Giant Beckett Skimmer build

[framerguy]

I'd like to document my skimmer build. Please hold off on posting in the thread until it is complete then post questions and I'll answer as well as I can.

I built this skimmer to be used on my system which will consist of a 375DT, and three refugiums including one 75g, one 55g, and one 30g. The system will also have a 100g sump and hopefully a future frag tank of unknown size. This skimmer design is based on Frankies and many others to be found on the net, just Google "Beckett Skimmer" and several come up. This particular skimmer will need a Reeflo Marlin pump to run properly.

I began by gathering my materials. I purchased the acrylic tubes and sheets from http://www.freckleface.com/

The beckett injectors, gate valves, and thumbscrews came from http://www.4coral.com/diy_parts.htm

The other fittings and pipe came from Lowes. The gasket material I got at a local gasket making company. I used 1/4 neoprene and purchased a 24 x 36 inch sheet of it.

For this build I used extuded acrylic tubing. One 8" diameter tube and one 4 1/2 diameter tube in 5' lengths. I purchased two 4 1/2 tubes to use for other things. I used 2" white PVC from lowes to save money in an area I didn't feel I needed to see what was happening inside the tube.
I ordered three 24 x 48 sheets of 1/4" acrylic, and had enough left over to build a calcium reactor.

Cutting acrylic on the table saw is extremely noisy. Always wear ear and eye protection!!! I cut the flat pieces to size. The pieces measured...
Top and bottom: 12 x 14 1/2. I cut three of these size and will use one for the tube bracing
Sides: 12 x 14 1/2 (two of these)
Ends: 12 x 11 1/2 (two of these)
inner partitions: one piece 6 x 11 1/2 and one piece 9 1/2 x 11 1/2
These are the pieces cut out...

I used a table saw to rough cut the pieces 1/8" oversize. Make sure to rough cut each of the same widths at the same time so they all come out the same size. I then set up my router table with a straight bit so I could joint each edge. I set up the fence at distances from the bit so each piece would come out the exact same size. For instance, for the 12" wide pieces (which were overcut to 12 1/8) I set the fence at 12 1/16 and passed one side through, then set the fence at 12" and passed the other side through. It is tedious but necessary for exact dimensions. It creates very clean and smooth sides for good glue joints.

I next measured and marked the holes. I created a rabbeted edge for the tubing to sit in and create greater stability. I cut all of the circles on the drill press set up with a 1/4" straight router bit with 1/2" shank. I set the press speed as high as it would go. Measure the precise center of where the tube will sit on the flat acrylic and drill a hole the same diameter as the finish nail you will be using as the pivot pin. Cut the heads off of several finish nails as you will use several of them over the course of the build. To create the rabbet edge measure the exact distance to the outside diameter of the tube. For the 8" tube, that would be exactly four inches from the pin hole. Move the piece to the drill press and position the piece to the outside edge of the bit corresponds to the mark you made...
This photo is merely an example...Imagine if you will this is a complete piece of acrylic and not a cut out.

Set the depth gauge on the press to drill 1/8" deep.

Drill a starter hole 1/8"deep at one location and turn off the press. After the press stops, bottom out the bit in the hole and lock the shaft in place and drive your pin into the center hole. You will need to hold the work firmly. Turn on the press and slowly pivot the acrylic on the pin cutting a circle in it that is 1/8" deep. After that is completed turn off the press, remove the acrylic and pin and move the the inner edge of the rabbet. The outer edge of the bit should be 1/8" closer to the pin hole. Set the new pin site and cut the hole the same as before, going 1/8"deep the first pass, then reset the depth to complete the cut fully through the acrylic. Be sure to hold the outer part of the acrylic as it will be free once the cut is complete and could take off on you. Turn off press and allow to stop spinning before moving pieces further.

TIP: MAKE SURE YOU CUT THE OUTER CUTS FIRST AND WORK YOUR WAY IN IF MAKING MULTIPLE CUT RINGS. It's no fun to make the inner cut and realize you just cut away your pivot hole!

That's the first installment of the build, more to come.

