where do I drill holes in my 90g?

[sanker]

1. I need to drill two sets of holes:

a. a closed loop with a t4 pump

and

b. feed my 75 sump/fuge in the basement and get water back up (dolfin 3000).

What hole pattern do you guys suggest? I can't find any DIY plans.

2.Dedfish lent me his 1-3/4" bit to drill my 90. I'm going to use my cnc Sharp mill. I've tested the mill and even though it says it does 0.1"/minute it looks like it is more like 0.1"/90seconds. NateHanson says it took about 20minutes to go through his 55. I think a 55 is about 0.375" thick. that comes out to 0.01"/minute. Is 1/2" in 7.5 minutes too fast? How long did you guys take to do it with a hand drill? I could rig up some form of weight like Nate but boy would using the automatic feed be cool.

-Sean

 

[NateHanson]

The 55 was 1/2" glass. As far as what's too fast, I've gotten the impression that most people go through much faster than we did, and I think it's a bit of a trade-off between speed and bit-life. We were borrowing the bit from Dedfish, and we had all day with nothing but kids to entertain, so slow and long-lasting seemed like a reasonable choice.
I think 7.5 minutes would be ok, but you just have to make damn sure that the bit doesn't get pushed through the glass faster than it can cut it. That would ruin a tank real fast. That's what I'd worry about with the auto-feeder (depending on how that sort of thing works). Is there a pressure setting where the auto-feeder can be set to trip if it is running into something it can't cut as fast as it's being fed?

 

[NateHanson]

As for hole placement, I'd suggest you take a look at Piscevore's 65g tank drilling thread. He's shows where he drilled, and what for. Also look at the picture I posted of James' tank in our tank drilling thread. He's also got 4 holes for a closed loop and one or two for a drain.

Nate

 

[sanker]

Thanks Nate.

In my haste I forgot about the feed override. I can go to 50% of the z feed. That makes it 0.05"/minute. Tested it this morning.

0.25" in 7 minutes
0.375" in 11 minutes
I'm going to test it on a 10 gallon. I can make the bit spin as slow as 60 rpm/minute. I'll set it to 100.

Hole pattern:
I like Piscevore's pattern and overflow.
http://www.bostonreefers.org/forums/showthread.php?t=10585

I think two overflows might be better to be on the safe side.

using the dolphin 3000 in my basement I will have an 11' head. According to this chart
http://www.marinedepot.com/md_viewItem.asp?idproduct=DP2300&ast=&key=
I would have 1800gph (30gpmx60min/hr).

if I use the reefcentral overflow calculator I get:
Recommended minimum drain pipe diameter = 1.75 inches
Recommended minimum linear overflow size = 27 inches

So, 2 x 1" overflows are good.

If I use Piscevore's slanted piece of plastic then I could put the two 1" overflows in there, and have one return from the sump (use the lockline to go up and over the plastic) to go back into the tank. The slanted plastic would also act as the surface skimmer and I would just make it the whole length 48". That covers the above 27" spec.

on the closed loop I could use lockline as well and have the tips just poke out of live rock.

I'm thinking two out and two in for closed loop. Hooked up to the t4 (1200gph)

don't know if the pic is going to come out ok...

top holes are 2" from the top and bottom holes are 5" from the bottom.

-Sean

 

[dedfish]

Sean,

Keep in mind the noise factor when thinking about overflows. I know you mentioned at one point that quietness was a concern. Most people are using some form of durso standpipe to quiet the sound of the overflow, be it a normal durso in a tank drilled through the bottom or an external durso with a tank drilled through the back.

Another thing I notice when looking at your diagram is that it looks like you have 4 holes for the closed loop, 2 feeds and 2 returns. In a closed loop most people choose to have 1 feed and the number of returns would depend on your return plumbing. If your using a SCWD you would need 2 and 4 for an OceansMotions. Some people choose to have some of these returns go through the back glass and some over the top.

 

[sanker]

Nate, the mill would trash a 1" roughing end mill (tough stuff) before stopping. In other words, it would munch 3/8 of glass for breakfast

-Sean

 

[NateHanson]

if I use the reefcentral overflow calculator I get:
Recommended minimum drain pipe diameter = 1.75 inches
Recommended minimum linear overflow size = 27 inches

So, 2 x 1" overflows are good.

Actually two 1" drains are much smaller than one 1.75" drain. The cross sectional area of the two smaller drains is 1.5 sq. in., and the cross sectional area of the single larger drain is 2.4 sq. in.

I'd go with two 1.5" drains for that much flow.

For your bit speed, I'd probably do 200. We did either 200 or 400 (I can't remember now) and with a water bath there was no heat at all, so I don't think turning the bit slower would help.

 

[dedfish]

I just double checked the ameriglas website. They recommend a speed of 500rpm for a 1" bit and 250rpm for a 2" bit. Sorry for the misinformation of 100rpm. Here is a link to the page with this info as well as some info on drilling pressure:
http://www.shopsmartxpress.com/AmeriGls/M9.htm

 

[sanker]

ok, rethinking placement.

sump:
how about one center overflow vs the whole top being 1 big overflow. 8" wide 4" deep with three 1" bulkheads (total of 2.25 sq. in. vs 2.4 for 1.5" but I don't have a 1.5, 2-3/8 bit, hole saw) 4 inches from the bottom. then go over the top for the returns (2)

closed loop:
2 feed (I see 1 as the norm but would having two hurt?) and two returns use scwd.

updated pic.

thanks for the update on speeds and feeds.

 

[sanker]

ok, drilled the first hole. Drilled it in the 75. took my time and just kept pressing stop/go on the feeder and it went through in 15 minutes. now on to the 90. here is the semi final sketch with the overflow on the far right.
-sean

 

[dedfish]

Make sure you have room in the over flow to accomadate any plumbing parts. You may also want to consider if you have enough room to get your hand in there in case something like a fish or snail were to fall over the edge.

 

[sanker]

went with two holes for the corner overflow. sump return will be lockline over the top., going to make the overflow box this week. 8"wide x 4"deep x height of tank (24), did two in and two out holes for closed loop. If two is overkill I can always cap one. big hassle to go empty tank and drill another., each hole took about 15 minutes. I had the controller set to 0.05"/minute but was nervous about trashing dedfish's bit and my tanks so I let the auto-feed go for 5 seconds, press stop, wait 3 seconds, press go, repeat.

took 6.5 hours from beginning to end (2x4 base around mill to final loading of tanks back in to Explorer)
each time the bit would pop through it made me jump. When drilling the first hole, my co-worker was behind me and snapped a piece of thin plastic which sent shrapnel all over. Absolutely jumped out of my skin. He'll get his...
link to pics of the process.
I need to get them out of the Explorer before I can take finished product pics.
http://homepage.mac.com/sanker/PhotoAlbum37.html