3D Printing

[SteelRat]

Really just after some general advice when it comes down to getting in to 3D Printing, particularly in respect to RC parts, especially for custom chassis where bits are either no longer available, or simply don't exist for the specific application.

Specifically:

* Recommended printers - cheap and cheerful / "don't spend less than £x if you want something half decent"
* Materials to print in that lend themselves well to RC parts
* 3D modelling software.. is Blender any good for this? (I've used it a fair bit for other stuff)

I'm still finding my way around Google searches to find out the right questions to ask, if I'm honest, but some pointers in the right direction from any of you that have some experience would be gratefully received.

Cheers!

[ad456]

Yeah, Blender will certainly do the job, I’ve designed tons of stuff in it(the latest being a mod clod chassis, suspension arms, axle link mounts, etc). Once you get the hang of it you can design fast. It’s not proper CAD but it’s a great 3d modelling software and does a million other 3d things, plus you can’t beat the price. I’ve been using it for over a decade but only know what I need to. Plenty of tutorials on YouTube as well so you won’t be stuck going “how do I do xyz?”
 

I have a cheap(£130 4 years ago) Prusa i3 clone. It’s been a nightmare at times but still works well and I’ve learned loads from it so regret nothing but if I was buying another I’d definitely not go cheap. You certainly get what you pay for.
 

I print in PLA which is fine for accessories and non structural stuff but a stronger material is needed to hold up for anything else. My machine and setup doesn’t lend itself to other materials at the moment so have never gotten further with that part. I believe PETG, ABS and nylon are the go to structural materials. They will all have their own unique properties for printing and when printed.

[SteelRat]

Thanks @ad456.. so yeah.. I've tinkered with Blender more recently for tweaking 3D files of sim racing mods and you're right, the level of info and tutorials and whatever is fantastic.  That , the price and the fact that I wouldn't be learning completely from scratch again is why I wondered if it was any good for 3D printing.. glad that it is!

I think the tricky bit is going to be deciding on what printer to go for.  It's one of those bits of kit that you can almost pay what you want, but it's difficult to know at what point is the real "minimum" to have a better initial experience, but I guess it's equally true that it's also the case that not only are you going to have issues at whatever price point you drop in at (learning curve), but also just because you spend a decent amount (I was thinking in the region of £4-500) it's not going to guarantee rainbow pooping unicorns!

Thanks for the pointers in terms of materials too - I'm assuming the choice of machine will also be governed by the type of materials that I choose to print with?  Do you know if that also governs what the entry level price is going to be (perhaps, different materials have different pre-reqs to make them printable, which in turn could require more expensive or complicated parts?).  Is it also true that the more different materials a particular machine can print, the more expensive it's likely to be?

[ad456]

No worries @SteelRat, it’s a rabbit hole in itself. I went with mega cheap due to budget and being unsure of wether I’d stick with it. The i3 being open source and running a marlin firmware was how I managed to get it to run properly. No worrying about modifying breaking a warranty or even if the company goes bust means it’s a lemon. I’m regularly looking at a genuine Prusa i3 for my next one but I want a 300mm bed. 
 

Most printers will print a range of materials at your budget level. The more fancy materials sometimes need some extra heat or the like to print but PETG is what you might want to likely work with as a benchmark. You can check out various materials other RC folk use and see if there’s anything that needs a special process that you may need to factor for but I think ABS, nylon and PETG just need a bit extra heat so check the specs on some filaments and then decide what the top end is. Most beds are heated and a part cooling fan should be helpful too. 

[silvertriple]

6 hours ago, SteelRat said:

Really just after some general advice when it comes down to getting in to 3D Printing, particularly in respect to RC parts, especially for custom chassis where bits are either no longer available, or simply don't exist for the specific application.

Specifically:

* Recommended printers - cheap and cheerful / "don't spend less than £x if you want something half decent"
* Materials to print in that lend themselves well to RC parts
* 3D modelling software.. is Blender any good for this? (I've used it a fair bit for other stuff)

I'm still finding my way around Google searches to find out the right questions to ask, if I'm honest, but some pointers in the right direction from any of you that have some experience would be gratefully received.

Cheers!

If you want to print chassis, size matters. That was my approach initially. I got an Ender 5 plus for that reason.

Later down the line, after few months, and with the experience of online services to print in materials I can't print myself, I would say any size could be good enough as long as you can print PLA properly. Approach would be to use PLA to validate dimensions, and use an online service to print in MJF PA12 after the dims are validated (and you don't need to print the full part for that, you can do it in pieces).

And for 3D modeling software:

- Tinkercad is an easy web based tool, with the possibility of free account, very intuitive and user friendly.

- Fusion360 is much more powerful, allow as well for a free account for personal use, but is less intuitive and user friendly, and it requires a computer a bit powerful...

 

Hope that helps.

