Pellet Fan
Pit Talk -- Comments and Questions Regarding These Pellet Pits => recteq => Topic started by: okie smokie on March 05, 2022, 11:24:02 PM
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In another life I designed a new diffuser for my Blaz'n Grand Slam. But when I sold the Slam I kept the mod cause it was a 10" by 10" by 3/16" piece of 304 stainless. Have had the 590 for almost 3 yrs now and like many the diffuser has warped. I have known that RT has replaced them when requested, but saw no sense in doing so, since the replacement would no doubt do the same. They have replaced the diffuser in the newer model with a cast iron diffuser but do not offer that one as a replacement for the original. So I took the mod and adopted it to the warped diffuser with SS hardware. The thickness of the mod plate pulled the warp back out of the diffuser nicely. Cranked it up to 400* for about an hour. Noted perhaps a bit slower to heat up but negligible IMO. Cool down was slower but otherwise it worked well with no after-warp noted. Just removed the long bolts and replaced with 1". Drilling the diffuser required getting the guide holes properly placed but was easy.
(https://i.imgur.com/RlYh0UTl.jpg)
(https://i.imgur.com/vETNGdWl.jpg)
(https://i.imgur.com/wAhevNel.jpg)
(https://i.imgur.com/rmfXADzl.jpg)
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This brings back fond memories of when I had my Traeger. Did the same thing. I also noticed longer warm up & cool down times with my 1/4" SS heat deflector reinforcement. The temperature swings were
also slightly reduced. That is what a heat sink does.
I noticed the expansion rates of the two pieces were different due to their thickness differences. That led me to loosening the 4 pieces of 1/4" attaching hardware slightly to allow movement. This eliminated a
slight creaking sound @ warm up and reduced any stress caused by temperature changes. Fussy I know - just me.
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This brings back fond memories of when I had my Traeger. Did the same thing. I also noticed longer warm up & cool down times with my 1/4" SS heat deflector reinforcement. The temperature swings were
also slightly reduced. That is what a heat sink does.
I noticed the expansion rates of the two pieces were different due to their thickness differences. That led me to loosening the 4 pieces of 1/4" attaching hardware slightly to allow movement. This eliminated a
slight creaking sound @ warm up and reduced any stress caused by temperature changes. Fussy I know - just me.
Wow! Deja Vu all over again!(ala Yogi) I also noted the clicking sound but was at a loss to understand at that moment. Your experience and mine are the same! Perhaps I should have the two pieces welded as others have done? How did your hold up over time?
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I thought a few years ago they fixed or tried to fix the warp issue, by having a border the whole way around the top. Pretty much had a piece welded on both sides to connect the front and back. They billed it at the time as doing it for a place to put pellets for additional smoke. It much have been to costly o have that extra step done.
You should not have an issue with warpage any longer.
They always said it didn't effect the cooking of it but the past try to fixing it and now the cast diffuser make one wonder if it does effect the cook or if they were just tired of all of the complaints about them warping. I had seen some pictures that warped so much it pushed the drip tray up.
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This brings back fond memories of when I had my Traeger. Did the same thing. I also noticed longer warm up & cool down times with my 1/4" SS heat deflector reinforcement. The temperature swings were
also slightly reduced. That is what a heat sink does.
I noticed the expansion rates of the two pieces were different due to their thickness differences. That led me to loosening the 4 pieces of 1/4" attaching hardware slightly to allow movement. This eliminated a
slight creaking sound @ warm up and reduced any stress caused by temperature changes. Fussy I know - just me.
Wow! Deja Vu all over again!(ala Yogi) I also noted the clicking sound but was at a loss to understand at that moment. Your experience and mine are the same! Perhaps I should have the two pieces welded as others have done? How did your hold up over time?
I would NOT have the two pieces welded together. Why? The uneven expansion will continue and could very well end up cracking the thinner material as it expands and cools faster in the thermal cycle. You will
continue to hear noises. The creaking noise could very well develop into a rather loud pop. If one of the two pieces required replacing, both pieces would have to be replaced as they are now one.
As far as holding up goes: I had a good two years of use from the set-up and off to my daughter it went when I got the Memphis. She has had it close to three years w/o issues as far as I know. It doesn't get
the use it did as when I had it.
To allow for the different expansion rates, all the holes need to be slightly larger than the bolts, ~ 1/8 to 3/16" larger.
To keep things together, double nutting is a good way to go. The first nut barely finger tight; with that being held along with the bolt, then firmly tighten down the second nut. This will allow the two parts to float
or move independently from each other yet keep them together.
