INTRODUCING: the "Roto Damper"


 
Hey, you are using the SG90, not the MG90? How did it fit into the roto damper?

Oops, sorry, I had originally ordered and received the SG90 and posted that, I actually ordered the MG90S and used that in the Rotodamper, so I need to go back and fix my post, thx
 
Did you happen to try and fit the SG90 into the the roto damper? I am curious if it fits or not? I have one somewhere but haven't been able to put my hands on it to try.... At any rate, the MG90 is a better unit to go with, having metal gears and all.....
 
Did you happen to try and fit the SG90 into the the roto damper? I am curious if it fits or not? I have one somewhere but haven't been able to put my hands on it to try.... At any rate, the MG90 is a better unit to go with, having metal gears and all.....

Yea I do have a couple of SG90's, I'll try it and let you now
 
I've put my MG90's through a LOT of abuse and they haven't burned up, maybe got a little tired, but didn't give out... I accidently left the one I am using now flailing for more than a day like shown in the video I posted in the Servo Booster thread, I thought for sure it was dead when it jammed up a bit past it's 100% mark, but I got it free'd up and it's still working fine. So I am pretty happy with the MG90, but was curious about the SG90, if it was too loose or too tight, or too shallow or whatever...
 
If I remember correctly, it wouldn't fit in the servo opening. So, too tight. It has been a while ago... don't quote me on that.
 
Hi Ralph,

I sent you an email a few days ago. Can you send me the files for the rotodamper? I'd like to get one printed (have a local source). I have a Broil King Keg and I am about to order the parts for the HeaterMeter.

Thanks,
Mike
 
I thought I had responded to your email, perhaps that was someone else... Please check your spam filter in case it got caught up, and I will check over my inbox for a message from you that I may not have responded to...
 
It has just come to my attention that Bryan has an "alternate" blower listed from Mouser that is not the same as the long time standard HM blower. The standard blower mount that I have for the roto damper will fit the standard HM blower (from Digikey) but will NOT fit the alternate blower from Mouser.
 
This is correct. Since you bring it up I should probably change it to said "different" instead of Alt. The specs are similar but they are completely different shapes.
 
Ralph,

I'd be interested in trying out the RotoDamper and sent you an email earlier today asking for the files. I recently built a HM 4.2.4 and it works very well controlling a BBQ Guru blower on my Primo L. Still, it would be nice to not have to adjust the manual damper ...

Steffen
 
Ralph (or anyone else)

On the HM board, where do you actually jumper the probe ground to, from the RJ45 jack pins? Over to pin4 ground for the servo/blower, or over to another ground on the board? eg over to the power jack ground? over to the pit probe ground?
 
The servo and blower wires are already connected to the CAT5 jack (on HMv4.1 and newer). Those connections use the center most pins. The two pins on the outer side (1,2,7,8) are unused, you can use them however you want. To use them for the probes you have to jumper wires over from the probe jacks to the spare pins on the CAT5 jack (I also do a dedicated ground for the probes). The best way to connect the wires to the probe jack end is in a similar manner as the ambient temp thermistor, connect to that third leg on the onboard probe jack. This way the probes coming in through the CAT5 jack will work by default, but if you plug a probe directly into the HM that probe will function instead of the one on the CAT5 cable.
 
I'm specifically asking about the dedicated ground. Where do I jumper the ground to on the board, from the pin I choose to be ground on the RJ45 jack?
 
The idea of a dedicated ground WIRE is about preventing the blower and servo power from running through the same WIRE in the CAT5 cable as the probe ground, so rushes of current from the blower and servo over this wire will not cause probe noise. For a similar reason (this time induction between wires) it is best not to run the servo or blower wires in the same twisted pair as the probes. On my current HM I just jumpered over the ground pin from the CAT5 jack to a spare pin and it works fine. It would also make sense to take the ground from over in the sensor region of the board, probably from the onboard probe jack ground.

In my experimentation with earlier versions of the HM board when the servo support was just being developed (and many HMv4.2 refinements had not been developed yet) I found that sharing a ground (wire in the CAT5 cable) with the power components (servo and blower) caused noise on the probes, initially on HMv4.0 boards and even worse on HMv4.1 boards. The HMv4.2 board has evolved quite a bit, Bryan did an AWESOME job or redesigning the board to isolate noise and implemented several hardware and software improvements that greatly reduce the noise on the probe lines. I have been a bit too busy to experiment with wiring lately, but I suspect the HMv4.2 board is designed so well that you probably could share one ground wire for everything and not have a problem. With the new voltage mode blower driver and the RC filters I think the probe signals will probably be clean when they hit the ATMega even when grounded through the same wire.
 
I believe Mike is asking about where on the HeaterMeter board to use for ground. Ground is all over! I'm not sure if you're on 4.1 or 4.2, but 4.1 I'd use the GND connection on the probe header, and 4.2 I'd use the GND on the barrel input jack. Just whichever is closest.
 

 

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