So, not sure exactly why I need to post a discussion in a thread here for warranty work. I guess its because most of your users are inexperienced?
I have 45 + years in RC, I know RC servos.
I developed software professionally 35+ years. I know software.
I am doing robotics in retirement, spiked3.com, I know robots.
So I have a DOA servo, buzzed for a while, got real hot (odor hot), never moved at all.
Pretty sure it is a bad servo, but we can discuss it if you'd like
It is one of the (visible) servos I can see without a 'QC passed sticker', some have the sticker some do not.
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Did you fill out the human varification window?
And did you tick the box stating that you are "NOT" asking for technical assistance?
If you have done these, then there should be no reason why you should have been directed back to here. Also, as you have started this thread, when writing out your claim, copy and paste this threads URL in to your claim as well.
As long as the servo was not under excess strain, the servo horn screw is not too tight, or servo cables have enough play as not to pull when a servo moves, then it's possible you do have a faulty servo which, although it doesn't happen often, like most things, unfortunately does happen from time to time. The guys from the office will help you out with your claim in no time.
If you check out the "Learn" section
Found at the bottom of this page, and search for servo "Calibration", there are few links that may help you in the future, as well as lessons for the Revolution robots. Below is one example...
Lever servo calibration
The bad servo is just the first one that burnt out. There is one other that also has a broken gear and will burn out soon. and at least one other with a chipped tooth. Its hard to tell if its just one as they all sound so bad. If you paid the supplier more than $1 for these servos you are being ripped off.
So I need to completely disassemble the robot, rebuild the gear train in every servo, except the one replacement I just got because I did that before I put it together. The teeth need to be filed and the cheap grease cleaned and replaced with lithium servo grease. I'm not sure I want to go through all of that after spending $450 for a 'ready' to use robot.
It is very sad this is how you are introducing beginners to robotics. I'll assume the factory has pulled one over on you. How you react will tell the story of your company.
When I first applied for warranty I found a web page that said I must post to the forum first and copy paste the post #. I did, and received a friendly and helpful reply from Aislinn. So I received the replacement yesterday and was able to run JD for the first time.
Then I noticed what I consider a egotistic reply to my original forum post. In particular "although it doesn't happen often," I find BS. Every one of my servos are of less than standard quality.
What I said is how you react to finding out you might have a manufacturing problem will define your company. I can see where its going.
FYI, have a good long read through this forum such as project showcases, search the web for the many MANY positive customer reviews from various outlets, then search again for all of the news and magazine articles written praising and promoting the EZ-Robot... then you will see "the story" of the company.
I get that you are frustrated, but what a way to introduce yourself. Putting customers and forum members down by calling everyone "inexperienced" before you even spoke to anyone. You may have some knowledge on the subject, but so do many others... Some of which who know a lot more than you probably do. If you want help, you're going the wrong way about it.
And as for my "egotistic" reply for TRYING to help and advise you, I was stating a fact and trying to reassure not just you, but anyone else reading. If you don't want my help or advice, then that's fine. I've got better things to do with my time, like helping other members.
Hello. I would like to address what may be some of the problems with your robot. I suspect you have, or at least had, a problem with servo conflicts. I experienced this recently myself and got some great guidance from Steve G. Like you I experienced buzzing and servos getting rather warm. I knew this was not normal as my JD had worked fine in other respects, running actions just fine. In my case it was all the result of setting one of the leg servos to 0 at one point in a set of frames (using the AutoPosition module). It seems that setting it to zero, even once, causes that servo to reset. That means it "thinks" it's last position is something other than what it actually was. There is no actual feedback from the servos to the controlling PC. When you get it's position in a script, for instance, all it does is read a saved value for that servo. The PC just assumes it is at that position since that's where it was commanded to go last. After being reset by being set to zero position, the servo thinks otherwise.
