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JackH
OfflineAdmin
· 07/04/2020 10:27 AM
Happy 4th of July! jazzyhands

JackH
OfflineAdmin
· 06/24/2020 7:58 AM
@Mark McCornack, Please post your question in the forum.

Mark McCornack
Offline
· 06/15/2020 9:28 PM
Hi! Looking for a legacy inlet temp sensor on 13 yr old Gene Cafe. It seems they've changed it and now you need new mother board and new sensor. Any ideas where I can find compatibile old one? Mark

Samaniego
Offline
· 06/09/2020 6:39 PM
Wich thermometers Can i buy for my roasting machine compatible with usb or macbook?

JackH
OfflineAdmin
· 06/05/2020 5:38 PM
peveleth, It is better if you start a post in the forum with your question. These shouts go away in time.

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Another 1.5kg or 3lb drum roaster from scratch
oldgrumpus
I'M STUCK! In my gas setup, I can't seem to get enough pressure through my safety valve to run my burner. All the safety valves I've looked at run with only 1/2 psi on the input side.

(FYI: a safety valve is what you have on your forced-air furnace or your gas water heater. It runs the pilot light and the burner. Also, if the pilot light goes out then everything shuts-down so nothing will blow-up.)

If any of you are running a setup with a safety valve and a pilot light, please help me out if you can. If I don't hear from any of you, then I'll ditch the safety valve and go to running my roaster like a BBQ.

Maybe someone is using a gas fireplace log setup with a pilot light? I don't know... just throwing out ideas...
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Nearly complete drum roaster shown on this forum
https://goo.gl/photos/qZJw8PxDa6K4wfqw5
 
JSA Coffee
My Primo Roaster uses a gas valve and control module similar to a furnace. For the time being, I am running it off of a 20# propane tank with a standard regulator. Maybe I can help? Have you checked the wiring diagram to make sure you have the right voltage going to the right terminals?

Also make sure you have the valve adjusted for the right pressure output. Just a couple places to start with.
 
Ringo
My safety valve runs 12 psi. I had trouble finding it. I will look when i get home and see if i can find a part number on it. I recommend using one because if i drop my roasting pressure too much the flame will go out. At 1st crack I usually go to 5 psi and everything is ok but if I go to 4 the burner may go out.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
Ringo
No luck only thing on the valve was an ink stamp t-86. Tried to look it up but no luck. I remember it took me a lot of looking to find one. I will look through old records and see if I can find anything but it’s been 9 years sense my build. One think you might look at is flame eye fire sensors Commercial boilers and home furnaces are all using that now. The mechanical valves may just not be sold now.
Edited by Ringo on 01/17/2019 6:28 PM
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
oldgrumpus
Thank you Ringo! If you can’t find any info, a photo might help ...
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Nearly complete drum roaster shown on this forum
https://goo.gl/photos/qZJw8PxDa6K4wfqw5
 
oldgrumpus

Quote

JSA Coffee wrote:

My Primo Roaster uses a gas valve and control module similar to a furnace. For the time being, I am running it off of a 20# propane tank with a standard regulator. Maybe I can help? Have you checked the wiring diagram to make sure you have the right voltage going to the right terminals?

Also make sure you have the valve adjusted for the right pressure output. Just a couple places to start with.


Thank you too JSA! Please send a photo of your valve or a brand name/model number if you can! ????
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Nearly complete drum roaster shown on this forum
https://goo.gl/photos/qZJw8PxDa6K4wfqw5
 
Ringo
Always had trouble posting pictures but will try. Did not work sorry.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
JSA Coffee
The valve on mine is a Robertshaw Grayson 7200 IPER converted to propane.
 
JackH

Quote

Ringo wrote:

Always had trouble posting pictures but will try. Did not work sorry.


Hi Ringo, sorry you are having trouble posting photos.
Please email me the image file or link if you are using a hosting site to me and I can post it for you.

My email address is in my profile.
---Jack

KKTO Roaster.
 
oldgrumpus
UNSTUCK! YAY! I think I have things mostly figured out now. I was overlooking the obvious. After all the messing around with various regulators, I neglected to adjust the safety valve output after changing the regulator from the high pressure one back to the low pressure one. Consequently, the flame height being too low flummoxed me until I realized that the output pressure adjustment on the safety valve had to be changed to correspond to the new lower input pressure. I am now at the maximum pressure adjustment and I get 7" W.C. on the output side of the safety valve with the burner running full-blast. According to the BTU calculator I'm at 29,600 BTU. The burner is rated at 31,300. If that's enough, I think I'm good. One caveat is that I had to also dispense with my fancy adjustment valve. The valve created an additional 1-1/2" W.C. pressure drop!

Is 29,600 BTU enough?

Many thanks to all who offered their help and suggestions!
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Nearly complete drum roaster shown on this forum
https://goo.gl/photos/qZJw8PxDa6K4wfqw5
 
allenb
Good to hear things are working out. My advice would be to swap out the needle valve for a low cost brass globe valve with 1/4" female pipe thread and re-adapt the fittings from the gas valve to accommodate. Working with low pressure propane or natural gas requires much larger valve ports than most small needle valves will have. Anything less than 1/4" porting within the valve will create pressure drops across them as you are experiencing with your needle valve. You can find these at Ace hardware or any plumbing supply at less than $20. Even though it won't be a true "needle valve", it should provide good control.

