Using 80/20

d_bertko

Active member
I tend to agree with Vic that it should not be a problem.

I suppose you could move the two hinges closer to the ends and add a third where the cross bracing is.

Or add cross bracing behind the hinges if you're not using top for access. The ladder-type cross bracing on my atv ramps let me use a mere 1/4" plywood panel for a seat.

Dan
 

Philj

New member
Maybe a real engineer out there can explain the relationship between deflection and the moment of inertia of an extrusion. If I remember right the deflection is related to the moment of inertia.
The moment of inertia, also called the second moment of area very simplistically is a measure of where the material is in the cross section of a component about an axis which it bends about (neutral axis). With knowledge of the Youngs modulus of the material (stress vs strain characteristic) and the loading regime, deflections, curvature and stresses can be calculated along the beam. You have to be careful when using the second moment of area that the correct neutral axis is used. Beam calculations can be very difficult if you want to work from first principals with varying sections or very simple if you want to just use formulae from beam bending tables. Care does need to be taken when using the tables that you use the correct loading of the beam to get the correct answer.

Dan is correct rectangular sections are stiffer for a given mass than square sections for a load applied in the direction of the longer side for a rectangular section I=bd^3 (^3 is cubed not sure how to superscript text on this). better still for material efficiency are hollow rectangular sections and better still I beams as it places the material in the best place to do some work.

i can work through a simple beam cals if you are interested but you may have to wait a few days (newborn twins demanding most of my time!)
 

Graphite Dave

Dave Orton
A couple of more discoveries from the 80/20 catalog. Bought a rubber bumper part # 2849 to add to the corner of a cabinet to protect my head. The cable mounting block part # 12316 works great to mount electrical cables or hoses to the 80/20. You just stick it in the slot and turn it 90 degrees and it is locked. Put tie strap through the base to hold the cable or hose. Mount is fixed in position even in vertical slot. Another part I bought but have not used yet are the "nylon T-slot nut" part # 3346 or 3348 that is used in a slot to give threads for a sheet metal screw.
 

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Graphite Dave

Dave Orton
Now that I am about done with the conversion I came up with a new way (for me) of attaching 1/4" panels to the 80/20. I inset the panels 1/8" from the front face of the 8/20 because I think it looks better. Used two 3/16" x 1 1/2" aluminum angles bolted together with one bolted to the 80/20 and the other with a tapped hole for bolting the panel to the second angle. The first angle that is bolted to the 80/20 is 1 1/8" long with the hole 3/8" from one edge and 3/4" from the other edge. The hole to bolt on the other angle is also 3/8" from one edge and 3/4" from the other edge but from opposite edges. The second angle has one leg 1 1/2" long and other leg shortened to 1 1/8" long. Second angle has 11/32" hole 3/8" from one edge and 3/4" from other edge to bolt to the first angle. Other leg of the second angle as 5/16-18NC tapped hole for the panel screw. Hard to describe but pictures should explain.
 

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OrioN

2008 2500 170" EXT
I agree with the recessed panel profile!!

However....

I'm still using stock Panel Mount Blocks, and having the face machined down 1/8" - 3/16". There is no structural issues with this procedure. On a 2427, there is 0.192" material, and 3/16" = 0.1875, so the set screw is still free and clear.

Screenshot (13).jpg
 
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Graphite Dave

Dave Orton
I looked at the 3114 but as you say they mount the panel flush and I want it inset 1/8". It is less expensive and faster to just make the angles than to machine the blocks. The other way I have done it is to bolt a piece of 1/4 x 1 1/2" aluminum flatbar to the back of the 80/20. One hole for 5/16" bolt and one tapped hole for a long button head screw. Just made wood or plastic spacer between panel and flatbar to get my 1/8" inset. The flatbar method is easy but does not work in some locations (at a corner where you do not want end of flatbar to show). Angles should work everywhere.
 

68protour

07 D 144 high rebadged MB
Now that I am about done with the conversion I came up with a new way (for me) of attaching 1/4" panels to the 80/20. I inset the panels 1/8" from the front face of the 8/20 because I think it looks better. Used two 3/16" x 1 1/2" aluminum angles bolted together with one bolted to the 80/20 and the other with a tapped hole for bolting the panel to the second angle. The first angle that is bolted to the 80/20 is 1 1/8" long with the hole 3/8" from one edge and 3/4" from the other edge. The hole to bolt on the other angle is also 3/8" from one edge and 3/4" from the other edge but from opposite edges. The second angle has one leg 1 1/2" long and other leg shortened to 1 1/8" long. Second angle has 11/32" hole 3/8" from one edge and 3/4" from other edge to bolt to the first angle. Other leg of the second angle as 5/16-18NC tapped hole for the panel screw. Hard to describe but pictures should explain.

Nice. If we had seen your post earlier, maybe would have caused us to rethink our cabinet panels in the 80/20. The way we inserted the panels was to route 1/4 inch around the edges of the 1/2 inch prefinished plywood. (When we ordered the plywood, it had to be a better grade to still have the strength we needed with removing 1/4 inch of it all around panel edges.) It seemed like a tight enough fit, but there was a lot of play and rattle. So, we considered caulk/silicon, but then just squeezed in a thin plastic cording (from a craft store) all the way around to eliminate the play. Pain in the butt, and temp changes will cause the cording to pop out in places.

BTW, you were a huge inspiration to our build and the impetus to us discovering and using 80/20.
 

GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
I have 1/4" plywood panels inserted to both sides of my sofa bed and will have more 1/4” panels in my cabinets. To prevent rattling I inserted 2 cutout pieces of 1/16" handishims, both with sharp edges in. First piece went in easily but the second had to be pushed in with a flat screwdriver; it took a good hand slam on the screwdriver to insert the second piece. Time will tell if they stay permanently. There are more options to use cutouts of these shims. I place them about 6“-8” apart.
http://www.amazon.com/gp/product/B0035HE2O0/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1
I am thinking about getting 1/8" shim and see if I can insert them.

George.
 

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GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
8020 makes 'locking' gaskets specifically for this application.
Indeed, #2120 (0.240" max) and #2115 (0.236" max). Both of them have to be inserted during assembly, perhaps #2115 could be inserted after final assembly but it would be too tight for 1/4" plywood (~0.240). Neither one will work with 1/4" HDPE witch is 0.250". Personally I prefer to do it after assembly.

Did you use it and that is why you recommending it?

George.
 

OrioN

2008 2500 170" EXT
Indeed, #2120 (0.240" max) and #2115 (0.236" max). Both of them have to be inserted during assembly, perhaps #2115 could be inserted after final assembly but it would be too tight for 1/4" plywood (~0.240). Neither one will work with 1/4" HDPE witch is 0.250". Personally I prefer to do it after assembly.

Did you use it and that is why you recommending it?

George.
I'm a .250 hdpe man...

Haven't used 8020 yet, but will be, I am drawing up my new build as we speak.
Did research, was told possible...


2120: Rigid HDPE gasket- will work with .240 plywood, not .250 hdpe

2115/2178: Rubber gasket - may/should work with .250 hdpe, as it is malleable. Use lubes.




.
 
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68protour

07 D 144 high rebadged MB
I agree with the recessed panel profile!!

However....

I'm still using stock Panel Mount Blocks, and having the face machined down 1/8" - 3/16". There is no structural issues with this procedure. On a 2427, there is 0.192" material, and 3/16" = 0.1875, so the set screw is still free and clear.

View attachment 50541
This 80/20 component is interesting as well, had we come across it during design and install. Love the 80/20, but the shipping of multiple orders can add up, if you are figuring it out as you go!
 

Graphite Dave

Dave Orton
I wanted most of my panels to be removable for access so only put a 1/4" plywood panel in the slot as the bottom of the overhead cabinets. To keep them from rattling I just filled the gap as much as possible with silicone. Have not had any rattling.
 

OrioN

2008 2500 170" EXT
This 80/20 component is interesting as well, had we come across it during design and install. Love the 80/20, but the shipping of multiple orders can add up, if you are figuring it out as you go!
Hehe...

I am designing my new build entirely in 3D, as we speak. I will start the fabrication/assembly in 2014.

Here is the slideout-galley being drawn and fab's in 8020, it will be right down to the last bracket, cap, etc.

Highlights: left to right

1) left side drawer is for 2 5Gal filtered water jugs, on 8020 sliders.
2) that's a foot pedal, under sink, for control the main water line, hot and cold flow, so that no water is wasted while washing and having to touch the faucet lever.
3) right of sink is a bank of drawers
4) space for Force10 (Marine) range/oven, already in storage.
5) next is fridge/closet opening.
 

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Graphite Dave

Dave Orton
If you are comcerned about cost, just make your own connectors out of aluminum angle and flatbar. The other advantage is not having to wait for delivery. Just go over to chop saw and cut a piece, drill a couple of holes, deburr and presto you have your connector. Make them as you need them. In general the 80/20 connectors are stronger than what is required for our use. I used all 3/16" except where I needed a tapped hole and then I would use 1/4". 2 x 2 x 3/16" angle needs to be used in 90 degree corners if you are using carriage bolts so bolts are far enough apart to be able to install the nuts. I have found that the serrated flange nuts I used will loosen due to vibration. 80/20 says the deformed slot tabs keeps bolts tight but next time I will use all elastic stop nuts.
 

Graphite Dave

Dave Orton
Another method of installing panels is to make blocks out of aluminum or UHMW polyethylene. Attached are pictures of 1" thick blocks with 11/32" hole for 80/20 bolt and a 5/16-18NC tapped hole to attach the panel. Buy recycle UHMW since it is less expensive than virgin and has more accurate thickness. 80/20 hole is 3/8" from the edge of the block.
 

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GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
My preferred way, not the cheapest one, is to do exact drawing and let the factory cut to size and to tap. I would be struggling to get their accuracy and precision. Their cuts are also deburred. My preference is to use factory fasteners but they are expensive, about 30-50% of total costs.

For my most complex 80/20 module, the sofa/bed, I made only two 80/20 cuts and some tapping. A very useful tool was the drill fixture #6120. The most inexpensive useful thingy is a little spring #3010 holding t-nuts in place on vertical bars.

Some of my hinges I did by myself and for that I have the great tool, found it to be my most useful tool for accurate drilling. I bought it over 30 years ago in a garage sale for $5 and I hope I will outlive it, in tracing a hole this tool punches a drill mark with bull’s-eye accuracy.

George.
 

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d_bertko

Active member
Ok, just intellectually curious about you folks worried about rattling insert panels,

Have you considered the widely varying coefficients of expansion for your panel material choice?

Wood has about 1/4 the thermal expansion of aluminum. Plastics are all over the place.

A trial calculation of wood-metal over 100F of temp range looked like around 1/16" over 40" length. Sounds like a tolerable float. Maybe a problem if you screw the panel to fixed holders? Is adhesive caulk better for dissimilar coefficients?

Probably not a problem. Seem to remember that you float the center inserts on panelized kitchen doors. My 120" stickhouse Corian counter needed adhesive caulk to mate with the wood cabinets underneath.

Here's a useful table:
http://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

Dan
 

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