Metal axles, portal covers or both? Servo 'Y' harness?

[niro750]

Hi guys, I am currently ordering bits for my new TRX-4 defender, I haven't got the truck yet so it's a new build and I have very little experience.

I have various parts on order such as a mod to mount the batteries on the side skids, a HH servo, HH brushless motor and mamba x ESC, proline dual compound tyre inserts, hydrax tyres and some gmade sr02 wheels.

I am now pondering whether I need to get metal portal covers or axles or a kit for both. I'm kind of at the end of the budget now but if I'm going to see a good difference in handling I would possibly invest a little more to get this right first time. I'm not interested in increasing the rotating mass, I want to use as little weight as possible to make as big a difference as possible. I'm thinking that 400g of full axles might not be completely beneficial Vs some good portal covers etc... But I could be completely wrong.

Does anyone with experience wish to chime in with advice? I'm in Scotland and getting some of these bits seems hard. Ideally I would like black parts and of a reasonable standard. I realise you can use chemicals to blacken brass parts and I have an airbrush and metal etching primers etc... If I have to paint any brightly coloured parts.

Also, to use the 2 speed servo to trigger the Aux mode on the Mamba, do I need to buy some sort of a y harness?

Thanks guys

 

[AnimalHippie]

IMO I'd say brass knuckle weights and brass outer portal covers. That's 300g/10+oz. That's about what I have on mine, but I only have knuckle weights & a steel bumper. Might add some otter portal covers in the future. Too much weight can be a bad thing. Maybe some adjustable knuckle weights for the rear. The plastic axle housings slide over the rocks better then the metal ones.

Sent from my SM-S975L using Tapatalk

 

[vipers28]

I put Samix on mine and have been very happy with it. Samix was added to both front and rear.
TRX-4 Brass Steering Knuckle, C-Hub, Portal Cover & Scale Brake Rotor Set by Samix

 

[Topher Builds]

I’m running the ssd portal covers, hot racing diff cover, Samix c hubs, samix knuckles, and the xtra speed axle housings. I’ve noticed performance gains with all of them. This little truck goes vertical quite well. FWIW the ssd portal covers have more weight than samix.

I don’t have many clips of this one crawling but here’s the only example I could dig up https://splice.gopro.com/v?id=9GAZKy

With that being said, I’m not suggested to do it all at once. Start with the portal covers and go from there until you’re happy.

Also, to use the 2 speed servo to trigger the Aux mode on the Mamba, do I need to buy some sort of a y harness?

Yup, for channel 3. You’ll need a castle link/field card to be able to set the aux mode function as well.

 

[niro750]

Guys that's fantastic info, thanks very much.

Now I just need to find suppliers of bits that don't charge millions in postage!

 

[Inspector86]

Hi guys, I am currently ordering bits for my new TRX-4 defender, I haven't got the truck yet so it's a new build and I have very little experience.

Why don't you wait until you have actually had a chance to drive and evaluate your new TRX4 before blindly throwing a bunch of money at it? I have four TRX4s now and you can do as much or as little to these rigs as you like to suit your driving style. Problem is a lot of the upgrade parts on the market are totally useless and do nothing to improve performance. Case in point, side mount batteries. I recommend you get the truck, drive it, and then decide what you want to change or upgrade.

 

[niro750]

Why don't you wait until you have actually had a chance to drive and evaluate your new TRX4 before blindly throwing a bunch of money at it? I have four TRX4s now and you can do as much or as little to these rigs as you like to suit your driving style. Problem is a lot of the upgrade parts on the market are totally useless and do nothing to improve performance. Case in point, side mount batteries. I recommend you get the truck, drive it, and then decide what you want to change or upgrade.

That's a fair point, the way I see it is that I wanted to add a few bits right from the off so that I didn't have to keep messing with it later. I also don't want to add way too much weight as that's a bad idea too. I was just looking for opinions on whether people found you really needed loads of unsprung weight to make the car handle better.

I agree that a lot of parts are snake oil but a lower centre of gravity and some unsprung weight will help with the heavy body which I don't want to change. Surely dropping the batteries to the skids is going to have a reasonable impact over one big battery at least 1" higher?

As it happens I've only bought the heavy portal covers and some light aetheric pieces because I did in fact decide that maybe the axles and diff covers were overkill for me. Also I liked the comment above about the plastic sliding over the rocks easier and also plastic has some give in it which may stop parts shearing or breaking as quick in certain situations. But that's debatable.

Cheers for your input, happy to discuss further.

 

[Inspector86]

I agree that a lot of parts are snake oil but a lower centre of gravity and some unsprung weight will help with the heavy body which I don't want to change. Surely dropping the batteries to the skids is going to have a reasonable impact over one big battery at least 1" higher?

This is a good example of getting familiar with your truck before buying parts. The side plate real estate is very limited and not easily moved given the location of shift servos, ESC and RX. Before trying to relocate that stuff to make room for side mount batteries, I would go with the BowHouse RC 3D printed low CG mount battery tray.


https://www.shapeways.com/product/X...ay-for-trx-4?optionId=63009264&li=marketplace

 

[HumboldtEF]

Just a quick heads up on the Gmade wheels, I tried the same set and and they do fit over the stock portal covers but after adding some larger brass weights the wheels no longer cleared. They are also on the narrow side (track width) and I believe the tires tucked under the fender flares just a touch, looked good to me I just thought it was something worth mentioning.

