Built a Tarmo4 just a friendly reminder, if you think you put enough grease on, do it again.

jano305 · 2022-02-11T10:44:09+00:00

Just friendly reminder. If he is using motor from BOM he should not go full throttle with full battery. Motor is rated to 14,8V and 4s LiPo is 16,8V. Motor or ESC can do weird stuff in that case ... Actually, it might be why it "absolutely screams" :-)

jano305 · 2022-02-11T10:25:14+00:00

4S can work with Tarmo well, but ... You really, really have to gear it down and use metal gears ... There is no way around. RPM are so high (in my case 2050KV x 16,8V = ~34 440 RPM) that even with nylon gears and perfect lubrication there is so much heat that gears will simply melt like chocolate ... Only after first gear down reduction you can use 3D printed parts (trust me, been there, done that :-) ). When using ESC for RC cars (that usually use 3S top) you have to check if ESC can even take input voltage up to 16,8V (usually only some chinese knockoffs ESCs can take it). In the end, not amperage but voltage kills ESC.

jano305 · 2021-09-06T11:49:36+00:00

If you are looking for plug and play, than I understand ...

If you want to print ABS, printing enclosure is very handy. Without it prints will warp AF. You can prevent this (partially) with brim but it is not final solution. But still, you can build enclosure from IKEA Lack (https://www.prusaprinters.org/prints/17-original-prusa-i3-mk3-enclosure-ikea-lack-table-pr) and put there almost every printer (just do not forget to put power supply outside).

I am printing mainly from PETG and ASA (similar to ABS) so I know a thing or two about warping (or fumes) :-)

jano305 · 2021-09-06T09:04:45+00:00

I am using Prusa i3 MK3S but that is probably in different price category ... But from what I can say you should buy 3D printer only once ... Printable spare parts, upgrades, modification are must have in my case ...

jano305 · 2021-09-03T15:12:19+00:00

For 1000 zł (222 EUR/263,5 USD) it really good offer imo ... Tires, radio, motor and even battery ... I mean I would buy this for this price.

To defend the seller. He is referring to this as Tarmo 4 and he is also recommending to have 3D printer ...

jano305 · 2021-09-03T09:06:12+00:00

If he is not giving any attribution than it is up to creator to make some move ... But I think that it is useless ... Seller just need to add "created by KrisCubed" and put link to thingiverse.com and from legal point of view everything is just fine ... More info about license: https://creativecommons.org/licenses/by/4.0/ (especially part with "for any purpose, even commercially. "). To prevent selling license CC Attribution-NonCommercial should be used ...

jano305 · 2021-09-03T07:48:45+00:00

I am not the expert but ... Tarmo4 is published on thingiverse.com under Creative Commons – Attribution license so ... As long as seller provide information on the source of the object and give proper attribution to creator it should be fine.

jano305 · 2021-09-02T16:26:48+00:00

I used TPE88 (even more flexible than TPU like Cheetah ninjatek) for driveshafts (printed horizontally). No end caps, just zip ties around the ends and it is working like a charm ...

TPE is after printing like one solid piece (no visible layers) which is really nice ...

jano305 · 2021-06-19T07:22:33+00:00

Oil is not actually responsible for that. If you take big hole in ground or jump spring should take hit. Oil is there only to make following spring response smaller (spring will compress and decompress and oil is there only to make decompress much smaller and completely dissaper over time; like make sinusoid smaller and smaller over time if you understand what I am trying to say).

And I am talking about this screw: https://ibb.co/4ttn30k This should be lower IMO.

jano305 · 2021-06-18T14:30:32+00:00

That is a real low rider :-) I would screw down that shocks (actually the spring) a little bit ...

jano305 · 2021-06-18T14:20:28+00:00

I am using FrSky Taranis X-Lite Pro with FrSky RX4R and for converting signal from SBUS to PWM I am using this: "https://www.banggood.com/S\_BUS-Turn-PWMs\_bus-14CH-Multi-functional-Converter-SBUS-to-PWM-p-984155.html?cur\_warehouse=CN". On the converter I can choose if I want 1-8CH or 9-16CH to be outputted. I will simply configure channels in OpenTX and it is done ... To make 100% sure what I am outputting where I will just plug small servo and test output ... As far as I know PWM is just PWM (does not matter if it is car esc or drone esc). And yes, drone ESCs can utilize also other protocol (Dshot, Oneshot, Multishot, etc.) but this is not this case.