 

[framerguy]

I locate and mark the holes for the Beckett tubes. The centers of mine are marked 2 1/2" from the back, and 3" from the sides. While I am cutting the holes for the top I also mark the holes for the tube support using the same measurments. The only difference in drilling the support is there is no rabbet, the hole goes all the way through for the largest diameter. Back to the tubes...I use a forstner bit to drill these holes as it cuts a nice flat bottom hole...

The larger bit is used first to cut the rabbet. Use a 2 3/8"bit and drill 1/8 deep. Switch to the 2" bit and cut all the way through.

The bottom partition needs to be cut for the size tubing you have chosen. I used 4 1/2" pipe so I could use it with regular PVC 4" fittings in my other DIY projects. The cuts will be performed the same way as described above with a rabbet cut on the drill press for the tubing to sit in.

Next decide which end piece is the return end and cut a hole size corresponding to the size bulkhead fitting you have chosen. I used a 1 1/2" fitting and drilled a 2 3/8 hole for it. Drill it as close to the top and side as the fitting will allow. Mine measured 2 1/4 x 2 1/4 to center of fitting. Now, all of the pieces for the box should be drilled and ready for assembly. This is where I struggle a lot.

The method I used to glue the pieces looked like this...

Since the skimmer is finished and I didn't take photos of this step, I created a mockup to take a photo. Imagine those finish nails are toothpicks (I am out of toothpicks now). I used four plastic speed squares. Notice the corner of the square has been mitred. I located the square so that the side would be flush with the end and taped the square in place. I set up the side and used a spacer made of toothpicks to create a gap and use another square to hold it up and straight. Then I carefully filled the gap with Weld-on 16 glue. As if by magic the glue is sucked into the seam. I let it sit for a 30 second count then remove the toothpicks and the seam welds itself. Let it sit for at least an hour before gluing the other sides, this is time consuming.

After the ends have been glued on to one side, I position the partition pieces and scribe (with a sharp awl) a line to indicate where they will go. Cut thin (1/2" wide or so) strips of acrylic and glue them along the lines to make it easier to glue the partitions. It also makes a stronger bond. I then glue the partitions into place. Finish with the final side, then glue the bottom and top into place. After all the parts are dry, install the bulkhead fitting. Make absolutely sure it is nice and tight, you only get one chance! Your box should look like this...

The only thing I would add to the box at this point would be a nice handy dandy drain fitting such as a John Guest threaded cutoff valve so you can empty the water. This thing is very heavy when full of water and difficult to move. Drill a hole corresponding to the size fitting you choose and tap the hole with a tap and die.

That's the box. Next we will work on making flanges using skills we learned cutting the tube openings for the box.

Feel free to post questions and we will have a mod clean up the thread once it's completed. I want to point out- rather emphatically- that I am no expert on anything and if any of this stuff can be done easier/better I'd like to hear it! This is just how "I" did it. Thanks for looking.

 

[framerguy]

I thought I would add a part about making the tube support. Cut the holes to correspond with the hole locations used to make the box top. Then, cut it into whatever shape you would like or think is cool looking... here's mine...

There may be a bit of waste doing it this way but I couldn't think of another way to cut the 8" opening and have it perfect. You could bandsaw the arc and save some material if you are good at bandsawing! I don't have a bandsaw or I might have tried it.

 

[framerguy]

This installment deals with making flanges. It is relatively simple though some patience is needed. There will be four flanges cut 11 1/2" in diameter, and eight cut 4 1/2" in diameter. They will all be made relatively the same way. You are going to need two other round pieces so let's make them at the same time. One is the bottom for the collection cup. It measures 8" diameter. The other is the top for the inner 4 1/2" tube. It gets special treatment discussed later. So to reiterate, you need to cut several squares of 1/4" acrylic; 4@ 11 1/2", 9*@ 4 1/2", 1@ 8" (*one of these is the top for the 4 1/2" inner tube)

Using a straight edge, find the center by making a line from corner to corner. "X" marks the spot! I didn't use a protractor although it would have made things a lot easier...I lost mine in the move and haven't gotten another. Instead I very precisely measured from the center mark and made tic marks where the outer edge of the router bit would be.

