Honza

The lower ambient temp increases warping of the print, if you start with bad adhesion, it makes the issue worse. It shouldn't have any effect on measurements, because the printer preheats the bed first. Yes, it's definitely too high on both prints. I'd guess around 0.1mm. There should be no visible gaps. The arm looks better thanks to long regular infill lines, but I'd say that the first layer is same as on Benchy. If you got more sheets with the printer, check the menu, if you got right preset for the smooth sheet. Then proceed with the first layer calibration , or check the first layer while it's printing and tune live-Z. I don't think you need to print another Benchy, you've already identified the issue. That is, unless your target is to have one completed 😃

The prints shouldn't come off that easily. The smooth PEI sheet ha very good adhesion for PLA (and too good for most other materials), so there's some problem. Take a look at the bottom, check if you have nice, uniform layer. My guess is that the initial layer is set too high, which is visible on the bottom of the bow. Unlike newer printers, that tap the print sheet directly, MK3 is sensing the steel plate below, and the offset has to be set manually. Check this article https://help.prusa3d.com/article/live-adjust-z_112427 Also, here's manual for Benchy to evaluate your result: https://www.3dbenchy.com/wp-content/uploads/2015/04/3DBenchy_Broschure_3DBenchy.com_.pdf Also, if the nozzle is crashing to the print regularly, it's sign if over extrusion. Check some tutorials how to tune flow.

Wow, it's been a while since I posted in this topic. Well, maybe because there are not many updates, the car just works. The only update were XV-02 shocks - I got them cheaply, so why not? But over the course of last season I noticed, that the center diff started to act weirdly - it needed significant effort to get it unstuck and rotate. Last week, I found out why. Well, turns out that it's not the best idea to use 3D printed parts as friction pads 😁 I reprinted the parts and added a teflon shim as a quick fix - but I'm aware that it needs a complete redesign - something I had in mind for a while. The new design requires helical gears, so I tried to do a little test of design and printing - it turned out great! They are just a little hairy because of wet filament. For reference, those gears are 9mm in diameter, module 0.8.

Check the article I linked earlier. Without modifications, you can fit 35T/48p or 48T/64p. For larger pinions, you'd need to file part of the chassis.

Great that he listed through the manual. Now I know that the rear gearboxes are a separate U-parts tree. I wonder what's the length of swing shaft. Unfortunately it's not covered in the video and the resolution is too low to make up the PN from the manual.. I'm disappointed with tires though.. I hoped they'd at least make softer compound - that really changed standard rally blocks from unusable to great. Otherwise, it really is just smaller XV-02 😃

I don't have experience with these, since I haven't work with materials that are moisture sensitive, I just throw a roll into the drier once in a while and it will do for a few weeks. From what I've read, if you start with dry filament, the storage boxes should keep it dry, but some, especially cheap, material is wet even new and dessicant might not be enough to absorb all moisture.

Right choice, PLA+ can be used for functional prototypes, it's not as brittle as the regular one. PETG is better for final parts, but it can be sticky, which might be an issue on finer details. But with right settings, it can be printed with almost uniform strength even in Z-axis. One notice: never print PETG directly on the stock smooth PEI sheet. It can ruin it fairly quickly. There are companies that collect waste filament and recycle it. There are even ways to build your own extruder for recycled filament, if you want to invest into that. One another part to add to your list - filament drier. PLA becomes brittle while it absorbs moisture, PETG becomes much more stringy when printed and very wet filament will cause voids during printing. If you don't want to invest into specialised filament drier, a cheap food dehydrator with temp setting will do. Enjoy your new toy! 😁

It's size of teeth (and 68T, marked on TT-02's spur means number of teeth). Tamiya uses metric 0.6mm profile on TT-02, 48p is equivalent of 0.53mm - the lower number means finer teeth. A 48p equivalent of TT-02's m0.6 68T gear will have around 77 teeth.

That also requires adjustable motor mount to set-up proper mesh Although 48p can work with the original mount, the adjustable mount provides more options and precision.

I'd be happy with a re-release of TB-03 with gear differentials and TRF420 suspension 😃

Not exactly specific, but I'd like to build another mini rally and this chassis opens numerous possibilities: - the separate rear gearbox, if it's easily available, could be used to make a custom composite chassis for XV-02/XM-01 - XM-01 suspension, which is compatible with XV-02 mounts, could be also used to make a mini XV-01 - uprights compatible with M-07/8 would make them even more capable as rally chassis

All I need to know at this point is, if the rear diff case is available as a separate part and if the uprights are compatible with M-07/8 😁

TB-series were great for that. Combination of fully enclosed transmission with fully adjustable suspension and good materials. Unfortunately they are not made anymore. It's been replaced by other three shaft-driven models, neither of which fully replaces it. TT-02 lacks the quality materials, TC-01 is too complex and heavy (though, its suspension apparently provides enough travel to run as a rally car) and XV-02 has higher CG and rally-optimised suspension, which isn't the best choice for high traction runs.

MB-01 and BT-01 have an extra differential gearcase within the bulkhead for this exact reason - to easily swap direction. The whole chassis is rotated when swapping between front and rear motor position. That means, there's no space to put a second motor. Unless you somehow Frankenstein two "motor" chassis halves together.

