Stampede RT-590 Burn-In Data

[hunter306]

Just ran my new smoker through the initial burn in after it was delivered this Monday. I did have a flame out after about 15 minutes because I didn't add enough pellets initially to keep it primed, but once I tossed a few more in, and the auger was properly primed, it took off for the recommended 400 degree setting in just shy of 20 minutes! Not bad at all.

I did install my FireBoard 2 in the smoke box as well, to monitor the consistency of the PID's read out-- I know, probably overkill, but I love the fireboard, and I'm curious if this is about what I should expect for results.

You can see the full hour break-in data here, for reference: https://share.fireboard.io/563164

I noticed that once everything equalized (the probe for the Fireboard was added once the box hit 400, so there was a little time to get it up to temp) that the fluctuations were about 12 degrees to set point. I observed 388-402 on the fireboard logging, while the recteq app, and build in pid, showed 400 dead straight the entire time. I will admit, that the fireboard probe was mounted a bit lower (so a slightly lower observed temp wouldn't be shocking) but without opening the lid for the full hour, I was expecting a tighter temperature performance.

It is 45 degrees here, so that may also be contributing a bit to the lower reading on the FB, but the swings were what i was most curious about.

Attached some pictures of the app readings, as well as probe placement. Bear Mountain Gourmet Pellets, fresh bag, just purchased.

Maybe I'm expecting too much from the variance on the temperature, because honestly, I don't think it would affect a bbq or smoke too much.

Anyone care to geek out on the data with me? Feel pretty normal?

Probe placement;

Hardware readout, note the 30 minute graph of temperature variance:

RecTeq Temp Chart:

Fireboard Screencap (you can see the full run at the link I shared above: https://share.fireboard.io/563164 )

 

[Wslayer]

Hard to duplicate the temp with where the probes are. I placed mine in center of cooking grate and made the adjustments to match the RT probe. Adjust auger rate If needed, and then fine tune with offset calibration. Videos on both.

 

[hunter306]

I was considering moving the Fireboard probe up next to the pid's probe for more consistent temperature results between the two readings, but I suppose what I'm more curious about is if the swings in temp that I'm seeing, which the RT Pid and graph don't necessarily reflect, are to be expected.

The RT Temp Chart doesn't seem to sample as quickly, which is fine, but even when comparing the two data sources, you see a much larger swing on the FB than the RT Pid. I have some assumptions about smoothing that happens to keep the PID from trying respond to quickly, so I guess I was just trying to understnad a bit more about that side of the result.

For reference (set temp at 400 on the grill, lid not opened except at beginning of the hour):
RT Pid for the hour swung from 396-402.
FB for the hour (if we null the first 20 minutes, which I believe were time to soak the probe and cable) was closer to 388-402 degrees.

I did check the app setting, it looks like the feedrate is 3.0% -- In the app, it says normal is 6.5%, but I didn't adjust this, and after doing some searching it seems like 3.0 is the standard feed setting. Since I had no trouble getting to temperature, after my initial foible, I assume feedrate isn't going to help much with the variance question... But maybe I'm wrong? Thanks for adding some thoughts.

 

[geauxfish24]

Glad you posted this. I also received my 590 yesterday and did the burn in. I got to 400 in around the same time as you, however, I experienced a temp drop to 350 about 40 mins in. It did go back up to 400 after about an hr and 15 mins. I called RT this morning and they said that is a normal occurrence, but still somewhat worried prior to my first cook on it.

 

[ndfan6464]

I have the same issue on my 590. The installed probe always reads higher then what my Thermoworks says by about 15-20 degrees. I've even gone in an calibrated the probe and it always is off. I've never messed with the feed rate. It's still at the factory setting of 6.5.

In order for me to reach 225 I have to set the smoker to 230 or 235.

What I have noticed is and to me it's an issue, is that with any smoke that's over 13 hrs the temps really start to climb up. The longer the smoke the higher the temp gets. For example. I did a park shoulder and it took about 19hrs to get to 205. At that time frame my cooking temp was almost up to 250 degrees even though my set temp on the 590 was set to 230. Fortunately with pork shoulder and butts it can take that. But for brisket, for the way I like to cook it, that's not...

I think it has to do with all the ash build up in the fire pot. Just acts as more fuel to burn...idk...

 

[hunter306]

@geauxfish24

I didn't see quite that dramatic a shift in temperature. 50 degrees almost sounds like it ran out of fuel, or the pellets flamed out. When I started mine for burn in, that's kinda what happened to me- I put a very small handful of pellets into the bowl, then closed up the spreader, drip tray and grates and turned it on via the app.

The feedtube from the pellet hopper didn't quite get fuel into the bowl fast enough, so I flamed out.

You can actually see where it flamed out here (happened around 13 minutes, I didn't catch it until 18ish):

 

[hunter306]

@ndfan6464

Thanks for your feedback! Most butt smokes that I do I ran at 230 on my old MES30, and that registered 227 on the Thermowork Smoke (yeah, I also have that thing).

I'm actually not really concerned so much about making the probes match- that doesn't bother me, I always just adjust the cooker up or down until I get the reading on want on the Fireboard/Thermoworks since thats usually placed right near the actual protein I'm smoking.

I'm more interested/concerned in your comment about the temps spiraling outside of the ability for the pid to control. My burn in variance of 10-12 degress is acceptable, although I was expecting better. Over 25 degrees would be disappointing especially if the issue consistently compounds during long low-and-slow cooks. Most of my butts will go 15-19 hours. The MES30 would easily keep temps within 3 degrees of where I was holding.

Here's a butt smoke on the MES30 for reference Temp Stability was pretty impressive.. obviously easier when you're just cycling a big ole electric element. (You can see why I got rid of it, that Maze Smoker was driving me nuts). https://share.fireboard.io/6B3D8A

Hmm.

 

[Wslayer]

I have the same issue on my 590. The installed probe always reads higher then what my Thermoworks says by about 15-20 degrees. I've even gone in an calibrated the probe and it always is off. I've never messed with the feed rate. It's still at the factory setting of 6.5.

In order for me to reach 225 I have to set the smoker to 230 or 235.

What I have noticed is and to me it's an issue, is that with any smoke that's over 13 hrs the temps really start to climb up. The longer the smoke the higher the temp gets. For example. I did a park shoulder and it took about 19hrs to get to 205. At that time frame my cooking temp was almost up to 250 degrees even though my set temp on the 590 was set to 230. Fortunately with pork shoulder and butts it can take that. But for brisket, for the way I like to cook it, that's not...

I think it has to do with all the ash build up in the fire pot. Just acts as more fuel to burn...idk...

You can certainly get that closer . Turn your feed rate down to about 5 or 5.5 and see where you are at. Then "watch" offset calibration video and adjust from there. You won't mess anything up, you can always go back to the factory settings.
I have mine set at 5. I may need to increase again this winter, will see.

 

[geauxfish24]

Well y’all got me nervous but I’m about to put on a 10lb butt overnight. Oh well...gotta start somewhere.