Jak vylepšit převodovku GMade BOM TC GS02F: detailní průvodce a zkušenosti z terénu

po douhé obě jsem se podíval na fórum. Hledal jsem v ETKA převodovku s kódem ATD, tu jsem nenašel. Našel jsem ASD, která se montovala do VW Golf třeba v roce 1997. Má stálý převod 3,15 a převodový poměr 5. stuně 0,72, takže je asi "nejdelší" ze všech 5 stupňovejch převodovek. Když montovala Škodovka k motorům ATD 5 stupňové převodovky, tak třeba JDH, EUH, GQQ, JCR, které mají stálý převod 3,38 a 5.stupeň 0,743. 6 stupňové převodovky pro diesely mají celkový převod na 6-ku 2,125.

Jestliže Vy máte motor ASV (81kw) a 5 stupňovou převodovku, tak byste mohl mít kód převodovky EBF, EGS. Já mám od EuroTuning 6. stupeň s převodem 0,647 a celkový převod je 2,186. Pro mě nebylo řešení jezdit po vrakovštích a shánět převodovku s konkrétním kódem. Zkusil jsem to, ale je hodně převodovek s obvyklým TDI odstupňováním, ty "dlouhé" nejsou. Navíc jsem nechtěl riskovat a měnit svoji dobře fungující převodovku za "nějakou".

Najedu cca 3000 km měsíčně, cena nafty šla mezitím o 2 koruny nahoru a klesat nebude. Jsou určitě levnější řešení, ale je to o náhodě, kontaktech, stráveném čase a dalších aspektech.

Co GMade BOM TC GS02F nabízí a co zvažovat při výběru převodovky

Meet the GMade BOM TC GS02F, a builder’s kit 1/10 scale RC rock crawler. In the world of RC rock crawlers, there are ready-to-run (‘RTR’) models and there are builder’s kits. RTR vehicles generally come with everything except the batteries. Both RTR and kits give you essentially the same finished product. Kits come with a possible learning curve and a time investment up-front. That investment yields satisfaction for a job well done at the end. I open with this thought because the GMade BOM TC (GS02F) is a builder’s kit.

It requires you to get the tools and electronics onto the workbench before you can enjoy this refined machine. The GMade GS02F BOM TC is a 1/10 scale RC rock crawler with a truggy body. It was the first 4X4 crawler, either kit or RTR, to finish all 6 closed circuit test problems, and in stock form! Clearly, rock crawling performance is a great strength of this special truck. If you haven’t enjoyed kit builds in the past, or even if you’re new to them, this is a pretty nice starting option.

Everyone has their own preference when building an RC model. I personally like to start with painting the body. Whilst this isn’t overly difficult or time-consuming, it’s something I don’t particularly enjoy. My preference is to get it done and out of the way, so that I can then enjoy the mechanical assembly process. Speaking of the body, it’s only a half body to be painted: just the cab and hood, really. The truggy bar work on the rear half just go together as part of the assembly process.

Vlastnosti převodovky a jejich dopad na výkon

The transmission is a tidy, one-piece unit. It incorporates the motor mount at the front, opposing-direction output shafts (per torque twist elimination, as above), overdrive gearing options of 0%, 14.29% and 22.22%, and a two-speed selector with integrated standard servo mount and arm. It’s an updated design that replaces the weaker GS02 implementation. The GS02 mated the top half of the transmission down onto the skid plate, which used to house the gears. It was a weak design, prone to lifting and breaking.

Overdrive helps the rig to follow where you’re pointing the front wheels. It’s a common engineering approach for rock crawlers that is often achieved by changing the ring and pinion gears in the diffs to get the speed difference, so to be able to have overdrive from the transmission instead means the diffs can retain their strength with full-size gears. The GS02F diffs are the let-down for this otherwise stellar performer. The diff gears are made with a cast manufacturing process. Casting is cheap and useful for many things. A decade ago, most crawlers had cast gears. In the 2020s, the norm is now hardened steel - and even the GMade here uses cut steel gears in the transmission. It’s such a shame GMade went with the cast process for the diff gears, as they’re considerably weaker in comparison to hardened steel. Our test unit took this damage after 90 minutes of driving.

It’s a big deal, as it is the one factor that keeps the BOM TC from being the best mass-produced RC rock crawler of its type ever produced, from a performance perspective. It really is that good. The GMade GA44 axle is a single-piece injection-m moulded plastic part. It features an up-angled metal diff cover and a rounded pumpkin bottom to help the vehicle slide over rocks. Indeed, the entire undercarriage is designed with this in mind.

The kingpin angle is set to minimise tire scrub at full servo throw and the high-steer arms on the knuckles assist with clearance. The middle of the diffs feature a cast metal locker. This is one place where cast metal is completely acceptable. If only the diff gears were not cast, it’d be perfect!

This brings us to the logical question: is the GMade BOM TC any good even with the weaker diffs? Well, yes - as long as you fit an appropriate power system. In my test video I started with some premium gear, with the Holmes brushed ESC and 40T 540 Expert brushed motor. I ran it on 4S (14V), before I realised the diff gears were cast. After the initial review, my subsequent driving was done on 3S LiPO instead of 4S (that’s 11V nominal instead of 14V). My recommendation at this point is to run the GS02F with a 16T or 20T 5-slot (or 5 pole) 540 motor. For ESC, consider a HobbyWing WP-1060 or WP-1080.

