Acrylic fabrication questions? I can help!

[Acrylics]

I don't see any need for anything but 1 hole, the rest will get in the way at some point. On my 5 x 10' table, just 2 holes; each of them 18" from the front and end and that's it. Material/paper will catch in the rest.. JMO/JME

Again, IMO/IME, don't over-think this; keep it simple

James

 

[peppie]

I am not a acrylic fabricator as you know. But I do have 20yrs+ in the woodworking world. So here is my insight.
I vote for #5. (that has been moved 3''toward the rear) It is located far enough from the edges that a 4' sheet can be edged or cut while more than 1/2 the sheet is laying on the table. No worry about tipping.

 

[txmike2]

#2 will let you get good support from table when feeding sheet in lets you set your rip to 4' .#5 could help in some edging/flush cutting.I have a 6' X 4' table 1 mount with router at 20" in from front and 12" from right side .So far it has worked well for me .

 

[Floyd R Turbo]

Thanks for the advice, I really appreciate it! Taking this all and thinking about it more, I think that this layout should work pretty well:

So one position, 18" from the front and 12" from the right. The 12" is mainly driven by the support frame underneath - there's a nice spot lined up for a router every 12" from left to right.

The bars on the left and top left are where fences could be placed, at the extreme. The top left one is a little too extreme, but I was just trying to get an idea of the maximums!!

Works for flush trimming also over #4 and #5 because you're working on the left side of the bit anyways, when standing at the front. So you want all the left space you can get.

Works relatively the same as #1 if I wanted a long feed, just use a fence angled toward the back left corner, and would have the same issue with supporting the sheet on the feed side, so there's no benefit to #1 over this spot.

As is with most things in life: Keep It Simple...

 

[Bedroomgangsta]

I have a question! I know someone in my hometown who works at a place with tons of acrylic. Im going to ask him if he can make me a tank! I want the tank dimensions to be 48"x24"x18". How thick will the acrylic need to be in order to have those dimensions-rimless. Will i inevitably need a cross brace in the middle on top or can I make it work without it? Im sure I can get him to build this thing extra cheap for me or at least cut me the pieces so I can do it myself. Any help would be appreciated!!! Also what is THEE best silicone?

 

[Floyd R Turbo]

No silicone used on acrylic - solvent weld.

I'll leave the calc up to James but for a 48" long 18" high tank you're probably talking on the order of 3/4" and probably 1" and big $$. Add a eurobrace rim and cost will go down significantly as the thickness goes down to likely 1/2" to 3/4". It depends on how much bowing you want (or don't want).

 

[Bedroomgangsta]

Well, i guess no bowing would be preffered but those are the dimensions im dead set on and just figured maybe if i went acrylic it could be cheaper through someone i know who works at a place with tons of it. I just want it too look as clean as possible, like a rimless glass tank but that may not be an option i suppose? And let me ask you this...why acrylic? Benefits/pros/cons....

 

[Floyd R Turbo]

That's a whole other discussion. There are threads on this site regarding that I'm sure.

One thing you have to be aware of is that while your friend works with acrylic, does he make tanks that are designed to hold water, or does he make more general pieces like display cases and product holders? What materials does he use? Cell Cast is all that should be used for aquariums, generally speaking, and specifically, Polycast, Acrylite GP, and Plexiglas-G, in that order. Extruded could potentially be used, as long as it's domestic and overbuilt, but the incremental cost difference between a good cell cast and a thicker extruded is generally not that much, so why skimp. The tank is the #1 piece of equipment so don't skimp on that. The materials are not the major cost, it's the labor.

 

[Bedroomgangsta]

Fair enough, thanks a bunch for the info, mucho appreciated!

 

[Floyd R Turbo]

I got the 2x6 top frame done, 4x4 posts on, leveling screws on, and called it a day. The day included completely re-arranging the garage and throwing a bunch of stuff on the curb for the spring clean-up day (or pickers, whoever gets there first) in 90 degree and 80% humidity. No time for pics but I'll get them up when I get a chance.

One question, I made the 4x4 posts 36" long and about the leveling screws seem to make sense to set at 1" minimum for easy adustment, the 4x4s are short 1/2" to the underside of the top (when I get that) so with two 3/4" MDF sheets the top surface will be at about 39" or 40" above the floor. I am 6'0". Do you think I should chop a few inches off the legs? Will that make much of a difference as far as ease of use, or is that just a personal preference?

