Steering servo replacement - need help

[drabina]

I bought Hitec HS-645MG servo to replace a non-working steering servo in my TwinHammers. The original servo has an additional gear (silver one) mounted on top of the servo's gear (gold). Any ideas how to remove it? It looks like the additional gear is stuck on the servo and I do not have a puller that's small enough.

Photo shows the original servo with the additional gear.

[dbuus]

With violence...
I did it with violence

[nosyajg]

place a lat head screwdriver between the bottom of the gear and servo case, and twist...keep doing this while moving the flat head around the circumference of the gear...that's how i got mine off...

[KxRacer4]

What servo do you guys recommend? Ordered my TH a while ago and was gonna go ahead and order a steering servo. Would like something that's not gonna break the bank though, thanks.

[drabina]

Thanks for the replies. Flat head screwdriver with a little violence did the trick.

KxRacer4: I just installed a Hitec HS-645MG servo as a replacement. Paid $26 at my LHS. No runs on the car yet as I have to work on some cable management issues.

[KxRacer4]

Originally Posted by drabina

Thanks for the replies. Flat head screwdriver with a little violence did the trick.

KxRacer4: I just installed a Hitec HS-645MG servo as a replacement. Paid $26 at my LHS. No runs on the car yet as I have to work on some cable management issues.

Did the spacer fit on the Hitec servo? I have heard they have a different number of teeth.

[drabina]

Originally Posted by KxRacer4

Did the spacer fit on the Hitec servo? I have heard they have a different number of teeth.

It didn't fit. The adapter was 25T and the servo is 24T. I had to use servo horn supplied with the servo. I think Vaterra sells servo horns with four different adapters. I may get that as the servo horn supplied with the Hitec is not as sturdy as the original one.

[meatmonkey]

Yeah, it seems that most RTR servo's use a 25 spline horn, but most Hitecs (except for some of their newest models) use a 24 spline.

I ended up not running the stock horn as I felt there was too much slop between the metal adapter piece and the plastic horn. I'm currently running the slim blue aluminum horn that comes with most Hitec servos with the hole drilled out to just-shy of 3mm so the bolt threads through the horn with a jamb nut on the backside.

I think your going to find that even a 645 isn't enough torque for the Twin Hammers, especially if your rock crawling with a locked front diff. If you exclusively bash at speed it may be suitable.

I'm running a 7950 and still occasionally want more torque. I know it's one of the more expensive servos on the market, but cheap servos just don't last in crawlers, and replacing the servo is quite a bit of work on the Twin Hammers, so I wanted reliability foremost.

[KxRacer4]

So maybe a Savox 1256TG? There very expensive though, maybe I can find one on eBay.