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MES-40 Model 20070512 Temperature Problems

Discussion in 'Masterbuilt Electric Smoker (MES) Owners' started by holyfeld, Nov 5, 2013.

  1. I recently purchased a MES-40 Model 20070512 from Amazon.com  I mainly smoke pork butt, ribs, and brisket at 225F. My experience has been the smoker runs 25 Deg F less than the setpoint. 

    I use an iGrill with two probes. I checked the probes in boiling water. I live at 3000'. Probe 1 read 206. Probe 2 read 209. Water boiling point at 3000' is 209 so the probes don't seem to a large source of error. To prevent emf possibilities and to keep the probe in air, not touching metal, I put it through 2 sets of 4 corks. This is blurry, but should give you an idea what it looks like.

    On Sept 19 I smoked a  prime rib. Being in a bit of a hurry, I set the factory controller to 270, put a probe in the rib, and one in the chamber next to the rib. Around 7:12 PM I gave up and put the rib in the oven. The white line is the meat temp and the red line is the chamber temp. The three major dips occurred when I opened the door to spray the rib.

    I understand the on/off control creates the oscillating temperature.

    Then I took some out of town work and didn't have time to smoke or worry about this.

    Knowing I would be back in town I ordered an Auber Instrument WSD-1503CPH so I could replace the on/off control with PID control. The WSD is rated to 1800 watts and the MES-40 pulls 1200 based on the face plate information.

    Today I bought the additional parts (replacement cord to plug into the controller for controlling the heating element, new drill bits [never miss the opportunity to get new toys [​IMG]]) opened the access panel and looked at the wiring. 

    I had to cut the heat shrink off to see I should have also purchased spade connectors. I disconnected both connectors to the heating element and measured the element resistance. 12.5 ohms. Using E/R = I that computes to 9.6 amps. Exhausting the rest of my electrical knowledge I used P = EI getting a nominal value of 1152 watts. Close enough to 1200 so this shouldn't cause the 25 degree offset. 

    Tomorrow is back to Lowe's to get the wire connectors, wire in the WSD controller, and mount the wall mounted temperature probe. Then an empty chamber cycle to see what happens to the chamber temperature. 
  2. Sounds like your on your way to a fix. Did you contact MES first?

    Happy smoken.

  3. I sent an email on 9/19. Then I got busy. Never did a follow up or push for a reply. I think I'm going to be pleased with the WSD from Auber. 

    I had a MES-30 I loved except when I tried to do brisket. I like the wideness of the MES-40. I like the cross flow ... although I'm grooving on the AMNPS for smokes that start in the middle of the night. Sleep is good![​IMG]  

    When I get this wrinkle unkinked, I'll talk about the heat radiating device called "the see through window".
  4. geerock

    geerock Master of the Pit SMF Premier Member

    Good old masterbuilt....... still selling cookers that you have to fix and spend more money on to get to work correctly. This has been a known issue for them for quite some time now and they continue to sell this junk. I will tell you this.... the auber PID will get you straightened out. It will give you rock solid temps after you run the autotune feature and hopefully will get you many successful smokes (assuming another part of the mes doesn't crap out). Considering you probably have over $600 invested by now I certainly hope so.
  5. I owned an MES-30 that worked great. My son now has it and smokes every other week with it. Just bought the dual probe Maverick from Todd so he can wander around while smoking. 

    I can't claim innocence. I read reports here including Todd's. http://www.smokingmeatforums.com/t/131879/2012-mes-40-dissappointing-right-out-of-the-box But I wanted a wider smoker, and the MES-30 worked so well.

    I knew eventually I wanted to go to PID control. I smoke on a covered deck. The smoker sits on a rolling cart so I can turn if I get back drafts (hasn't happened yet). And I'm a member here. What could possibly go wrong that I couldn't find an answer for?

    I'm sure I'll like the Auber. The auto tune feature means I don't have to worry about details like smoking a 20# brisket or 3 pounds of pork tenderloin. Set the temp and the controller will keep the chamber temperature where I set it, even better than the kitchen oven.

    Actually, the WSD-1503 just had a price reduction. If I'd waited until this week, I'd have $ 485 invested. As it is, I have $ 515 in the smoker and controller. That doesn't include all the other goodies I've picked up over the last couple of years.
  6. Continuing the PID modifications ....

    Here I've tie-wrapped the original wiring. I'm not sure in what universe I would choose to hook the original controller back into the heat system, but I can if I want to.

    Then connect the new wiring. Being somewhat anal retentive, after crimping the new spade lugs, I also soldered them. 

    Then it was time to button things up. I bought grommets to prevent the sheet metal from abrading into the wires.

    I also learned (in my house) that battery powered drills don't go as fast as powered drills. The access panel suffered a bit while I learned this. OTOH, installing the chamber wall probe benefited from this new learning.

    Next came mounting the wall mount probe. I wasn't sure how the "dangle" probe would work with the my smoker's side exhaust vent, so I chose the wall mount. Following the instructions went well until I tried to tighten the probe on the inside of the chamber. I've done most of my smoking on the 2nd and 3rd racks, so I chose to put the chamber temperature probe just below the second shelf.