You may want to recheck your btu value using the btu calculator. I got a much larger btu value when entering .253 psi (7" H2O) with a .120" orifice.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
Thanks Allen, I am playing with the numbers on the BTU calculator. It is nice to have the maximum available sweep on the dial on the "inches of water" gauge as possible. If I can match the maximum rating of the burner with the maximum available sweep on the dial, I can make use of that when making adjustments during roasting. The larger the orifice, the lower the reading on the dial. Ideally the "10" on my dial would be matched to the 31,300 BTU of my burner. Since 7" WC is now my maximum, I can get just over the rated BTU output with a #50 drill bit.

I think that is amazingly cool.
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Nearly complete drum roaster shown on this forum
https://goo.gl/photos/qZJw8PxDa6K4wfqw5
 
allenb
I see why my btu calc came out much higher than yours. I thought you had used a .120 diameter drill on your orifice but with the #50, you will be in the right range. According to the btu calculator, at 10" H2O, with an orifice diameter of .070, you would be at 38,640 btuh which, as you stated is just a max output if you happened to valve it open that far and only if you had 10" available.

When you get a moment, shoot us a video of the flame at 7" once you get everything set.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
OK. Here's the video. But amazing good fortune! As I was cleaning up my workbench and going through stuff, the box that the safety valve came in, had the propane conversion kit... not installed! I thought it came already propane-ready and completely missed seeing the kit, which consist only of a very small spring that is meant to replace the stock spring. All that to say that NOW I'm getting the full 10" W.C. gas pressure to the burner!


Edited by oldgrumpus on 01/19/2019 6:38 PM
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Nearly complete drum roaster shown on this forum
https://goo.gl/photos/qZJw8PxDa6K4wfqw5
 
Ringo
That really looks great.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
oldgrumpus
I've been busy...
Bent some sheet metal to isolate insulation from roaster drum. Installed insulation on-top, but lower parts will need some added support to hold insulation in-place.
oldgrumpus attached the following images:
5-img_1558.jpg 6-img_1557.jpg 8-img_1553.jpg 9-img_1552.jpg

Clever Coffee Dripper
Grinder: Macap M4
Roaster: Nearly complete drum roaster shown on this forum
https://goo.gl/photos/qZJw8PxDa6K4wfqw5
 
oldgrumpus
Also played with the bean hopper, dump system and stainless sheet covering. Looking at two options for the bean hopper, but think I like the airplane spinner best. Will probably need to cut it down some as it is way too big but it's got a nice shape to it. The bean dump valve is Home Depot dust collector gate valve for $8.00 or so. Cheap. I like cheap. A lot!! Grin
oldgrumpus attached the following images:
7-img_1556.jpg 3-img_1564.jpg 4-img_1563.jpg 1-img_1566.jpg 2-img_1565.jpg

Clever Coffee Dripper
Grinder: Macap M4
Roaster: Nearly complete drum roaster shown on this forum
https://goo.gl/photos/qZJw8PxDa6K4wfqw5
 
BobbyS
All right Ralph! cool

This is coming together very well. Nice quality work on all of it. I like the bean dump from a dust collector; very inventive I must say. Looking forward to this bad-boy kicking some beans out!
 
Chiarch
Have you made any more progress on the roaster? Seems like you were making a lot of headway at the end of January!
 
oldgrumpus
I've been on another hiatus and now I'm back, hopefully to finally finish this beast. I wish I could say I was saving the best for last, but as I've been working on it these past couple of weeks, it seems like making it all come together has been quite daunting.
Challenges:
1. Fitting a bunch of control components inside a nice, neat, compact control panel. I might just "make it work" and then modify when inspiration comes. It's a long list of power-supplies, speed controllers, valves, transformer, Phidget, RPM gauge and circuit board, gas pressure valve, gas pressure gauge, variac, voltmeter, switches, etc!
2. I ordered a "high-temperature" blower from Aliexpress (China) and am very disappointed. It came with a speed control and looked like decent quality. It has has multiple issues. Internal wiring in the non-vented, sealed motor was dragging against the armature. I know because I tore it apart and fixed it. Once working, I thought I had ruined it because there were sparks at the speed control when I tested it. One of the two wiring labels was incorrect which meant I hooked input to the output. All that to find out that the sealed motor gets too hot after running for 10 minutes or so. I'm certain it won't last. Maybe not even for a single roasting session.
3. Ordered another exhaust fan from Grainger. Waiting for delivery.
4. Trying to figure out super-simple bean cooling. Maybe manual stir or no-stir. We're only talking 3 lbs which in my thinking doesn't necessitate a rotating device (which would be great! but... maybe not essential)
5. SO ANXIOUS to get this puppy roasting!!
6. Considering whether I should use a speed control on the exhaust fan or a butterfly valve on the exhaust tube. Speed control sounds simpler at this point.

Anecdotal story. Was at Online Metals in Seattle to pick up stainless rod for the bean-dump door and met a fellow there that has scratch-built 3 drum roasters of various sizes. This was totally random! Amazing.
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Nearly complete drum roaster shown on this forum
https://goo.gl/photos/qZJw8PxDa6K4wfqw5
 
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