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Steering issues and brake failure

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S

Spikes

RCTalk Basher
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Rogers, Ar.
RC Driving Style
  1. Bashing
I bought a used Savage with a Ofna .26 pull start. It's a really fun truck to run, except for one inherited issue and one new one.

I was wearing my dog out (she can keep up with full speed runs by running a smaller diameter circle) doing circle laps on a flat two acres of mowed grass last weekend. I was occasionally stopping to pull a nice wheelie or hitting a little natural ramp for some air when I tried to stop to avoid a tree in the path and the truck kept going. There were no brakes whatsoever. I rolled it to a stop and the brake disks were just spinning on the driveshaft.
I didn't look in to this yet, but I assume I will need a new brake hub assembly and brake disc.

My biggest problem, however, is that it takes a full acre to turn a circle with this truck.
My T-Maxx will turn a fairly controllable and tight circle. It will flip over if I don't slow down before tweaking a tight turn. The Savvy, however, will turn the tires fine when held off the ground and will turn fairly well under acceleration, but takes a full acre of land to do a circle. Under the right conditions I can do laps full throttle and full steering lock all day with no rollovers. The tires flop around like there's just a thin rubber band holding them over.

I have tightened the servo saver and realize I need to shave some plastic off the workings, but please - with fresh batteries - is this not a bit much?
 
poopy servo....You need something with real torque. 200 oz at least. Also a good rechargeable 5 cell 6.0 volt rx pack, I assume you are saying that you are using alkalines, only 4.8 volts. The savage is just too heavy for that.
Buy the Savage X brakes and hub off E-Bay.
Oh yeah, one more thing....tighten the steering tie rods a little equally. This will make the front tires toe out and increase initial steering response drastically.
 
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Spikes said:
My biggest problem, however, is that it takes a full acre to turn a circle with this truck.
Click to expand...

I almost (literally) threw my Savage in a ditch when I first bought mine because of that. Drove me nuts.


Sounds like your running one of the earlier savage models. If so, then with what you explained it still has that stock steering saver in it. Replace that thing asap..its junk. (That mod will help greatly)

The stock steering servo is weak...what are you running for a steering servo? Check your steering linkage. You may can adjust so that if gives you a better turning radius.
 
Scrogg said:
poopy servo....You need something with real torque. 200 oz at least. Also a good rechargeable 5 cell 6.0 volt rx pack, I assume you are saying that you are using alkalines, only 4.8 volts. The savage is just too heavy for that.
Buy the Savage X brakes and hub off E-Bay.
Oh yeah, one more thing....tighten the steering tie rods a little equally. This will make the front tires toe out and increase initial steering response drastically.
Click to expand...

Once again, thanks for the input!

I haven't looked into different servos yet, so that will be a fun shopping experience...

I really want a rechargeable RX pack but price and lack of need have been hold backs. I clearly need power for steering here though.

Do you know of a reasonably priced servo that will work for this truck?

Thanks!!!!!

wannarunem said:
Sounds like your running one of the earlier savage models. If so, then with what you explained it still has that stock steering saver in it. Replace that thing asap..its junk. (That mod will help greatly)

The stock steering servo is weak...what are you running for a steering servo? Check your steering linkage. You may can adjust so that if gives you a better turning radius.
Click to expand...

I have no idea what steering servo or saver I am running. It is an earlier setup. What do I need to search for to order parts? Sorry I'm so vague here, but I just got started with the T-Maxx before I got the fever and bought the Savvy!!!!
 
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wannarunem said:
I have this servo in my savage...works great.

http://www.servocity.com/html/hs-645mg_ultra_torque.html
Click to expand...

Little quicker, stronger, cheaper:
http://www.horizonhobby.com/Products/Default.aspx?ProdID=JSP20071

Really though, if you want a servo that's strong, quick and will last a good long time, bite the bullet and step it up a bit:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXMUS4&P=ML

Ran one in my revo for a good amount of time for steering and it slapped the tires around without a problem. I use them now as throttle/brake servos in my savage and aftershock. I run stock 590's (two) on my aftershock for steering and I got a hella deal at my LHS 3 years or so ago on a nice JR digital that I use on my savage for steering. If I didn't have that though, I'd have another 985MG in it's place.

Sometimes it pays to pay a little more. Servo's and engines are two of those things you should spend a bit more on. Believe me, I've learned that lesson many times over the years. ;) I'm 100% basher and it's frustrating to have a cheap servo end your day or a picky "cheap" engine ruin a bash session or 10...

If you don't have the adjustable saver that wannarunem posted, get it. 10 times better than the servo mounted variety. Then you just use a solid horn on the servo.
 
Spikes - you wrote "I rolled it to a stop and the brake disks were just spinning on the driveshaft. I didn't look in to this yet, but I assume I will need a new brake hub assembly and brake disc."

That may not be the case as you may have snapped or lost the long tail grub screw (Screw shaft) locking the brake hub/drive cup to the drive-shaft and need to replace that instead. There may be other issues, but given your description...

I ditto Olds comments above.
The Hitec that he recommended is close (at 6V) to the magical 200oz.in. that you want in a steering servo for a truck of this size.
You should notice a vast improvement if you upgrade the servo. While you're at it replace the AA's with a rechargeable battery pack.

The AA's give you 4.8V while the rechargeable battery pack will give you 6V.
May not sound like much, but it will make a world of difference with the servo's performance and it will cost you less in the long run. You can also set it up to recharge so you don't have to go digging into the receiver/battery compartment every time you want to run it. You can find adequate battery/charger combos for under 20 bucks.

FYI - If it doesn't already have one - get and install a failsafe - cheap insurance.
 
The servos do have SF-1 and SF-2 on them. I'll start E-Baying for parts.

What do I need to look for on the rechargeable battery setup for around $20? I see Harbor Freight has a nice temp gun on sale 'till Jan 1st too! :)

I truly appreciate all you guys' help. I'm going to go through and read all the links now.

I did toe the wheels out a little. Thanks, Scrogg. That helped a little. I can see now how much the servo saver is flexing. That's insane!
 
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You have the original servos.
The SF-1 is basically worthless.
However you can save some money by reusing the SF-2 as your throttle/brake servo.
It'll provide you with adequate service in this role.
 
Servo saver kit ordered. What charger do I need for the Orion Marathon 1600mah hump pack?

The servo will have to wait until after Christmas. We are buying another house right now and the wife is about to have a melt down. :)

Thanks!
 
Metalhead Matt said:
Any charger that will charge around .08 amps and is 5 cell compatible.
Click to expand...

Should that read ".8 amps"? Usually, your safe charging receiver packs at 1A for quick charge (still will be 1.5 hours for a 1500mah pack thats dead). I charge mine with a charger that does .5A to not stress the pack so much while charging.

A cheap wall charger will do the trick as well, you will have to wait overnight though.

This pack comes with a wall charger:
http://www.onlybatterypacks.com/showitem.asp?ItemID=11130.17

Not a bad deal for $22.
 
The one in the pic will be fine. You will not even have to unplug it or remove it from the truck. Let the charge lead hang outsside the rx box.
i charge my packs @ 1-2 amps, never had one die, blow up or any problems.
 
Sorry, didn't realize the site did that.

This one is what I usually go with:
UNIVERSAL-JR/Hitec/Airtronics Male (BATTERY SIDE)

It's a 3-pin connector that helps avoid plugging things in wrong. Even then, if it doesn't fit into whatever you need to plug it into, you can always trim the 3rd empty hole off.

Most receivers are 3 hole with the negative(black) closest to the edge of the case.
 

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