[SteelRat]

Thanks both.. some really great tips and definitely given me stuff to look at!

Firstly, it shows that my budget doesn't need to be as high as that to get what I'm after.  I'm not really after printing chassis; more things like axle arms or shock towers, or details like rear engine cages, engines, drivers - that sort of thing.  Looking at a couple of videos and various bits, other than the bed size it seems the only other limitation is imagination!

Ender 3 Pro is getting a lot of love in the bits / reviews / videos that I've seen.  Prints in PETG (seems to be fairly universally best material for strength, even if it's a bit sticky) , requires assembly (but I wouldn't be here if I was afraid of that )  and even on Amazon comes in at half my original budget "punt"

 

(*Edit* - I can't believe I originally came back on TC after a 10 year hiatus to sell stuff for a clear out and I'm already looking at things to make more!  Not saying the bug has re bitten, but it's definitely having a nibble!)

[Honza]

I'm using original ender 3 - it needs careful assembly and manual bed leveling might be annoying sometimes, but it does decent job with PLA and PETG after some tinkering. However, it's Bowden, so it's limited to ~250C temperature - that means you can use PLA, PETG, maybe ABS.

I used PLA+ on arms and other parts and it seems to hold well (normal PLA appeared to be too brittle). I even managed to print PETG 0.8 gears with 0.2mm nozzle in a reasonable quality. 

[silvertriple]

47 minutes ago, SteelRat said:

Thanks both.. some really great tips and definitely given me stuff to look at!

Firstly, it shows that my budget doesn't need to be as high as that to get what I'm after.  I'm not really after printing chassis; more things like axle arms or shock towers, or details like rear engine cages, engines, drivers - that sort of thing.  Looking at a couple of videos and various bits, other than the bed size it seems the only other limitation is imagination!

Ender 3 Pro is getting a lot of love in the bits / reviews / videos that I've seen.  Prints in PETG (seems to be fairly universally best material for strength, even if it's a bit sticky) , requires assembly (but I wouldn't be here if I was afraid of that )  and even on Amazon comes in at half my original budget "punt"

If you are considering parts such as shock towers, arms and so on, ideally, you would prefer to print in Nylon/CF material rather than PETG. It requires en enclosure, and probably a direct extrusion (as opposed to the bowden extruder you have on a Ender 3 Pro). And that would give you more possibilities in terms of material (flexible material such as TPU, or Carbon filled materials, requiring more force to get thru the nozzle)...

As per my short experience, PETG strength works up to a certain point, but for durablility, there is certainly better...

[Collin]

I have to strongly agree with @silvertriple

Go and get youself a printer which can do PLA, make your own parts until they fit and THEN! you let them make from an industrial printer.
Everything else, and thats my own opinion and experience, will not make you happy. A main reason is, that so many of our RC parts have holes or roundings or bearing seats in two or even three axes. This is the weak spot of FDM (homeprinter with filament). Only a few sides of the object look great and have the stability you need.

Also PLA is easy and quick to print, low oozing and just nice as it is, perfect for prototyping and much stronger than many people say. It just does not like strong UV light and heat.

Beside large parts, I print so many spacers or stencils for drilling holes in carbon plates ect. You just think about redesigning rare plastic parts and you figure out, how many little helpful parts you can print.

Go and buy you a printer. If you have money, go for a prusa mk3. If you dont have, buy a Creality Ender Pro (dont know which model exactly) which a friend of mine is using in his modelshop (huge architacture models). His prints are fine, the printer was cheap and is reliable in a very dusty space plus it is realy silent.

 

[SteelRat]

Thanks @silvertriple and @Collin .. I do take on board what you're saying.

One thing I don't understand though and that's the thing about using a 3D printer to print PLA prototypes which you use to perfect the base model file which you then use to to send to an industrial printer to print in a more resilient material.  Isn't that a bit of a false economy?  How much do these companies charge to do those sorts of prints?  I mean I guess if you print something in a weaker material, break it constantly and have to reprint it then sure, that makes sense; it's better to only have to print something once in something sturdy than constantly have to reprint weak stuff.  And I suppose you have to realistically think "how many of these parts am I actually going to make?"  Probably what would also govern that (for me) is how likely or frequently those "weaker" parts are going to break.

How tough do you guys run your cars?  And that's a serious question.  I've only ever used my Traxxas Slash for doing jumps and the like and I rarely break things on my Tamiyas.

[silvertriple]

54 minutes ago, SteelRat said:

Thanks @silvertriple and @Collin .. I do take on board what you're saying.

