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View Full Version : Firgelli L12 versus Hitec 5990TG



Vsions
08-24-2008, 07:58 PM
Hi Everyone, I am new to this hobby. I just started building a machine using the Lynxmotion SES system. I am currently waiting to purchase some firgelli L12 actuators for the arms thinking they would be more powerfull than a 5990TG, but I read some one on the forum saying that the power coming from an L12 translates to:


100mm (63:1 reduction): 14N = 50oz
50mm (210:1 reduction): 45N = 162oz


compared to about 416oz. Does this mean that I should stick with the 5990TG? I know there is a price difference, but that is not one of my deciding factors. I thought linear force would be better than rotational force but I am very new to this hobby and have alot to learn. I would appreciate any helpful advice on this stuff. thanks


Dennis

sam
08-24-2008, 08:09 PM
That's waht I thought when I saw Firgelli.First :

Do you think they are small enough for the SES?

Second, it will be different. If you put your actuator 1 inch from the center of rotation, it will give you the specs given. If it is at 2 inches, it will give you 324 oz. in. 3 inches 486 oz.in.

If you want the torque mesurement you must multiply the strengh of the actuator by how far it is from the center of rotation. Thus you get the mesure oz./in or pounds/feet or kg/cm.

The problem is when you put it further from the center, it takes a longer time to get the full movement of the arm. It's not a bad idea. :wink:

4mem8
08-24-2008, 08:18 PM
Vsions: Welcome to this forum, Personally I would stick to the HSR5990 servos, Are you building a humanoid or hexapod? Humanoid will need more Torque 330oz @ 6v and 440oz @7.4v, Just my two cents worth.

sam
08-24-2008, 08:26 PM
Forgot to say welcome! :sad:

If you are new to robotics I would stick with the 5990's. You might be more difficult making precise movement with lianear actuator. you would probably have to make a big part of your code.

I sincerly hope you stay in robotics! It's so much fun and so much to discover!

DresnerRobotics
08-24-2008, 08:43 PM
The Firgelli's Actuators in question are actually controllable via PWM, so no different than a servo. Now that said- these type of actuators aren't going to compare to an HSR-5990TG until you look toward much larger versions. Also keep in mind that the higher torque they are, the slower they usually are. I wouldn't suggest using these as the main actuator on a humanoid until the technology has matured a bit, or you're looking at a large scale industrial-grade project.

Vsions
08-24-2008, 08:52 PM
Thanks guys, I appreciate all the info. I guess I will stick to the 5990. Sam I saw you mentioned the coding aspect and I am very much terrified of that part cause I dont know anything about that at all, I have never done anything like that. But I like building stuff and felt it was something I would tackle with alot of help from this forum. Eventually I hope to learn enough to contribute to this forum and be as helpful as you guys are.

Vsions
08-24-2008, 08:56 PM
By the way here is a WIP of my machine

http://i331.photobucket.com/albums/l456/Vsions/DSC00377.jpg[/URL]


http://i331.photobucket.com/albums/l456/Vsions/DSC00375.jpg[URL="http://i331.photobucket.com/albums/l456/Vsions/DSC00375.jpg"] (http://i331.photobucket.com/albums/l456/Vsions/DSC00377.jpg)

sthmck
08-24-2008, 09:27 PM
Wow that looks really cool. What do you plan on doing with it?

4mem8
08-25-2008, 02:58 AM
Looking good Vsions, Are you going to fit a Pico ITX M/B in it?? Love to know what you plan for it.

Vsions
08-25-2008, 09:19 AM
Thanx for your positive feedback guys, I intend on doing robot combat with it. Funny thing is I had always wanted to do something like that since I was a kid. My friends and I used to build totally custom rc cars to do combat with and have small competitions. Then I saw the mechwars forum and thought it was a great that someone was actually doing it. I am still going to try to start my own tournaments that probably wont be quite as big as mech wars but my tournament is significantly different that mech wars. My version also does not limit the kind of robot as far as wether it can walk or not because the scoring system is significantly different. Although my tournament will not allow ramming or fliping and what not. But it will allow projectile and melee. So I am building two machines for now so that I can demo my idea and then I will reveal all the rules once I have tested what might work and what doesnt. I will be posting a video of it so that people can see if they want to get involved... 4mem8, Im sorry but I dont even know what a Pico is. I am very new to this and still have much to learn. I can say that I intend on keeping the machine user controlled. Wait till you guys see my second machine. Now that I have become familiar with the bracket system and dimensions I was able to design my second machine which I am very excited about. But I have to finish this one first. So hopefully in 2-3 months I will have the second one build for u guys to check out.