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You get the same even heat distribution you got in Blazn?
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You get the same even heat distribution you got in Blazn?
In the Blaz'n I completely changed the shape from round to square, and thus the distribution was different. In the RT the added square is completely covered by the deflector, so no change in shape or size.
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This brings back fond memories of when I had my Traeger. Did the same thing. I also noticed longer warm up & cool down times with my 1/4" SS heat deflector reinforcement. The temperature swings were
also slightly reduced. That is what a heat sink does.
I noticed the expansion rates of the two pieces were different due to their thickness differences. That led me to loosening the 4 pieces of 1/4" attaching hardware slightly to allow movement. This eliminated a
slight creaking sound @ warm up and reduced any stress caused by temperature changes. Fussy I know - just me.
Wow! Deja Vu all over again!(ala Yogi) I also noted the clicking sound but was at a loss to understand at that moment. Your experience and mine are the same! Perhaps I should have the two pieces welded as others have done? How did your hold up over time?
I would NOT have the two pieces welded together. Why? The uneven expansion will continue and could very well end up cracking the thinner material as it expands and cools faster in the thermal cycle. You will
continue to hear noises. The creaking noise could very well develop into a rather loud pop. If one of the two pieces required replacing, both pieces would have to be replaced as they are now one.
As far as holding up goes: I had a good two years of use from the set-up and off to my daughter it went when I got the Memphis. She has had it close to three years w/o issues as far as I know. It doesn't get
the use it did as when I had it.
To allow for the different expansion rates, all the holes need to be slightly larger than the bolts, ~ 1/8 to 3/16" larger.
To keep things together, double nutting is a good way to go. The first nut barely finger tight; with that being held along with the bolt, then firmly tighten down the second nut. This will allow the two parts to float
or move independently from each other yet keep them together.
Good advice John, I think I have enough bolt length to do so. Will look into it. I wonder if the second nut is really necessary since the heat and soot pretty well locks the nut in place anyway? Really took some tork to get the original nuts to move when removing the bolt/legs. A little research is in order---.
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I had made a lot of mods to my Blazn' GridIron when I had it.
Posted them back on the PH forum.
Don't know if I have any pictures around, I'd have to look. Have some drawings I think.
I made a funnel for the hopper for easier filling, Extra weight on lid (was always worried about wind blowing it closed), new heat deflector, new grates (the roller grates sagged), New longer handle for opening lid, shelf for side to set thermometer(s) on, and added a Smoke Daddy.
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I also ditched the roller grates. Surprised they still use them after all the complaints, i.e. sagging and not rolling. I replaced with custom 3/8" 304 SS. I also put insulation on the floor because a hot spot there kept the paint peeling on the bottom. Otherwise the pit was a good one. Online service was also good. All USA made.
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I also ditched the roller grates. Surprised they still use them after all the complaints, i.e. sagging and not rolling. I replaced with custom 3/8" 304 SS. I also put insulation on the floor because a hot spot there kept the paint peeling on the bottom. Otherwise the pit was a good one. Online service was also good. All USA made.
You jogged my memory, I put metal plates in the bottom for same reason.
Tim was always great with helping out.
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Yes Tim was helpful. I had no trouble selling the pit. Someone came up from Oklahoma City and carried it away. I got a good price for it as well. Never heard again from the buyer so assume he was happy.
Except for the warped deflector, I am satisfied with the RT products and service.
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Just had email exchange with RT Service. Got an immediate response as follows:
1. Warp is common and does not affect the cooking characteristics
2. They don't replace the diffuser any more since it will just warp again.
3. He did not respond to my comments on change made by the mod. i.e. Slow cool down, and altered high temp.
4. Said he would remove the mod and ignore the warp.
Conclusion: Will think on it.
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Just had email exchange with RT Service. Got an immediate response as follows:
1. Warp is common and does not affect the cooking characteristics
2. They don't replace the diffuser any more since it will just warp again.
3. He did not respond to my comments on change made by the mod. i.e. Slow cool down, and altered high temp.
4. Said he would remove the mod and ignore the warp.
Conclusion: Will think on it.
RT service is correct. Traeger says the same thing... I feel any warpage in a pit is due to poor design based on cost. In this case, thicker, more expensive material shouldn't warp. RT as well as others have
added no cost stiffener ridges to to reduce warpage of their heat deflectors. Their effect is minimal @ best.
