# Need howto for homebrew power servo



## fritz42_male (May 5, 2009)

I remember seeing somewhere a howto on how to make you own high power servos.

Does anybody have a link to this please?


----------



## spinman1949 (Jun 29, 2009)

*Doc did this.*

Doc used a wiper motor and a driver board board from a servo that as I recall he utilized the signal output to drive some op amps. I will look for the thread. In fact I just got a recent response from him re this. Search that Dragon thread. I mentioned automating the prop and mentioned his power servo. He is in process of working on a prop using them.

Found it. http://www.hauntforum.com/showthread.php?t=12435&highlight=servo

Here is the link you want. The first link is Doc discussing how he will use the Monster Servo's

http://www.hauntforum.com/showthread.php?t=10575&highlight=mosfet

PS. I think I meant to say mosfet instead of op amps. Regardless. His thread explains how he does it.

PPS. Oh and this you will want to look at. http://www.lynxmotion.com/Product.aspx?productID=648&CategoryID=52


----------



## fritz42_male (May 5, 2009)

Thanks very much Tom.

However none of these look like the article I saw (which wasn't on Hauntforum). I'll keep looking and will post the link when and if I find it.


----------



## Dr Morbius (Sep 21, 2004)

I remember seeing one too, but I can't find it either. I'll keep looking and let you know.


----------



## Dr Morbius (Sep 21, 2004)

Is this the one?
http://homepages.which.net/~paul.hills/Circuits/PowerServo/PowerServo.html


----------



## fritz42_male (May 5, 2009)

Nope - not that one either but thanks for trying.

I have a feeling that the one I saw was based on the Lynxmotion board in Spinman's post but had lots of actual pictures showing the setup


----------



## spinman1949 (Jun 29, 2009)

*Docs post.*

The link Doc found made my eyes do a Marty Feldman. LOL !!!

"Holy Crappers Batman, all we want is some extra torque? "


----------



## HomeyDaClown (Oct 3, 2009)

How much torque do you need? 

Wiper motors vary in torque but I believe most supply between 8 and 12 ft.-pounds of torque.

You can always use a Hitec HS-805BB Mega Torque servo which is rated for 
275 ounce-inches (about 1.5 ft.-pounds) of torque at 4.8V or
343 ounce-inches (about 1.8 ft.-pounds) of torque at 6.0V. 

They run about $30


----------



## fritz42_male (May 5, 2009)

A wiper motor is exactly what I was thiking of using.

In the meantime, I found this

http://www.lynxmotion.com/images/html/ht01.htm


----------



## hpropman (Jul 27, 2008)

Fritz that board will not provide enough current for a wiper motor. A smaller motor maybe what are you going to be moving.


----------



## fritz42_male (May 5, 2009)

Hi mate, the HS5475 board info says it provides up to 4.5A with 2A continuous at 6V. I'm aware that a wiper motor can pull more than this although I might do some tests to see just how much it pulls under moderate loads.

For smaller motors the HS5475 ought to be fine though - I'm going to trawl around and look for geared motors to play with.


----------



## hpropman (Jul 27, 2008)

Try this one. It works really well - it should be fine for light loads ~2 lbs - I will need to check the current though I think it is about an amp. I am using one for my peeper I can test the current if you like also they are using them for FCG


----------



## fritz42_male (May 5, 2009)

No link?


----------



## hpropman (Jul 27, 2008)

sorry here it is:

https://www.surpluscenter.com/item.asp?UID=2009112315303278&item=5-1587&catname=electric


----------



## azdude (Jun 26, 2009)

If you are wanting to stay with a standard servo motor system you should look here at the "Pan" and "Tilt" systems that servo city offers. These are essentially gear boxes bolted onto standard servo motors that get you a huge increase in torque. I have used their 'medium duty' pan motors for 2 props I built and have had no problems.


----------



## fritz42_male (May 5, 2009)

Thanks for the links guys. I also came across this link. It uses Picaxe chips as well which makes it convenient.

http://letsmakerobots.com/node/1524


----------