sam
08-25-2008, 03:39 PM
The Firgelli's Actuators in question are actually controllable via PWM, so no different than a servo. Now that said- these type of actuators aren't going to compare to an HSR-5990TG until you look toward much larger versions. Also keep in mind that the higher torque they are, the slower they usually are. I wouldn't suggest using these as the main actuator on a humanoid until the technology has matured a bit, or you're looking at a large scale industrial-grade project.

My point was just that calculating where the arm will be when the actuator is at such a distance from center of rotation and that much elongated. It envolves trig and all wich just makes it more complex to program (at least longer).


Thanks guys, I appreciate all the info. I guess I will stick to the 5990. Sam I saw you mentioned the coding aspect and I am very much terrified of that part cause I dont know anything about that at all, I have never done anything like that. But I like building stuff and felt it was something I would tackle with alot of help from this forum. Eventually I hope to learn enough to contribute to this forum and be as helpful as you guys are.

Yep this is waht the forum is for. We can help you probably. It's fun trying to control stuff you've built yourself (like a board, thats what I have been doing ;))

VERY nice robot by the way. I love the aluminium tubes, it adds something more.

strix
11-20-2008, 04:19 PM
Regarding the HSR5990 servos, when they are not powered is there backlash? The Frigelli L12 (in theory) can take a good deal of back lash. But typically servos go limp when there is no power, I need a servo which remains rigid when powered off....any ideas?

DresnerRobotics
11-20-2008, 06:34 PM
Regarding the HSR5990 servos, when they are not powered is there backlash? The Frigelli L12 (in theory) can take a good deal of back lash. But typically servos go limp when there is no power, I need a servo which remains rigid when powered off....any ideas?


No servos I know of, including the 5990TG servos, remain rigid when powered off.

Not sure on an actuator that does...

Adrenalynn
11-20-2008, 06:49 PM
Any screw-driven actuator would remain rigid without power.

You're probably wanting a clutched servo.

Quantum
11-20-2008, 06:56 PM
I actually have a few of the PQ-12 and they do stay rigid. They are pretty cool but slow.

strix
11-21-2008, 11:02 AM
I have a set of PQ-12s and they stay rigid when the power is off...I'll look into the clutched servo idea. It sounds promising. Thanks!:veryhappy:

Adrenalynn
11-21-2008, 01:15 PM
They're screw-driven, so absolutely they'll stay rigid.

Think about it: If you push straight down on a nut that's threaded onto a bolt - does it back out? Same concept here.

robot maker
12-22-2008, 11:25 PM
there are screw driven small servo motors ,i think 6 phase,i had one sample from work small without controller just motor and leadscrew,looking to make my own for my johhny five eye design ,when i get ready for it

Quantum
12-23-2008, 01:19 AM
They are not 6 phase, there a simple dc motor with feedback pot. 4 pin connection. Depending on the model depends on the gearing.

robot maker
12-23-2008, 01:39 AM
sorry i meant a stepper motor NOT SERVO,4 drive and 2 power
use to remember the 2 types but forgot been very long time since i have used them ,last time was 5 years for a phototach final tester for a company i work for,stepper with optical encoder feed back with refective tape spaced evenly apart on a disk i think it was 3% design till i found a way to covert a harddrive to the design and low rpm a floppy drive R&D said using the design was super good,wasent design of the year ,but i did make a ac/dc source(not power source) but a super high precision pure ac sine wave voltage and high current source and same with dc source
one of my biggest designs,another bigger one was 3 phase power source


They are not 6 phase, there a simple dc motor with feedback pot. 4 pin connection. Depending on the model depends on the gearing.