The reason I reinforced the heat deflector on my Traeger is I didn't want it getting worse (warpage) and felt straight & true just felt better to me. Much like well organized lines(ropes) on a sail boat. Neat and
tidy wins.
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Wow, that is not what one would expect to hear from the best customer service out there.
I can not imagine wanting to remove you plate, you just upgraded your cooker and made it better.
I have to believe that warping depending on how bad would throw temps off some side to side.
If that is their stance I wonder why they ever replaced any of them under warranty.
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Hey Dave, I believe they decided that after many replacements that just warped again. For what it has cost them in replacements, they could have made them out of heavier gauge SS for a few bucks? Not complaining really since most other brands do the same. The Blaz"n was a round, cupped, 3/16" SS. It did not warp, but because of its shape and support arms, it arced the fire downward and caused the hot spots that peeled the paint off the bottom-underneath.
Not sure I will keep the mod. Want to make sure I can live with the slower rising temp and even slower declining temp. I can resolve the clicking by loosening the bolts by a turn, the soot and such will keep them from turning loose otherwise OR can use another nut and lock washer to position them. The higher actual temp on hot cooks is no big deal as I can adjust the set temp if necessary. At smoking temp of 225* it is right on. RT is right about one thing IMO, the warp was no problem other than it irritated me from an OCD standpoint. Like having a nice new car with 3 black tires and one red tire. Plan to play with it a while longer.
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Curious how it took longer to come to temp or come down. The flame and heat would just come out the sides I would think. The flame isn't enclosed. Hard to imagine that piece of SS changing much. What do I know, you have the test data.
One would think if people called in now and complained of the warpage, they would offer to sell them one of the new cast iron ones.
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Curious how it took longer to come to temp or come down. The flame and heat would just come out the sides I would think. The flame isn't enclosed. Hard to imagine that piece of SS changing much. What do I know, you have the test data.
One would think if people called in now and complained of the warpage, they would offer to sell them one of the new cast iron ones.
Fire pot is like a blow torch, it turns the metal plate into a heat sink. The thicker the plate the more heat it stores. Ought to make it more efficient, and the PID should adjust as needed to keep the temp at what you order. Unfortunately, the bigger the heat sink the longer it takes to heat up or lose heat. So if you overshoot with your initial requested temp, it takes longer to compensate and you are overcooking while waiting for it to adjust and visa versa. That PID has been programmed to interact with the factory characteristics of this grill, including the time it takes to heat up all the inner parts to a steady temp as ordered and also the time it takes to go to a lower temp or higher one. I am not sure how sensitive all that is, so I am going to test all that out before committing long term. If the delays are inconvenient, or if the temps are unstable compared to original then I will consider laser cutting out a large central portion of the 3/16" plate, maybe a 6" circle. That will reduce the mass of the "heat sink" hopefully enough that the effects on temps etc. will be reduced so as to be insignificant. Meanwhile the remaining plate should still be rigid enough to block the warp. I'm an unemployed 86 y/o with nothing better to do..
I suspect that the new diffuser is not offered because it installs differently? Don't know that, but who wants cast iron in their nice SS interior anyhow?
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Spent most of this cold, gray day testing and adjusting. After loosening the nuts and locking with lock washer and extra nut, I cranked up the 590 set at 225*. Placed two temp sensors, one on left-central, one right central. After reaching the temp and 30 minutes to stabilize, the control read 225* and the left center was 217*, the right center 235*. I switched the sensors to make sure they were both accurate and got essentially the same readings. (left 216-; right 239*). Then for final, I placed both sensors in the center/central position, and they were identical at 230*. So I went into "Offset" while the machine was running and added 1+ unit. After about 20 minutes they both read 225+-one or two, while the control sensor read 225*. Best I have ever gotten a match. I think the reason that the left central reads colder is because the fan blows from left to right and the flow favors the fire pot holes on the left and center as compared to the holes on the right. ? Not sure of that logic but seems reasonable to me. I have an old solution for evening out the heat from the diffuser--cut out the side slots an extra half inch on one side only, and then tweak it a little to the right so that more heat escapes on the left side of the diffuser. I did this on my old Traeger with excellent balance on both sides of the grates. Does not take much offset to get a better distribution of the heat. There were no clicking noises! And after satisfaction at 225* I kicked it up to 400* with both extra sensors still in the middle and they both read 417-420. No big deal:at that temp. So I added my portable griddle and grilled salmon for dinner. It was wonderful, with fries in the air fryer, and left over cranberry sauce. I noted that the cool down was not delayed in an obvious way, so declared the mod a success. Will keep it as it was at the end of the day. Thanks for all the input. :bbq:
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Great to hear it is working and you are getting temps to where you want. I think GMG diffuser gets slid one way or the other to help with evening temps.
