XV-01 Very Slow Build

[Pylon80 3757]

3 minutes ago, alvinlwh said:

Me! Not bought but with included CVA.

I think the molding of the CVA are getting tired or poor QC. Never had this problem in the past which makes me think it is the newer ones that are the problem. Now I hunt for other brand shocks, buying up various brands from RCM and AT to try out and the plus side is, for example, a set of metal YR shocks cost the same as a set of Tamiya CVA and they come with the fancy V pistons, or you want to pay even more, Qutus with on the fly adjustable piston holes without needing to dismantle the shocks.

My first set was bought around 2018 and the second one in 2021. Just like static models get "flash" when the mold wear out it's quite possible that the CVA molds would wear out as well.

I have tried the Qutus and they are very good! The transparent bladders are pretty cool to spot bubbles before you screw the tops 😀 You can also set them up with the regular (included) pistons which is what I did and the result is very similar to a TRF damper.

[alvinlwh 7251]

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[Kowalski86 4316]

32 minutes ago, alvinlwh said:

The ones I noticed a problem was on the HS2 BHM, which is a fairly new kit.

Qutus (and TRF) is kind of too expensive for me to stomach. I had tried some other cheap brands like Team Raffee Co. (mixed, some good some poor), GPM (very poor, just like no brand shocks with oversized balloon bladder), Boom Racing (good!), boxed YR (good), cheap bagged YR (ok), Xtra Speed (meh, ok for price) and 3R (a bit like Tamiya CVA but cheaper). The about of money I spent on them could probably buy a set of TRF shocks but just a set. I got aboit a 50% keep rate with these and multiple data point on how good each shocks are so I think it is a win-win.

On the one hand, a number of the CVAs in my Tamiyas either let in air or squeak, on the other hand, I bought then used so I always wrote it off as "wear and use", but it wouldn't surprise me if the molds are getting old.

Honestly, I wouldn't buy TRFs without changing your RCs ball connectors for screws, or something that doesn't wear the eyelets out. For the price of new eyelets, you could buy a new set of super mini CVAs.

Yeah Racing Shocks are good, just replace the eyelets (in time if they get brittle) and o-rings with Tamiya parts.

[Pylon80 3757]

12 hours ago, alvinlwh said:

The about of money I spent on them could probably buy a set of TRF shocks but just a set. I got aboit a 50% keep rate with these and multiple data point on how good each shocks are so I think it is a win-win.

All a question of philosophy. In another distant life I had a GF who would buy one pair of jeans every year for 200 bucks. That used to infuriate me as the markup was probably over a thousand % but then her point was that it's nicer to have one pair she really likes than 10 pairs she hates. The same philosophy can apply to RC!

And I am not writing this because yesterday I bought the set of 42102 I have been wanting for 3 years 

Over to you @skom25, sorry for digressing on your otherwise excellent thread

[skom25 2210]

No worries!

I will build CVAs with all upgrades mentioned on my last Post. At the same time, I am not saying "No" to TRF shocks if they will appear in nearest future.

[skom25 2210]

Spur.

I read somewhere, that there is just a little thread which sticks out from Spur Gear, so it is easy to damage mount. I can confirm this.

I decided to measure everything and choose best solution. Now interesting part.

- Stock JIS M3x6 screw has around 5.5 mm. I found that all JIS screws are just a bit shorter than specified.

- Aluminium M3x6 ( I really wanted to use them... ) are exactly 6 mm. I checked also steel M3x8 and they have 8 mm. It seems that only JIS are shorter.

- Stainless M3x6 has around 6.5 mm, maybe less but were longest.

I tried also to use M3x8 screws with 1.5 mm spacer. It was perfect in terms of thread in Spur Mount, however I was afraid that screws heads will touch motor cover.

At the end, I used Stainless because they were longest.

I really recommend to tap mount first. At beginning I thought that maybe it is better to not do this, because screw will sit tighter. It is true, but without tapping it is hard to find point when screw starts to tighten parts. It is easiest way to damage threads, because of too much force.

When I tighten screws, I hold key using only three fingers. It gives good feeling when it is tight enough.

Then I put chassis to bag and then to desk. Why?

 

I have feeling, that I am bit tired with this build. I started to overthink things. E.g. I spent two (!) evenings only on belt tensioner. I really like effect and I do not want to change anything, but it is definitely moment to stop for a moment. I do not know for how long. Maybe two days, maybe week or month.

I need to finish DT-03 rebuild, check few things in TT-02B and try to solder few things. That last skill will be necessary during this build.

One question at the end:

I want to mount fan. Does anybody know, what size it is?

 

[skom25 2210]

After last Post about shocks and pistons, I bought new set with three holes. Mainly because:

- Probably one set will be used in TT-02B 

- I wanted to have exactly the same setup of both shocks at start

They were cheap, so no big deal.

I also bought 3x18 Aluminium Turnbuckles to solve issue on rear which I mentioned previously. Again, no big problem because I will have some spares in that situation.