Making the 11 1/2" flanges: Mate two pairs of squares and tape them together one on top of the other with masking tape. First I marked where the thumb screws would be located. There is an "X" already, so I divided each section in half and made another "X". Then divided those sections in half again with "X"'s. That last part may have been unnecessary but I thought 16 screws would be better than eight. So you should have a nice star pattern of lines now all meeting in the middle. The circles of thumb screws will be 5" from center so make a mark on one of the lines at 5" from center.

Slow the drillpress speed down to 1/2 speed (that's 1500rpm for mine). Drill through both pieces at center with a drill bit the size of the nail pin just as before.

One note here, if you intend to tap holes for the thumb screws then use the 17/64 bit. If you plan on using the screws and wingnut, then use a 5/32 bit. Put a 17/64 (if you are tapping) bit in the drill press. Locate the acrylic so the bit meets the mark you made for the screw and set the pin into the wooden drill table. Next carefully and slowly drill through both pieces , then rotate the acrylic to the next mark, continue until all holes are drilled. Drill the other pair of 11 1/2" pieces the same way.

Separate the acrylic and peel back a little paper at two corresponding holes and scribe into the plastic something to tell you those two screwholes are mated. I scribed the words "top 1" and "bot 1" on one pair, and "top 2" and "bot 2" on the other. In a perfect world it shouldn't matter and the holes should line up no matter which ones you match, but my world isn't perfect so I have to adapt

.

Put the router bit back in the press and set the speed to the highest setting (3100rpm for mine). Set the pivot pin to cut the outside of the 11 1/2" cirlces. Remember you are cutting with the bit on the OUTSIDE of the line! Set the bit to cut halfway at first pass, then all the way through on the second and cut as before. The difference this time is you are keeping the inside. Cut all four 11 1/2" circles before moving the pin.

Once this is complete, then the top for the cup is finished if you are using wing nuts. If you are tapping for the screws then you need to drill out the holes a little bigger on the top pieces ONLY.

Collection cup and riser tube bottom flanges (both are cut the same): CUT THE RABBET INTO THE BOTTOM OF THE FLANGE AS MARKED! Set the pin to route a rabbet at 4" (for the 8" pipe). Remember to set the bit on the inner side of the line this time. Route the rabbet at 1/8"depth. Measure to make sure the diameter is absolutely correct. You can fix it now, but not after cutting the next step. Move the pin to route the hole at 3 7/8. Cut all the way through in two passes. Remember you are KEEPING THE OUTSIDE THIS TIME. It will leave a little burr at the end point. File this off with a flat file. Once the hole is cut test fit the flange on the tubing. If it fit's then it's time to tap the holes for the thumb screws.

Riser tube top flange: this flange needs to be cut for the collection cup neck. I used 4 1/2" tube so I cut the rabbet to accomodate that. REMEMBER TO CUT THE RABBET INTO THE TOP OF THE FLANGE AS MARKED. Cut using the same techniques as before, measuring and test fitting.

Collection cup bottom: Set the pivot pin at 4" to cut an 8" circle. set the bit to cut on the OUTSIDE of the line. Cut the outside to shape. This next cut is absolutely critical. Err on the side of cutting too small, you can always us a file to make it bigger. Set the bit to cut a hole the diameter of the neck. 4 1/2" in my case. Take your time and set it right. CUT TO THE INSIDE OF THE LINE. Make the cuts. Test fit to see if the tube fits through the hole. You want a snug fit. The top of the neck is 4" from the bottom of the collection cup. Just to get a picture in here, this is what it should look like...

Next drill a hole to accept whatever size drain fitting you want. I used a 1/2" barb fitting. I drilled the hole, put the threaded fitting through and used a gasket ring and plastic nut to hold it in place. Here it is...

Test fit and then use Weldon #16 to glue the pieces together. I used paint cans to weight things down while they dried. I just realized I haven't given sizes for the collection cup tube. The collecion cup is 8" tall. The neck is 10" tall.

 

[framerguy]

CUTTING THE TUBING: Cutting the acrylic tubes is relatively easy on the table saw. You will need to make a sled to provide support for the pieces while you rotate them. Mine looks like this...

