XV-01 Upgrades and Hop Ups

[skom25 2179]

Any advice which servo I should choose? I checked many Topics, read a lot and... many of them are not available. Poland is terrible in that terms, really...

I found that:

https://www.srt-rc.com/index.php?id=130

It is really expensive and more like emergency choice, not something I want to buy.

BTW, it is HV servo. I see that it can work from 6V to 8.4V. I will use HW1060 ESC which gives 6V but I heard that sometimes is more like 5.5V than 6V. Will that servo work fine?

[FuzzyFlynn 75]

SRT CH6012 is a nice servo. Fast and strong. I use it in my XV-01 with HV on a 2S battery and have no complaints. My other servos are Savöx 1251 and 1252 and CH6012 is in the same league but a little stronger and faster if you can power it with HV.

I never ran the CH6012 with a HW1060 but I can report that this ESC can power my Savöx servos just fine, even though these servos are known to be rather power hungry. I never measured the BEC voltage, though.

[skom25 2179]

I use NiMh 7.2V battery. HW1060 spec says that BEC is 6V.

If I will not find anything cheaper which will fit, I will probably buy that SRT.

[Pylon80 3684]

5 hours ago, skom25 said:

Any advice which servo I should choose? I checked many Topics, read a lot and... many of them are not available. Poland is terrible in that terms, really...

I found that:

https://www.srt-rc.com/index.php?id=130

It is really expensive and more like emergency choice, not something I want to buy.

BTW, it is HV servo. I see that it can work from 6V to 8.4V. I will use HW1060 ESC which gives 6V but I heard that sometimes is more like 5.5V than 6V. Will that servo work fine?

I measured a 1060 at 6.1v the other day (no load). It's a good basic BEC.

If that is available in Poland, you might want to consider a Hitec 625MW as a very good value that will also do high voltage. They are available for 40$ in the US. Hitec is a 'major' brand (as opposed to a lame copy of a copy of a copy) if that is valuable to you.

[alvinlwh 7227]

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[skom25 2179]

6 hours ago, alvinlwh said:

I got the LV version.

https://a.aliexpress.com/_Ewbu47L

I only use HV servo when I can supply the required voltage, either with the Tamiya 101/104 (no BEC), Radiolink Cool 9030 (7.5V) or ISDT ESC70/90 (up to 7.5V).

Is there something wrong with using HV servo with "low" 6V BEC?

[FuzzyFlynn 75]

1 hour ago, skom25 said:

Is there something wrong with using HV servo with "low" 6V BEC?

No, HV servos work perfectly fine with 6V. It just means that they will not be fried if you feed them higher voltages. 

[skom25 2179]

What Torque ( in kg) should be fine for XV? 7 kg is too low or enough?

I found shop with many servos, so maybe I will not be limited to only few.

Are cheap Savox ( around 25-30 Euros) fine?

[FuzzyFlynn 75]

1 hour ago, skom25 said:

What Torque ( in kg) should be fine for XV? 7 kg is too low or enough?

From what I read, the lower limit for touring cars is about 6 kg. So, for pavement 7 kg is probably fine. On the other hand, the XV-01 is heavy by touring car standards. I never ran less than 9 kg (Savöx 1251) in mine, so I do not have any first hand experience here, unfortunately.

My recommendation would be to get a nice servo from the 50-60 € range (like Savöx 1251 or SRT 6012) and rather, for now, hold back on some of the other hop-ups you appear to be considering (e.g. carbon damper bridges).

The XV-01 is a fine car already out of the box. I know that I would have more fun with a stock chassis with nice servo than with a hopped-up chassis with a servo that is slow, does not center properly, or has other deficiencies. But that is just me. 🙂

[alvinlwh 7227]

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[skom25 2179]

I need to think about servo bit longer. I was almost decided to buy Savox 1251 but I read that it is "power hungry" and can cause Brown Outs. I had this issue few times with current cars, so I do not want to risk.

On 11/14/2023 at 1:36 AM, Pylon80 said:

Hitec 625MW

It is available and it looks nice but I am not sure if it will fit XV-01 :| 

[FuzzyFlynn 75]

3 hours ago, skom25 said:

I need to think about servo bit longer. I was almost decided to buy Savox 1251 but I read that it is "power hungry" and can cause Brown Outs. I had this issue few times with current cars, so I do not want to risk.

I can report that I never experienced any power issue running my Savöx 1251 with a Hobbywing 1060 ESC. This ESC's BEC is rather strong, rated for 3 A at 6 V (compared to e.g. the Tamiya TBLE-02S with just 1.5 A at 6 V). Even if you run into power issues, this should be solvable by getting a BEC buffer capacitor.

[skom25 2179]

I have Sanwa radio/ receiver and I heard that it has tendency to Brown Out... 

Can you send me link to any BEC capacitor? I read about this, started to search and I cannot find anything. Probably I am not looking for right thing...

[alvinlwh 7227]

.

