Big thanks to everyone including John Bostwick and a couple of beginner questions

I would like to say thanks to all that have contributed to this project. There are a few obvious people as well as countless others! Thanks so much, this is truly awesome!

That said, I owe a thanks to John Bostwick. He helped build my HM 4.2.4 with RD3 and Aux board. He was great to work with and he did a great job!!!!!!!

Now that I have had this thing for a few days, I am ready to give it a try on an attended cook. I have some short plate ribs ready to go on my Primo XL! (probably tomorrow)

I have a couple of questions, here they are:


1.) Can I use a dremel to connect the RD3 to the BBQGuru adapter? I am 0.03" from getting it to fit. I think it may just be the lip at the tip of the RD3. I would like to go straight from RD3 to the BBQGuru adapter if safe and possible. Otherwise I found a PVC pipe and coupler that work with the existing clearances.
2.) What is the heat tolerance of the plastic case of the RD3? What type of plastic is it? ABS?
3.) Can I get the HM to recognize a Pit probe on the Aux board? That way I can leave the HM plugged in but out of the way by the house. I have set all 4 probe coefficients to use the TX-1001-OP and toggled the switch. Maybe I need a TC probe?


I think this is the full description of what I have:
HM 4.2.4 with RD3 and Aux Board v 6.1(?)
OpenWrt Attitude Adjustment 12.09 / LuCI 0.11.1 Release (0.11.1) with HeaterMeter Information Version 20150531B
1/8" Probes:TX-1003X-AP and TX-1004X-SP

Take your caliper the way it is set inside the RD3 output cap in the picture, pull back on it with your thumb applying pressure and then rotate the cap. This will easily widen that hole for you... Do it little by little because you want the fit to be tight. Most likely all you need to remove is the little lip from the first layer squish on the 3D print.

As for type of plastic and temps, I use only ABS filament because it softens up at a higher temp than PLA (and I just seem to have an easier time printing it). ABS will start to soften up about 90C, a while back Bryan did some thermal imaging of a RD on his BGE and it maxed out around 45C, so around half the temp where it would start to soften up. I've never heard of one melting, so I wouldn't worry about that.

As for your probes, I assume the jumpers are in place on your HM board (John B probably did that for you?). The RDTC has TC Pit Probe, so you would need the select Thermocouple as the probe type on Probe 0 and plug your TC into the RDTC board.

Thanks for the quick reply Ralph! I had a ribeye coming off of my Hasty Bake that I had to take care of before I could get back to you

Thanks for the tips on the 3D print lip, I will try what you suggested. I have to admit that I am waaay more careful with these items since I can't run down to Home Depot and get a replacement if I break something.

Thanks for the info and reassurance on melting the plastic!

John Bostwick mounted a switch to the HM that switches to the probes on the RD3. I agree with you assumption on the jumpers - I have no idea.

I will have to pick up a TC pit probe. Do you have a favorite you can recommend? Thermoworks website isn't the easiest and I am seeing some crazy numbers like $55. Otoh, I have read about some of the pit probes from Auberins can be delicate...
Thanks,
John

Auber instruments has cheaper TC, and have some with clips to make mounting easier. Their website is under maintenance, but they give you a link to shop on their older site. I have had the 4 inch with clip, and it worked great until I accidentally pulled the wire out of the probe after getting the TC really hot.

Thanks John. I bought the Auber that goes straight to an alligator clip. Hopefully that works well.

My first RD3ed cook went very well yesterday. I did a reverse ramp - I set it to 225f for the first 5 hours and then I bumped it up to 260f to speed things up. Switching to 260f over shot by 10f and then came back down within 30 minutes. I changed fan max to 80% and fan startup to 80% to help with that. Is that the right move?

I would post my HM graph but I ran the HM overnight before my cook, so the timeframe is too long to show the graph properly. It was running inside, but when I unplugged it to move it outside it resumed the old archive. That wasn't what I wanted to happen in that scenario but I can see how that is a pretty cool feature in normal circumstances where you might unplug briefly during a cook.

Edit: I was also curious about the PID chart at the top left of the Home screen. Is there somewhere on here that I can read about that?

On the overshoot when you bumped up the temp, yes, you are on the right track thinking you should reduce the blower speed. TBHWY I haven't been able to fully predict when the HM will decide to revert to Startup Max when you change pit temp, so I can't really tell you which one to lower. It seems if the temp bump is small the HM stays with the MAX setting but if you bump it up a lot it reverts to Startup Max. Not fully sure, and I have had a lot of snapshots installed in the past months so hard to say if what my HM is doing is what your's will do... But yes, in general lowering the speed the blower runs when bumping up the temp will limit the overshoot, PID settings can also have a big effect on that too....