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Old 09-20-2015, 10:34 AM   #271
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Im also having the problem with steering. Bought a stronger servo and will change it next week. I will let you guys know if this solves my problem.
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Old 09-20-2015, 10:45 AM   #272
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Guys have you seen this cool video of the Sport 3?

https://www.youtube.com/watch?v=tVzl07JGxNo
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Old 09-20-2015, 11:14 AM   #273
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I'd love to be able to get camera view like that.
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Old 09-20-2015, 12:18 PM   #274
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Quote:
Originally Posted by Billy Kelly View Post
I'd love to be able to get camera view like that.
It has nice aerial shots.

Anyways, from all the posts I've read, I would do the following on the RS4 Sport 3.

1. Replace axles with CVDs from Spec R or 3Racing

http://www.tqrcracing.com/shop/produ....asp?p_id=1168

2. Replace servo (your choice) - personally I would replace the servo horn with this: http://www.spec-r.com/default/index....roducts_id=726

3. Replace links with adjustable turnbuckles

I would also:

1. Install a spool upfront (or rear. depends on what you want to do with the car) for better handling. http://www.hpiracing.com/en/part/114436

2. If installing a spool, I would get DCJs from here:

http://www.tqrcracing.com/shop/produ....asp?p_id=4351

Or this:

http://www.spec-r.com/default/index....roducts_id=244
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Last edited by SagadSetup; 09-20-2015 at 12:37 PM.
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Old 09-20-2015, 03:15 PM   #275
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Quote:
Originally Posted by Endaar View Post
This is HPI's strongest servo, the SF-50WP. The stock servo did the same thing which is what prompted an upgrade.

I just checked the voltage the receiver is sending to the servo, and it's 6V as expected. What am I missing?
If it has 160oz of torque as those specs show then it should easily return to center unless it has a bad servo motor pot and cannot properly sense its center point.

What you want to do is;
1. Charge battery and turn all power on including the radio.

2. Disconnect the servo turnbuckle and try and move the servo horn by hand.

3. Watch and determine if the horn moves/slips without the servo turning. If so then servo saver is at fault.

4. Or determine if the servo horn is not slipping on the servo but instead the servo output gear is able to turn/move by hand each direction. If so then faulty servo centering pot.

Another thing to do is try swapping servos between your 2 cars to see if it works better with different servo and servo horns.

Lastly check your radio steering wheel- is it turning freely or is it 'sticking' when you turn it?
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Old 09-21-2015, 07:57 AM   #276
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Yeah what is up with the HPI RTR servo? SF-50WP had weird claims online back when introduced by HPI as early as 2012. The reason I know this is it was the stock RTR servo I my 1/8 Apache C1 Flux I've sold already a year ago.

Try adding an external Castle 10A BEC and remove the center wire off the Esc to bypass the esc's onboard BEC. I am not sure which rebranded Esc HPI is using in the Sprint 3 Flux I have coming in this afternoon or early morning tomorrow but I'll take pics.

Either way other solution is to run the cheapest Savox metal gear digital waterproof servo like the SW-0231.

http://www.ebay.com/itm/NEW-Savox-Hi...25.m3641.l6368

I have that on my Bullet ST Flux no issues at all turning those big 2.8" tires even when not in motion. That servo should make easy work of any 1/10 TC the setup.
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Old 09-21-2015, 08:48 AM   #277
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True Alex, I removed my heavy duty HPI servo from my WR8 and installed a Protek and never looked back, just as Protek's advertising claims

Nice Protek servo with nice price. Not as good as my $120 KO servos but pretty darn good for $50!
http://www.amain.com/rc-cars/protek-...-100ss/p253591
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Old 09-21-2015, 03:17 PM   #278
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Quote:
Originally Posted by MikeR View Post
If it has 160oz of torque as those specs show then it should easily return to center unless it has a bad servo motor pot and cannot properly sense its center point.

What you want to do is;
1. Charge battery and turn all power on including the radio.