[FuzzyFlynn 75]

44 minutes ago, skom25 said:

I have Sanwa radio/ receiver and I heard that it has tendency to Brown Out... 

Can you send me link to any BEC capacitor? I read about this, started to search and I cannot find anything. Probably I am not looking for right thing...

Servo power is provided by the ESC BEC. So, my understanding is that the receiver is irrelevant here, unless it is very power hungry itself, leaving not enough power for the servo. However, I never heard this about Sanwa receivers, TBH.

Example search that gives me multiple BEC capacitor results: https://www.rc-kleinkram.de/en/search?sSearch=capacitor

[skom25 2179]

Any advantage of Aluminium Pulleys over stock? I see that many people use aluminium, but to be honest, I have not found any information why.

[Pylon80 3684]

On 11/15/2023 at 4:11 AM, FuzzyFlynn said:

Servo power is provided by the ESC BEC. So, my understanding is that the receiver is irrelevant here, unless it is very power hungry itself, leaving not enough power for the servo. However, I never heard this about Sanwa receivers, TBH.

Example search that gives me multiple BEC capacitor results: https://www.rc-kleinkram.de/en/search?sSearch=capacitor

That's right, receivers use a tiny fraction of the overall power consumption. The servo is the issue in the case of "brown outs". A glitch buster goes a long way although to solve the problem at the root one can pick a smooth, perhaps slower, high quality servo if that's acceptable. I converted all my (very small) fleet to Futaba and Hitec servos and it's been really nice.

[skom25 2179]

I have not mentioned that but I bought Savox 0220MG+. I checked specs and when locked, it draws 1.5A. Even if it is not fully true, there is still plenty of margin to 3A provided by ESC.

[Pylon80 3684]

3 hours ago, skom25 said:

I have not mentioned that but I bought Savox 0220MG+. I checked specs and when locked, it draws 1.5A. Even if it is not fully true, there is still plenty of margin to 3A provided by ESC.

I suggest you make a test to confirm that you like how it returns to neutral. I have had one (1) bad experience with a similarly priced Savox, whereby it would not return to neutral which is very frustrating when driving.

Since you're car is not built yet you can make a bench test by gluing a 'giant' 10cm index (stryrene sheet or cardboard) on one of the horns that come with it. Then you can go left or right and back to center and any problem becomes really obvious. This is something you will never find in specs obviously but that is really important on a steering servo.

[skom25 2179]

Of course without cardboard but I checked how servo works few times. I have not found anything wrong.

I have idea for bit different test but it will clearly show how it returns to neutral position.

I hope it will be fine, because I really to now want to start my servo "journey" once again.

To be honest, I will be surprised if something will be wrong. Maybe it is not top model but it is far away from cheapest on market.

[skom25 2179]

@Pylon80

I attached toothpick to chassis. It pointed directly into center of upper hole in horn. 

I moved servo both directions, fast, slow, quickly changed direction etc. and every time it returned to the same position.

Good to know that it is worth to check also that kind of things. Thank you!

[Kowalski86 4274]

On 11/22/2023 at 2:11 PM, Pylon80 said:

I suggest you make a test to confirm that you like how it returns to neutral. I have had one (1) bad experience with a similarly priced Savox, whereby it would not return to neutral which is very frustrating when driving.

I can vouch for double checking Savox servos, I had one of their "budget" models and while it was responsive, it wasn't great at returning to center consistently.

It's a bit silly, since most of my Bangood/no name servos return to center fine.

[skom25 2179]

I decided to go upgrade my XV-01. I do not want to replace parts just to have them. I am looking more for "nice to have".

What is installed already?

- TRF Servo Horn

- H/M/S Springs set

- Wheel Hexes with screws

- Front universals

- Carbon Shock Towers

- Aluminium Pulleys

- Aluminium Diff Covers

- Aluminium Turnbuckles

- Resin suspension balls

- Carbon Reinforced Parts

- Hard Hex Ball Connectors + Hard Rod Ends

Probably I missed some parts, but more or less it is as above.

Waiting for installation:

- Sway Bars

- Motor Fan Mount

- Rear Universals

- Aluminium suspension mounts ( not bought, but will order them tomorrow)

- Tamiya Hex screws ( Steel + Aluminium)

- TRF Shocks

However, I see some parts which are available:

- Aluminium Steering Set #54451 and # 54454. I wonder, if there is any advantage of this set over Carbon Reinforced.

- Diff Cross Shafts #54311. I do not want steel gears, because they increase resistance, but steel shafts look interesting and should make diff even smoother. Am I right?

Anything more what I missed?

 

[Rijkvv 66]

Just as I reserved a Savox SC0253MG for my XV-01, I read here that it might be a bit weak. 🤔

Did you replace the pinion for a steel one? You did mention it in the opening post, and it's something I upgrade on all of my vehicles.

[skom25 2179]

I have Hard Coated pinion which is also fine.

Mentioned Servo looks like bit weak. I think something between 6- 8 kg will be fine. I do not remember which model I have, but it is around mentioned range and is totally fine.