Quantum
12-23-2008, 02:02 AM
Nope there still are simple dc motor with a pot feed back. Or Pwm which would stil make them a dc motor with a feedback. These guys are to small for a stepper type step up

robot maker
12-23-2008, 02:41 AM
nope sorry you are wrong,i took one apart a larger stepper motor and they have different winding each w field has wires no pot
here is some info on how a stepper motor is made,if need a photos of inside one of my stepper motors no problem
http://en.wikipedia.org/wiki/Stepper_motor
one type also i remember is bipolar and cant remember other type

Nope there still are simple dc motor with a pot feed back. Or Pwm which would stil make them a dc motor with a feedback. These guys are to small for a stepper type step up

Adrenalynn
12-23-2008, 02:50 AM
RM >> no pot

Best drop Firgelli a note and let them know that! They're confused: according to the datasheet it has a

Feedback Potentiometer
2.75 kΩ/mm ± 30%, 1% linearity


nope sorry you are wrong,i took one apart a larger stepper motor and they have different winding each w field has wires no pot

The L12CR: RC Linear Servo


The L12 CS: 2 wire with limit switches.

The L12 CL: Integrated controller with Industrial and RC servo interfaces


The CP ? : Simple analog position feedbacksignal, no on-board controller




The six wire version isn't a stepper either:

Wiring:
1 (green) Current Input Signal
2 (blue) Voltage input signal (used for the 0-5v interface mode and PWM interface)
3 (purple) Position feedback signal (from the non existent pot)
4 (white) RC Input Signal (used for RC-Servo control)
5 (red) Motor V+
6 (black) Ground

So it would appear that their datasheet, specs, and schematics are all wrong... Or Quantum is correct.

robot maker
12-23-2008, 03:02 AM
i guess nobody really read my post i guess,i was talking about a STEPPER motor with a screwdrive
firgelli is a SERVO MOTOR and all have pots


RM >> no pot

Best drop Firgelli a note and let them know that! They're confused: according to the datasheet it has a

Feedback Potentiometer
2.75 kΩ/mm 30%, 1% linearity



The L12CR: RC Linear Servo


The L12 CS: 2 wire with limit switches.

The L12 CL: Integrated controller with Industrial and RC servo interfaces


The CP ? : Simple analog position feedbacksignal, no on-board controller




The six wire version isn't a stepper either:

Wiring:
1 (green) Current Input Signal
2 (blue) Voltage input signal (used for the 0-5v interface mode and PWM interface)
3 (purple) Position feedback signal (from the non existent pot)
4 (white) RC Input Signal (used for RC-Servo control)
5 (red) Motor V+
6 (black) Ground

So it would appear that their datasheet, specs, and schematics are all wrong... Or Quantum is correct.

Adrenalynn
12-23-2008, 03:06 AM
Well, the point of confusion is probably that this is a thread about the Firgelli L12. Not random stepper motors. That's in the random stepper motor thread.

And, no, not all L12's are pot-based-feedback. Some have nothing but simple limit switches.

So again: Quantum - you are quite correct. The L12 [that is the point of this thread] is not a stepper solution.

robot maker
12-23-2008, 03:09 AM
here is the post i did and the one before it,except made a small mistake calling mine a servo instead of stepper motor
when i heard about using leadscrew for linear actuator,that why i gave my idea on one i have
i just its mostly i misunder standing and reading my post wrong


sorry i meant a stepper motor NOT SERVO,4 drive and 2 power
use to remember the 2 types but forgot been very long time since i have used them ,last time was 5 years for a phototach final tester for a company i work for,stepper with optical encoder feed back with refective tape spaced evenly apart on a disk i think it was 3% design till i found a way to covert a harddrive to the design and low rpm a floppy drive R&D said using the design was super good,wasent design of the year ,but i did make a ac/dc source(not power source) but a super high precision pure ac sine wave voltage and high current source and same with dc source
one of my biggest designs,another bigger one was 3 phase power source

Adrenalynn
12-23-2008, 03:12 AM
Is it a Firgelli L12 or Hitec 5990TG? If neither, it's Off Topic. These threads are getting drug off into the weeds. Let's bring 'em back around please.

Responses not on topic will be deleted. Thanks.

robot maker
12-23-2008, 03:22 AM
ok just thought is was only a idea for a different linear actuator
i do like the firgelli l12 to buy some for a design i have on johnny five it look good for it


Is it a Firgelli L12 or Hitec 5990TG? If neither, it's Off Topic. These threads are getting drug off into the weeds. Let's bring 'em back around please.

Responses not on topic will be deleted. Thanks.