Servo whine ?


 

James_Brouillette

New member
So just got all my stuff in the other day (thanks Bryan for the soldering! and all you do )

And it works !!! , one slight issue , it seems the servo whines all the time is this normal ? is it going to burn out ? I've repunched down the keystone a few times to be sure i didnt' cross a wire or something causing interference or feedback . I did pickup a spare servo on amazon i've not tested that one yet . I need to find a shorter Ethernet cable , could it be the 6 foot length cat6 cable causing it ?

You will notice in the video if it tap it or jiggle it , it seems to stop or lesson almost like its binding but its not ..

it is working perfectly just wondered before i start using this on a 10 hour cook if this is safe ? and well its a bit annoying of a sound .

Please watch video so see it in action and hear it .



Also one other slight thing , is it normal for a uncalibrated k-type read a bit high and climb in temp when first starting up .. after i turn on the heatermeater temp seems to slowly raise a few 10ths of a degree every min .. it eventually does seem t stabilize . I'm getting another k-type in, in a few days and will test that one , this one will be sealed so i can properly test it in boiling water and calibrate it , the one i have now is exposed and i dont' think its a good idea to dunk in water and risk water seeping into the braided part.

Anyways thanks guys for all your help and hopefully the video better shows the issue .
 
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GSpinelli

TVWBB Member
The cheap servos tend to do that. Sometimes adding a capacitor to the servo power leads helps. Something like 30uF.
 

James_Brouillette

New member
The cheap servos tend to do that. Sometimes adding a capacitor to the servo power leads helps. Something like 30uF.
ok so its not like "running" when its making that noise , or going to burn up. I just find it odd it kinda stops when i tap it . i'll give my spare servo a go and see if it stops . Thanks !
 

Bryan Mayland

TVWBB Hall of Fame
Usually if it is sitting there buzzing it means it is stuck and isn't getting enough current to move. Make sure there isn't any stickiness at all on the mating faces of the damper, sometimes buffing each of them with a soft cloth for a minute can remove any surface residue form the 3D printing process and make them move more freely. Also be sure the dial isn't tightened down so that there's any friction in the movement. It is better for it to be a little loose and have a bit of a gap than to have it tight and bind up on small movements. Some have suggested assembling it with a sheet of paper between them then slide the paper out, but I'm not sure that's necessary.

The thermocouple temperature rising a little after powering up is normal. The amplifier warms up just a bit which affects its measured temperature. I believe the temperature it measures at first is the more accurate one, but it isn't enough to affect normal operation I don't think.
 

James_Brouillette

New member
Usually if it is sitting there buzzing it means it is stuck and isn't getting enough current to move. Make sure there isn't any stickiness at all on the mating faces of the damper, sometimes buffing each of them with a soft cloth for a minute can remove any surface residue form the 3D printing process and make them move more freely. Also be sure the dial isn't tightened down so that there's any friction in the movement. It is better for it to be a little loose and have a bit of a gap than to have it tight and bind up on small movements. Some have suggested assembling it with a sheet of paper between them then slide the paper out, but I'm not sure that's necessary.

The thermocouple temperature rising a little after powering up is normal. The amplifier warms up just a bit which affects its measured temperature. I believe the temperature it measures at first is the more accurate one, but it isn't enough to affect normal operation I don't think.
Yeh i think it's binding i may try using a capacitor. got any more explination on using that on wires to servo? Can it cause any damage to heater meter. Could you better explain the type and where to connect?

Also Shorter cat 5 cord didn't help and my spare servo doesn't work at all doa :(. I've got some decently long wires left going to servo and fan I'm going to try shorting them as much as i can and I'll also measure the voltage.

It does seem to be mostly working but i worry it's going to burn up and frankly it's an annoying sound at least indoors!
 
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WBegg

TVWBB Pro
Capacitor shorts between +5V and GND. Electrolytic Capacitor. I use a 10-25 volt rating. Be sure to install with correct polarity. I install it right at the RJ45 jack.

ETulf5c.jpg
 

Bryan Mayland

TVWBB Hall of Fame
Yup just like WBegg demonstrated. It just needs to be virtually any capacitor, 0.1uF to 470uF of at least 10V rating. This specifically targets where the servo actually freaks out and goes full open / closed randomly, but it doesn't hurt to have it even if you're not experiencing that behavior.

