Uds #6/#7

Discussion in 'UDS Builds' started by helljack6, Aug 18, 2009.

  1. helljack6

    helljack6 Meat Mopper SMF Premier Member

    So, after a long wait, I've finally brought myself to building UDS #6 and #7 of my fleet. #6 is now built and smoking and #7 will be an identical clone. Some of the most notable changes for these two from their brethren are:

    - Single 2" inch intake drilled centered at 2.5 inches from the bottom v. the original three or four 1/2 or 3/4 intake drilled centered at 2" inches from the bottom

    - Spring loaded slider cover to regulate air intake v. ball valve

    - 2" inch conduit nuts both inner and outer to hold pipe in place and create a seal

    I haven't spot welded the slide cover to the intake pipe as of yet because I don't own a welder but that will get done this week. She's on her initial burn and locking in desired temperature has never been so easy. One slide cover to adjust with minimal bending or squatting. The reasons I chose this design are:

    - a single hole v. several holes reduces overall air leak potential
    - (hypothesis) primary air intake should be equal in size to primary exhaust
    - less holes drilled = better drum integrity
    - ease of operation

    With ease of operation comes the set back in money. For the build I ended up spending probably $35 MORE than normal, however I think at this point that the investment was well worth it. I'll post more pictures as the initial burn goes on.

    The lid on this barrel is from another barrel so it's not seated 100% down. I got a wild hair up the arse today while waiting for the electrician to show up and didn't want to go through the process of removing the rubber seal so I just swapped lids. I'm sure that will have an impact, but I again only forsee it being minimal at best. Test is being ran in my garage with the front door 6" inches off the ground and the back door wide open for ventilation, wind is not a factor in this test.
  2. beer-b-q

    beer-b-q Smoking Guru OTBS Member

    Congratulations. Sounds like you are getting to be an expert at building them... [​IMG]
  3. swindler

    swindler Fire Starter

    How is the Spring loaded slider cover attached to the intake pipe?
  4. helljack6

    helljack6 Meat Mopper SMF Premier Member

    When it's done correctly, the locknut will be welded to the outer side of the intake and then you adjust tension via tightening the bolt a couple turns.
  5. the dude abides

    the dude abides Master of the Pit OTBS Member

    That's a fine looking build. Congratulations!
  6. richoso1

    richoso1 Smoking Guru OTBS Member SMF Premier Member

    Congrats on some fine work my friend. You are a skilled man, it's all good my friend.
  7. ddave

    ddave Master of the Pit OTBS Member SMF Premier Member

    Looks good. [​IMG] And I would agree with your assessment of all of the features except . . .

    Not necessarily. I would think you would always want the exhaust to be more than the intake. If they are the same volume, you can accomplish the same thing by keeping the intake closed somewhat. The intake only needs to be as big as required to get the temp range you want. You wouldn't ever want the intake and exhaust to "balance" exactly or you would lose your draw. You want the exhaust to be "pulling" fresh air in through the intakes for combustion and to keep the smoke moving.

    Of course this is from the perspective of a former wood-fired boiler operator.[​IMG] To test the theory on a drum, you could always just open them both up all the way and see what happens. I would predict the fire would go out due to lack of oxygen, but I could be wrong.

    If this led to temps higher than what you would cook with, then it's kind of a moot point.

    At any rate, it's a good lookin' drum.[​IMG]

  8. rickw

    rickw Master of the Pit OTBS Member

    Nice looking drum.
  9. solaryellow

    solaryellow Limited Mod Group Lead

    I am still learning about UDS's in anticipation of building a couple in the near future so I hope you don't mind a stupid question. Does raising the intake like that have any effect on draft? My initial thought is no because the intake is technically at the bottom of the drum but I am not certain.
  10. helljack6

    helljack6 Meat Mopper SMF Premier Member

    No it doesn't. I'm more inclined to think that what DDave stated about the size of the airtake being equal to the size of the exhaust is more of a factor than anything.

    I built #7 out of order because I was home that day waiting for the electrician. I'm going to complete the build on #6 testing DDave's theory as I have drilled the intake hole to 2" and will thread in a 1 3/4 pipe and see if that has any effect on the draw. From what i've seen so far, equal intake/exhaust doesn't have any effect, but then again, I haven't ran it wide open to confirm that it would in fact stall. I'll let you know as I continue a series of tests/cooks with this particular setup.
  11. ddave

    ddave Master of the Pit OTBS Member SMF Premier Member

    But that will make the exhaust more than the intake and you will still have positive draft. [​IMG]

    To fully test the theory you would need 2" unrestricted intake and 2" unrestricted exhaust. Leave them both wide open, iight the basket, close the lid and watch the temps. I'd be curious to see how long it goes and at what temps.

  12. helljack6

    helljack6 Meat Mopper SMF Premier Member

    This I can do with #7 as it's equal and the slide cover goes from partial cover to complete wide open.
  13. billbo

    billbo Master of the Pit OTBS Member

    Looking good Nutzman!

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