Slow progress Christmas project...

[Buelligan]

This is a project I started last year, but with a house move last March it got derailed. The plan is to have a sleigh mounted on truck chassis, and some reindeer mounted on an old tank engine chassis. Last Christmas I got a 3D printer and had some promising results, then had to pack it away when we moved house and since then I've not had the time to get it out and set it up again. I finally dug it out about a month ago, but just couldn't get any decent prints off of it. I priced up some upgrades for the frame etc and found it was actually cheaper to just buy a new printer! I've had that a couple of weeks now and got some half decent prints now.

I tried a couple of different designs for the sleigh and different sizes, and finally settled on a design and managed to get it printed at the right size. To print it, it needed support which it prints itself. Twice I tried to print it and just as it got to the end of the support structure, it started to curl at the edges, detach from the bed and then failed! I tried a few different things to fix it without success, and in the end the simplest of things fixed it, change the filament for a fresh roll!

I've now got a sleigh I can use, took me an hour to cut away the support structure on the underside, just leaving the sleigh runners in place. I now need to paint the sleigh, and maybe a Santa to sit in it, with some presents to put in the back, and I need to sort the scale for the reindeer.

Here's some photos of what I've got so far. The first is the design I didn't go with, looks ok from here but its an irregular thickness due to the print peeling part way through:



This 2nd one is the same design, bottom was a trial print to see the size, and stopped once a couple of layers were down. The top was after I'd played with the dimensions, but again, part way through the print it popped off the bed, hence the blob in 1 spot as it ket moving around with the nozzle so built up a blob, then just started a stringy mess everywhere.



And these are the reindeer I'll be printing, but they need to be a lot smaller:




This is the sleigh I'm going to use, 1st and 2nd photo show the support under the sleigh that had to be printed, the 3rd is after I've cut it all away and placed on the truck chassis to see if it was the right size, which it was for as I'd planned, but now I'm thinking of making it slightly wider so the sleigh runners fit tight to either side of the truck, reducing the overall height.







*edit* just found a couple of photos of the failed prints of my chosen design:

[Mountain]

Love it!

[Buelligan]

A little more progress. I managed to scale and print the reindeer. The file was for a set of 9, though I probably won't use them all. I stopped off on my way home from work Tuesday and bought a few tins of paint, and had a few minutes spare this evening to have a quick go at painting. The painting has highlighted all the issues with the print, so I will do another once I've got the printer fine tuned a bit more. However this will still be good to do it and get it working, then rebuild with better printed parts at a later date.

As usual, photos below of progress:

Freshly printed reindeer on the print bed:



Not sure I'll be able to fit 4 on, but it'd look good:



Painted the reindeer antlers, will need a couple more coats as the paint seemed quite thin and watery:



Painted sleigh and reindeer held up for size:



This photo shows how rough the print has come out, looked much better when it was unpainted!

[Daveyboy]

Love it!

Did you get it all finished in time for the ‘big mans’ visit?

Always tricky balancing time between hobbies and families but I would love to see the end result.

[Buelligan]

Love it!

Did you get it all finished in time for the ‘big mans’ visit?

Always tricky balancing time between hobbies and families but I would love to see the end result.

No, sadly not, the week leading up to Christmas I ended up working 12 hour shifts, so between work and wrapping presents I had no spare time. It's now slipped well down the list of priorities, as I won't need it for another 11 months now, though I'm sure that'll fly by!

[Dad-1]

I expect to see this running next year !!

Geoff T.

[Buelligan]

I decided to get a good start on this ready for next Christmas, partly as a trial for a bigger project, which I'm hoping to have done for next year also, but that will take up a lot of time.

So I started trying to sort out a body for the loco, that I can attach the reindeer too. 1st photo is the first trial print, as a general idea of what sort of size I'd need. it was too short, a little too narrow, and I'd set it as a 2mm wall, which turned out to be far thicker than it needed to be.



Next photo is the 2nd attempt at a loco body. Still needs some tweaking, I got it the wrong way round, so the loco would have to run in reverse for the reindeer to face the right way, but that's an easy fix. I also changed the wall thickness from 2mm down to 1mm. It's still strong enough, but cut down the print time a lot.



This is the body placed on the loco chassis, with the reindeer placed next to it to see how many I can fit on, and the answer seems to be 7!



I'd chosen a rounded body for ease of drawing it up, fitting around the motor, but I'm now considering making something squared, to reduce the overall width, mount the reindeer higher and further inboard, but still allowing room motor inside. Maybe a cross between a squared body, with the rounded section as in the above photos, over the motor.

[Bigmet]

However you finally arrange this clever idea, remember to incorporate a wiring path to the red LED in Rudolf's nose...

[Buelligan]

I managed to remember my tinkercad login and spent my lunch break at work playing around with a new design. In the 1st image it's the middle design, the other 2 are just copies so I could make changes without losing the original. Second image is just showing the screen used to set it up for the 3D printer.

Bigmet, I had considered a red nose, and I think I've got a box with individual LEDs in it, so might see if I've got any red. Also thought about fitting Nav lights to the sleigh.

The random way my mind works, and always coming up with new little projects for myself, with the openings at the side on this design (to allow some air flow for the motor), it got me wondering about an EDF (electric duct fan) powered loco...

