Zephrant
Premium Member
DIY- Ultra Skimmer
I had been looking at my Monster Beckett that I am running on my 200g system, and thinking that I'd like something bigger, so off to the shop I went.
This time I went with a 8" dia. cast main tube, and dual 3.5"x30" cast injector tubes. The mixing box size is about 14"x10"x12", and made out of 1/2" cast acrylic.
As before, start out with making the box. Cut on the table saw, then run it across the jointer (or setup a router table to joint) to clean up the edge. Build the 4 sides of the box first (see the Monster Beckett thread for details.)
Make the top of the box next- The 3.5" injector tubes penetrate the top of the box for the strongest joint. The downside is that they have to be carefully aligned with each other before you glue them, or they may be crooked. Get a tight fit here, and use Weldon #4. The 8" main tube sits in a 1/8"x1/8" groove in the top, which precisely locates it and allows more surface area for the glue to adhere too. If you have a snug fit, use Weldon #4, if it is a little loose, try some Weldon #16 in the groove, then push the tube down in to it, and put a weight on it.
Thinking inside the box:
Since I had two injector tubes, I couldn't do the mitered tube construction I used in the Monster Beckett, so I came up with a simple baffle setup in the mixing box. I have a false bottom installed that is walled off from the main tube, but not from the injector tubes. The foam is forced down below that baffle, and is only allowed to escape up through the 4" coaxial tube in the middle of the 8" main tube.
Thinking outside the box: (and gluing on the main tube and 10.5" flange)
The flanges are all made as done previously- MDF patterns are made up by printing out a CAD drawing 1:1, and using 3M77 to stick it down to a square piece of 1/2" MDF. Then it is center-drilled, and a 1/4" shank is installed in it. I then put it on the mill, and spin the MDF against a bit to get it to the correct round shape. Leaving it setup there I move it over and drill the holes for the key-holes and all, using the printed pattern as a guide. (I'll do a flange DIY with more detail soon. ) This design used 13 flanges made from 5 patterns.
The injectors are similar to last time too- I used 3.5" cast acrylic again, with 6" dia flanges, but I went to 4 holes instead of 6 to make removal easier. The O-ring grooves are 1/8" wide x1/16" deep, and I use Buna-N O-rings available from All O-rings in packets of 10-50, depending on the size.
The finishing touches seam to take the longest time. I hand sanded all the edges with 220, 400 and 600 Wet/Dry sand paper, then hit it with a $20 car buffer and Novus #3 buffing compound. The result is a mirror-smooth finish, but is extremely time intensive. Look for tips on flame polishing in the future.
(I still don't like flame polishing for tanks, but I'm thinking it's a great idea for low-stress areas like flanges. )
I found some "Banjo" 1" quick disconnects at the local farm supply store, and used them ($12/pair) on the inputs to make it easier to setup/teardown. The output is a 2" gate valve from Aquatic Ecosystems . I also used some 1/2" rubber grommets to mount the 3/8" air valves. This required drilling a 1" hole in the cast acrylic, which I don't like to do, but I think the rubber will help protect the joint as it will flex some when the valve is bumped. Hard gluing that joint would be asking for a leak IMHO. Reports from the test running are that 1/4" air valves would be adequate too.
The acrylic was purchased from the local Laird Plastics in 6' lengths.
Tube cuts:
8" tube: 2' section for the main tube, and a 6" section for the overflow cup
4" tube: 18" section for the coaxial injection, 8" section for the neck
3.5" tube: two 30" injector tubes, two 3.5" sections for the Beckett injectors
Look for a DIY tube-cutting jig for a table saw thread coming soon.
I used SCH80 elbows and nipples mostly for looks- Grey looks better than the white PVC, but also for strength. if someone over-torques these, they won't break nearly as easy as SCH40 threaded elbows do.
Injectors, ready to run, with the 3/8" speed-fit air valves, Monster Beckett still running in the background.
Finished, and wet-testing it:
Over all I really like the design. The baffling in the bottom box is far easier to assemble than the mitered design on the Monster Beckett, and the "Banjo" connectors give it a "high-tech" look.
More (and better) pictures after it gets run some.
Zeph
I had been looking at my Monster Beckett that I am running on my 200g system, and thinking that I'd like something bigger, so off to the shop I went.
This time I went with a 8" dia. cast main tube, and dual 3.5"x30" cast injector tubes. The mixing box size is about 14"x10"x12", and made out of 1/2" cast acrylic.
As before, start out with making the box. Cut on the table saw, then run it across the jointer (or setup a router table to joint) to clean up the edge. Build the 4 sides of the box first (see the Monster Beckett thread for details.)
Make the top of the box next- The 3.5" injector tubes penetrate the top of the box for the strongest joint. The downside is that they have to be carefully aligned with each other before you glue them, or they may be crooked. Get a tight fit here, and use Weldon #4. The 8" main tube sits in a 1/8"x1/8" groove in the top, which precisely locates it and allows more surface area for the glue to adhere too. If you have a snug fit, use Weldon #4, if it is a little loose, try some Weldon #16 in the groove, then push the tube down in to it, and put a weight on it.
Thinking inside the box:

