Introduction: Train in a Christmas Tree L2 (3D Printed Version)

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I took The Hornby OO scale Santa's Express Christmas Train Set (R1248) which is meant to go around the bottom a Christmas tree and built a platform for it to go around the middle of the tree above the reach of toddlers and small dogs.

This is the second version of one that I did a few years ago mostly our of timber (available on instructables). This time it is 3d printable on a 230mm square bed.

Original SolidWorks files included.

Future developments may include N scale above, O scale below to give Three Trains in Chistmas Tree! STL files are on printables as well.


I will admit that my documentation of this project could be better but you'll figure it out :)

TBH this isn't even probably proof read when I get time i will do that.

Attachments

Supplies

See attached BOM for a full list of everything you need. It is mostly built from 3D printed parts and common hardware that you can get in your local hardware stores, motor factors or German discount supermarket. For the 3D printed parts I mostly used PETG but that is because I had it available in red but PLA should work just fine. For the threaded brass inserts I designed around and used the CNC kitchen ones as I have found those to work best.

Attachments

Step 1: 3D Print

Print all the parts in the quantities in the BOM and one of each of the STLs that starts with the word Jig in the file the purpose of those will become clear later. I can't remember how much print time but it was a long time for the whole thing and I did on and off over a few week when I had a minute or two.

Step 2: Modify the Track for Hooking Up the Power

This train set is meant to go around the bottom of the tree on an oval track but this project requires a circular track. This means that the power connector to the controller needs to be moved from a section of straight track onto a section of curved track.

  1. Remove the plastic bits from around the connector.
  2. Carefully break the spot welds to the track with a pliers
  3. Remove two sleepers from the middle of one of the curved sections of track with a junior hack saw and pliers.
  4. Persuade the connector to fit
  5. Solder it to the curved track
  6. Replace the plastic bits


Step 3: Insert Hinge Swivel Into Track Section With Support

Refer to the BOM:

The fist piece of assembly is to attach the item 5 "Track frame section 2" to item 18 "topper for threaded bar MK2 design" with a 3X24mm roll pin. Use small drill pits to ensure that there is interference fit between the pin and the mount on the track section and that there is a loose fit between the topper and the pin.

Place the track seciton in the jig "jig for track section assembly" and the topper in the parts named "Jig Hinge for pin hinge insertion track section pivot 1" & "Jig Hinge for pin hinge insertion track section pivot 2" and then place in the overall jig using clamps to hold everything in place. Using the smallest hammer you have available insert the pin.

Repeat X 6

Step 4: Assemble Support Lenght Adjuster Sub Assembly

Use an M5 tap to create the thread for the grub screw

Use a soldering iron to insertion the M3 threaded inserts.

Assemble as per drawing

Repeat X 6

Step 5: Assemble the Tack Platform

Insert threaded brass inserts use filament as locator/antirotation pins and screw it all together alternating between track secitons with a mount and those without.

Repeat 12 times

Step 6: Secure Track to Platform

Use a dremel (or a junior hacksaw) to carefully cut the about 0.5mm off the end of each curved section of track so that it will fit propery, otherwise it'll be too big for the platform. Make sure you removed the burrs with a needles file or you will have derailments.

offer the track up the platform using sticky tape to temorary hold it in place

Using the item 31 "Bracket securing Track to platform" place all of these on the track to the left of the holes that already in the trackes for tack/nail. There is a locating nub on this part. Then mark the track where you will drill.

Remove the temporary installed track. Drill holes for M3 threaded inserts where you marked using the instructions provided by CNC kitchen (or whoever you got them from) on hole size and depth.

Assembly securing the track to the platform with M3 countersink screws through the afformentioned brackets.

Step 7: Hub Assembly

For each of the six parts (item 12) "link from collar to support 2022", thread the holes for the grub/set screws and insert the roll pin to the collar components. Use something as a shim while inserting the pin to take up the slack so that you don't crack the component while hammering the pin home (the file "Shim for pin insertion hub" will work as a shim). Clean up of holes will probably be required especially if you have a old and badly dialed in printer like myself. I did print a Jig for this job but it is probably overkill and I can't find the file anymore. It is unecessary use a shim combined with a vice with soft jaws a SMALL hammer and pin punch (for line up the holes) and you'll be grand.

Step 8: Drill a Hole in the Support Tubes

With Jig part "Jig for grub screw holes^Jig for drill grub screw holes" drill a 3.3mm hole (M4 tap drill) through the end of the support tube that will attached into the hub so that the grub screw have something to engage with.

Step 9: Threaded End of the Support Tube

Take item 14 "Bushing tube support to threaded bar" and insert an M5 brass threaded insert into the rear of it (larger hole) with a soldering iron and then attach it to the support tube with gorrilla glue or even bog standard superglue (CA glue).

Step 10: Collar Assembly

This doesn't seen much explanation just follow the drawings.

Step 11: Install on Tree

I will be brief and vague here good luck.

  1. Offer up the platform to the tree and find where you want it then measure down 230mm(ish) and this is where you will install the collar.
  2. Install the collar
  3. Install the support tubes complete with threaded bar (small note here file a flat on the end that goes into the platform) and secure with grub screws
  4. with help affix the platform to the 3 of the supports
  5. then level it
  6. then fix the rest of the supports
  7. spend a long time geting it level a laser level helps but so does a carriage
  8. hook up power
  9. run train
  10. pour a drink
  11. sit back
  12. enjoy!