[Bufferstop]

I notice your failed print has the dreaded raft curl which I spent ages trying to cure until I discovered it's not down to failure of the raft to stick to the bed. I've come to the conclusion it's due to arithmetic errors in the slicing software. I found I could sometimes improve the performance by rotating the model ninety degrees on the bed and sometimes by including a large sacrificial mass beyond the end of the print. I think it's to do with limitations on the number of decimal places the computers maths processor can handle.

[Buelligan]

Indeed, I had a few failed prints, failed to stick to the print bed. That's why I tried the raft, which managed to stick to the bed, but then curled up. For me it was cured simply by changing the filament. I hadn't realised it would soak up moisture and be affected that way, so after moving house the filament roll had spent about 8 months in the garage. I changed to the small test roll that came with the printer, and it came out fine first time with no tweaks to the G.code, so I bought a new roll of filament and everything comes out pretty well now without much problem. The grey roll is in a plastic quality street tub, with a load of silica packs from work, on top of a radiator, I'm going to have another go with it tomorrow and see if it's dried out at all.

Printer is currently running with the above design, about 75% of the way through at the moment, not sure if it'll be finished before I go to work.

Also found several downloads for EDF's and regular propellors, so that may be another project to play with, just need to find a suitable chassis.

[Bigmet]

The random way my mind works, and always coming up with new little projects for myself, with the openings at the side on this design (to allow some air flow for the motor), it got me wondering about an EDF (electric duct fan) powered loco...

That's potentially great fun. The Mrs had a small handheld battery fan purchased in the USA decades ago which got dropped and thus no longer of interest. Well not to her, but I hung onto it...

With the advent of DCC and Bachmann's excellent pinpoint pickup on their DMU's , while altering the DMU's I temporarily used one of the unpowered chassis with the fan unit and a spare Hornby decoder that was destined to be the light switch for a pair of trailer cars, to try aero drive. It was really interesting in that acceleration built up gradually, and very fine control was possible. The motor was only 6V rated and eventually evaporated its brushes, or I would still be running it.

[Buelligan]

I have a cheap drone I bought from China, never could get it to work properly, I've kept it as a source of parts. The motors being very small, lightweight, and powerful, I placed on using 3 on an Ekranoplan build, and the remaining motor will be used for the Aerotrain. To do it cheaply and simply, I was looking to pick up a cheap Hornby HST dummy car chassis, and use the pickups that would normally power the lights, to connect to the motor. A rough sketch on TinkerCad and it's looking a lot more like a submarine...
I've got to fit that in with this current Christmas project, the Ekranoplan, and an air boat I'm planning for the kids. Starting to wish I had multiple printers!



Anyway, back on track, Christmas project. Progress so far, I've managed to design and print a different body for the engine that the reindeer attach to, it's a bit angular, but personally think it looks better than the rounded body, there's also a couple of cutouts in the sides that should allow some airflow over and around the motor.





I decided it would look better if the sleigh runners sat astride the truck chassis, so I scaled it up and reprinted it. Unfortunately I encountered 2 problems:
1: I'd got the measurements wrong! I measured the width of the truck chassis, and the width of the sleigh runners, added them together to give me the overall width the new sleigh needed to be. However I didn't account for the fact that as I scaled up the width of the sleigh, the runners would become wider, leaving less room between the runners for the truck!
2: The file for the sleigh was to print it as a whole piece. This meant that it needed to print supports between the runners, before it could print the sleigh body. The runners are very fragile, and the supports are very close to them, so I ended up breaking them off both sides while trying to remove the supports. The runners were then too thin and too small a surface area to be able to successfully glue them back on.

So this time I decided to figure out how to cut the file into parts, so I could print the body as a single piece, and then 2 individual runners, with a long straight piece at the top to give a good surface area to glue. Once I'd split the file, I resized it again and printed it again. Much better results this time, wish I'd done it a lot earlier! Over the last couple of days I've painted it (wish I'd not printed it in black filament as it took a few coats to cover it, and it's still not great), but this is what I've ended up with:



Very please with this result, think it's looking good having the truck chassis hidden behind the sleigh runners. It has created another couple of problems though. The runners from the sleigh will now hit the reindeers rear leg on anything but a dead straight, so the reindeer will need repositioning, not too difficult a job, just glue in a different place, or print a new body with the holes further forward. But also the reindeer now look far too small for the sleigh, so they will also need making bigger. But if I do that, I'll only be able to fit 4-5 on, instead of 6-7 that I wanted.



So that's as far as I've got, I might make a 4 reindeer, and a 6 reindeer version of the body, and then decide which looks better.

PS. please let me know if the images come up too large, they look ok on my laptop, but not sure how they scale on other devices.

[Buelligan]

I predicted having a slow night at work last night, so I took the various parts and tools in with me and got this sleigh and reindeer almost finished. Theres still little touches that need sorting, finishing painting the reindeer, maybe a bit of detailing for harnesses, a Santa for the sleigh, and a sack or pile of presents in the back. But the main thing is, its all together, and it works. It's a little juddery, I'm hoping that will smooth out with some more running, but the kids are happy with it. Now to decide whether to make a track for under the tree (though it would get covered in sap), a window display, or possibly even make use of a timer and have it run along the front of the house as part of the Christmas lights I put up.

The 2nd is supposed to be a video, never sure how to get it to work, if the embedded link doesn't work, hopefully copy and pasting the address at the bottom will work.






https://i.imgur.com/DreEoNX.mp4