Witness the birth of a new monster...the IS-4

[tankme]

While working on the IS-7 I thought to myself it would be a good time to start printing his sibling...the IS-4. And I couldn't help but post one of the siblings after getting the side hull off the printer. The turret is currently printing and it's going to take over 9 hours, but it's printing all in one piece which is why even my speed demon printer is going to take a long time to print it with 0.16 layer height. There is a pretty large gap between the upper deck and the sloped sides, but that's because I haven't cleaned up the flash around the edge yet.



Some of the pieces are way to big or at the edge of my printer bed so the designer (Inkor) has kindly cut them up so most of these were printed in sections. The upper deck was in two pieces. Since it's printed in PETG, a little MEK was used to join the two pieces. After joined I used some failed flat print plastic, cut it into strips, and MEK'd it to the back of the deck for additional strength. The MEK melts the PETG pretty well. Just have to be really careful with the stuff it's pretty nasty.



Before:



After:



Derek

[clyde66]

Derek,Your 7 is amazing. Is the new project a design by RC3D(found on Cults)?

[Herr Dr. Professor]

Yes! This will be a great build to watch! By the way, MEK is getting hard to find around here (upper Midwest). Where do you get it?

[tankme]

Derek,Your 7 is amazing. Is the new project a design by RC3D(found on Cults)?

No, but I do own the files for his IS-7. I like some of the parts on his better than mine so I'm mixing and matching. My IS-7 came from Drupelo RC in the Czech Republic. I bought it from Lukas before I had a 3D printer of my own.

Yes! This will be a great build to watch! By the way, MEK is getting hard to find around here (upper Midwest). Where do you get it?

Amazon of all places. This is what I'm using, but I should've bought the smaller can. I put just a small amount in the dropper bottle at a time as the stuff is highly flammable and evaporates really fast. The can has a metal seal on it that has to be puncture so I just put a hole big enough to get my pipet in there to draw out a small amount.

https://www.amazon.com/dp/B079J3T9YV?ps ... ct_details

And after 9.5 hours of print time and 195G (mostly supports) of filament later...a turret emerges. Yes, I tried tree supports and got two 6 hour in failed prints as the tree supports would come off the bed mid print.




Here it is almost all cleaned up from the supports which was a PITA BTW. PETG supports are notoriously hard to get off. The support surfaces are really rough, but they won't show in the finished tank.




And of course a side by side of the two brothers from two different mothers:



Printer is already hard at work on more parts.

Derek

[Herr Dr. Professor]

I would think that the supports would be relatively easy to cut off a turret print. I have cut supports off 1/16 figures, sometimes with disastrous results because the supports attach to parts of the figure too delicate to take the shock of even initial cutting on the end away from the figure.

[tankme]

The issue is the material. PETG supports like to stick. They can sometimes be bad to get off. It's not the most forgiving material to print either, but it will handle the heat and that's what I need it for.

Derek

[Raminator]

What an absolute beast, tankme. You're going to need an IS-3 and T-10 to complete the family, now!

[tankme]

Yeah...I've already been thinking about that, but I haven't found any decent models of each yet. The IS-3 kit from MK is based on the KV-1 chassis and it's resin so that's a no go for me. Lukas from Drupelu RC has an IS-3 and a T10 (IS-8) that he built for himself, but since the war in Ukraine broke out he's been hesitant to do Russian tanks. Neither tank is a "kit" like the his IS-7 was...yet.

Derek

[tankme]

Made quite a bit of progress on this guy recently. At least most of the major components are printed. After doing the initial assembly I really didn't like the fit of the deck to the sides so I reprinted the sides from the new Sunlu PETG-G I got. The Bambu had a few firmware updates that seemed to fix the initial issues I had printing them so I was able to print them as one piece now. The fit is so much better. This is how she stands at the momemt. That pile is 160+ track pieces. Not a lot of post processing done yet. I wanted to get the mechanicals and physical build out of the way before disassembling it to do the finishing work.



Better shot of the track quality. Printed them 54 at a time and it took 6.5 hours per sheet at a 0.08 layer height. They were printed at an angle so that both sides had good surface quality. Only supports used were specified as "critical areas" and only touching the bed. They came out quite nice. I can't assemble them until my spring steel wire arrives on the slow boat from China.



Close up of the muzzle brake:



View of the suspension. I have some gearboxes arriving today so I can get the sprockets mounted soon.



Another side view.



Rear view.

[Ecam]

Masochism comes to mind when I look at all those track links!

Fabulous work...