My HM build for UDS

Hi All,

first time poster here from Downunder. Though been reading the HM posts on this forum for quite a while now, ordered my HM from Bryan, built it and got it up and running with no hiccups - great kit, great instructions, great forum! Used the HM a few times so far on my UDS with great success and ease. Though the tinkerer in me being never satisfied, I explored various options with the setup of my HM, fans and dampers to minimize wires and stuff dangling around the UDS.

The current result of my tinkering has my HM and servo / damper inside a single enclosure, and three little 50x15mm 12v blowers mounted underneath the UDS inside round PVC electrical junction boxes which are connected to the HM/damper enclosure via corrugated tube and a metal square tubeing. (this metal square tubing also serves as the mounting post for the bottom part of the HM/damper enclosure to the side of the drum away from heat)

Here a few photos of the enclosure, i will upload some photos of the UDS with the enclosure mounted over the coming weekend. Most of the components used with my UDS and HM setup are recycled items, I have not spent much money on anything other than the HM itself.

But a LOT of hours went into the making of it. The damper plate and face plate of the enclosure is anodized aluminum that used to be the lid of an old electronics enclosure, I only used a hacksaw, cordless drill and a handfile to fabricate the metal parts out of it which did took a while since I sort of designed it whilst fabricating it.

I plan to put the HM's three LEDS on the 3 spots marked above the LCD over the weekend, and install an external power connector on the enclosure and also thinking of trying etching the labels of the buttons onto the aluminum as currently marked in green marker.

For anyone interested, here some additional photos of my HM & UDS.

Did a 12 hour smoke last weekend, loaded the UDS with 2 chickens, a pork butt, lambroast and a chunk of corned silverside. HM held temperatures within a couple of degC over the entire period and managed really well with the few times I opened the lid. Settings are P=3 , I=0.00035 , D=5, LID open detection 10%, duration 240secs.

All meats came out beautifully, every dinner during the entire week had some form of smoked meats in it lol. Its almost like the smoky flavor develops even more with the meats after a few days in the fridge...

Looks like you put a lot of effort into that setup. Nice job.

Thanks Darren, yeah I like to tinker and spent a fair bit of time on the HM but spread over a couple of months. A very satisfying little project this one! Building the UDS a couple of years ago only took me a couple of days and much more beer, welding it up at a friend's workshop with his MIG.

nice setup - love the all-in-one heatermeter+Damper box.

Thanking you - I did a 11hr cook this weekend (pork butt) and the HM worked like a charm. I was away from home most of the time during the day but still kept an eye on things remotely on my phone, some of the tech challenged people I visited just couldn't fathom the concept of remote monitoring AND controlling a BBQ and especially it being charcoal fired!

Here the graph of the cook; I am extremely happy with how the HM controls things but just out of curiosity I would love to get some advice from the PID tuning experts here on which parameters to fine tune in order to smooth out some of the bigger oscillations a bit when it tries to recover from a temperature change (at around 12:00) and lid-open events. Not that it is required at all I know, it is already very impressive how it controls the temp - its just that the tinkerer in me cannot leave anything as it is

My settings are:

P: 3.5
I: 0.0035
D: 6

Fan Pulsed, on above 45%, min 0%, max 45% startup max 50%

Edit: I should mention that my pit probe is a Thermocouple with the junction / tip exposed, so it is super sensitive to temperature changes - this may give a different dynamic to using a probe with a bit more thermal mass?



About 5 and half hours into the cook, lid opened twice to add a few things to the cook.




And the entire 11-ish hour graph, two more lid open to remove the smaller items again; the lid open event just after the 20:36 marker must have been the cooling effect of the fans triggering a false lid open. I dropped the temp to 80degC when I was away from home at around 20:00 as the butt reached the desired temp of 80degC, though I removed the butt from the UDS after I switched off the HM at around 21:30 when arriving back home.