Silk789

Hi guys,

I hope its ok to ask this question but I am planning to take the dimensions of a 1/35 model, scale it up, and then Print almost everything from it to build a complete RC Tank.

actually I plan building a French hotchkiss H39
so it will be relative small and not as heavy as a big tank.

tracks I would use the plastic ones for the Opel Maultier from Asiatam.

so what would u think, which Material should I use?

is it better to use shapeways or to buy an 3d printer for my own?

greetings

Crius

Either pla or ABS will work fine for printing a tank, and I would definitely get my own printer. For the price of a dozen parts from shape ways you can buy your own printer and all the plastic you need to print several tanks.

Ex_Pat_Tanker

Hi Silk,
I'm also interested having the H39 in 1/16th, what CAD package are you using? I use Autodesk Fusion 360, as its free and quite similar to what I use in my day job...

Personally I'd consider using shapeways for small fine detailed parts as the affordable FDM home printers aren't up to producing intricate items like headlights or brush guards, and the SLA resin printers are still quite expensive right now. (And if you did get an SLA printer, you'd still want a FDM type for printing the bigger parts anyway). I would not go to shapeways for the whole tank to be printed, as it would be cheaper to buy the printer! (and also you'd be able to trade your CAD model with others and print out their designs )
I use a couple of Creality CR10s' for PLA work and an Anet A8 for printing vehicle tyres in TPU. The CR10s' are a bit more money (around 400 to 500 euro's vs 150 for cheaper printers), but they have a large print bed area of 300 x 300mm which you'd need for a bigger model like a tank. The Anet has only 200 x 220mm, and only really suitable printing for Dodge 4x4's and jeeps. Print quality is about the same for either machine, using better quality filament makes more of a difference. I print very fine layers of 0.06mm and with a low speed of 30mm/sec (transition speed is about 45 to 60mm/sec) - printing at those settings can take many days but the quality you get makes it all worth the wait as there is very little need for part clean up.

PLA is fine for making models - my only caution would be to keep in mind that the parts will warp if left in the sun for prolonged periods think about thickness, stiffening ribs, etc, some of the hoods on my Dodge and GMC trucks got 'sunstroke' at the last show
( to be fair resin castings can also suffer on hot days) ABS lets off toxic fumes when you print it, and having spoken with a few folks I'm not convinced that its actually any stronger, unless you are maybe printing tracks - I haven't tried that, so I can't speak to that topic, generally PLA does not have a lot of strength in thin sections, so maybe ABS would be better there?

PLA sticks together well with standard plastic model glues (I use plastic weld), and can be bonded to styrene just as easily - I'm my expereince ABS can be a little tricky to stick to styrene unless you are using some of the nastier stuff like Plastruct Bondene (MEK based) which doesn't seem to be as easy to get here in Europe as it was in the US. PLA wet sands ok with 240 grit or finer, and I use ordinary plastic car bumper primer for as a base apint coat, which sticks pretty well and can be lightly sanded and recoated if you really need to get a smooth finish.

If you need any help or advice feel free to give me a shout, good luck with the project

(Another possibility for tracks: https://www.robotshop.com/uk/tamiya-...wheel-set.html - not as good as the asiatam ones, but might be more readily available?)

Crius

I've been looking at SLA printers myself, Ex-Pat, for exactly the reason you mentioned, better quality for fine, small parts like head and tail lights, and they say an SLA printer will make a much better tire. The only hold up is price. Even a small SLA printer starts at around $400 USD. Better save my pennies, eh?

Ex_Pat_Tanker

I think in 3-4 years we'll see much more affordable SLA units come along, that will be less hassle to use and have bigger print areas, so I'm going to wait for them. Don't forget that what we are using today used to cost $3k or more not so many years ago, and I'm hearing talk that we're not too far away from the possibility of metal laser sintering machines for home use...

Nope, for now I'm quite happy to go to Shapeways for the occasional detail part for now. I think they will soon have to start lowering their prices to something more reasonable, or else they will be out of buisness in 5 years or so...

casualTanker

PLA is fine for most parts, is easier to print and better for your health than ABS. For high-stress parts, PETG is a great choice, and is even healthier to be around than even PLA. Anything beyond PLA requires that you buy a printer with a heated bed. DIY3DTECH did a series of YouTube videos on 3D printing air quality. Bottom line: avoid ABS if you care about your health. PETG does anything ABS does, and more. It's stronger than PLA, but a bit more tricky to print.

