modifying servos
shang
2-4 high torque futaba servos to swing a 4 bar linkage on a robot. Any help
would be appreciated. Thanks in advance.
Steve Thone
http://www.rdrop.com/~marvin/explore/servhack.htm
--
Steve Thone (sth...@home.com)
http://members.home.net/sthone/
Old enough to Know Better, Too Young to Care
Jim White
you can't do it.... at least without MAJOR mechanical mods that would
amount to building your own.... the feedback pots only turn 270
deg....
Jim White
AMA 2466
WB2WOY
WPMPA/BCF/PFC
SouthShoreSoftware
Treasure Island, FL
Ken Battersby
>"shang" <sk...@uiuc.edu> wrote:
>
>>Has anyone tried to make a servo turn 360 degrees? I'm attempting to modify
>>2-4 high torque futaba servos to swing a 4 bar linkage on a robot. Any help
>>would be appreciated. Thanks in advance.
>>
>
>you can't do it.... at least without MAJOR mechanical mods that would
>amount to building your own.... the feedback pots only turn 270
>deg....
>
>Jim White
Hi
Being interested in toy planes rather than toy boats I'm just
guessing, but what about a model yacht sail winch servo? Do they turn
360 deg?? I don't know for definite but I've definitely seen pictures
of these servos showing a pulley wheel on top, implying that they turn
through at least 360 deg.
Regards
Ken Battersby
To reply by Email please remove X from <GlobalnetX.co.uk>
Ted Burns
cameras, and did the following
The output gear on most servos has a stop - cut it off so it can turn
freely.
Disconnect the internal feedback pot and install an external one on the
"whatever" you are controlling. the pot should be about 5K ohms- common
variety will work but use what fits. I have used 10-turn pots for
applications that needed several "output" turns to do the job, but gearing
the output to the pot can would do it too.
You can "trim" the output throw by adding resistors to the "ends" of the
pot, for less throw, or, adding a "divider" to the wiper to get more throw.
The idea is to get the same voltage output at the full throw points as you
originally got before you modified the servo, measure one of yours before
you start, as they seem to vary depending on the model. By the way this
seems to work with all he newer servos on the market - if you have some old
(more than about 10 years old) servos that used the feedback pot to control
a one-shot it won't work - I don't think any recent manufacturer uses this
method anymore (viv la I.C.).
hope this helps.
Ted Burns
AMA 1150
N6PXA
Steve Thone wrote in message <36D78E92...@home.com>...
Pé Reivers
remove the arrester nock inside the servo housing, then add a 2 K-ohm to
each end of the pot. Use small resistors (1/8 watt) They will fit in the
corner between the motor and the housing. Now, if the resistor is chosen
right, there will be a larger servo arm travel, richt up to and over the 270
deg angle, If the servo is lightly loaded, it overshoots this position and
starts anew on the other side, hapily turning, and turning. A useless servo
of course, but fun!
Go for the external pot which has revolution reduction! Worrrrrrks like a
charm! In tis case, also remove the arrestor nock for the output shaft.
Pé Reivers
shang
that we won't use as a guinea pig. I'll let everyone know how that turns
out.
shang wrote in message <7b7jss$jko$1...@vixen.cso.uiuc.edu>...
A.T.
with robots and other items in the movie/TV industry here = also in
models which have motors mounted on a tube which rotates inside another
tube. The center tube has a pulley with belt to the winch servo and
allows vectored thrust for tug boats,harrier jets experimental
helicopter/planes like the Rotodyne etc.
see full specs at = http://www.khobby.co.nz/servo.htm
(NB 12.5% GST is deducted for exports from prices shown NZ$1 = US$0.55)
regards
Alan T.