40% sailplane servo selection

[Mark9]

Steve,

The 7955 is max voltage of 6 V. Also, it has a lower torque rating. Also, it is .03 sec. slower over 60 degrees @ max V, doubt you be able to sense that though.

https://www.servocity.com/servos/hitec-servos

[JimD]

The HS-7955TG is rated for operation between 4.8-6.0 volts while the HS-7954SH Is rated for operation between 6.0-7.4 volts. I have used both of these in my planes using A123 2-cell 6.6 volt packs with no problems at all. Here is a link to e Hitec site:

https://hitecrcd.com/products/servos

[JimD]

BTW, my preference is for the HS-7955TG...just seems smoother to me because of the gear composition. Work just fine with the A123 packs.

[stevekremer]

Got the impression from Lens post that they both work at HV. If you run both at 6v, they are both rated the same torque. Is it better to get the HV whether you run it at 6v or 7,4v? That way if you upgrade to HV your servo is already there?

Steve K

[JimD]

My understanding is that the HS-7955TG is routinely used along with 2-cell LiPo packs with no problem. Was also told (by several people that should know) that electronics are identical, just different gears...but his is not stated by Hitec!

[lenb]

Yup.

Been operating them on HV for years. Its an untold truth. I actually did finally confirm it somewhere a while back.

[Mark9]

Guess all of what has been said lays question to published servo specs?

[gunny11]

You couldn't believe what you've read on the Internet and now you can't believe anything that's written on print! What's this world coming to?

[Sinkhappens86]

Yup.

Been operating them on HV for years. Its an untold truth. I actually did finally confirm it somewhere a while back.

Here's some confirmation from one of the Hitec guys, in case anyone was skeptical.

https://www.rcgroups.com/forums/showpost.php?p=40080015&postcount=61673

[lenb]

experience usually wins. I rather know someone who has actually done something than just reading about it.
( although that is what we're doing here isn't it)

[JimD]

In health care, this is known as an "off label" use.

Hitec has a new line of D servos that have direct replacements for the HS servos. Here is the one for the HS-7955TG

https://hitecrcd.com/products/servos/ultra-premium-digital-servos/d955tw/product