One thing I don't understand though and that's the thing about using a 3D printer to print PLA prototypes which you use to perfect the base model file which you then use to to send to an industrial printer to print in a more resilient material.  Isn't that a bit of a false economy?  How much do these companies charge to do those sorts of prints?  I mean I guess if you print something in a weaker material, break it constantly and have to reprint it then sure, that makes sense; it's better to only have to print something once in something sturdy than constantly have to reprint weak stuff.  And I suppose you have to realistically think "how many of these parts am I actually going to make?"  Probably what would also govern that (for me) is how likely or frequently those "weaker" parts are going to break.

How tough do you guys run your cars?  And that's a serious question.  I've only ever used my Traxxas Slash for doing jumps and the like and I rarely break things on my Tamiyas.

Well. First, I can only 100% agree on what @Collin said about FDM and resistance of the printed parts. It only works in some axis, not on the z axis, generally, so you would play with orientation to do a compromise. MJF PA12 or SLS PA12 are printed using a technology that offers resistance in the 3 axis, which is also dimensionally more accurate in all direction, and further allows things that FDM does not. There is a lot of explanation on how it works on iternet and would not detail that: you just have to search. The thing is the printer capable to do this are much much much more (even more than this) expensive than a FDM home printer.

And as regards of the printing services, they have all a way to establish the cost:

• some are dealing with an initial cost for each prints, and then the way to go is to group parts in a cluster or a box to reduce the cost
• some are dealing with a cost based on the time the print
• some are doing a combination of both
• some are highly expensive

Just as an example, I printed a set of part in a box to reduce the cost of my parts at some point (have a look in my Marui thread, there is mentions of it): compared to the cost of each print taken separately (about 200+taxes+shipment), it was much cheaper to get the same result (about 60+taxes+shipment). Since then, I'm trying as much as possible to group my prints, and to do evaluation of cost on multiple services, setting my prints in different ways: clusters/boxed/separately/... And my final parts are much more resistant than FDM parts (which will take time on the printer each time you have to reprint because it's broken)...

For your last question, my son broke in the first 6 months of RC runs : a brand new Traxxas slash twice and a DT03 chassis once. It depends a lot of things : environment is one thing, temperature and storage is another thing. That being said, I made some test with both PLA and FDM arms : they won't be as resistant as original Tamiya plastics, unless you increase the thickness with a 100% infill: it's not always possible: and there is always limitation to what you can do because of z axis resistance lower than x/y resistance... And I know it is a lot of things to take into account: I did not had those elements in mind when I started to work out the choice of my printer one year ago.

[Honza]

I use my 3D printed parts in a rally car, with lot of rollovers and some jumps - so far, I didn't break any PLA suspension part (front arms took some direct hits, but being a rally car, they were relatively low speed). And when I tried to break one of the prototype part with pliers, it took considerable force.

For PETG, I have center part of MF01X printed out of it and managed to brake it - however, during the crash, original rear part cracked in similar fashion - PETG part was intentionally designed with same material thickness as original polycarbonate part to test its strength.

As long as you design your parts with weaker materials and lower strength between layers in mind, FDM is usable. Only if you need part that cannot be optimised/strenghtened, is too detailed or needs to withstand higher temperatures, then it's time for SLS prints.

[Collin]

First row: SLS/MJF (Laserprinter):
Second row: FDM (Filamentprinter):

 

I think this explains everything pretty good in one shot. I dont want to have things breaking, even if I could reprint them again. 3D printer need a lot of resources, so its not the Idear to permanently reprint broken things, its the idear to make small patches or single prototypes.

Any idea about the PA12 nylon powder? It touches and feels like liquid, such a fine grain. That's the real microplastics, pure poison somehow. Also the FDM printer send lots of microparticle to your environment. I really print carefully, trying to avoid missprints through clean prepairations, its not only your own time you waste. One of those bulkheads take about 3h at the homeprinter.

This is my Dyna runner. Its 99% 3D printed parts from PA12 nylon:

 

And this is where I run it : ) HARD!

[SteelRat]

8 minutes ago, Honza said:

I use my 3D printed parts in a rally car, with lot of rollovers and some jumps - so far, I didn't break any PLA suspension part (front arms took some direct hits, but being a rally car, they were relatively low speed). And when I tried to break one of the prototype part with pliers, it took considerable force.

For PETG, I have center part of MF01X printed out of it and managed to brake it - however, during the crash, original rear part cracked in similar fashion - PETG part was intentionally designed with same material thickness as original polycarbonate part to test its strength.

As long as you design your parts with weaker materials and lower strength between layers in mind, FDM is usable. Only if you need part that cannot be optimised/strenghtened, is too detailed or needs to withstand higher temperatures, then it's time for SLS prints.

 

Thanks @Honza - that's a useful insight.  Interesting that you're having success with PLA and particularly interesting that your PETG part failed in the same way as the original part!

