Using 80/20

OrioN

2008 2500 170" EXT
I realized one other after thought. For a "bomber" tee-junction it is possible to use 2X anchor fasteners on opposing sides of the leg of the extrusion whereas you are limited to only use one end connector so there is an example of when you might want the max holding power and chose one over the other.
Anchor Fasteners are over-kill for these 'furniture' type applications, and mostly used in 'material handling or structure' type applications with larger series t-slots. Loctite will eliminate any vibration issues.
 

GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
I used anchor fasteners in the overhead cabinets for rigidity in order to maximize the load on the very strong lower mount and to move upper load to the roof ribs mounts from tensile towards shear loadsZGR22482.jpgDSC00473.jpg. There is only one place where anchors are visible.
 

99sport

Active member
I used anchor fasteners in the overhead cabinets for rigidity in order to maximize the load on the very strong lower mount and to move upper load to the roof ribs mounts from tensile towards shear loadsView attachment 148938View attachment 148939. There is only one place where anchors are visible.
I think I get what you are saying - you are trying to carry the load in the wall of the van rather than the roof since it is much stronger - the rest I didn't follow.

The stiffness of a bolted joint is not determined by the stiffness of the fastener or the preload on the fastener - rather, it is determined by the stiffness of the mating parts surrounding the fastener (or more correctly it is the stiffness of the joint and fastener in parallel - and the stiffness of the fastener is so small as to be negligible). As long as the preload is not overcome and the joint does not gap (or in the case of 8020 you don't open the drop lock), the stiffness of the screw is irrelevant. Of course, once the joint gaps the stiffness of the bolt is the ENTIRE stiffness.

This is not intuitive and confuses a lot of MEs, but you can verify this by drawing a free body diagram and convincing yourself.

While the anchor fastener may be stronger than other joints, may provide for more preload, and may better resist vibration, it is not likely to lead to a stiffer joint - unless the two 8020 profiles you are bolting together are unusually flexible.

Or maybe I misunderstood your intent.
 

Graphite Dave

Dave Orton
You are all working too hard at what is a simple problem. IMO expensive machining extrusions is never required in a van build. Just use DIY angles and flats with the lightest 15 series. The angles and flats do not need to be 1/4" thick. Made all mine out of 3/16" and they are overkill. Used 3/16" instead of 1/8" so they can be tapped if that is required. Not a lot of threads but again the application does not require proper thread depth. I did use end fasteners in one location where angles and flats would not be attractive.

The use of series 15 makes is easier to add panels to the structure. How would you install panels with series 10? All my panels are inset 1/8" from face of the extrusion. Joints are stronger with series 15 because the connector is 1/2" longer than it would be with series 10. Series 15 also makes it easy to add doors with full length aluminum hinges.

Drawings for the DIY parts and the assembly are down loadable in PDF format at this link:


My 80/20 (actually T-Slots) is one large structure in the van. 80/20 floor is the base for the cabinets and cabinets are bolted to the walls and roof beams and to each other.
 

OrioN

2008 2500 170" EXT
You are all working too hard at what is a simple problem. IMO expensive machining extrusions is never required in a van build. Just use DIY angles and flats with the lightest 15 series. The angles and flats do not need to be 1/4" thick. Made all mine out of 3/16" and they are overkill. Used 3/16" instead of 1/8" so they can be tapped if that is required. Not a lot of threads but again the application does not require proper thread depth. I did use end fasteners in one location where angles and flats would not be attractive.

The use of series 15 makes is easier to add panels to the structure. How would you install panels with series 10? All my panels are inset 1/8" from face of the extrusion. Joints are stronger with series 15 because the connector is 1/2" longer than it would be with series 10. Series 15 also makes it easy to add doors with full length aluminum hinges.

Drawings for the DIY parts and the assembly are down loadable in PDF format at this link:


My 80/20 (actually T-Slots) is one large structure in the van. 80/20 floor is the base for the cabinets and cabinets are bolted to the walls and roof beams and to each other.
Why anyone would spend time making $1.50 non-anodized L-brackets is beyond me..... :nonono:
 

Graphite Dave

Dave Orton
Why anyone would spend time making $1.50 non-anodized L-brackets is beyond me..... :nonono:
Simple answer: No waiting for the UPS truck to deliver ordered parts and the holes can be in the correct location on angles to use carriage bolts in both extrusions. One hole in an angle must be 1" from the apex in order to get both nuts on the carriage bolts with series 15.

Cost is only one part of the answer. I can cut a part, drill holes, debur and install in 15 minutes instead of waiting a week for delivery. Visible angles/flats are ugly. That was why I used the end connectors on bottom rail of the overhead cabinets. Did not want to see the angles in the openings.

The DIY angle and flats are anodized. The cuts are not. After 5 years use in the Sprinter build I did not see any change due to corrosion. 98% of my connections are not visible. They are inside the cabinets behind panels.
 

RVBarry

Well-known member
I used anchor fasteners in the overhead cabinets for rigidity in order to maximize the load on the very strong lower mount and to move upper load to the roof ribs mounts from tensile towards shear loadsView attachment 148939. There is only one place where anchors are visible.
Hi George, what are those red and white latches/tabs on your bypass slider doors?
And the dark object on the first righthand door edge?
Thanks!
 

GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
I think I get what you are saying - you are trying to carry the load in the wall of the van rather than the roof since it is much stronger - the rest I didn't follow.

The stiffness of a bolted joint is not determined by the stiffness of the fastener or the preload on the fastener - rather, it is determined by the stiffness of the mating parts surrounding the fastener (or more correctly it is the stiffness of the joint and fastener in parallel - and the stiffness of the fastener is so small as to be negligible). As long as the preload is not overcome and the joint does not gap (or in the case of 8020 you don't open the drop lock), the stiffness of the screw is irrelevant. Of course, once the joint gaps the stiffness of the bolt is the ENTIRE stiffness.

This is not intuitive and confuses a lot of MEs, but you can verify this by drawing a free body diagram and convincing yourself.

While the anchor fastener may be stronger than other joints, may provide for more preload, and may better resist vibration, it is not likely to lead to a stiffer joint - unless the two 8020 profiles you are bolting together are unusually flexible.

Or maybe I misunderstood your intent.
Agree, stiffness is primarily depended on flatness of the mating surfaces and tightness of the joint. My parts were machined at the factory so flatness should be good. Regarding tightness, I used the strongest fastener from 8020 for tightness. I likely could use end connectors but they require access holes which I didn’t want on eye level overhead cabinets. Agree that stiffness of an 8020 joint has nothing to do with stiffness of screws.
 

Airtime

Active member
You are all working too hard at what is a simple problem. IMO expensive machining extrusions is never required in a van build. Just use DIY angles and flats with the lightest 15 series. The angles and flats do not need to be 1/4" thick. Made all mine out of 3/16" and they are overkill. Used 3/16" instead of 1/8" so they can be tapped if that is required. Not a lot of threads but again the application does not require proper thread depth. I did use end fasteners in one location where angles and flats would not be attractive.

The use of series 15 makes is easier to add panels to the structure. How would you install panels with series 10? All my panels are inset 1/8" from face of the extrusion. Joints are stronger with series 15 because the connector is 1/2" longer than it would be with series 10. Series 15 also makes it easy to add doors with full length aluminum hinges.

Drawings for the DIY parts and the assembly are down loadable in PDF format at this link:


My 80/20 (actually T-Slots) is one large structure in the van. 80/20 floor is the base for the cabinets and cabinets are bolted to the walls and roof beams and to each other.
Dave - I've read your posts and I know you are OP on this thread. I really appreciate your contributions, your documentation is incredible, and I respect your experience. I know you like to make your own connectors, and I'm sure it's a fine solution for you. But my impression is that you hyper-optimize on the cost of the connectors, while just accepting the 2X cost of series 15 vs. series 10 extrusions.

If I use series 10 and pay for machining, I'm guessing I will be similar in cost to your series 15 plus homemade connectors--with a lot less use of my time in fabricating things in the shop.

As for panels--I need to look into that more. WIth a 1" profile and a 0.25" slot, that leaves 0.375" on either side. With a 1/8" recess, that leaves 0.25" plus the slot. Seems like there must be a workable solution for series 10 with recessed panels.
 

Airtime

Active member
Avoid 8020.net if you can due to their highest cost. I use Tnutz now and save over 50% on machining and tapping and they do not charge for cuts where 8020 is $2 per.
Thanks for the tip on Tnutz. I checked it out and you are right it seems like close to 50% less. I built a shopping cart with same extrusions and anchor connectors from my drawing above, on both sites. 80/20 total was $365.28. Tnutz was $205.40. Big difference!

EDIT: I modified it to include end connectors rather than anchor connectors, and machining to tap the extrusions, but not the access holes. It was $182.60 plus shipping, $239.96 total. I placed the order. Looking forward to trying out my first module.
 
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Graphite Dave

Dave Orton
But my impression is that you hyper-optimize on the cost of the connectors, while just accepting the 2X cost of series 15 vs. series 10 extrusions.

Seems like there must be a workable solution for series 10 with recessed panels.
As I said my reason for the homemade connectors was not cost of the parts or shipping. That was just a side benefit. Not very important to me.

There were four primary reasons:

1. I could work continuously without stopping to wait for parts.

2. I did not have to take the time to order parts.

3. Some of the standard parts do not have the holes in the correct location to use carriage bolts which I considered important.

4. Some of my connectors are custom and not available from any source.

I suspect there might be an easy way to add panels to 10 series. Have not tried to do that. Obviously you could bolt them to the face but I would not like all the visible fasteners or panel edges. Insetting the panels 1/8" so the panel edge does not leave a gap due to the 1/8" corner radius of the series 15 provides a clean appearance.

It was interesting to me that when I first saw a conversion that used the 10 series my reaction was not positive. One look and I decided that I had made the right choice using the 15 series. That was my eyes so others could react differently.

Hope your conversion works out well no matter what series you use. It is a fun process and suspect you will learn some new skills as I did.
 