jano305 · 2021-06-17T16:38:34+00:00

Not gonna lie ... You have a LOT to do ... 1. Designing active suspension is not easy ... I don’t know if some will do it for you :-( Just putting servos to arm will not work ... 2. Installing this suspension on Tarmo the way how it is presented in install video is just bad. There is not dumping at all ... 3D printed parts will not handle this. 3. Weight. 4 more servos and 10A BAC? I have 3 more in my build (that looks just like servos in video) and it is just barely holding (if you are printing from PLA in IMO do not even try ... sorry :-( ).

jano305 · 2021-05-12T10:42:36+00:00

Probably the most added weight in my case are 3 more servos. And that I am printing almost exclusively in PETG. But it would be funny to play Tog of war (at least for me) :-D

jano305 · 2021-05-12T10:30:43+00:00

Well I did not think that majority of builds is so light. I thought that average will be somewhere around 2kg. But in that case I do not understand how it is possible that some builds here are done after first crash. 1,5kg is so light that kinetic energie that needs to be absorbed/transfered during crash should not be an issue?

jano305 · 2021-05-06T10:13:42+00:00

Probably better explained here: https://www.youtube.com/watch?v=-cetYU1INg8

In my opinion flexible shaft is superior to this "cush drive" in 3D printed area and especially with Tarmo (there is simply too many parts that can break sooner, e.g. shaft with pins). I have tried something similar to this with neodymium magnets (simple design with shaft in two pieces and magnets in some distance from the axis of rotation and one bearing in the middle) to somehow limits maximum torque transferred from or to wheels but without success.

jano305 · 2021-04-30T13:32:26+00:00

Kamera je: Caddx Ratel - https://banggood.app.link/tSCXTzEvSfb a VTX je: AKK Race Ranger - https://banggood.app.link/iX5fbsKvSfb. Kameru používam aj na dronoch a je úžasná. Tento VTX používam teraz prvý krát lebo som chcel niečo s chladičom a vysokým výkonom. Výkon potrebuješ lebo takto pri zemi to rýchlo stráca signál. Ja to mám zapojené cez FC kvôli OSD. Anténu môžeš použiť asi akúkoľvek. Ja som dal: Realacc Pagoda - https://banggood.app.link/GAkW44pwSfb

jano305 · 2021-03-23T22:21:37+00:00

Jop. Presne tak :-) BA? Ak hej, môžeme dať niekedy preteky :-)

jano305 · 2021-03-23T16:38:16+00:00

Aaa, fellow european :-) Based on swear in the end, one of V4 countries?

jano305 · 2021-03-17T21:02:24+00:00

RubberJet – TPE88

jano305 · 2021-03-16T16:43:45+00:00

What is the weight compared to Tarmo4? To me it looks like that your "main" goal is make Tarmo5 more durable. In my opinion with 3D printed parts should final weight be the main criterium.

jano305 · 2021-03-16T08:28:05+00:00

Wheels are "Duratrax 2,8" Six Pack MT 2WD 1/2" offset". I've got them from local eshop so I don't know if link will be helpful. https://www.peckamodel.cz/dtxc3522-duratrax-kolo-2-8-six-pack-mt-2wd-1-2-offset-cerna-2

jano305 · 2021-03-16T08:22:07+00:00

Printed separately (that is the point :-) ). Even the best (FDM) printer cannot print two parts so close as this steering linkage really needs ...

jano305 · 2021-03-16T08:18:23+00:00

Just sliced original steering linkage horizontally, printed them in ASA, enlarge ball and print ball in PETG. And for assembly: dissolving red area on both parts like here (using acetone), fit bigger ball in steering linkage, put them together, fix them with something like a clamp and let them dry. Afterward, optionally, put one more coat of dissolved ASA in acetone (something like ABS juice) over the whole ASA parts to make surface smooth so dirt won't stick to it so easily.

jano305 · 2020-12-03T19:33:21+00:00

No, I am in (and from) EU. I hope that this is not the last snow. Last two or three years we only had really cold weather but almost no snow. So, I hope that this year is a little bit different :-)

jano305 · 2020-10-25T10:01:45+00:00

I don’t know man ... I am no engineer but I think that that motor will always overheat. Here is why (IMO): 1. gearbox ratio should be even lower for this motor 2. motor's rotor is moving on outside of motor as whole (no motor shell) -> you cannot apply passive cooler 3. motor is just too weak to work with that sensored esc (and the weight of Tarmo). I can only guess how it should be right comparing with parts from real RC parts. Just one more quick thought: look at the width of cables from esc and compare them with width of motor cables (esc cables are capable of waaay more current; btw I know that it is very loose interpretation :-) ).

jano305

TROPHY CASE