2. Disconnect the servo turnbuckle and try and move the servo horn by hand.

3. Watch and determine if the horn moves/slips without the servo turning. If so then servo saver is at fault.

4. Or determine if the servo horn is not slipping on the servo but instead the servo output gear is able to turn/move by hand each direction. If so then faulty servo centering pot.

Another thing to do is try swapping servos between your 2 cars to see if it works better with different servo and servo horns.

Lastly check your radio steering wheel- is it turning freely or is it 'sticking' when you turn it?
Thanks for the thorough reply and suggestions.

With the battery peaked and the servo saver tightened as much as possible, I can force the servo saver to move a little, but it requires a LOT of force and I think something in the suspension would break before it could exert that level of force on the servo. Nonetheless I tried replacing the servo saver with a fixed servo horn and the steering behaved the same.

The horn cannot be moved by hand with any reasonable degree of force.

This is the second servo in the car; the SF-50 was bought to replace the stock SF-10 on the assumption the steering issues were a result of the stock servo being too weak.

Without the steering linkage attached, the servo seems to have no issue centering consistently. Once the linkage is attached though it struggles to do so. It will get about 90% of the way back to center immediately, then you can hear the servo motor continuing to run for perhaps another 1/2 second, possibly pushing the wheels slightly further, before eventually stopping roughly 95% of the way back to what should be center.

The best way I can describe it is that the centering force of the servo doesn't seem strong enough to center the wheels, which seems crazy given the specs. And this is the second servo, so while I could write off the stock servo as being kinda weak I have trouble accepting that HPI's strongest servo has the same problem. It seems more likely the linkage is just terrible and doesn't give the servo enough leverage to move things properly.

Right now I'm struggling with a reason to spend $50 on yet another servo to hopefully fix things when for another $100 on top of that I can get a TC4 chassis that should work a lot better. I dunno...I want to like this car but the steering is terrible.

EDIT: I should add I'm just running this thing casually in the street. I'm not looking for out and out performance but given that I'm on a somewhat narrow street, having a car that doesn't wander is the difference between having enough room to play and frequently hitting the curbs.

Endaar

Last edited by Endaar; 09-21-2015 at 03:32 PM.
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Old 09-21-2015, 05:05 PM   #279
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Quote:
Originally Posted by Endaar View Post
Thanks for the thorough reply and suggestions.

With the battery peaked and the servo saver tightened as much as possible, I can force the servo saver to move a little, but it requires a LOT of force and I think something in the suspension would break before it could exert that level of force on the servo. Nonetheless I tried replacing the servo saver with a fixed servo horn and the steering behaved the same.

The horn cannot be moved by hand with any reasonable degree of force.

This is the second servo in the car; the SF-50 was bought to replace the stock SF-10 on the assumption the steering issues were a result of the stock servo being too weak.

Without the steering linkage attached, the servo seems to have no issue centering consistently. Once the linkage is attached though it struggles to do so. It will get about 90% of the way back to center immediately, then you can hear the servo motor continuing to run for perhaps another 1/2 second, possibly pushing the wheels slightly further, before eventually stopping roughly 95% of the way back to what should be center.

The best way I can describe it is that the centering force of the servo doesn't seem strong enough to center the wheels, which seems crazy given the specs. And this is the second servo, so while I could write off the stock servo as being kinda weak I have trouble accepting that HPI's strongest servo has the same problem. It seems more likely the linkage is just terrible and doesn't give the servo enough leverage to move things properly.

Right now I'm struggling with a reason to spend $50 on yet another servo to hopefully fix things when for another $100 on top of that I can get a TC4 chassis that should work a lot better. I dunno...I want to like this car but the steering is terrible.

EDIT: I should add I'm just running this thing casually in the street. I'm not looking for out and out performance but given that I'm on a somewhat narrow street, having a car that doesn't wander is the difference between having enough room to play and frequently hitting the curbs.

Endaar
Sure no problem. Hate to see your car struggle with that issue.
I guess the next step is to remove left and right turnbuckles and the servo link- then check to see that the left/ right steering knuckles move easily and then check that the steering rack moves easily. If one of these 3 areas are bound up then you've isolated a potential problem. Might be as simple as a screw or ball end is too tight.