Running a 3S (11.1V) LiPO battery will be fine with stock gearing, as long as you have a 5-slot motor. Or, if you end up with the more common 3-slot motor, say, a 35T or 45T 540, stick to 2S (7.4V) for best results. The GS02F will fit a 540 or 550 motor. The chassis includes a cooling fan bracket as part of the bracing between the front suspension towers. The battery tray sits in a horizontal position over the top of the transmission, behind the front wheel arches. Because the motor is up-front, the battery tray can be nice and low. This helps keep the COG (Centre of Gravity) nice and low.

Nastavení kol, podvozku a dojmu z jízdy

The wheels are 1.9” with 12 mm hex, 0.5 mm positive offset, 23 mm wide, non-beadlock. Tires GMade MT-1904 1.9” M/T Off-Road are excellent, 121 mm high and 45 mm wide, inner diameter 48 mm. Tire setup with standard foams. The chassis allows adjustment of wheelbase between 313 mm (stock) to 324 mm, accommodating larger bodies. The front suspension is standard for crawlers; rear suspension uses cantilever, coil-sprung shocks that work surprisingly well. There’s 4-link rear and 3-link/panhard front with CMS arrangement for precise steering, close to zero bump steer.

The model features a forward weight bias of about 55%, which helps with traction on the front wheels during climbs. For general crawling, 50/50 to 60/40 is a good range. However, excessive forward weight can make descent problematic. Overdrive can be both a feature and a drawback depending on intended use; for trail play, 0% overdrive might be preferable.

In wet running conditions, the electronics are your responsibility in a kit build. The radio receiver box is well shielded against water, with potential silicone grease protection after installation. Bearings are a weak point: they are naked/unshielded, which can lead to grease loss when wet or dirty. Consider aftermarket all-weather bearings with rubber shields for protection, ~30 USD spend, to avoid greases and seize-ups in damp conditions.

Praktická doporučení pro vylepšení

• Vhodný motor: 5-slot 16T až 20T 540 pro lepší výkon v terénu.
• ESС: HobbyWing WP-1060 nebo WP-1080 pro spolehlivou kontrolu a plynulý výkon.
• Převodovka: preferovat 0% overdrive pro trail/rekreační použití, případně měnit idlery pro změnu převodů.
• Domácí tinkering: používání silikonového oleje do tlumičů a výměna beztlakových ložisek za uzavřená ložiska s gumovým štítem.
• Podvozek: přizpůsobení rozvoru 313-324 mm pro lepší prostor pro těla a stabilitu.

Unshielded ball bearings a cast diff gears aside, the GMade BOM TC GS02F is an absolutely exceptional machine. It’s lightweight and has a gorgeously flat undercarriage. Its components are well thought out in nearly all elements and it’s a joy to drive. Coupled with the right power system (ideally a 5-slot 16T brushed motor) a used primarily as a rock crawler, this rig will leave competitors in its wake. It will just impress and perform wherever you run it. It is the most capable crawler of its class in stock form we’ve tested to date!

Pokud hledáte alternativu pro trail/klidnější jízdu, zvažte Traxxas TRX-4 Sport v kitu, nebo Redcat Gen 8 V2 v RTR formě. Pro náročnější terénové výzvy je BOM TC GS02F vynikající volba pro rock crawling; co do celkové kvality a výkonu stále patří mezi špičku mezi RC modely.

Osobní zkušenosti a úpravy uživatelů

Three of us go out for walks, but we only had two “big” crawlers, which meant someone would have to drive something else if they wanted to join in. Building the BOM is quite an old-school experience. The parts are bagged individually instead of following the build steps, and it feels like the Gmade engineering team challenged themselves to use as many different screw sizes as possible! The fit and finish of the parts is extremely good. Even something as complicated as the two-speed gearbox drops straight into place, despite being assembled from several different mouldings.

One concern is the size of the hardware used - there are lots of M2 and M2.5 screws used in areas that could be under load, and where I would have expected M3 screws to be used as a minimum. I don’t build my kits with a bunch of options - I always run them stock at first to see how they are intended to work - but I have made a couple of changes. First was to use some silicone shock oil instead of the mysterious brown liquid they supply. And the second was to fit some beadlock wheels. The kit wheels are plastic and require you to glue the tyres on - which I would never do with an expensive crawler tyre! So I treated the truck to some of Gmade’s own SR02 steel beadlocks, mounted with Pro-line BFG Krawlers.

Another interesting experiment was with Hobbywing’s Fusion motor, which has an integrated ESC, yet still only takes up the space of a 550 can. I’m running 2s LiPo batteries, so I chose the 1800Kv version. Fitting was easy, with far fewer wires than usual to worry about. The Fusion exhibits throttle matching that maintains constant wheel speed across terrain, providing excellent downhill control. Drag Brake Rate can be tuned for better trailing speeds and control. The bodyshell remains a standout feature, with a Ford Ranger-inspired front half and a cage-like rear.

Co se týče jízdních vjemů, front-wheel bias a torzní charakteristika konstrukce vyplní svou roli na tratích s různým sklonem. V některých situacích je nutné provést úpravu vzduchu tlumičů a převodů, aby se dosáhlo ideálního kompromisu mezi ovladatelností a trakí.

Tabulka souhrnných parametrů

GMade BOM TC GS02F je lehký a má velmi hladký spodní podvozek. Komponenty jsou promyšlené a řidičský dojem je výborný, zejména při terénní jízdě a skalních překážkách. Celkově jde o mimořádný model pro rock crawling, nikoliv pro trailové použití, kde by mohla být výhoda jiných modelů větší.

tags: #upgrade #prevodovky #gmade #bom