lauter tun copper tubes: notched or drilled?

vmpolesov · 01-08-2008, 06:39 AM

Most plans I have seen call for cutting notches in your copper tubes. Time consuming and tedious.

I have a CNC mini mill which I got so that I can sit around and drink beer while the computer does the grunt work, on projects like this. Drilling lots of holes - no sweat.

So will holes work or does the geometry require notches (large enough to let plenty of liqued through but not bits and pieces of grain)?

**bradsul** · 01-08-2008, 02:38 PM

My manifold is drilled (I had to do it with a little less complicated drill press though

) and I have no trouble at all. I can't remember the bit size I used but it was very small (diameter is less than the width of a hacksaw cut) so I get VERY little grain matter in the output. I drilled the wholes every 4mm. There's a picture in my gallery (though it's not very good).

rdwj · 01-08-2008, 02:41 PM

I see no reason why drilled holes wouldn't work. Just make lots of them and make them as small as possible.

Grimsawyer · 01-12-2008, 08:42 AM

I use to work at a circuit board shop as a cnc drill operator. We had some extremely small bits. .0015" is about as small as it got. not .015", .0015" they could make smaller but that was as small as we used. They were very tiny. Made of a tungston carbide alloy. Tycom was our supplier. The bits from the tip of the tool to the end was about an inch and a half. Those bits were as thin as a human hair, and they went through 10 layers of circuit board... they were nuts. You could get 500 hits off of a single bit... anyhow, I would suggest a #77 or a #76 drill bit for your holes. Put them really close together, really close. Then just go around that pipe. If ya get it close enough would look almost like a screen bent into a cylinder if you went around the whole pipe. Personally I'd put 8 or 9 rows the length of the pipe, very close together on one side, simulating cuts. Don't forget to deburr!!! If you could figure out something to stick in the center of the pipe that fit snug against the metal you won't have any burrs on the inside of the pipe. Not sure what would work on that though. And if you have an entry material that would cut down on the burrs on the outside as well. I hope I've been of some help.

MikeFlynn74 · 01-12-2008, 09:40 AM

I drilled holes in mine- used 1/8 or 3/16 on mine. I get some bits on the first run but I re run them and get nothing

vmpolesov · 01-15-2008, 07:40 AM

Interesting post grimsawyer. I am adding a 4th axis (rotary table) to my CNC when I can spare time from my beer brewing and drinking responsibilities.

Once I have that I can chuck the pipe in the rotary table and put as many rows of holes in it as I want, always drilling straight down not on a slant. With that in mind what angle would you recommend for the radial segment that I drill holes thru? 10,20,30 degrees worth of circumference, etc? I would guess that 180 would be the limit because you don't want holes on top obviously.

As to preventing burrs, lets see here, just some ideas:

1. cram a wooden dowel into the pipe then drill it out when done.
2. fill the pipe with some sort of non-toxic castable stuff, drill, remove. I thought about some other options here but ruled out techniques that would be okay for machining/tubing bending applications, but not something you want touching anything you are going to eat/drink.
3. ream pipe ID after drilling holes.

thanks,

**bradsul** · 01-15-2008, 03:11 PM

Quote:

Originally Posted by vmpolesov

...With that in mind what angle would you recommend for the radial segment that I drill holes thru? 10,20,30 degrees worth of circumference, etc? I would guess that 180 would be the limit because you don't want holes on top obviously...

Keep them as close to the bottom as you can, your syphon will break at whatever height you go up the sides of the tube and you want to leave as little behind as possible.

mr x · 01-15-2008, 03:15 PM

I put my slots at 90 degrees. It doesn't leave too much good wort behind because I double batch sparge. I did this because I use steam to mash and I didn't want the steam directly at the plastic bottom. You may want to consider this for future modifications. I love the steam mashing. Plus, I can use the steam to sterilize my cfc and hoses.

SuperiorBrew · 01-15-2008, 04:03 PM

Quote:

Originally Posted by mr x

N 45 39' 28.2"
W 62 26' 54.2"

Near Big Island Road? Hows the fishing there?

mr x · 01-15-2008, 06:12 PM

Right off the Big Island Road. Fishing isn't bad, but it's gone downhill from when I was a kid. Now I don't even know if you are allowed to fish off the wharf.

And now there's a seal(s) that's appeared in the last few years that's probably making a dent in the trout and bass. C'est la vie. I have a Passat G3:

http://www.seawardkayaks.com/prodproductsview.aspx?key=4130&idProduct=4130

I get out as much as possible, some dedicated fishing trips are on the agenda once the girlfriend gets more comfortable in it.