RoboSavvy Forum

Info HS-M7990TH Hitec

2012-02-08T09:36:21+01:00

The thing i like most about servos is that Digital servos do not need to be programmed to operate. They work great right out of the box and purchasing a programmer is not mobile spy necessary.

Statistics: Posted by kenp — Wed Feb 08, 2012 9:36 am

Info HS-M7990TH Hitec

2011-10-17T23:38:23+01:00

I-BOT, you were really so good.

I now have a better understanding of the various issues.

Before this post, I was tempted to buy a pair.

But now I think I'll have to read up more before I go to spend a lot of money for nothing.

My dream to make Robonova hip is still far away.

I'm trying with 5980SG, but how strong are they heat up and hiss a lot when I go to lift leg sideways.

thank you again.
landyandy

EDIT:
I was wrong to insert the image.
These are the 5498SG.
However, it is the same thing with 5980SG.
Much less, but unfortunately are not as strong as I would like.

Statistics: Posted by Landy — Mon Oct 17, 2011 11:38 pm

Info HS-M7990TH Hitec

2011-10-17T20:44:28+01:00

The positioning does not depend on the HMI extensions to the PWM protocol. The position is determined in a closed loop within the servo in proportion to the pulse width.

I do not know much about the HS-M7990, especially since it has a magnetic encoder and so unknown angular range. The C3024 is set for a specific relationship of pulse width to angle. You may need to adjust the servo parameters in the HS-M to give the same as an HSR. Alternatively you could adjust software values or mechanics if this is not a direct replacement.

The reading of the position is used for capturing poses into Robobasic. Very valuable, but not essential.

Statistics: Posted by i-Bot — Mon Oct 17, 2011 8:44 pm

Info HS-M7990TH Hitec

2011-10-17T17:51:29+01:00

Thanks for the answer.
Now everything is clear.

The major difference is that the HMI protocol is used by the C3024 to read the servo position. This means that the functions in Robobasic which read the position will not work with the HS-M

....This means, (sorry if I'm not sure) that if I enter through RoboBasic command "move 100 100 ecc." servo motors will not line up in the right position because it lacks the "feedback" that only through "HMI" can be achieved.

Right?

Too bad because this really is a beautiful servomotor.

greetings.
landyandy

Statistics: Posted by Landy — Mon Oct 17, 2011 5:51 pm

Info HS-M7990TH Hitec

2011-10-17T15:05:20+01:00

As you already noted the HSR servo is HMI and the HS-M is not.

The C3024 sends PWM signals in the range 550 to 2450 us as described here:
http://robosavvy.com/Builders/i-Bot/HSR ... 0Servo.pdf

The C3024 is capable of sending PWM to either the HSR or the HS-M servos, but you need to check the range of angle to pulse duration.

Programming of the HSR is done with an HMI programmer, and I understand the HS-M is programmed using the special Hitec servo programmers. The C3024 does not program the servo in normal operation. You may need to do some programming to get the same range of rotation.

The major difference is that the HMI protocol is used by the C3024 to read the servo position. This means that the functions in Robobasic which read the position will not work with the HS-M

Statistics: Posted by i-Bot — Mon Oct 17, 2011 3:05 pm

Info HS-M7990TH Hitec

2011-10-17T13:25:36+01:00

Hi all, I was wondering if anyone has knowledge about the servomotor in the picture.

Control System: +Pulse Width Control 1500usec Neutral
Required Pulse: 4.8-7.4 Volt Peak to Peak Square Wave
Operating Voltage Range: 4.8-7.4 Volts
Operating Temperature Range: -20 to +60 Degree C (-68F to +140F)
Operating Speed (6.0V): 0.21 sec/60° at no load
Operating Speed (7.4V): 0.17 sec/60° at no load
Stall Torque (6.0V): 500oz/in. (36kg.cm)
Stall Torque (7.4V): 611oz/in. (44kg.cm)
Operating Angle: 45 Deg. one side pulse traveling 400usec
360 Modifiable: No
Direction: Clockwise/Pulse Traveling 1500 to 1900usec
IdleCurrent Drain (6.0V): N/A (Testing Now)
Current Drain (4.8V): N/A (Testing Now)
Current Drain (6.0V): N/A (Testing Now)
Dead Band Width: 1usec
Motor Type: Coreless Carbon Brush
Potentiometer Drive: Magnetic Encoder
Bearing Type: Dual Ball Bearing MR106
Gear Type: Titanium Gears
Connector Wire Length: 11.81" (300mm)
Dimensions: 1.72" x 0.88"x 1.57" (43.8 x 22.4 x 40mm)
Weight: 2.76oz (78.2g)

In particular I would like to know if I can use it to replace an HSR-5990TG, by using the classical MR-C3024 board used on the Robonova.

Control System: +Pulse Width Control 1500usec Neutral
Required Pulse: 3.3-7.4 Volt Peak to Peak Square Wave
Operating Voltage Range: 4.8-7.4 Volts
Operating Temperature Range: -20 to +60 Degree C (-68F to +140F)
Operating Speed (6.0V): 0.15 sec/60° at no load
Operating Speed (7.4V): 0.12sec/60° at no load
Stall Torque (6.0V): 333.29 oz-in. (24kg.cm)
Stall Torque (7.4V): 416.61 oz-in. (30kg.cm)
Standing Torque (6.0V): 433.27 oz-in. (31.2kg.cm) 5 degree deflection
Standing Torque (7.4V): 541.59 oz-in. (39kg.cm) 5 degree deflection
Operating Angle: 60 Deg. one side pulse traveling 450usec
360 Modifiable: Yes
Direction: Clockwise/Pulse Traveling 1500 to 1950usec
Idle Current Drain (6.0V): 3mA at stop
Idle Current Drain (7.4V): 3mA at stop
Current Drain (6.0V): 300mA/idle and 4.2 amps at lock/stall
Current Drain (7.4V): 380mA/idle and 5.2 amps at lock/stall
Dead Band Width: 2usec
Motor Type: Coreless Metal Brush
Potentiometer Drive: 6 SliderIndirect Drive
Bearing Type: Dual Ball Bearing MR106
Gear Type: 4 Titanium Gears
Connector Wire Length: 11.81" (300mm)
Dimensions: 1.57" x 0.78"x 1.45" (40 x 20 x 37mm)
Weight: 2.18oz (62g)

On the site I have seen both of which are driven with the same width PWM.
My doubt is primarily the HMI is lacking and therefore I can not program it without his specific program.

Can you give me more information please?

P.S. sorry for my bad english.

best regards.
landyandy

Statistics: Posted by Landy — Mon Oct 17, 2011 1:25 pm