DIY- Ultra Beckett

[Zephrant]

Amigo- Close, but in your analogy, there is more volume in the 14" straw, hence the longer contact time. If the volume is the same ( as it is inside the skimmer ) then the swirling just means the water moves faster. Contact "TIME" is identical. Contact "DISTANCE" is greater.

As far as I know, no-one is claiming that distance has an effect on the foam generation.

Again, I'm not saying swirling does nothing, just that I don't understand the physics behind the claimed benefits. I fully intend to try it myself some day.


Hey Hector- Little trick on the 7-7/8" circle cutters. Take a grinder and grind off the stop on them, and you can open them up to 8-1/4". Run them REALLY slow, and they chatter like crazy at that diameter, so grind a negative rake on the cutting edge so it drags on the acrylic, instead of cuts. (Think of what a drill bit looks like where it cuts, if you run it in reverse. It just drags, which works well in acrylic.)

For the 12" diameters, I use the Mill and spin the work against the stationary bit to make an MDF pattern. It's a PITA, but I don't have to do it often. The pattern is vacuum clamped to the acrylic, rough-cut on the band saw, then flush-trimmed on the router table.

Wait 'till I get my CNC put together, and I'll rip a set of patterns out of MDF for you in minutes.

Zeph

[tigershark]

1 word.... scary!!

[kanankeban]

Run them REALLY slow, and they chatter like crazy at that diameter

How many RPM do yo suggest?
Regards---
Hector

[H20ENG]

Zeph, you've got PM.


kanankeban,
S--------L-------O-------W.

This thing will shake, so the slower the speed, the tighter the press is bolted down, the tighter the calmps on the work, the better. Keep clear!
Give us your experiences, Zeph. Counterbalancer?

[Zephrant]

My mill goes down to 120 RPM, but I have to swap two belts to do it, so I rarely bother. I can run down to 770 RPM with a quick belt adjustment, so that is what I use. I should be using 500 RPM or less though.

I have not tried a counter-balance, but that would make a huge difference.

Note that the material is vacuum clamped to the table, meaning that about 10psi is applied to it, or 860 pounds clamping force for a 10.5" circle. (A little overkill, but it works well.)

I have also used four corner clamps to hold the material in place, that works fine too although sometimes the material bows a little in-between the clamps.

Zeph

[kanankeban]

Zeph,

Note that the material is vacuum clamped to the table

Do you use a special table, or did yo make it, if so, what do I need to make one...
Regards..
Hector

[Zephrant]

For starters, a Vacuum pump. Search Ebay for Gast vacuum pump, a typical wet/dry will not pull enough psi.

I make vacuum jigs as needed, but really, corner clamping as I said above is fine for low volume. The vacuum is really quick to clamp/unclamp.

Zeph

[wedfr]

hey zeph, i was thikning about making one of these myself and was gonna PM but since someone go tto it before i did ill just continue here. I did a search on EBay is there a specific pump i should look for? they have rotary vane, oiless, lab etc and also various HP what should we be looking for here?

Also some pictures of some of yrou jigs and setups would be awesome if you dont mind.

[geshields]

I got my vacuum pump from surpluscenter...here is a link to it:

Link

Note that mine is 220V version though. If you go off those specs though, you will do fine. Once the vacuum is applied, no human force will dislodge it...

Greg

[StirCrazy]

Zephrant, what was your reason for using 1/2" for the box? did you hapen to get some cheep? I am thinking with your baffles glued in 1/4" might be ok but if not 3/8" should be more than enuf.

Do you think this skimmer would be able to handle between 4 and 500 gal of total water volume?

Also for pumps I have seen a becket run on a magdrive 1200 and on a Iwaki 55 and my next tank is going ot have a skimmer driven by the iwaki 55's.. (one for each becket)

Steve

[Zephrant]

Wedfr- I'm not much of an expert on thinks that suck... er... Vacuum pumps. I did my research and was about to buy a rotary vane oil-less, when a friend at work came up with a oil-filled piston pump for cheap (and no shipping) so I am using it. The plus is that the pucka-pucka that it makes it pretty quiet, while the same person's rotary vane that he runs in his shop is at least as loud as a router.

I haven't done a DIY on vacuum clamping yet- I'll try to make some time for it soon. Ask away if you have any specific questions of course.

