Go Back   RCCrawler Forums > RCCrawler General Tech > Electronics
Loading

Notices

Thread: xr10 servo 7980,7950 or s9157

Reply
 
LinkBack Thread Tools Display Modes
Old 06-14-2011, 11:27 AM   #1
RCC Addict
 
Join Date: Oct 2009
Location: Nanaimo, BC (Vancouver Island)
Posts: 1,153
Default xr10 servo 7980,7950 or s9157

So I have a jr8711 that has just a little bit of gear trian slop and that is just not gonna do for me and my pricy xr10. I rebuilt it with a new case and gears and it's way better but my old 5955tg has zero slop after years of use in my 6.5lb creeper and had no issues other than it runs rather hot. So here is my issue, I can get a hitec 7950th, 7980th or a futaba s9157. What is the best voltage to run the hitec hv servo's at safley. I hear alot of people fry them running at 7.4v. I'm using the futaba r2104gf rx from my 4pl rated up to 8.4v

I wanna know if the 7980th will fit without mods, I have the bwd servo mount so thats all good but does anything on the axles need to be shaved for clearance, will my rowdy servo protector work with it?

Issue with the futaba I'm having is that I don't want it to develop gear slop too since it is steel geared but I have no experiance with them to know so hoping someone can let me know how it works.

The 7950th sorta seems like the best option cause the rowdy servo protector I have will work with it, has lots of torque and is ti geared so I assume it wont develop any slop like my 5955tg

This is a hard decision because it sorta comes down to price here since I can purchase all of them at a similar one but I don't wanna hack stuff to make it fit, it has to be protected with a servo plate and it MUST NOT HAVE ANY SLOP

Thanks for whatever input you have for me.
Kurt

Last edited by kurtus; 06-16-2011 at 05:23 PM.
kurtus is offline   Reply With Quote
Sponsored Links
Old 06-14-2011, 11:51 AM   #2
I wanna be Dave
 
Join Date: Nov 2010
Location: 07456 N. NJ USofA
Posts: 8,314
Default

I recently bought a 7950 to upgrade my 7955, power seems good.
The 7950 is rated to 7.4VDC, the 7955 is rated to 6.4VDC (IIRC), thus you should have no issues with the 7950 @ 7.4VDC.
This is in a 2.2 Bully @~6.7lbs

The 7980 is a stronger servo, but a tiny bit bigger in all dimensions. You can look up the sizes online to see if it creates a clearance issue.
Charlie-III is offline   Reply With Quote
Old 06-14-2011, 11:53 AM   #3
20K Club
 
Harley's Avatar
 
Join Date: Jul 2004
Location: Sending illegals home one Hayabusa at a time.
Posts: 22,981
Default

BLS157 would be the servo to get. Over 500 oz/in of power at 7.4 and in a standard size case.
Harley is offline   Reply With Quote
Old 06-14-2011, 01:36 PM   #4
RCC Addict
 
Join Date: Oct 2009
Location: Nanaimo, BC (Vancouver Island)
Posts: 1,153
Default

Quote:
Originally Posted by Harley View Post
BLS157 would be the servo to get. Over 500 oz/in of power at 7.4 and in a standard size case.
funny you mention that cause I was just about to start looking ito this one. Thx
kurtus is offline   Reply With Quote
Old 06-14-2011, 01:39 PM   #5
RCC Addict
 
Join Date: Oct 2009
Location: Nanaimo, BC (Vancouver Island)
Posts: 1,153
Default

Quote:
Originally Posted by Charlie-III View Post
I recently bought a 7950 to upgrade my 7955, power seems good.
The 7950 is rated to 7.4VDC, the 7955 is rated to 6.4VDC (IIRC), thus you should have no issues with the 7950 @ 7.4VDC.
This is in a 2.2 Bully @~6.7lbs

The 7980 is a stronger servo, but a tiny bit bigger in all dimensions. You can look up the sizes online to see if it creates a clearance issue.
I think the 7980 is going to be more of a pain in the ass and overkill just hard to decide because of the 7 dollars differance here, I see guys are pulling their 7950 out and replacing with the brushless futaba servo's so I may look into that as well. I am really just looking for peoples bad experiances with these so I can determine whats the best fit for me. Thx for the reply.
kurtus is offline   Reply With Quote
Old 06-14-2011, 01:41 PM   #6
I wanna be Dave
 
