom Layer Count - 8, any more will make the base like armour plating and impossible to get off the plate.

- Transition Layer Count - leave at O as the Kelant does not use this.

- Exposure Time - 8.5 - 11 sec for white or grey resins, translucent resins can use 7.5 - 10 sec and dark colours 9 - 12 sec.  The shorter times will leave the print soft and liable to warping after printing when it finishes curing, the longer times will mostly complete curing in the printing process.  For organic shapes (no straight edges) the shorter times work fine but for geometric shapes use the longer times as post print distortion is far more noticable with them.

- Bottom Exposure Time - 50 sec for white or grey, 45 sec for translucent and 55 sec for dark colours.

- Light Off Delay and Bottom Light Off Delay - 0 sec, not required for most uses.

- Bottom Lift Distance (Kelant call this First Lift) - 4mm.  Listen to the machine in use and you can hear it speed up as it gets to normal lift speed, you should hear the film tearing off the print before this happens.  For a small print in the middle of the plate increase this to 5 or 6mm as the film flexes more with a small print, the film separation must be complete before the first lift is finished.

- Lifting Distance (Kelant call this Second Lift) - I use 5mm but it can be up to 15mm.

Bottom Lift Speed - 15mm/min, this must always be very slow.

Lifting Speed and Retract Speed - both can be 200mm/min.

Advanced settings -

- Leave both light settings at 255

- Anti-ailiasing should be ON and I use Level 4.

- Do not use Grey Level or Image Blur

When saving files for printing use zip format, it is the only option that a Kelant can use.  File names must have no spaces or special characters, use underscore for spaces if you add to the file name.  When ready to print, turn on the machine but do not insert the flash drive until the machine has finished loading or it will not detect it.  Use the flash drive supplied which is of the long skinny type, fat bodied ones will hit the casing before making connection and will not work.  Find the file and select it for printing, all the parameters you set in Chitubox will be displayed on the screen.  You can make changes before printing to the speeds, exposure and distances but do not alter the layer height, to do this you must start again in Chitubox with the new layer height set there.  If you want more than 1 print, save any changes you make and it will use the new settings for further prints.

I am happy to answer individual questions by email but this should get you started, the settings the machine and Chitubox default to will work on most small printers but not the Kelant and I suspect not any printer with a larger print area.  It is mainly the film separation forces that are the problem, a bigger film has much higher forces that have to be avoided by careful settings.  Kelant's solution is to use a lot more supports which uses a lot more resin and does nothing for the print quality.  None of the settings are written in stone, they can be varied but may have adverse affects on quality or adhesion, if you try some that are better, let me know and I can try them myself.

As above but for the Anycubic Photon

These machines are very forgiving with settings, even if wildly wrong they still try to do the job.  Initial setting up is automatic in most slicers but the settings required are -

Resolution - X - 1440, Y - 2560

Size of print area - X - 68.04, Y - 120.96, Z - 150, Z is slightly bigger for the S2 version.

Print settings - 

Layer height- 0.1mm gives good results, less will not be much better and will take a lot longer to print.

Bottom layer count - 4

Normal exposure - 12 to 14 secs, a little less for translucent and more for dark colours.

Bottom exposure - 55 to 60 secs.

Light off delay - 0 secs, not normally required.

Bottom lift - 5mm.

Normal lift - 5mm.

Bottom lift speed - 10mm/sec.

Lift and retract speeds - 200mm/sec.

Anti aliasing ON at level 4, do not use the other advanced settings.

These settings will give good results with most resins, if you have problems it could be caused by other factors, see below.

Other factors affecting prints

There seems to be a lot of conflicting advice but very little actual research into why prints fail now and then.  I have found that temperature has a bigger effect than most people think, I find a print temperature above 20C is needed for consistant results.  My two Photons have their internal fans disabled and an extractor takes fumes from the back vent, the bottom vent is covered with card taped on.  In use the resin temperature is normally 25 to 30C, this makes it thinner so flows better and negates adhesion problems.  My Kelant still uses its internal fans but the pipe ducting the fumes outside restricts the flow leading to a temperature rise for the same results.  I have a thermometer on a shelf above the printers, if it reads much lower than 20C I put a small print on first and abort it after about 20 minutes, this gives the machine time to warm up and I can then print whatever I wanted.  If the machine is in use all day this only has to be done once as the UV lights cause the temperature to stay higher.  I also have a cover on all 3 machines, the Kelant has an old zip up fleece pulled over it and the Photons have dark T shirts draped over the windows.  Apart from keeping them warm it also keeps the light out and the resin can be left in the machine for longer without a strip and clean, I recently forgot there was resin in the Kelant and one Photon and left it there for 3 weeks, it was still OK even after that long.

Another factor is the colur of the resin in use, I find that darker colours need up to 10% longer to cure and translucent about 10% less.  This makes sense as the light will struggle to get through dark colours but translucent will allow it through easier.  If this problem crops up seperate files will be needed with different exposure times for different resins.

Similar to above, different makes of resin will have an effect, Anycubic and Elegoo resins seem to be much the same but I recently tried Sunlu and the raft on the build plate was bullet proof, I ended up destroying the print before it came off.  The solution was to knock 8 seconds off the bottom layers time.  I also tried Anycubic Craftsman which comes out wobbly and poorly attached, even after increasing times it was still poor, I won't be buying that one again.  I was recommended to try Siraya Tech and bought a bottle but have not tried it yet.  When I decide which one I like best I will stick to that only and adjust the exposure times in the files to suit.

One last factor is shaking the bottle before use, obviously required but be careful.  If shaken like an aerosol can it will create bubbles which take time to disperse and will affect the print, not enough shaking and the pigments may not be fully mixed.  The solution is to shake it like a cocktail mixer, but slower, so you are sloshing it from end to end in the bottle at a leisurely pace.  This will mix the pigments but not create bubbles.  In use the resin stays mixed but will settle out after standing for a day or two, to use it without draining the tank and starting over, use a plastic spatula to gently stir the resin until the colour is uniform but be careful not to stab the film with a corner, I have rounded off the corners of my spatulas with a file.

I hope these notes are useful and I wish they had been available when I first started printing, it would have saved me a lot of money.

Locosnstuff is owned by Mark Clark of 12 Adelaide Road, Gillingham, Kent, ME7 4NJ, UK

You can contact me at borsig1958@gmail.com anytime or on 01634 575081 before 8pm