While SLA printers a coming down in price, the resin is still way more expensive than filament for an FDM printer, and waaay more messy. I agree that Shapeways is pricey, but they do offer great quality and some materials you won't be printing at home anytime soon. There's desktop laser sintering tech on the horizon, but I wouldn't hold my breath; it's gonna cost an arm and a leg for some time, and I would be very wary of breathing the dust. Better left to the pros for some time.

Silk789

Hi guys thanks alot for you answers.

So did i got it right

PETG would be the best, after it would be ABS ?


I would draw the parts on Solidworks, cause I had it 3 years before in technician scool.

but till now I didnt do anything in this direction, first I went to know if it's posdible/doable before I take my time drawing it.

greetings

casualTanker

Ex_Pat_Tanker

@ Casual - What would you use to glue PETG together with? Its not something I've ever worked with before.
I just checked the prices of a reel and it is about the same as PLA - I guess even if it is harder to glue, using it for tracks would still be an option?

@ Silk - Honestly PLA can do what you need, you don't need to mess with ABS. I had the exact conversation with a friend when he was looking out for my first printer for me, and his arguments against ABS were 1) the fumes, 2) its more brittle than PLA, and 3) you need higher bed and print nozzle temperatures, which increases your electricity costs (and make you more likely to burn yourself if you touch the print bed while fiddling with the machine set up!) and shorten the life of your power supply. (I just look up PETG printing - its almost as bad as ABS for temperature requirements )

I've now done 4 outdoor shows this summer with my PLA trucks sitting out all day in the sun, and apart from those thin section parts that had warped (and which are easily modified in CAD, and replacement parts printed) they have all been fine.

casualTanker

Ex Pat: Superglue works, especially if you're careful to clean/sand the surfaces. Epoxy (Araldite) is better. SciGrip 4 explicitly lists PETG, but I've got no personal experience. My preferred solution is to combine with good 'ol nuts and bolts, which works especially well if they're provided for at the design stage. Tapping screws with appropriate size holes and surrounding material. Machine screws with inlaid SQUARE nuts. The latter saves on the design stage, and also helps actually locking in the nut at small sizes like M3, M2.

Forgot to comment on use of PETG vs PLA. I don't see a need to use PETG for the whole tank unless you want to make life easy and stick to one type of filament. It's tougher than PLA, which may be useful for road wheels, tracks, or detail parts that could snap off against grass/shrubs. Maybe also some internal stress parts. My use cases are actually not in tanks at all so far: high impact parts on (fast) RC cars, planes/drones. As such, I'm yet to prime and paint PETG and can't comment on that stage - but PETG is what's in your plastic water bottle, so easy to experiment with both glue and paint. Bottom line is that if you get a good printer (with heated bed), you buy yourself freedom to do more types of parts (eg flexible filament for tires) - and in my view; why use ABS when you can use PETG.

Additional comment on having your own printer vs using Shapeways: "measure twice, cut once" in 3D printing world works out for me like "measure twice, print 10 times". This applies especially when you want to interface a new part with an existing construct, where you don't have full control of tolerances between parts in your CAD app. So even if you want to use Shapeways for high quality parts, you'll save yourself plenty of grief by prototyping/honing the part on your own FDM first.

Wozwasnt

I found PLA to be good for just about anything tank related. I have used ABS but found it to be much more problematic with very little benefit.
My PzI is PLA and thats been running around with no problems for nearly three years now

-

Silk789

Wow nice

thanks alot looks amazing

did you printed your pz1 by yourself or shapeways?

Wozwasnt

Printed it myself except the MG's (which I got off SW).

Just reread my blog and some of it was done in ABS-
Warren Hudson Modelling: 1/16 Pz Kpfw I AusfB (build)

Also did a Pz II-


Warren Hudson Modelling: 1/16 PzKpfw II Ausf F (Build)

I gave up using ABS as it was more trouble then it was worth and PLA wasn't disintegrating in the heat or damp like some people suggested it would do.

Shorty54

This is all great info, as I am looking to get a 3D printer soon.
My biggest concern was printing with ABS, but after reading this, I dont think I see any reason to.
That also makes it a little easier on narrowing down on a printer.
Enjoy,
Shad

casualTanker

Woz: ABS or PLA for the tracks, and how do they keep up? Also, assume you used metal pins for the track pins. Tracks seems to me the most obvious candidate for PETG (or nylon) on a tank, as it's more pliable than PLA. Assume the relatively low load on the PzI tracks helps...

Wozwasnt

Think I used ABS but on one and PLA on another. They hold up OK. They do snag on carpet but so far I've not had any breaks.

50koruny

Try to use ASA instead of ABS.Its so much easier to print and have better properties.ASA is on the same base like ABS.Same properties.But much less cracking.
My first printed tank was from PLA and was melted on the sun very fast.