Gone for diving
Contributor
Oooh !!!
I like the double waist slots...
What is the approx overall hight of the plate,?
I like the double waist slots...
What is the approx overall hight of the plate,?
Gauging Interest in DH backplates...
- Thread starter SubseaSports
- Start date
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OP
SubseaSports
Contributor
I really like your latest back plate design.
If I may make a suggestions, it is to round the inside corners of the slots. Sharp corners in aluminum (and other metals) tends to concentrate corrosion and the possibility of cracking (from corrosion).
The 90 degree corners also creates a sharp corner that will tend to cut or wear the webbing.
I am not as concerned at stress concentration on a sharp corner since the loads are relatively low, but corrosion is a significant issue with time (especially with salt water).
Either a full radius at the ends of the slots (my personal preference) or just a partial radius in the corners would help a lot. With laser cutting it would be trivial to round the corners.
Rounding the edges will also help reduce wear on the webbing, but that can be labor intensive if you don't have the right equipment. Just a little dulling of the edges help a lot.
If I may make a suggestions, it is to round the inside corners of the slots. Sharp corners in aluminum (and other metals) tends to concentrate corrosion and the possibility of cracking (from corrosion).
The 90 degree corners also creates a sharp corner that will tend to cut or wear the webbing.
I am not as concerned at stress concentration on a sharp corner since the loads are relatively low, but corrosion is a significant issue with time (especially with salt water).
Either a full radius at the ends of the slots (my personal preference) or just a partial radius in the corners would help a lot. With laser cutting it would be trivial to round the corners.
Rounding the edges will also help reduce wear on the webbing, but that can be labor intensive if you don't have the right equipment. Just a little dulling of the edges help a lot.
When I designed the plate for VDH, I added the second (inside) set of slots to match some wings that were available at the time. I can’t remember who made them or if they are still available anymore.
With the tank band going thought the narrower set of slots (and the wing) and then around the cylinder there was a slight concern of the tank having the ability to rock slightly (due to the narrower footprint). But it turned out not to be an issue. That was particularly true with those wings, since they had built in roll-control spacer rod in the side of the slots.
I saw those wings about 10 years ago, and I haven’t seen them since, so this may not be a consideration anymore.
With the tank band going thought the narrower set of slots (and the wing) and then around the cylinder there was a slight concern of the tank having the ability to rock slightly (due to the narrower footprint). But it turned out not to be an issue. That was particularly true with those wings, since they had built in roll-control spacer rod in the side of the slots.
I saw those wings about 10 years ago, and I haven’t seen them since, so this may not be a consideration anymore.
OP
SubseaSports
Contributor
Thank you for the compliment and your valued input Luis.
I deleted the exaggerated corner radius on this model as I reverted to the same design as my older Diver Rite plate. I theorized and have somewhat experienced that a slot that restricts movement also prevents wear which would be beneficial using a standard harness.
I picked some bulk webbing at a local shop that was a lot stiffer than I like and installed. It was very difficult to conform to the slot pattern (I have a shorter not as stiff harness than installs perfectly). I have added a semi circle radius to the ends, which elongates the slot a wee bit for final run and will fix this issue.
I have softened the edges of the slots by hand as well all edges and believe them to be acceptable as is (I don't think this shows in the picture).
The plate is ideal for open slot air cells like Dive Rite and most DGX stuff. I approximated the inner slot on the earlier versions to match some wings, I believe OMS, but also I thought it might be handy to have a narrower section for smaller diameter tanks. I used the outer tank band slot in initial testing and the tank was secure. I did notice flexing in the section between the inner and outer band slots while the tank was secured and could even flex the section with my fingers with no equipment installed.
Anyhow, I deleted the inner band slots as I feel they are compromising the design at this point.
Also, I have a set of thinner tank wedges made as well.
I am going to make an attempt tomorrow to dive it, fingers crossed it has cleared enough, and no gators
I deleted the exaggerated corner radius on this model as I reverted to the same design as my older Diver Rite plate. I theorized and have somewhat experienced that a slot that restricts movement also prevents wear which would be beneficial using a standard harness.
I picked some bulk webbing at a local shop that was a lot stiffer than I like and installed. It was very difficult to conform to the slot pattern (I have a shorter not as stiff harness than installs perfectly). I have added a semi circle radius to the ends, which elongates the slot a wee bit for final run and will fix this issue.
I have softened the edges of the slots by hand as well all edges and believe them to be acceptable as is (I don't think this shows in the picture).