[SteelRat]

@Collin there is of course no doubt as to the additional strength and quality that your preferred method of printing generates - that Dyna is a work of art!  It's also clear that if you're running cars at a proper track, you're going to need additional performance and reliability.  Whilst I appreciate that is probably the ultimate goal, I'm not convinced that level is really necessary for me?  This thread has really shown the sheer range of "the possible" for 3D printing and as was indicated at the top of the thread by ad456, it's a real rabbit hole.  RC parts isn't the only application I'd be using for 3D printing either.  I think I'm going to start with an entry level machine and experiment just so that I can learn about the basics.  If I get to the point where I want to upgrade to the sorts of applications and things that you're talking about, then at least I've got a direction for that as well!  I do definitely appreciate you taking the time to share your experiences though.

[Honza]

9 minutes ago, SteelRat said:

Thanks @Honza - that's a useful insight.  Interesting that you're having success with PLA and particularly interesting that your PETG part failed in the same way as the original part!

I think that part of reason why they failed in similar fashion is design - This part is ideal for FDM, as all holes and forces in its application are in XY direction none in Z. Also, original part cracked, but didn't break apart like the printed part.

I use ST-PLA (or PLA+), which is less brittle variant of PLA. It has advantage over PETG in better layer adhesion - I even managed to print functional ball diff outdrive out of it, which required some 50kg of  tension being transmitted through small volume of material, although I doubt it'd actually worked with power applied to it.

But PLA becomes soft at some 60°C and I'm not sure if its properties will remain as good over time - some filament rolls I have became more brittle as they absorbed some humidity from air.

[SteelRat]

2 minutes ago, Honza said:

This part is ideal for FDM, as all holes and forces in its application are in XY direction none in Z.

This is the particularly interesting part and I guess applies to things like suspension arms.  Whilst the holes go through on the Y axis, the forces on them act on the Z axis, which is where the weakness is.  A guy on YT that I saw who was extolling the virtues and reliability of printed parts for his Slash made a point of making sure that his in fill was set at 100% and also he was printing the arm at a 30 degree angle, so the angle of the forces acting on it never lined up to the plane of weakness.  I wonder if that would also be true if you printed it edge ways.. so that the thinner long edge of the arm was facing downwards.  Your Z axis in that scenario would then run along the longer width of the arm where fewer snapping type forces would be acting.

[Honza]

41 minutes ago, SteelRat said:

I wonder if that would also be true if you printed it edge ways.. so that the thinner long edge of the arm was facing downwards. 

I meant that holes go through XY plane.

That's how I printed them - standing on long edge and using shafts with e-clips and nuts to share some forces in Z direction. They'd probably split around holes if I printed them flat, exactly for reasons you mention.

Full infill wasn't needed, I just added wall thickness

[SteelRat]

All interesting stuff!  Think I'll have to get myself a printer fairly soon and start experimenting.

[Collin]

49 minutes ago, SteelRat said:

All interesting stuff!  Think I'll have to get myself a printer fairly soon and start experimenting.

You will never regret it.

[markbt73]

For what it's worth, I'm about 2 months into 3D printer ownership myself. I bought an Ender 3 V2, and had no trouble assembling it or setting it up. I'm using Cura for slicing files, ans haven't tried designing anything myself yet. Only used PLA so far. Take a look at my CARToons Corvette build and you'll see the supercharger and scoop I printed for that one.

[SteelRat]

2 hours ago, Collin said:

You will never regret it.

I've just bought one.  It comes on Friday.

 

[SteelRat]

27 minutes ago, markbt73 said:

For what it's worth, I'm about 2 months into 3D printer ownership myself. I bought an Ender 3 V2, and had no trouble assembling it or setting it up. I'm using Cura for slicing files, ans haven't tried designing anything myself yet. Only used PLA so far. Take a look at my CARToons Corvette build and you'll see the supercharger and scoop I printed for that one.

Love that Vette Mark.. love creative thinking and ideas like that.. just brilliant and the blower looks superb!

[Collin]

29 minutes ago, SteelRat said:

I've just bought one.  It comes on Friday.

 

That was quick! which one did you bought finally?

[SteelRat]

15 minutes ago, Collin said:

That was quick! which one did you bought finally?

I went for the Ender 3 Pro bought a spool of filament and some vacuum bags to minimise water / humidity contamination for storage when not printing.  I figured it's the sort of thing I could spend ages agonising over, so sometimes it's just best to jump in with both feet.  That machine seems to be a popular choice, is well recommended, much less than the expected price point and even has the scope for Nylon/CF printing further down the line (you can print out an adapter for the 300 deg head needed as well as buying enclosures for it - if I get that far, it may not be the best choice for it, but I'll cross that bridge when / if I get to it).

The more I've read / seen / browsed about 3D printing, the more I want a piece of the action.  Printing not just RC bits, but figurines, little nik naks for the passion that sorta replaced RC, which is Mountain biking; the applications are endless and I can well imagine it being one of those, "How the badword did I survive without one of these things?" purchases.  I'm relishing the learning curve too!