Clark TK 40 board killing my recoil servo

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quitcherbitchen
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Clark TK 40 board killing my recoil servo

Post by quitcherbitchen »

My Clark board works great, but I just added the recoil to my Panzer III and the servos don't survive 20 minutes before they heat up and stop working. They buzz too. I know buzzing is bad. I tried changing the PWM setting in my Horus Radio but that didn't solve it. I have the S bus receiver--so does that mean I need S bus servos? I thought the Clark board had 3 PWM slots even if S- Bus. Please help me as burned up a couple of expensive Hitec servos.
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Re: Clark TK 40 board killing my recoil servo

Post by tomhugill »

The servo buzzing is probably because the Clark board is using end points different to what you had before. The motors are in a permanent state of stall for the time before they burn out. You need to change the horn position on the servo so when it's at rest it's not stalling out.
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Re: Clark TK 40 board killing my recoil servo

Post by quitcherbitchen »

So I found my servo tester and the Hitec servos seem to work fine, except with the Clark board. They worked initially, but now don't react. They both got really hot before not reacting. They work fine with the tester. A cheap tower hobby servo works fine so I am using that now. The elevation servo still won't react to the Clark board except in large exaggerated studdered moves. Very strange. The endpoints don't seem to matter. I messed with those and nothing changed.
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Re: Clark TK 40 board killing my recoil servo

Post by tomhugill »

Take the horns off and see what the situation is. If it works disconnected from the mechanism then you know where the issue lies. Some times the servo driver does go bad but it's pretty rare.

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Re: Clark TK 40 board killing my recoil servo

Post by General Jumbo01 »

"The endpoints don't seem to matter. I messed with those and nothing changed"

That shouldn't be the case as the end points will affect the distance the servo arm travels - the throw. An incorrectly adjusted servo will buzz when an end point exceeds the physical limit of travel and will then simply burn itself out.

Tom's suggestion will confirm whether you have a problem with a servo or the mechanism it is try to operate but if it operates smoothly when disconnected you will still need to adjust the end points when reconnected so as to get realistic travel of the part you are moving and to ensure the servo throw is not exceeding the physical limits of the moving parts.

I've no idea of your experience but, in case you are new to RC, the end points are set by the transmitter software which some budget systems may not have. As a rule, Hitec servos may not be the absolute best but they are normally good and reliable.

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Re: Clark TK 40 board killing my recoil servo

Post by quitcherbitchen »

I am new to tanks and the Clark board. Not new to RC. 30+ years and my radio is running OpenTX with Frsky S bus receiver. I should have explained that I did the test with the horns off and on. Same result. Endpoints I went from -50 to +50 to -100 to +150 and everything in between. Same result. Seems the Clark board has a very weird neutral band setting for the PWM. 1500 and the tower hobby servo works. 1287 and I can get the very Cheap Chinese servos to spin, but not stop. At 1500 the cheap servos won't react either. This tank was made for battling at the local club which has been closed since Covid and only just reopened. I will try and meet someone there to see if they have any suggestions as well. Thanks for the help by the way. This one is a doozy.
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Re: Clark TK 40 board killing my recoil servo

Post by dgsselkirk »

I have run Clark boards for almost 10 years. Yes, I found that depending on the servo it had issues like that especially Hitec brand. I am no electronics whiz as people here will attest to! But I find these servos to be absolutely faultless with the Clark board and have used them in well over 50 tanks I have built. So I guess my suggestion is buy some of these to try. I am sure they will work and are relatively cheap! This is the best price I have seen in a while for 6

https://www.banggood.com/6PCS-MG90S-RC- ... rehouse=CN
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Re: Clark TK 40 board killing my recoil servo

Post by quitcherbitchen »

Thank you for the info. Much appreciated.
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Re: Clark TK 40 board killing my recoil servo

Post by tomhugill »

dgsselkirk wrote:I have run Clark boards for almost 10 years. Yes, I found that depending on the servo it had issues like that especially Hitec brand. I am no electronics whiz as people here will attest to! But I find these servos to be absolutely faultless with the Clark board and have used them in well over 50 tanks I have built. So I guess my suggestion is buy some of these to try. I am sure they will work and are relatively cheap! This is the best price I have seen in a while for 6

https://www.banggood.com/6PCS-MG90S-RC- ... rehouse=CN
Those aren't fully metal gear, just the first gear and horn.

These are full metal and cheaper per servo

https://www.ebay.co.uk/itm/10X-Metal-Ge ... 635-2958-0

I'll also speak up for the compatibility of these servos. When I say endpoints I'm not talking EPA on the radio I mean mechanical end points of the mechanism.
.
For servo elevation you need the enable that in the settings using a ir remote and programmer.

Worth getting some of those alternative servos to test.

If you're still struggling Clarks tech support is pretty good, if not a little slow because of the time difference

Support email: sales@clark-model.com

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Re: Clark TK 40 board killing my recoil servo

Post by quitcherbitchen »

So elevation is as easy as using the tv remote to activate? Wow I did not know that. That explains the weird servo movement. I will read the clark manual for the thousandth time and see what I have to do. Can't believe I missed that. Thanks for the tip.
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