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OrioN

2008 2500 170" EXT
Dave - I've read your posts and I know you are OP on this thread. I really appreciate your contributions, your documentation is incredible, and I respect your experience. I know you like to make your own connectors, and I'm sure it's a fine solution for you. But my impression is that you hyper-optimize on the cost of the connectors, while just accepting the 2X cost of series 15 vs. series 10 extrusions.

If I use series 10 and pay for machining, I'm guessing I will be similar in cost to your series 15 plus homemade connectors--with a lot less use of my time in fabricating things in the shop.

As for panels--I need to look into that more. WIth a 1" profile and a 0.25" slot, that leaves 0.375" on either side. With a 1/8" recess, that leaves 0.25" plus the slot. Seems like there must be a workable solution for series 10 with recessed panels.
Panels, and depending on their thickness, can be made to fit and located where you want with dado cuts on one or more of its faces.

Here is pic with 0.375" thick hpde (Marineboard) panels 'flush faced' with the t-slots. 0.75" x 0.25" anodized aluminum flat-bars will be bonded to the back of the panel and overhang the edges on the back side using VHB tape. The flat-bars sit in the t-slot. The front edges of the panels are rounded-over with the same radius as the t-slots.

Annotation 2020-08-06 090829.jpg
 
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Graphite Dave

Dave Orton
Panels can be made to fit and located where you want with dado cuts on one or more of its faces. If you prefer flush faces, create a 'raised panel' by using a dado and a round-over bit with the same radius as the t-slot profile. Makes a nice look....
Picture?
 

GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
I recall buying a few end connectors from T-nuts on the E-bay, I hope my memory is not failing me that it was the T-nuts company. In comparison to 8020 they were made from thinner sheet metal. I didn’t use them and stayed with 8020.
 

Airtime

Active member
As I said my reason for the homemade connectors was not cost of the parts or shipping. That was just a side benefit. Not very important to me.

There were four primary reasons:

1. I could work continuously without stopping to wait for parts.

2. I did not have to take the time to order parts.

3. Some of the standard parts do not have the holes in the correct location to use carriage bolts which I considered important.

4. Some of my connectors are custom and not available from any source.

I suspect there might be an easy way to add panels to 10 series. Have not tried to do that. Obviously you could bolt them to the face but I would not like all the visible fasteners or panel edges. Insetting the panels 1/8" so the panel edge does not leave a gap due to the 1/8" corner radius of the series 15 provides a clean appearance.

It was interesting to me that when I first saw a conversion that used the 10 series my reaction was not positive. One look and I decided that I had made the right choice using the 15 series. That was my eyes so others could react differently.

Hope your conversion works out well no matter what series you use. It is a fun process and suspect you will learn some new skills as I did.
Thanks for the clarification. We each have our priorities... and you have the experience gained by building two vans, I'm just starting. But on your four reasons, here's how I see it:
1. I'm more interested in least total effort than in continuous progress. I'm juggling a few other things and I'm fine with doing work in stages.
2. I'm not too concerned about this. Ordering my utility cabinet parts took maybe 10 minutes including specifying machining.
3. I believe this is for your corner brackets? I'm still learning but after more comments here I'm thinking to use mainly end connectors--strong and out of sight, and the required machining operations are simple and non-precision.
4. Good point, and I do expect to fabricate some custom things--looking first through your excellent documentation on parts you've created. But the bulk of my connectors will be standard off-the-shelf with standard machining services.

As to 10 series not looking right to your eye... I'm most interested in maximum function in a small space. With 10 series, I gain a full 2" in opening width across my back gear garage which has 3 bays. This is huge when I'm trying to fit 24" wide sailboards in the righthand bay, 2 bikes in the middle, and the utility cabinet on the left.

Also for drawers in my galley--an extra 1.5" in width is available for same outer galley dimension and sink bay dimension. Vertically, an extra 2.5" in total for drawer heights in a 4 drawer bay.

As for aesthetics, some people like Craftsman style with wide trim and others like European frameless cabinets. I happen to like both, just depends on the house they're in. For my van, I'll have a utilitarian function-driven design. For my taste, I'm not seeing any reason to use double the amount of aluminum at double the weight and cost, while sacrificing precious space, just to have 1.5" extrusions. But that's the beauty of a DIY conversion, to each their own!
 

Airtime

Active member
I recall buying a few end connectors from T-nuts on the E-bay, I hope my memory is not failing me that it was the T-nuts company. In comparison to 8020 they were made from thinner sheet metal. I didn’t use them and stayed with 8020.
Thanks for the heads up. I'll order a few from both 80/20 and Tnutz and then decide on what to use overall.
 

OrioN

2008 2500 170" EXT
I recall buying a few end connectors from T-nuts on the E-bay, I hope my memory is not failing me that it was the T-nuts company. In comparison to 8020 they were made from thinner sheet metal. I didn’t use them and stayed with 8020.
I have use and compared Tnutz & 8020 10 Series End Fasteners. They are the same or have the same steel thickness. Even if they were thinner, it shouldn't effect the connection strength as it sits directly between the screw head and t-slot contact points.

8020 in CAD, Tnutz in caliper.

20200806_110223.jpg
 

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