Blue Ball Connectors. I am still not sure, but maybe will use them on shock mounts.  

Nuts just to have them in spares.

[skom25 2210]

Rear turnbuckles changed from 3x23 to 3x18. Not perfect, not much better but better enough. 3x23 were very tight and it was hard to turn them. With less thread, it is easier.

I also changed Ball Nuts for blue version, but only in upper shocks mounts. 

Small tip:

To not damage surface of fancy parts, I use foil. It separates metal from metal, but also makes fit bit tighter. I use it with spanner and with Hex keys.

[skom25 2210]

I think that CVA shocks build is something, what everyone here did or saw more than once. In that case, I will show only things which are not usual.

As I wrote, I used TRF shafts and three holes pistons:

On o-rings, I used TRF Shock Grease:

Some kind of service stand is necessary to build shocks. You can buy it or just build from materials you have. I used plastic sheet and five screws:

Because I used 400 oil on front and 300 on rear, I decided that I need to mark them somehow. I used small red stickers on front pair:

Firts build of new shocks is quite nice, because everything is clean and oil free. Rebuild is always messy and that is the reason why I do not like to do this.

Now I think if it was good idea to buy "1 mm up" retainers...

I have not installed shocks yet, because I need to buy alcohol to degrease them. I really do not like when dirt sticks to greasy parts.

[NM Frontier 13]

Looks great, good idea with the small stickers to label the shocks. 

[skom25 2210]

Shocks installed.

Before installation, I thought that springs are quite hard. After installation, I see that suspension is really soft.

All changes I have done, caused that shocks are very smooth. It is not level of TRF shocks, but really good.

Additionally I found that it is not possible to mount motor cover, without shock disassembly...

I read many times that XV-01 is complicated, but I have not expected so many "connected" parts.

It seems that now it is time for electronics. I need to learn how to solder and then choose motor, solder wires etc, so...

See you later!

[Pylon80 3757]

31 minutes ago, skom25 said:

After installation, I see that suspension is really soft.

You are also at the hardest possible setting on the shock towers. It will get much softer still as you move the shock heads closer towards the center.

[skom25 2210]

16 minutes ago, Pylon80 said:

You are also at the hardest possible setting on the shock towers. It will get much softer still as you move the shock heads closer towards the center.

I will try to change rear settings. As far as I know, it is not possible on front.

[skom25 2210]

I still cannot decide: Torque Tuned, Sport Tuned or Super Stock?

I am not sure about last one, because of heat, short run times and possibility, that I will ruin it during soldering

What about TT and ST?

I used all of them but in Buggies, which are bit different than Rally.

[alvinlwh 7251]

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[skom25 2210]

One question more about RZ. Recommended Gear Ratio is 7.5 and lower. Stock XV-01 has 8.04 FDR. Can I use it?

I know that TZ would be better, but it is not available.

[bavee 1180]

And what pinion to use?

I use a 22T (as per manual) steel pinion on a silvercan but I think I can go bigger.

 

EDIT: Haha, we cross posted.

[skom25 2210]

22T pinion. I already bought steel version, so I want to stay with it.

[alvinlwh 7251]

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[BuggyDad 5989]

1 hour ago, skom25 said:

One question more about RZ. Recommended Gear Ratio is 7.5 and lower. Stock XV-01 has 8.04 FDR. Can I use it?

I know that TZ would be better, but it is not available.

Higher FDR is lower gearing, if that makes sense - the ratio is the speed reduction from motor to wheels, so a larger reducing ratio is being applied to motor speed. So easier on the motor, less top speed, less heat, more acceleration. Higher is not a problem. So you can almost certainly go for a bigger pinion although I can't say what because I've only run brushless in mine (10.5t on 25t pinion I think, no heat issues). 

[bavee 1180]

8 minutes ago, alvinlwh said:

It is always ok to go bigger in FDR numbers, it is smaller that can cause problems.

Silver can can go as low as 6.8 (on paper) but if you want even more speed, I had done around 5.5 and it lasted reasonably long. If you want to be safer, aim for just over 6.

Thanks! Yeah, I meant a bigger pinion so a lower FDR .

From the XV-01 manual:

So I could go up to 26T no problem.

I'm only running on paved roads so that should give me more speed.

 

[alvinlwh 7251]

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[bavee 1180]

Thanks @alvinlwh! I do know something about higher and lower gearing. But I do not know what the usable bandwith for a silver can in a 1:10 rc car with tc wheels and rallyblock tyres on paved roads is.

[alvinlwh 7251]

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[skom25 2210]

I decided to buy Super Stock, because...

I do not know. I still was not sure which to use, so I just bought it.

BZ version has not interesting grey cover and strange violet/ blue rear part. It is not even close to Tamiya blue... 

RZ looks great, with chrome cover and red elements!

I also bought spare brushes and set of cleaning brushes. However...

It is barely visible on photo, but edge/ corner is chipped. Can I use that cleanining brush or should throw it to bin?