But really tho a 160oz servo should not have any issues with that- unless the specs aren't real... in which case I would ship that servo back to the store or in the least have them help test the servo in your car.

If you are in the socal area I would be happy to check your car for you and try some of my servos. I still think the HPI servo(s) is the issue... never seen a good servo ship with a RTR... Bring your car to a local track- lots of experienced folks there happy to help remedy the steering I promise you. Even if you never race
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Old 09-21-2015, 08:21 PM   #280
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Quote:
Originally Posted by alexchen86 View Post
Either way other solution is to run the cheapest Savox metal gear digital waterproof servo like the SW-0231.

http://www.ebay.com/itm/NEW-Savox-Hi...25.m3641.l6368

I have that on my Bullet ST Flux no issues at all turning those big 2.8" tires even when not in motion. That servo should make easy work of any 1/10 TC the setup.
Can you confirm if that specific Savox servo fits in the Sport 3? It seems a little bigger than the HPI, which is already tight.

Thanks,
Endaar
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Old 09-21-2015, 08:26 PM   #281
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Originally Posted by MikeR View Post
Sure no problem. Hate to see your car struggle with that issue.
I guess the next step is to remove left and right turnbuckles and the servo link- then check to see that the left/ right steering knuckles move easily and then check that the steering rack moves easily. If one of these 3 areas are bound up then you've isolated a potential problem. Might be as simple as a screw or ball end is too tight.

But really tho a 160oz servo should not have any issues with that- unless the specs aren't real... in which case I would ship that servo back to the store or in the least have them help test the servo in your car.

If you are in the socal area I would be happy to check your car for you and try some of my servos. I still think the HPI servo(s) is the issue... never seen a good servo ship with a RTR... Bring your car to a local track- lots of experienced folks there happy to help remedy the steering I promise you. Even if you never race
Thanks very much again. The steering rack moves smoothly, so no issues there. I suspect you're right about the HPI servo so I'm going to do some more testing focusing on that. By time I get this resolved we'll have snow on the ground, lol. (I'm in NY, btw, but thanks for the offer.)

Endaar
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Old 09-21-2015, 08:40 PM   #282
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I have a savox 1258tg servo in one of my truggies and was going to try and fit it in and see if it makes a difference.

I will try and get a video of it or some pictures asap of it installed.
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Old 09-22-2015, 05:21 AM   #283
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Hello there,

I changed the original servo with an Graupner Servo 708 BB and the steering issues are almost solved.

When I turn to the left or right the steering Centers nice to the middle. So this is fixed.
I did a first test run yesterday evening and the steering was much better but not that good as I know it from my two sprint 2 chassis.
What was wrong?
2 or 3 times I had to re-calibrate the Center for the steering with my Radio control. Than it was fine for about 5-10 minutes.
I will check my steering and servo again and will let you guys know.

The servo fits perfect, its 1:1 like the original one. I paid about 35 for it.
To Change the servo I just had to open up 6 screws, that was really nice and I takes me only about 20 minutes.
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Old 09-22-2015, 05:45 AM   #284
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If you have time, please post pics of your chassis. I am very much interested in seeing your mods.

Regards!
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Old 09-22-2015, 08:53 AM   #285
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Hello everyone, I am new to this forum. Just got my first On-Road car, RS4 Sport 3 (have a few Off Road trucks). I am looking forward to learning a lot about these on road cars and a lot from you guys.

I am having the same issue with the front dog bone (really only the left one) popping out. I called HPI and they send me about 10 O-rings. Funny thing was when I took mine apart the right one had 1 O-ring on each side (wheel and Diff). the Left one only had one on the Diff side and there was a LOT of play in it. HPI told me to put two on the diff side. Those of you that used the O-rings did you put 3 total in (2 on the diff side and 1 on the wheel side). Seems to be OK that way but there is no play at all, I would think there needs to be some to allow the suspension to travel properly.

FYI I am going to order the SPEC-R CVDs today but this car has been down for 2 weeks and I would like to get some time on it.

Mike
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