Only thing I can think of is cooling improvement by using the motor mount and a strut base to mount the transmission assembly to the bumper plate - something similar to XV-01/M-06. But that would mean a major redesign.

Dusty workshop is not ideal, but the bigger issue is temperature - open printers tend to be quite sensitive to low temperature and temperature changes. If you'll print only pla/petg, it's safe to leave them inside (although It's advisable to keep it in an unnocupied room).

MK3 became obsolete more in terms of electronics, than mechanics, which are very similar to MK4 and solid. Unlike cheap Enders and similar entry models, there are not really upgrades needed to make it print reliably. The biggest disadvantage is its driver board that runs on 8-bit MCU, which limits its speed, connectivity and its UI is ugly. It's biggest disadvantage for your use case is lack of enclosure, which is needed for materials that require higher temps. But those are common on printers around price point of a new MK4. That was main appeal of Prusa. Instead of going through community forums to get firmware and slicer profiles that actually work, or even making your own (I owned an Ender before and it's been like that), Prusa continuously worked on everything to make their printers work seamlessly (although sometimes a while after they sent long delayed printers to customers cough cough XL). Others have caught up recently, but Prusa still generally does great job, with MK3 receiving updates relatively recently. Of course, that doesn't mean that it will just print anything that you throw at it. There are some things you need to thing about during design to make it print faster, with less supports and with right orientation. But generally, RC parts already have right shape for printing. You can still tinker with your printer if you want - there are things that can be upgraded - but you don't have to. Tamiya uses ABS, polycarbonate, nylon - those are available, even in fiber reinforced variants. But those are the exact materials that need enclosure and even then, PA and PC is not trivial to print. I use PETG, which is easy to print material strong enough to make a working model, but it's also quite brittle. There's also PCTG, which promises mechanical properties of ABS with printability of PETG. But I still didn't get to unpack my roll and test it. The biggest issue of FDM is Z-axis strenght. Some materials are better than others, but generally, bond between layers is much weaker that other directions. That's something that must be thought out during design. I'm not a type of person would would spend time printing various figures. I see it as waste of print time and material. Even then, my printer runs very often even if I don't work on any project, doing just that - various flexy animals are very popular among kids and even adults, and 3D printed figure stil has unique feel, so it's great little gift. There are opportunities for various functional prints, too - holder here, cover there, replacement for some obscure part that disintegrated due to crap material... And suddenly you printer has days of print time in a matter of weeks, even if you think it barely runs. So in the end, if you have good deal on a printer, get it. You won't regret it. It's a really useful tool.

That's reinforced nylon. GF gives the gray grained look, so I suspect that the old part is the same material. It's possible that they changed amount, type of fibre material, amount of pigment (PA is naturally white) or injection procedure, which resulted in different colour. If they reduced amount of GF, the darker parts would be more flexible. Otherwise, there shouldn't be a big difference.

Do you still have sprue? Material type (>ABS< or >PA<, for example) should be stamped somewhere.

Just FYI, I got to my M-05 and tried to measure the distance. Unfortunately, the shaft bosses are too deep within the chassis to reach with calipers, so I couldn't get reliable results.

A similar solution to the stock FF-01/TA02 mount/diff cover wouldn't work? Or something similar to what I did on my MF-01 conversion, with mounting screws in the middle of hinge pin blocks. Although that requires moving the diff up a little to make space for the mount and screws under the bearing.

A bit too late to the topic (sorry about the accident) but this is basically what X-ray did with their first 2WD buggy - They took the XB4 and throw away the front drivetrain and tweaked the geometry. That car was intended for indoor, for dirt, they introduced the XB2 and later did carpet version of that.

I was today years old when I found out that even the most hopped up versions of TA02 still use the U-shape hinge pin. Great job! Is there a way to make the suspension mount a separate part? Changing a whole gearbox half in case of a crash and damage to the mount is a bit of pain. (Ask me how I know 😁) It might be a way to fit the hinge pin as a reinforcement. It'd also allow you to make more variants of kick-up angle. One part I didn't like is that the bottom part of the gearbox is horizontal, going forward from the arms. Going in the plane of the suspension arms and then curve up around the motor before ending in the bumper would provide more ride height, which would be beneficial if you intend to do a rally variant. The disadvantage would be slightly higher CG due to motor moving up a bit, but considering Tamiya did a quite successful road going FWD with an XV-01 gearbox, I don't think it will be an issue. 🙂 I wonder if the gearbox fits under an M-chassis shell.. A mini FF-01 would be quite cool

You're right, I forgot about 3rd parties 😁 I only found the 3racing set, read some non-positive reviews, and never thought of it again. But the 16-24 range sounds good. You can also move the spur a little to gain space for larger pinions within the same motor position range, as alternative of speed tuned spur. Or TL-01 spur for something extreme 😃

That happened to me aswell. I counted 17T instead of 16 on the 0.8 part and found out when my V1 conversion has been almost finished. Luckily I left enough space around the gear to be able to fix the mistake. Here's quick drawing of the most important dimensions from my cad model.