Since I had two injector tubes, I couldn't do the mitered tube construction I used in the Monster Beckett, so I came up with a simple baffle setup in the mixing box. I have a false bottom installed that is walled off from the main tube, but not from the injector tubes. The foam is forced down below that baffle, and is only allowed to escape up through the 4" coaxial tube in the middle of the 8" main tube.
Thinking outside the box: (and gluing on the main tube and 10.5" flange)

The flanges are all made as done previously- MDF patterns are made up by printing out a CAD drawing 1:1, and using 3M77 to stick it down to a square piece of 1/2" MDF. Then it is center-drilled, and a 1/4" shank is installed in it. I then put it on the mill, and spin the MDF against a bit to get it to the correct round shape. Leaving it setup there I move it over and drill the holes for the key-holes and all, using the printed pattern as a guide. (I'll do a flange DIY with more detail soon. ) This design used 13 flanges made from 5 patterns.
The injectors are similar to last time too- I used 3.5" cast acrylic again, with 6" dia flanges, but I went to 4 holes instead of 6 to make removal easier. The O-ring grooves are 1/8" wide x1/16" deep, and I use Buna-N O-rings available from All O-rings in packets of 10-50, depending on the size.

The finishing touches seam to take the longest time. I hand sanded all the edges with 220, 400 and 600 Wet/Dry sand paper, then hit it with a $20 car buffer and Novus #3 buffing compound. The result is a mirror-smooth finish, but is extremely time intensive. Look for tips on flame polishing in the future.

I found some "Banjo" 1" quick disconnects at the local farm supply store, and used them ($12/pair) on the inputs to make it easier to setup/teardown. The output is a 2" gate valve from Aquatic Ecosystems . I also used some 1/2" rubber grommets to mount the 3/8" air valves. This required drilling a 1" hole in the cast acrylic, which I don't like to do, but I think the rubber will help protect the joint as it will flex some when the valve is bumped. Hard gluing that joint would be asking for a leak IMHO. Reports from the test running are that 1/4" air valves would be adequate too.
The acrylic was purchased from the local Laird Plastics in 6' lengths.
Tube cuts:
8" tube: 2' section for the main tube, and a 6" section for the overflow cup
4" tube: 18" section for the coaxial injection, 8" section for the neck
3.5" tube: two 30" injector tubes, two 3.5" sections for the Beckett injectors
Look for a DIY tube-cutting jig for a table saw thread coming soon.
I used SCH80 elbows and nipples mostly for looks- Grey looks better than the white PVC, but also for strength. if someone over-torques these, they won't break nearly as easy as SCH40 threaded elbows do.
Injectors, ready to run, with the 3/8" speed-fit air valves, Monster Beckett still running in the background.

Finished, and wet-testing it:

Over all I really like the design. The baffling in the bottom box is far easier to assemble than the mitered design on the Monster Beckett, and the "Banjo" connectors give it a "high-tech" look.

More (and better) pictures after it gets run some.
Zeph