Join Date: Sep 2005
Location: Houston, TX
Posts: 16,952
Default

Quote:
Originally Posted by kurtus420 View Post
I see guys are pulling their 7950 out and replacing with the brushless futaba servo's so I may look into that as well.
Actually, I did just the opposite. Futaba was not making any replacement gears for their servos for a while and I got tired of waiting to fix my three broken BLS152 servos....
JeremyH is offline   Reply With Quote
Old 06-14-2011, 02:29 PM   #7
RCC Addict
 
Join Date: Oct 2009
Location: Nanaimo, BC (Vancouver Island)
Posts: 1,153
Default

Quote:
Originally Posted by JeremyH View Post
Actually, I did just the opposite. Futaba was not making any replacement gears for their servos for a while and I got tired of waiting to fix my three broken BLS152 servos....
Thx, that's what I need to hear cause I'm done replacing gears so futaba may just give me the same outcome as my jr. Looks like the 7950th is possibly the most logical purchase, any bad experances with that servo and why are people replacing the 7950 with anything else?
kurtus is offline   Reply With Quote
Old 06-14-2011, 02:35 PM   #8
I wanna be Dave
 
Join Date: Sep 2005
Location: Houston, TX
Posts: 16,952
Default

Well, I run the 7950 in my 2.2 because of the standard size....it has the power to throw the truck around when I need it.
JeremyH is offline   Reply With Quote
Old 06-14-2011, 02:43 PM   #9
RCC Addict
 
Join Date: Oct 2009
Location: Nanaimo, BC (Vancouver Island)
Posts: 1,153
Default

sweet, my buddy fred0000 is running one and really likes it but he's running it at 6v because of the wantamix he uses with his 3r. What voltage you running at?
kurtus is offline   Reply With Quote
Old 06-14-2011, 02:47 PM   #10
TSK
Shelf queen
 
TSK's Avatar
 
Join Date: Aug 2008
Location: Internet
Posts: 5,857
Default

On the Hitecs, if you are worried about frying them, I heard that setting the overload protection value to 10% does wonders in saving them.
TSK is offline   Reply With Quote
Old 06-14-2011, 02:53 PM   #11
Quarry Creeper
 
Join Date: Aug 2009
Location: Phoenix
Posts: 224
Default

I was running a CS170 (7955TG) on my XR and changed out to the 7950TH just before our Summer Shootout.

There are a lot of guys in our club running the 7950TH as well.

My old setup was the CS170, BEC @6.1 volts powering rx and wantamix with 2 Mamba Micro Pro's (power wire removed to rx) with a DX3R.


With the new 7950TH I changed it up with BEC @7.4 volts direct to servo with Y-harness and Yellow and Black wire going to RX, wantamix with the 2 mmp's with one esc powering the RX with a DX3R.

I like it so far with no issues.
AZrcdriver is offline   Reply With Quote
Old 06-14-2011, 02:55 PM   #12
RCC Addict
 
Join Date: Apr 2010
Location: Ringwood
Posts: 1,233
Default

Hitec 7954 at 7.0v and in a 6.9oz bully no problum
asw27x is offline   Reply With Quote
Old 06-14-2011, 03:02 PM   #13
RCC Addict
 
Join Date: Jul 2009
Location: Santa Rosa, CA
Posts: 1,349
Default

I'm not impressed with my 7950 at 6v. I would turn it up to 7v, but my rx can't handle it.
shelby is offline   Reply With Quote
Old 06-14-2011, 03:45 PM   #14
I wanna be Dave
 
Join Date: Nov 2010
Location: 07456 N. NJ USofA
Posts: 8,314
Default

Quote:
Originally Posted by shelby View Post
I'm not impressed with my 7950 at 6v. I would turn it up to 7v, but my rx can't handle it.
Which is why most of us run an external BEC wired direct to the servo, you leave the RX out of it.
Charlie-III is offline   Reply With Quote
Old 06-14-2011, 03:51 PM   #15
RCC Addict
 