    This picture doesn't show it well, but the fitting didn't protrude far enough into the chamber for the internal nut to catch.

    My first thought was to go to Lowe's and buy a ball peen hammer (how did I get to be this old and not own a ball peen hammer?), but decided to use the face of the claw hammer and "compress" the internal wall until I could get the nut to bite and cinch down. This resulted in 

    where the WSD chamber probe is approximately directly above what I believe is the MES chamber probe.

    Time so far? I've spent more time documenting than I have doing.

    Cost? The WSD seems to be on sale now for $ 199.90 (I paid $ 215) The power cord and spade lugs about $ 15. 

    Next up: read the WSD manual. Do a "dry run" and look at WSD chamber temp, iGrill chamber temp, and maybe look at the MES internal chamber temp. 

    And then for Thursday supper I'm going to smoke Tenderloin on a Stick (complete with the red onions) http://www.smoking-meat.com/october-24-2013-smoked-pork-tenderloin-on-a-stick
  7. geerock

    geerock Master of the Pit SMF Premier Member

    I owned the gen 1 mes 40 myself for a couple years and loved it. But the element burned out and I got the gen 2. Nothing but problems. I ended up with one catching on fire, a replacement that was DOA, and a third that the controller was so far off it was useless. Put an auber 1203 on it and she works real well. Why masterbuilt can't put a more accurate controller in the units is beyond me. A non programable controller with a little better quality is only a few bucks more, yet they continue to sell the same units with the known problems. Its like buying a new car and having to pay to put in a new engine.
  8. Starting with an auto tune ...

    I wonder how the PID tuning parameters changed from the default. I must look that up ...

    And into the first smoke.

    I did the smoked tenderloin and red onions I mentioned. 1 hour in this smoker at 230 cooks much more than Jeff's recipe suggests. Meat fairly dry. I'm going to start checking much earlier next time.

    And as always, even the "bad" smoke was very edible. Works great as an addition to salads.

    I wish the 1503 had a longer cord. I can cure that problem with a heavy duty extension cord.
    Last edited: Nov 11, 2013
  9. jkuben

    jkuben Newbie

    Sorry to be bumping up a 6 month old thread but this looks like something I may want to do and I have a few questions.

    I just bought a MES-30, Gen I, and am also new to this forum. I have a PID controller that I use with a Bradley and am wondering if I can repurpose it to the MES. It is a WSD1202, a model they no longer sell and I'm not sure what they updated, but it still works fine in the Bradley. But here is my question.

    Looking at the pictures, which were very helpful, I'm seeing where you connected the controller to the heating element, no problem there. DaveOmak posted an electrical diagram with his rheostat mod showing that the hearing element and MES controller are in parallel. He put the rheostat in series with the heater thus was able to use the controller to set a max temperature. I'm guessing you simply disconnected the MES controller entirely. Is that correct? Could I just unplug the MES controller or am I missing something? Finally, on the bradley I just hung the meat and oven thermometers through the vent. You bulkhead mounted yours. Probably a better solution but I want to be able to move it back to the Bradley if I need to. Do you see any problem with dropping through the vent?

    I've just done my first smoke with the MES, a boston butt, and it came out great. But I can't leave well enough alone so I have an AMNPS on order and will do the mailbox mod as well. Also thinking about Dave's mod to even out the heat distribution. My plan is to do these hacks one at a time to work out any bugs before I try to add the PID.

  10. geerock

    geerock Master of the Pit SMF Premier Member

    you don't connect the auber to the wiring of the mes. You simply put an electrical cord directly to the element and then plug that into the back of the PID. There is no need for the mes controller, unless you want to save the light switch. Now, having said that, that gen 1 is not a bad unit as it is.
  11. jkuben

    jkuben Newbie

    Thanks geerock and a big duh for me. I knew I could plug the MES directly into the auberge but worried about ramping power to the MES controller causing problems. So I was going to connect directly to the heater and remove the controller anyway? What was I thinking! Thanks for the recalibration.

  12. Joe,

    My MES has a digital controller. I would set the time to 24 hours and the temp to where I wanted to smoke.

    When I added the Auber, I took the controller completely out of the loop and wired a new power cord into the MES heating element. The Auber has a TPO. I guessed that turning the controller on/off a few times per second was going to be a nightmare.

    I do not know what type controller the MES-30 Gen 1 has. In theory, you should be able to move your Auber to the MES. You may have to run an auto tune cycle to adjust the PID tuning constants.

    As for bumping the thread, I finally did a long smoke (pork butt) and have a temperature graph. I'm off for a week of ww kayaking in the land of little internet. I'll post the graph and Q-View when I return.

    Now I'm working on my mailbox mod and properly loading my AMNPS.
  13. And to finish my part of this thread ... The final (so far mods).

    Insulating the front door glass.

    As it came from the factory.

    My first pass at insulating. Cardboard & duct tape.