I would like to re-emphasize the importance of wearing eye (preferably full face) and ear protection while cutting acrylic. And guys, although it may be tempting in this hot weather, it's also a good idea to wear a shirt. Those little plastic pieces hurt.

Ok, cut the acrylic tube pieces by pushing the sled with the acrylic piece until the blade just cuts through the tube. It's handy to have an assistant hold the sled once the acrylic is in the blade. Then rotate the tube until the intire cut is made. Go slowly to avoid cracking the tube.

Cut the 8" diameter pipe to 32" for the mixing tube. Cut the 4 1/2" diameter tube to 24". If you don't want yours that big you could use a 24" mixing tube and an 18" uplift tube. I have seen others that are 24" tall and they are quite adequate. It's really up to you.

Bubble plate: Here is what we are making...

Cut one of the 4 1/2" pieces of acrylic into a 4 1/2" diameter. You should be a pro at it by now! After it is cut, mark cris-crossing parallel lines 3/8" apart to make a grid. It should look like a checker board. At each intersecting line drill a 1/8" hole all the way through. Next use a countersink bit...

and countersink each hole so it looks like the picture. I set the drill depth stop just as the bit hit the table.

Test fit and glue it to the uplift tube...

Now glue an appropriate piece of PVC with a 90* elbow to the bulkhead fitting inside the box. Point the fitting down. See final photo.

Glue the mixing tube bottom flange to the mixing tube. Glue the uplift tube into the rabbet of the mixing box partition. Make sure it is straight. Glue and set the mixing tube into it's rabbet, making sure it is straight. Let dry overnight.

 

[framerguy]

Now for the fun part!
Making the Beckett Injector housing: Since mine is already made, I did a cut-away drawing of the housing...

Ok, I hope that makes sense! It is drawn to scale. This is tricky so pay attention!

With the remaining 4 1/2" acrylic pieces we will make the flanges for the housing. There should be four pairs of acrylic. Mate them and tape them together just like the larger flanges. "X" the top piece to find the middle and drill that for the pivot pin. The thrumb screws are located 1 3/4" from center so drill for four screws in the manner you have chosen previously. (Either for tapping or for wing nuts). Once that is done mark them as you did the large flanges. "T1" & "B1", "T2" & "B2" and so on.

We need to rout a groove for the PVC to sit in. I used 2" PVC which is 2 3/8" wide so the 1/4" router bit needs to be set at the inner side of the line 1 3/16" from center. Rout this groove 1/8" deep. Make sure you rout the correct side for each piece!! The top side of the top flange and the bottom side of the bottom flange. It's important.

After the grooves are cut and test fit, then we will drill the correct size hole for each piece. See the key in the drawing above to find the correct size hole to drill. I use forstner bits again for all of them. The space between the flanges is Neoprene gasket material. It drills quite nicely. Use a sharp boxcutter blade to cut the material to size, then drill the holes indicated in the drawing for them at the same time as for the flanges.

Cut two pieces of 2" PVC to 3 3/4". Make absolutely sure the ends are square. I used a radial arm saw, but a mitre saw will work just fine.

Drill a hole in each piece of PVC to accept a 3/8" male speed fitting. You don't need to tap the hole for the threads. Just drill the hole the same size as the threads and use lots of teflon tape to make it secure.

Let's put it together...
Glue the appropriate flanges on either end. (see the drawing). The beckett injector should fit snugly inside. The gasket material and screw pressure will hold it in place.

Glue a 2"x1" reducer fitting into the top groove in the top flange.

Cut two pieces of 2" PVC to 34" for the downdraft tubes. Glue the appropriate flange (bottom flange of bottom set) to one end of this tube.

After all pieces have dried test fit with the beckett inside. The screw pressure with the gaskets in place should hold the beckett secure. If there is a gap then you could put a ring gasket between the large side of the beckett and the neoprene gasket to make a tighter seal. They come in various sizes and most hardware stores have a variety.

You may need an assistant to help put the tubes in place on the skimmer. In an earlier installment you should have made a tube support in whatever shape you liked. Here's mine again...