Steve- I have a customer that asked for the 1/2" base, so it would better withstand the rigors of commercial use. He is using a pair on a 3000 gallon reef system. Sizing a skimmer for a system is a hotly debated topic. There is no "industry standard", and using tank size as an indicator is poor at best. A real measurement would be on the amount of bio-waste that a system creates that needs to be removed. But that is difficult to quantify. So we use system size to make it easy. All that said, my best engineering estimate is that this design is good for at least a 1000 gallon heavily stocked system. More if you go easy on stocking.

I agree that 3/8" would be fine for home use, and a little cheaper.

See my Monster Beckett thread for a skimmer design that is smaller, but perfectly suited for a 500 gallon system.

Pump size also depends greatly on the bio load you expect to have. I run my own single Beckett skimmer (Monster Beckett design) on a LG4MDQSC. It is just barely big enough, but with a light bio-load in a 200+ gallon system it is great. An Iwaki 55 seams like a great match for a Beckett. I've seen a person run dual Iwaki 100's on this skimmer with awesome results (and a good size power bill!). I've also seen several people run AmpMaster 3000's on this design. It does not work as good as dual Iwaki's, but it runs far less power ($$$).

Thanks for the questions-

Zeph

[ikinne1]

Zephrant's ideas are so frustrating...I can't even seem to DRILL acrylic properly.

[Zephrant]

Lol- Are you drilling tube? I go to great lengths to avoid that, it really sucks.

As far as drilling sheet, it is not bad. The hard part is when the bit breaks though the back side. For small holes (1/4" or less) that I don't have specially ground drill bits for, I run forwards until I get close, then reverse the drill and force melt my way though the remainder. That is good enough if you are just going to tap the hole.

I have drills that I've ground for all the common sizes I use though.

Check this thread for tips on using hole saws.

Zeph

[SUMMERS]

You can also purchase acrylic drill bits from plastic shops.

[slug]

Regarding 7-7/8" circle cutter...

Run them REALLY slow, and they chatter like crazy at that diameter, so grind a negative rake on the cutting edge so it drags on the acrylic, instead of cuts. (Think of what a drill bit looks like where it cuts, if you run it in reverse. It just drags, which works well in acrylic.)

Could you possibly post a picture of what this would look like... I've had a hell of a time cutting nice flanges with my circle cutter, the edges always chip.

[Zephrant]

Use the cutter to make a pattern out of MDF. Then tape the pattern to the acrylic with double-sided carpet tape, and use a flush-trim bit (with the bearing at the end of the bit) to run around the pattern.

Perfect circles in minutes.

Zeph

[slug]

I have a flush cut router bit but no router for some reason. I hope santa told my wife to buy me a router for xmas. Would it be a crime to put a router bit in drill press until a get a router?

[Zephrant]

The drill press does not rotate fast enough- If you went really slow, it might knaw out a circle for you though.

You can also try end-mills, but hey don't have the bearing.

Zeph

[slug]

Santa did get me a router after all! I've re-built a few thing with nicer edges and want to make a new skimmer. I was think about making it recircultaing. I was wondering if you have ever built a recirculating beckett skimmer and if so did it work any better then a normal non recirculating?

[Zephrant]

Several of us are experimenting with recirculating Becketts- Nothing to report yet though.

The pump needs to be balanced to the design somewhat though- Not too big, not too small.

Zeph

[SUMMERS]

The best way to cut circles short of a CNC machine or laser, is to get a Jasper circle jig. It waste little acrylic, not taping or templates to mess with, and takes all of 30 seconds to cut out. Makes a perfect circle everytime without chipping or dents.

http://www.jasperaudio.com/

I use the model 200 and 400.


I finally finished my recirculating Beckett this weekend. Just need to get another Gen-X pump to try it out. I will let you know how it goes.

[Bnelson]

This is a great thread but I have a few ??'s. How are the beckets sealed from leaking, how is the becket chamber built and what plumbing is used, and how is the water levell in the skimmer controlled? I thought I read somewhere that becket injectors come in two halves with two rings that hold them together, so thats what I mean about how to seal them. Thanks for the info and that is one mean skimmer.

[ridetheducati]

The beckett proper is not sealed. The container that the beckett rests inside of is sealed with only one way for air to escape.

Duct tape works well for me.

As far as construction, I will let others take care of that.

[Bnelson]

Oh, ok so the actual becket body isn't sealed. I understand that the housing is created to allow for air controll, but what exactly do you use the duct tape for?

[ridetheducati]

Where the top of the housing meets the body of housing. There is a rubber gasket that supposed to prevent air/water from leaving the housing. I just wrap some tape around the edge.

I will take a pic later tonight.