Just make sure that when you add the capacitor it doesn't spread the legs of the RJ45 posts open juuuuust enough to cause intermittent connections in the posts. That's why I don't include one with the Adapt-A-Dampers I make, because I think they can cause more harm than good if inserted to the point it makes the other wires make bad contact.
 

WBegg

TVWBB Pro
i actually extend through and do not push them down. I solder to the outside of the wires. You may be able to make that out in the pic above.
 

James_Brouillette

New member
Thanks , i'll go salvage some old electronics and find one ! If this works its great ! and prob should be added to the wiki for troubleshooting servo issues ! I'm planning my first go at using it this weekend (ribs)
 

James_Brouillette

New member
well any i salvage barely have any leads left on them , i think i may just order up some flux and a cap set to have around . and solder it like WBegg

I want to understand how this works though , from what i'm thinking putting in between the 5v and ground , causes it to drain any electricity when not in use preventing it randomly firing off right ? and when servo is getting powered / in use gives it a bit more kick before it drains off ? ? am i close ? Sorry i'm a electronic amateur in practice . More a computer software and hardware geek .

this look good ? 10 bucks on amazon , be nice to have around anyways. From those what would be the absolute best to use ?

1617281984473.png
 
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Bryan Mayland

TVWBB Hall of Fame
Yeah the problem that some people experience is that the servo just flips the fudge out due to the 5V voltage dropping a little when it starts to move the servo, the capacitor adds just enough of a buffer that it prevents that. I'm really not sure it will do much for a servo that's just buzzing, although maybe they extra electrons available will provide just enough more oomph to let the servo make that small move. In these cheap servos, the amount of power applied to the motor is a function of the distance it wants to move. What you're hearing is the motor getting a little bit of power and making the servo rotate just a bit to turn back off, but the dial didn't move due to mechanical backlash so the servo settles back into the (slightly) wrong position and it turns the motor back on again, repeat.

Those capacitors look fine. The 100uF/10V WBegg has there is 5x11mm too. I'd say go with the 220uF/10V for the same physical size and a little extra capacity.
 

GSpinelli

TVWBB Member
While by no means necessary, if it bugs you too much, you may have better luck with a higher quality servo like this:
 

James_Brouillette

New member
While by no means necessary, if it bugs you too much, you may have better luck with a higher quality servo like this:
will that fit in the standard 3d printed damper case from the heatermeater store , Plug and play , no other modifications ? if so i'll buy it now lol .
 

GSpinelli

TVWBB Member
Sorry, I should have paid closer attention. I think the ones from the store use SG90 servos (not sure, have not bought one directly from store), which hare slightly different. Not sure if it would fit directly, probably not. I seem to recall the shoulder height is different.
 

Bryan Mayland

TVWBB Hall of Fame
No the MG90 and SG92Rs from the store (from Adafruit) are different sizes. The MG90 is different from most of the other plastic-geared 9g servos and need the hole to be designed for them whereas most the plastic ones are pretty close. I've gone through several different brands from generic SG90 to HXT900 "export quality" from HobbyKing to now using SG92R from Adafruit so it is hard to say what servo James actually has. Sorry about that!
 

Bryan Mayland

TVWBB Hall of Fame
Oh then that is one of the Adafruit ones and should theoretically be among the best of the plastic-geared servos. I've only been using them for 4 or 5 months though so I can't say that with 100% confidence yet, but it should be good.
 

Larry Naylor

TVWBB Member
James the servos we are using are CHEAP if you hear a whine ( usually gear noise from the gear train) it jamming or binding you might hear a growling sound. As long as it's not binding it will be ok. I think the capacitor would help with a jittery or twitchy servo. Either way keep us posted. Just reread Bryans post again what he is describing is servo hunting caused by gear slop or a dirty pot this could cause a buzzing noise. A wise man once said the simpler the machine the more problems it may have.
 
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James_Brouillette

New member
Ok so , i didn't get the cap in yet but just did the first run (with a air burner copper pipe setup ) and that servo performed perfectly even if it did whine half the time . i'm ecstatic !

i'll let you guys know what happens after i get the cap in it !


fyi , my first cook (just 3 racks of rips over 5 hours , went easy the first time. with airburner !)
THANK YOU ALL !
 
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