I ended up with a set of SSD stamped steel wheels which provide the maximum amount of space for clearing weights on the inside of the wheel

I agree that a lot of parts are snake oil but a lower centre of gravity and some unsprung weight will help with the heavy body which I don't want to change. Surely dropping the batteries to the skids is going to have a reasonable impact over one big battery at least 1" higher?

Also keep in mind having the battery on the side will make the truck less capable when sidehilling, ideally you want the battery low and centered between the frame rails.

there are some cool 3D printed parts available for slightly different battery locations like the one Inspector86 linked

 

[niro750]

More great info thanks. I had a look at the wheels in the wheels thread in these TRX forums and decided it looked like they would possibly just clear the parts I ordered, however if they don't I will be happy to either modify the portals or send the wheels back for a swap with the supplier who is in the UK, all the other parts are from abroad due to having less choice here. I decided to risk the wheels mainly because they were close to the look I wanted. I also ordered a set of 5mm longer wheel hexes in case there were other clearance issues because I saw that those wheels have a narrower offset (which will definitely affect sidehilling) but they really do look nice. They can be modified to suit the required length or returned as well.

I know what you mean about the batteries, the lowest centre plate I could find still had the battery sitting higher than the side skids, I didn't work out any figures but I guessed the moment of the battery on the truck would not be higher with them saddle mounted on a side hill because they are symmetrically placed at a lower point than a single battery slightly higher up. It's been a while since my engineering diploma days so I wouldn't probably be able to work that out now anyway! I was intending to do some trials and post some info on here using the truck with batteries in the standard position and then on the side skids just so anyone else who wants the info can get it. I'm not going to be too unhappy if it's not quite as good as advertised, as long as it does what I need. If it's really bad I'll send it back! I couldn't find any info on line as to whether it was any good or not.

I know I said earlier I wanted to keep rotating mass down but seeing as you guys are giving good advice, what are your thoughts on using some weights when the wheels will have the proline 2 stage foam inside? I'm guessing it will require modifying the foam and it may not be worth the effort of destroying it a little to fit them? As was suggested above, I will probably run them without the weights at first if I even did decide to do add them.

Cheers

 

[niro750]

This is a good example of getting familiar with your truck before buying parts. The side plate real estate is very limited and not easily moved given the location of shift servos, ESC and RX. Before trying to relocate that stuff to make room for side mount batteries, I would go with the BowHouse RC 3D printed low CG mount battery tray.


https://www.shapeways.com/product/X...ay-for-trx-4?optionId=63009264&li=marketplace

Just so you can see the mod

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/273309134536

If this is not allowed, let me know and I'll remove it.

I guess because I'm stuck on a rig in Egypt I'm basically buying stuff just to muck about with when I get home. I don't like getting home and having my 3 weeks thee spent waiting on parts! I just want to get the truck fitted up and take it out! Probably should have run it more stock first.

 

[HumboldtEF]

I wouldn't worry about adding weights with those wheels, they will bring plenty of weight with them (I think they're my heaviest set of wheels I recall seeing 2lbs all mounted up), but it would definitely complicate things with being able to fit weights and the foams.

 

[Inspector86]

Please consider starting a build thread here and keep us updated as you build your truck. We like pictures. I'm kind of ambivalent about that battery kit. I think it will be a lot more trouble and you will need to now run two matched batteries for a marginal lowering of the CG vs the BowHouse RC low CG battery tray which is a much cleaner solution but let us know how it goes. Did I mention that we like pics? Bottom line, HAVE FUN!

 

[niro750]

Please consider starting a build thread here and keep us updated as you build your truck. We like pictures. I'm kind of ambivalent about that battery kit. I think it will be a lot more trouble and you will need to now run two matched batteries for a marginal lowering of the CG vs the BowHouse RC low CG battery tray which is a much cleaner solution but let us know how it goes. Did I mention that we like pics? Bottom line, HAVE FUN!

Yes maybe when I get home I should sort out a thread. Good idea!

I did read about balancing packs, I bought a charger with a board to connect multiple packs. I will need to read a bit more to make sure I fully understand the concepts but so far I think you need to make sure they are within a few tenths of a volt of each other before charging? I bought 4 batteries all the same for the truck. Turnigy 1500 graphene packs and a new turnigy charger to go with.

Your point about it being more hassle than it's worth is also quite possibly true. I guess I'm a guinea pig now!

 

[niro750]

I wouldn't worry about adding weights with those wheels, they will bring plenty of weight with them (I think they're my heaviest set of wheels I recall seeing 2lbs all mounted up), but it would definitely complicate things with being able to fit weights and the foams.

That is a lot of weight for wheels right enough. My mountain bike wheels are probably lighter haha

 

[vipers28]

I was pretty surprised at the weight difference just by adding the Samix parts. Thought about wheel weights but I doubt for what I do with it that it would make a difference. Plus I am still running stock wheels, just can't find a new set that I will like for it, and the stock just work for me.