Anyway, the bottom line was that the leg servo that was set to zero and it's counterpart were in conflict. They were supposed to be going to the same angle but they weren't. Instead, the the servo set to zero jumped up a great deal and would probably have gone farther had it not been for the it's compliment on the other leg also coming to life and stopping it from moving. There is usually a bit of a delay before a given servo gets going. The servo set to zero had no such delay while the other waited a split second before going into action. If it had responded as fast as the other the conflict would likely have happened sooner, but it still would have happened.
All this caused a good deal of buzzing and servos getting hot. And not just the ones in question. Even the foot servos were getting hot because they too were being pulled away from their set position. On both legs even, because the complimentary one on the other leg could not go into position, causing conflicts between it and the foot servo. All that made it hard to pin down the root cause and produced stress on all the servos on both legs and feet. All because of one servo that was out of wack. The servo causing the problem was not defective, but had I left the whole thing running like that too long it would have become defective.
I'm not saying this IS the problem you had, but servo conflicts can cause servos to go bad. The buzzing you were experiencing made me think of my experience. My problem was not caused by mis-wiring, as is often the case, or even bad programming or bad software. It was caused by a simple mistake in settings just one time in one operation. So it doesn't take much. I found that if I cycled the power on my JD and reconnected, all was fine again until I ran that one action. After that the JD would not act right no matter what I tried. Including things that normally work well.
I tell you this in hopes of preventing a repeat of your problems. Good luck and have fun with your JD Sorry I got so wordy. Can't help myself. Darn this curse of being to type well!
Yes, EZ sometimes asks that you come here for assistance from other users first before you make a warranty claim. They do this to ensure you have a legitimate problem. Sometimes it does end up being a wiring issue and not a warranty issue. They can look at the thread, see what has already been tried, and decide from there what to do. Sorry if that lumps you in with rookies but that's the most efficient way for this small company to operate.
If you are comparing these servos to the high speed, high torque $200 dollar servos that you might use in RC racing, then you will find a substantial difference. It's not cost effective for EZ to provide that type of servo for the lightweight applications of these Revolution robots.
The folks trying to help you on tis board are just users of the product and not affiliated with the company. Since you indicated you got a reply from the company and a replacement servo, I'm not sure what you are referring to here.
First I meant no disrespect to anyone. I completely understand end users of ez-robots are mostly new to robotics. That is not disrespectful, just reality. That is fine, that is what they are made for, and the more that get started the better for the industry. In fact as an experienced robotics person, I purchased a JD to take a break from serious robots, and have something to show and get kids interested. I will be attending a large group of kids just for Robotics Saturday, and I had hoped to take JD to that.
http://www.spiked3.com/blog/ posted the day I ordered JD.
Steve G and I have already had a discussion. I believe there was some timing and mis-understandings and he and I are good now.
"So, not sure exactly why I need to post a discussion in a thread here for warranty work. I guess its because most of your users are inexperienced?" was directed completely at the warranty department, whose form I used required a post to be made. I received a friendly courteous and helpful reply and proceeded with no issues.
It was upon replacing the originally bad servo, I recognized that many were not of quality.
"If you are comparing these servos to the high speed, high torque $200 dollar servos " Did I say something that somehow implied that? Do you think in 45+ years in RC I only used $200+ servos? I am fully aware you can purchase fine 9gram servos for $2, and you can get stuck with junk. It all depends on the person you are buying from and if you did your homework or not. A good metal gear servo can be had from HiTech for $30 in consumer quantity of 1. (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXUZ89). Cheaper if you shop around, cheaper if you buy in quantity, and at least that half price if you buy direct. That works out to less than $10 for a high quality metal gear servo.
@WBS00001 had a very good post. Not applicable in this case, but none the less helpful to someone who may have had a similar problem and ran across this thread.
I appreciate folks providing peer support. Prices would be much higher if ez-robot had to do it, and I get that. I am simply pointing out a manufacturing problem that ez may or may not be aware of. In my own way also providing peer support as I hate seeing people get discouraged in robotics because they had a bad experience. The problem will get fixed, or not, that is someone else's call at this point. What I am now referring to is the overall quality of the servos, and the lack of QC.