Russian SU76M

[wibblywobbly]

I figured that for all the work that this build involves, it would be pretty much wasted if I didn't have tracks and sprockets, so I designed some links. They slot together nicely and take PanzerIII track pins, but I'll have to print the cleats separately and glue them on, as it will be easier that way.

I can't see why they won't work, but there is only going to be one way to find out. The guy who does the Scorpion kit at Stryker Workshops does them for his kit, and I have seen first hand how well they stand up to abuse, so it has to be worth a go.

[silversurfer1947]

You weren't tempted to print the whole track as a single entity including the link pins then?

[RobW]

You weren't tempted to print the whole track as a single entity including the link pins then?

Don't be silly. Plastic track pins would snap. He'll need a metal printer for that.....

[wibblywobbly]

I did, but the problem is the 'last link' and being able to clip them together. Having seen John's Scorpion, I could see that 3D printed tracks with pins were a practical proposition, so it has to be worth a shot.

I can print them as many as I want at a time, but cleaning out all of the pin holes is going to be a chore. They aren't 100% accurate, as I would rather go for strength than accuracy, if they work anything like the Stryker Workshop ones do I will be a happy bunny, as it means that this whole tank will be 3D printed, which is what I am aiming for.

phpBB [video]

[wibblywobbly]

You weren't tempted to print the whole track as a single entity including the link pins then?

Don't be silly. Plastic track pins would snap. He'll need a metal printer for that.....

These were taken straight off the printer...

phpBB [video]

[RobW]

Impressive - I've seen metal chainmail printed but always been told the flexible/jointed plastic was much weaker.

Just a thought for the link cleaning problem. Can you print a holder which you clamp under the drill? Clamp & line it up & then slot the links in so they're automatically in line with the drill.

[wibblywobbly]

The pin holes are preprinted in the links, so all I am doing is using a pin drill to clean them out. I'm printing 7 at a time, so I can clean one set while the next is printing...it will probably take until Christmas!

[Raminator]

Those tracks have come out really nicely Rob, a real testament to how well you've designed the parts and how well you've set your printer up. What material are you printing them out of? How will they hold up to running, do you think?

[wibblywobbly]

It's not going as smoothly as it looks....

The tracks are printed in PLA, which is tough stuff. I printed the ones above, then decided to try printing them with a tread pattern on, printed some of those, then adjusted them, printed some, got them ok, printed a few more, and then realised that they were too wide, so re-jigged them to the correct width this morning. Have yet to try printing those.

I tried printing the rear half of the lower hull, first attempt after 5 hours of of 10 hour print, the bed moved slightly....one wrecked print.
Tried again, after 2 hours the part was lifting off the bed.
Tried again, but just printing the side panel with the suspension mounts, nope, refused to stick after an hour...
Only just notice that somewhere along the line the mounting holes for the return rollers have been left out, so will need to fix that before reprinting.

I am suspecting that the almost empty hairspray can that I have used doesn't have any sticky stuff left in there, so will pay a visit to the supermarket and return to attempt this little adventure again.

I took a look on the PrintHub to see if anyone can print this as a one piece lower hull, but the cheapest I could find was £130. My only option may be to print the side sections and make the rest from styrene.

[AlwynTurner]

Hi Rob, I suspect the easiest approach and the least wear and tear on your nervous system is your final suggestion of using sheet styrene. It will be a lot quicker and may well prove stronger than trying to print the large flat parts of the structure.

Whichever route you take I hope it goes quickly, smoothly and with the least complications.

Alwyn