    I went to the local fire place store. They gave me a piece of ?something? with fiber on one side and foil on the other. I offered to pay and the person said "I have no idea how to charge for this. Keep us in mind if you need fire place help."

    Installed.I used high temp foil tape.

    Then I smoked for the family. The World's Best Baked Beans, Butt, Ribs (2-2-1) and Four Cheese Mac-n-Cheese.

    The Temperature profile for about 15 hours

    1. I opened the door for starting the braise. I put the butt on the 3rd shelf, just below the Auber chamber temperature sensor. The temp stayed fairly consistent around 225F.

    2. In with the ribs. Braising butt and my internal temperature sensor moved to the top shelf. Baby back ribs went to shelves 3 & 4. Temp on shelf 1 stayed about 230.

    3. Started the braise on the ribs.

    I stopped monitoring the chamber temperature when I pulled the butt to rest.

    And it looked like:

    World's Best Baked Beans

    Pork Butt


    Four Cheese Mac

    Overall, I'm now happy with the temperature control in my MES-40.
  14. And then again, maybe not. In this thread I learned there's a new MES-40, gen 2.5 available. I decided to do a temperature profile. Using Bearcarver's protocol, I set the smoker @ 225 and my probes on opposite sides of the same shelf. This resulted in the following graph.

    Other than an initial overshoot (common in PID loops) the side-to-side temps held within a couple degrees of 225. I use an iGrill with two probes. Normally one in the meat and one monitoring the chamber. This makes it difficult to see side-to-side variation during a smoke. Baby Back Ribs (done 2-2-1) is the one exception. This past weekend it was time to do ribs! 

    The Auber temperature probe sticks about 3 - 4 inches into the chamber. This means fat rendering from the meat can fall on the probe cooling the probe a bit. I'm considering ways to deflect the fat off the probe. 

    This graph starts about 1 hour into the braise and continues through the end of the smoke.

    The blue line is the temperature on the top shelf left near the smoke vent. The red line is the temperature on the third shelf right. This puts it above the heating element/chip tray.

    The 50 degree drop is when I opened the smoker to take out the ribs, remove the braising stuff (foil/liquid) and then put the ribs back in for the final hour.

    What's interesting here is a 25 degree offset from 225 (setpoint), even during the braise. It was cool the two temps tracked so close during the braise. The 10 deg difference between bottom right (red line) and top shelf left (blue line) seems reasonable and tolerable.

    As for the ribs? Here they are ... quite tasty.

    Next up ... two butts on shelf 2 with a protected temperature sensor. I wonder what will happen.
  15. So ... today (April 10, 2015) I smoked the 4 Cheese Mac & Cheese in a 1/2 size steam table pan and a 9x13x3 pan of the Planet's Best Baked Beans. 

    @Bearcarver  and I messaged and he said ... "I only smoke on shelf 2". (It's late and I may not remember correctly, but I'm hanging on waiting to put 2 butts in the smoker).

    I started the smoke @ 225. With the chamber at temp I put the mac on shelf 2 and the beans on shelf 3. The temperature over time looks like:

    And this is why @Bearcarver  only smokes on shelf 2. Given where my temperature probe sits in the chamber, putting a very large heat sink between it and the heating element causes a significant overshoot in temperature. 

    Would this matter for a 15 hour pork butt smoke? I'm not sure. For a 2 hour mac & cheese smoke, I got concerned.

    Next up ... two butts on shelf 2 monitoring chamber temp. When I wake up, I'll start the braise ...
  16. mummel

    mummel Master of the Pit

    Great thread, good info!  Why did you insulate the window?  What improvements did you see?
  17. When I started using my MES-40, I used a Thermo Hawk (touchless IR temperature device) to check the heat loss through the window. It looked something like this:

    The setpoint was 225. I did not document (and don't remember) how long the smoker had been at temperature.

    Essentially, the window is a heat radiator into the environment when I smoke. It is also difficult to keep clean. So I chose to insulate the window saving energy and removing the idea I should clean the inside of the window (which I wasn't going to do anyway).

    I haven't checked the temperature since I insulated the window. I guess I should do that some day.

    As long as the MES heating element has the capacity to generate enough heat to keep the temperature at 225, not insulating the glass shouldn't be a problem.

    My iGrill 4 probe assembly arrived! I can now monitor/record up to 6 temperatures when I smoke.
  18. mummel

    mummel Master of the Pit

    Fantastic.  Please report back about the temps.  Do you have a Kill A Watt meter?  I would be really curious to see the energy consumption pre and post insulation.
  19. I'll try to member to take temps the next time I smoke @ 225. It won't be for a few weeks. I smoke some Canadian Bacon late this week (@ 190) and then I'm out and about until late May.

    I do not have a Kill A Watt meter. It would be interesting, but I'm not interested enough to pull the insulation off the window. [​IMG]
  20. mummel

    mummel Master of the Pit

    Just a FYI - you guys can get a Kill A Watt for free on loan from your local library.  Really useful device.  I'm pretty big on energy saving (for the planet and my pocket).