Join Date: Oct 2009
Location: Nanaimo, BC (Vancouver Island)
Posts: 1,153
Default

Great replies guys, thx so much. I'm going for the 7950th and I'll run it at 7v to get that little extra life out of it, I'm fine with my rx running high voltage so I wont need to rewire my rig. Thats a great tip on the overload protection SCorpionKing, might have to get a programmer with the money I saved would be really handy to have thats for sure.
kurtus is offline   Reply With Quote
Old 06-14-2011, 03:52 PM   #16
cherry bomb
 
fred0000's Avatar
 
Join Date: Jul 2006
Location: Nanaimo, BC, Canada
Posts: 1,598
Default

Quote:
Originally Posted by kurtus420 View Post
sweet, my buddy fred0000 is running one and really likes it but he's running it at 6v because of the wantamix he uses with his 3r. What voltage you running at?
I was talkin to losikid (he curently builds the wantamix units) and he figures it can handle up to about 12v, so i'll be upping my voltage to 7.4 and see how it goes.

I am happy with the performance at 6v, but you can never have steering thats "too good" I upgraded from a HS-7954SH that I ran at 6v aswell.
fred0000 is offline   Reply With Quote
Old 06-14-2011, 04:06 PM   #17
RCC Addict
 
Join Date: Oct 2009
Location: Nanaimo, BC (Vancouver Island)
Posts: 1,153
Default

Quote:
Originally Posted by fred0000 View Post
I was talkin to losikid (he curently builds the wantamix units) and he figures it can handle up to about 12v, so i'll be upping my voltage to 7.4 and see how it goes.

I am happy with the performance at 6v, but you can never have steering thats "too good" I upgraded from a HS-7954SH that I ran at 6v aswell.
Well if your running at 7.4v we gotta at least be equal, I'm not giving you the upper hand here buddy
kurtus is offline   Reply With Quote
Old 06-14-2011, 04:32 PM   #18
TSK
Shelf queen
 
TSK's Avatar
 
Join Date: Aug 2008
Location: Internet
Posts: 5,857
Default

Quote:
Originally Posted by kurtus420 View Post
Great replies guys, thx so much. I'm going for the 7950th and I'll run it at 7v to get that little extra life out of it, I'm fine with my rx running high voltage so I wont need to rewire my rig. Thats a great tip on the overload protection SCorpionKing, might have to get a programmer with the money I saved would be really handy to have thats for sure.
The servo programmer is handy, but be sure to just download the software from hitec. it's much easier than trying to use the programmer alone.
TSK is offline   Reply With Quote
Old 06-14-2011, 05:21 PM   #19
RCC Addict
 
Join Date: Oct 2009
Location: Nanaimo, BC (Vancouver Island)
Posts: 1,153
Default

Quote:
Originally Posted by TheSCorpionKing View Post
The servo programmer is handy, but be sure to just download the software from hitec. it's much easier than trying to use the programmer alone.
thx
kurtus is offline   Reply With Quote
Old 06-14-2011, 05:34 PM   #20
Rock Crawler
 
Join Date: Apr 2010
Location: Kelowna, B.C., Canada
Posts: 529
Default

Quote:
Originally Posted by kurtus420 View Post
Great replies guys, thx so much. I'm going for the 7950th and I'll run it at 7v to get that little extra life out of it, I'm fine with my rx running high voltage so I wont need to rewire my rig. Thats a great tip on the overload protection SCorpionKing, might have to get a programmer with the money I saved would be really handy to have thats for sure.
But with the 7980 you can do this



Or this



I don't think with the 7980 and servo protector you would have to do many mods. I was able to get standard servo clamps to fit. It is only about1-2mm bigger in each dimension. On my xr it never gets warm and I have never stalled it out

The 7980 also has slightly bigger gears which will help with the strength of them.

Last edited by ax-10 crazy; 06-14-2011 at 05:36 PM.
ax-10 crazy is offline   Reply With Quote
Reply



Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 12:00 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO ©2011, Crawlability, Inc.
Copyright 2004-2014 RCCrawler.com