 

[Acrylics]

personal preference on that size table
I'm 6'3" and my tables are all 36" at the surface, this is best for me. My tables are big and the material is awkward at times on a large table. Having it a bit shorter helps me with leverage on the big tables but I know guys that like them taller.

James

 

[txmike2]

My old table was a bit on the tall side 40" I think the one I use now is around or a bit under 36" I think my new table is much easier and safer to use .Please keep the post coming as I am in the planing stages for a new table and want to see other tables to see how they work .

Mike

 

[Floyd R Turbo]

James & Mike, that's what I was thinking too. It's gonna be a pain to cut those legs. Darn it. I'll take a set of pics while I'm working on it.

The only step I skipped was ripping all the 2x6s. I tried finding a piece of material that was 'guaranteed' straight that I could screw to each piece and use as a rip guide, but to no avail. So I will be spending some time with a level, a planer, and a power sander at some point. Probably will be using some shims too.

I have a pretty good idea how to bond the MDF together, but what about connecting the MDF to the frame? I was just going to use corner brackets and wood screws. Probably one long galvanized steel bracket along the outside of each long run, then smaller ones on the inside.

Still toying with the aluminum mounting plate, might be able to get one for less, and have a local guy in the reef club who can mill it. Probably worth the wait, darn my impatience. Oh well that gives me time to think of anything else I missed and do it right!!

 

[Floyd R Turbo]

Ok, getting a 14" x 16" solid aluminum plate for mounting the router. So I'm going to wait (sigh) for another week to put the top on and make it all pretty and ready to use.

The plate will be about 9/16" thick so I will have to figure out some way of shoring it up so that it's flush before putting the formica on top. I want to stick to using 2 sheets of 3/4" MDF versus one 3/4" and one 1/2" and routing out the 3/4" by 1/16". But that might be easier, who knows. I'll have a better idea when I get the aluminum.

But for now, 2 x 3/4", then leveling screws or something. The problem is that every plan I've seen, the plate is accessible, so if the leveling screws need adjustment, you can pop the router plate off. With it laminated in permanently, that won't work. So I either need to 1) make it permanently, perfectly flush, or 2) install levelling screws adjustable from underneath.

I found an example of this on a woodworking website:

This may or may not work. Since the plate has to be secured down to the table, I assume with flush bolts from above and then nuts underneath, then these would push back up against those to keep the plate level and snug. Or I could just find washers to go between the plate and lower MDF that were the perfect thickness. Or I could set it in with slightly thinner washers, lock everything in place, then skin coat the aluminum with bondo so that it's flush with the surrounding MDF, and laminate.

Anyone else have a better idea, or a comment on mine?

 

[Floyd R Turbo]

Here is my revised layout.

I made the long 2x6s 71" each because I have them cut from a 12' 2x6 and it was easier, so now the table is a few inches longer.

In looking at other table designs, I'm thinking that having the pull-push mounting system from underneath would be fine. If anything ever got vibrated out of place I could make a fine adjustment instead of having to tear the table apart. So I think I'm going to do something like the pics above - have the hold-down screws in the 4 corners and the middle of each edge with push-up levelers on either side of the hold-downs. I may have to adjust the position of the plate to the left so that it's not directly over the 2x6 cross pieces.

 

[Floyd R Turbo]

Something like this

Or should I just forget this, set my router for 9/16" depth and make a 1" wide cut to depth around the perimeter of where the plate will set, then cutout through both sheets and just glue the plate in?

 

[txmike2]

i like the jack screws they will let you get the router dead perfect with the rest of your table.I may have to still this idea for my next table.I would use 4 hold down screws and 4 jack screws .

Mike

 

[TheFishMan65]

I would agree with 1 push up per pull down.

 

[Floyd R Turbo]

Yep, you're right. No reason to use 2 push-ups per pull down now really. That's just what I saw on every pre-built router table in the local woodsmith store. The physics of 2 are more complicated.

 

[TheFishMan65]

I almost suggested 3 sets since that would make a plane. Then I rethought and if the weight was off then you might get some corner tipping.

Another thought, my table saw has a removable plate for a Dado blade (I think). Anyway the leading edge is slightly below the table and the trailing edge slightly above. Would doing something like that be of any benefit?