Feed the tubes through the openings. Put glue in the rabbets located on the mixing box, and on the bottom of the tubes, and on the 8" radius edge of the support. Adjust the height of the support (this really is easier with two people) and put the tubes in their holes, then hold the support against the mixing tube while an assistant tapes it in place with masking tape. Allow it to dry overnight.

 

[framerguy]

Boys and Girls we're getting close! Some final steps.

Getting water to this thing! Here's what we are making...

I am going to give instructions that are different than I made mine. You will need four 1" 90's, two 1" unions, and two 1" ball valves. I bought some Spa Flex hose at lowes ($2.19/foot). In the photo just below the union there is a threaded fitting....eliminate that fitting and just glue the Spa Flex right into the union.

Next make the manifold using a 1" "T" fitting and two more 1" 90's, and a 1" ball valve...

Getting water out of this thing!! Here's what we are making...

I used a 1 1/2" gate valve for micro adjustments...you'll need them. The exit system depends on how you are setting it up in your system so I can't help much there. It does need a vent for it to work properly...

It's the part above the metallic tape. I haven't glued that yet, it's temporary until I move the skimmer to it's final place.

Drill a 3/8" hole in the top of the collection cup to keep the foam head from collapsing...

I think that's about it! I am sure I missed something and will go back through and see if I did. Please Feel Free to post questions. Thanks for reading my Beckett Skimmer build!

 

[framerguy]

I hope Frankie sees this and critiques it. If I missed anything or made any glaring mistakes please point them out! It was great fun to build. I spent about $700 buying the parts not counting the pump. I had enough left over to make a few more things.

 

[framerguy]

Ooopsy Daisy! I forgot to post a picture of the final product

 

[Frankie]

Awesome! I love this write up. I will use your thread asa referral because you gave such great dimensions. Wonderful contribution to the forum Greg. Thank you.
And let's not forget:
It's no fun to make the inner cut and realize you just cut away your pivot hole!

LOL! I see it was a learning experience for you ( I found that one out the hard way also)

 

[framerguy]

Thanks Frankie! I'd really like for you to look at the injector post and make sure it is correct. It's how I did it and it works, but is there a better way?

 

[Frankie]

Looks good to me. The only thing that bothered me was not tapping the speed fittings into the sides. Maybe you can use a lot o Teflon tape with pvc but your better off tapping them so you don't risk a blow out if there is a power outage.
Also i am a bit worried about the glue holding between the acrylic and pvc. Did you use Weldon #4 for this? It won't hold to pvc long term i have read. Time will tell. Other then that everything looks great. I will scrutinize it all tomorrow with a clear head and coffee if you like.

 

[framerguy]

Hmmm, I did use weldon... ah, as you say, time will tell. I didn't have a tap big enough for the speed fitting is the biggest reason I didn't tap it, well, and also because I thought it sucked it instead of blowing out with pressure on it.

 

[Frankie]

Not when it shuts off. It will back pressure from all the water in the 8" tube going back down. I added check valves to stop the water from shooting out. All is not lost! I am thinking of adding a larger fitting anyhow. It needs more air. So i will be tapping the hole bigger yet. You might need to also.

 

[deaclauderdale]

That skimmer is a beast!!

 

[framerguy]

Not when it shuts off. It will back pressure from all the water in the 8" tube going back down. I added check valves to stop the water from shooting out. All is not lost! I am thinking of adding a larger fitting anyhow. It needs more air. So i will be tapping the hole bigger yet. You might need to also.

Good idea on the check valve, I need to do that too because when I shut it off the floor gets WET! Why didn't I think of that . I am using 3/8 air line, it seems to get lots of air. What are you thinking of using?

 

[framerguy]

That skimmer is a beast!!

Hehehe, yep!

 

[Frankie]

I am going to tap it out for a half inch line. I won't be using quick connects this time. The inside of them choke the flow down.

 

[Woodstock]

Monster skimmer!!
Fantastic work Greg!

 

[KicksNJ]

Monster skimmer!!
Fantastic work Greg!

What happened to all the pictures??? There all gone.........