I messed with temps when I first bought the RT and it irritated me as they were not very close at times side to side. It was nothing to see 50 degrees right to left. When I bought the GMG I decided no need to be messing with temps. Just cook, I know it cooks a little hotter than set temp.
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Great to hear it is working and you are getting temps to where you want. I think GMG diffuser gets slid one way or the other to help with evening temps.
I messed with temps when I first bought the RT and it irritated me as they were not very close at times side to side. It was nothing to see 50 degrees right to left. When I bought the GMG I decided no need to be messing with temps. Just cook, I know it cooks a little hotter than set temp.
If I was unaware of the warp, no doubt I would not have suspected any problem and would have been cookin instead of lookin. But because of who I am, I would be more likely to go to bed and not sleep well, maybe think up a solution, get up at 2AM and go out and fix it.
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Striving for perfection is a sickness I suffer from as well..
Thanks for the update okie.
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Striving for perfection is a sickness I suffer from as well..
Thanks for the update okie.
So are we "special" or just "mentally ill" (in the context of today's society)?
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Striving for perfection is a sickness I suffer from as well..
Thanks for the update okie.
So are we "special" or just "mentally ill" (in the context of today's society)?
I like to think "old school". That is, we learn how things work and repair with pride.
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Striving for perfection is a sickness I suffer from as well..
Thanks for the update okie.
So are we "special" or just "mentally ill" (in the context of today's society)?
I like to think "old school". That is, we learn how things work and repair with pride.
I used to "repair" computers. Remove the bad component (transistor, capacitor, etc.) and solder in a new one.
Now it's replace the whole thing.
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Spent yesterday afternoon and night adjusting and testing with the mod and without it. Was worried that the time delay getting to temps would be irritating. But that was minor compared to benefits. First tested temps on left center, mid-center, and right center first without the mod and then with. Strange and surprising results. Using fresh LJ Hickory Blend.
First test at 225* set and without mod: The diffuser was warped about 1/2". Offset adjusted to +4 to get 225* actual temp. Left was 205*, center 225-227* and right was 241*. Not happy with sides. With set temp to 275*, I got L 261*, C 278*, R 301*. The above are all after letting the pit adjust for 30 minutes.
Second test with Mod included and at 225*: Had to adjust the Offset to +6 to get center temp to 225*+_ 2, Left 210*; Center 225*+_ 2; Right 236*. With temp set at 275*: L 258*; C 278*; R 304*.
Not a big difference. The real problem is the difference between left and right. I have made the notch in the center of the diffuser sides about 3/8" bigger on one end but saw no significant difference. Might make it bigger, but I have another idea. BUT will try it first before describing. Stay tuned.
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New idea: Okay I was thinking about why we call the diffuser, "diffuser," or "deflector". Well it does both, but we use it mostly as a diffuser--as it diffuses the fire and heat equally in all directions. I think of a deflector as shifting the heat in a specific direction. In order to do deflecting I would think you would have to tilt the deflector to increase flow in the direction desired. I have never seen any description of doing so.
Problem: MY 590 (and others I have read about) is cooler on the left side than either the center or right side:
With Mod and set at 225*, I get the following temps, Left Center 205* Center 227* Right Center 241-246*
So I lowered the right side of the Mod Plate by 1/4" by placing a nut between the plate and the deflector/diffuser at both right bolts. (no pics, sorry) which gives me a tilt that deflects more to the left side.
Result with deflection: Left Center 224-225*; Center 225*; Right Center 247. It took an some extra time to settle but was very stable at the endpoint. Almost unbelievable result, but it happens.
Impression: Makes sense and it worked, BUT had no apparent effect on the high right side. My diffuser/deflector was centered.
Question: What could make the right side significantly hotter than the left or center?
Answe?r:Drip pan is tilted downward to drain, and is significantly closer to the deflector on the right as it goes by, thus R drip pan is exposed to more direct heat and flame as it exits the d/d. Obviously the SS Mod plate lowered on that right side by 1/4" made little difference since the whole d/d is not lowered there.?? My assumption is that the drip pan is hotter in that spot and radiates that heat upward. Will look at the bottom of drip pan for any evidence.