The plate is ideal for open slot air cells like Dive Rite and most DGX stuff. I approximated the inner slot on the earlier versions to match some wings, I believe OMS, but also I thought it might be handy to have a narrower section for smaller diameter tanks. I used the outer tank band slot in initial testing and the tank was secure. I did notice flexing in the section between the inner and outer band slots while the tank was secured and could even flex the section with my fingers with no equipment installed.
Anyhow, I deleted the inner band slots as I feel they are compromising the design at this point.
Also, I have a set of thinner tank wedges made as well.
I am going to make an attempt tomorrow to dive it, fingers crossed it has cleared enough, and no gators
@SubseaSports ,
If there were three parallel slots (instead of two) at the waist straps, then there wouldn't be a need for those two SS harness sliders/keepers (whatever they're called) that people use.
(Is this clear?) You would thread the shoulder strap down through the outermost of the three parallel slots, then back through the middle slot, then back through the innermost slot, and then back through the slot that the shoulder strap entered. The waist strap would exit, lying on the outside of the shoulder strap (as it should, correct?), and the straps would essentially "lock" themselves without the need for a SS harness slider/keeper.
And adjusting the length of a shoulder strap is straightforward, without the need to mess with that (now deleted) SS harness slider/keeper.
Of course, in the case of only two parallel slots, you could always use the outside edge of the plate as the "third slot" (outermost slot), depending on how the two parallel slots are angled.
I used to thread the old-school, blow-molded plastic backpacks this way. More or less. This approach really helped with the somewhat flimsy webbing that sometimes came on those backpacks.
What do you think?
rx7diver
If there were three parallel slots (instead of two) at the waist straps, then there wouldn't be a need for those two SS harness sliders/keepers (whatever they're called) that people use.
(Is this clear?) You would thread the shoulder strap down through the outermost of the three parallel slots, then back through the middle slot, then back through the innermost slot, and then back through the slot that the shoulder strap entered. The waist strap would exit, lying on the outside of the shoulder strap (as it should, correct?), and the straps would essentially "lock" themselves without the need for a SS harness slider/keeper.
And adjusting the length of a shoulder strap is straightforward, without the need to mess with that (now deleted) SS harness slider/keeper.
Of course, in the case of only two parallel slots, you could always use the outside edge of the plate as the "third slot" (outermost slot), depending on how the two parallel slots are angled.
I used to thread the old-school, blow-molded plastic backpacks this way. More or less. This approach really helped with the somewhat flimsy webbing that sometimes came on those backpacks.
What do you think?
rx7diver
OP
SubseaSports
Contributor
@rx7diver good point.
The version in between this and the first one had a slight angle and two slots (I didn't post pics and barely mentioned it because it sucked). The angle wasn't enough. There would have been enough room on this version.
With the current version and it's proper angle, there is very little room for another slot. Yes, I could fit it in, but I like to leave as meat and material as possible between cuts. As it is, the outer slot is close to the edge of the plate.
I could make the plate wider, and have experimented with it in CAD, but ultimately decided on a more compact design.
I might play with this over the weekend. I need to get everything sorted soon to place an order prior to the next predictable price increase (cost's are adjusted weekly from what I have seen.)
Current version below, with added radius slots.
The version in between this and the first one had a slight angle and two slots (I didn't post pics and barely mentioned it because it sucked). The angle wasn't enough. There would have been enough room on this version.
With the current version and it's proper angle, there is very little room for another slot. Yes, I could fit it in, but I like to leave as meat and material as possible between cuts. As it is, the outer slot is close to the edge of the plate.
I could make the plate wider, and have experimented with it in CAD, but ultimately decided on a more compact design.
I might play with this over the weekend. I need to get everything sorted soon to place an order prior to the next predictable price increase (cost's are adjusted weekly from what I have seen.)
Current version below, with added radius slots.
Gone for diving
Contributor
Or just bump the bottom width of the plate out a bit....
This is a good general single tank backplate design, make in stainless and it would be even better.
OP
SubseaSports
Contributor
I can.
Getting to the point, what is someone willing to pay? Not being a jerk here.
When I started I was at $60 + shipping and thought this was a fair price for what it is. With things the way they are now and always changing, I am at $75 for .125" AL today.
12 gauge (.105") 304 stainless would be $135 today. I do not want to be perceived as a gouger, but buying in smaller quantities it is what it is. I am incorporating purchasing cut parts form my other products from the same vendor as well.
One critical thing I forgot to mention is weight....
AL = 1 lb 5oz actual
12 gauge SS = 3.6lbs theoretical per python.
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