What else could be done to lower temp on the right? Not sure anything is needed but to just know that and work around it or use it as needed.
Comment: I know that if I never knew there was a difference in grill temps from side to side, I would probably continue cooking great meals on this fine grill. I also know that this is not uncommon in most pellet grills on the market although the hot side is not always on the right.
Plan: Since I am old and unemployed, I will do a little more sleuthing before giving up on the right, but am very happy with the results to date and feel I have discovered new territory that might be worth a little research by the manufacturers to alter their rather rigid design concepts for diffuser/defectors (like adding little "tilt" where needed). Or maybe conclusions might include "Live with it! Its no big deal"
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I think the key take-away is that you know what the variances in temp are, and you can adjust your cooking accordingly.
I have not tested the Memphis I have, but would expect temps on both sides to be very close as the drip tray (flavorizer as Memphis calls it) slopes in both directions.
The center would be hottest since it is directly over the burn pot and there is no diffuser above the burn pot.
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I think the key take-away is that you know what the variances in temp are, and you can adjust your cooking accordingly.
I have not tested the Memphis I have, but would expect temps on both sides to be very close as the drip tray (flavorizer as Memphis calls it) slopes in both directions.
The center would be hottest since it is directly over the burn pot and there is no diffuser above the burn pot.
I agree. If you check, let us know. I pulled the drip pan and the picture confirms in my mind that indeed more heat is absorbed by the R dp as suspected. More soot and ashes on the right of the dp and clearly where it exits the diffuser. Now, what to do?? Not sure anything since lowering the d/d might diminish the direct effect on the drip pan, but would place the d/d closer to the fire pot, and perhaps it would gather more heat as compared to the left side of d/d itself. Think I will take what I've gotten and stop there for now. Pic of underside of drip pan speaks for itself.
(https://i.imgur.com/6vTmq3Fl.jpg)
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After all the above I was concerned about the size and weight of the SS plate. So I ordered a 1/8"" 304 SS 9" x 9" plate to replace the 3/16" 9"x 9". I applied it to the diffuser/deflector in the same manner with the right side lowered by 1/4" as before (assuming it would deflect more heat to the cooler left side as before but without as much heat sink effect).
1. After repeated tests at 500+*, the d/d did not warp. So IMO 1/8" thickness is enough to control and prevent.
2. With separate tests at 225* setting there was only about -8* on left and +13* on the right sides with the usual variations over time.
I believe the mod can be done with 1/8" steel as effectively as with 3/16" or 1/4" to prevent or correct warping.
Thanks for all the input. Appreciated. :bbq:
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I"ve had my gridiron for 6 years. its used an average of 3 times a week and i've never had a problem with the roller grates warping etc. possibly the ones that sagged was an older design.
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Are the grates hollow or solid? Mine were hollow tubes, and when you picked up a grate by the rollers, they would flex under the weight of the grate.
In any event, it should not have happened. I replaced them with 3/8" 304 SS. Problem solved. Forgot to say that others complained about them as well.(I even called Tim about it). Might have been a problem that was solved on newer versions.
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So with your finding of a 1/8" plate working, any plans on just building a new diffuser from 1/8" SS?
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So with your finding of a 1/8" plate working, any plans on just building a new diffuser from 1/8" SS?
With the warp corrected by bolting on the 1/8 plate, I see no need to build a new d/d. I have seen reports that the 1/8" diffuser offered in the aftermarket will still warp is some instances. I suspect that it is the altered shape and size of the single piece of SS that causes it to warp. i.e. a flat piece of 1/8 heated to 500 won't warp easily (very stiff). But if you bend and twist it into a different shape, you alter the characteristics of the metal in those areas affected. I am not a metallurgist but do know that various manipulations of certain metals changes their physical properties to some extent. Meanwhile if 1/8" 304 SS is stiff enough to do the job, that is what I would suggest to others, to correct that problem without altering the shape or position of the d/d. In addition, the change in slope of the plate (see previous comments) to balance the heat distribution does help, but in my opinion, is not at all necessary for good cooking, since most pelletfans have done very well by knowing how to use their pits for best results. I am more of a nit picker than a good chef but that is just me. Is 304 SS necessary? or even 430?. I don't know. Perhaps even just good carbon steel plate would do. I'll leave that for others to decide. I paid $20 for 1/8" 9"x9" plus $10 shipping. You could get it for less locally if available. I also used 1"stainless bolts and nuts to match, (lock washers also).