Chronicles of a home-made plate system

[SunSurfer]

Having watched all the different designs of plates emerging over the last year or two, I was determined to try my hand at making my own.

Of all the designs I saw and thought about, the system used by Benjamin Karl seemed the most fruitful starting point.

My aims were as follows:

Allow the board to follow its' natural curve as much as possible, eliminating the flat spots caused by attaching the bindings in the conventional manner.

Reduce the weight compared to Karl's - which appears to be made completely of aluminium.

Be able to attach the system to the conventional binding inserts on the snowboard.

A system like this needs to be hinged at both front and rear attachment points so that as the board curves, the plate moves independently of the board. Secondly, one of the hinge points needs also to slide, to allow for chord of the snowboard's arc to shorten as the curve deepens. One of the puzzles with the Karl & Apex Composites (Canadian team, not Apex Snowboards) plate systems is how

these features are accomplished.

I was aiming to make the system robust enough that wear was minimised at both the hinge and slide points.

Should I put the sliding attachment at the front or the rear of the board? My initial thought was to fix the front but a reply to a question to Jack Michaud made me go the other way - fix rear and slide front. That way the snowboard absorbs much of the energy of bumps, ruts etc. while the plate slides over the top.

Enough for now. I've been thinking, designing and beavering away over our summer in the Southern Hemisphere while you guys were carving it up in the North. I've just completed the rear attachment/hinge mechanism. (Photos attached). I hope to have this all up and running by the time our season starts in mid-late June.

The green plastic base plate is 1cm thick Ultra High Molecular Weight PolyEthylene (UHMWPE), i.e. P-tex as used in ski & snowboard soles, also as used in joint replacement bearing surfaces. The green pigment indicates that this particular version is particularly abrasion resistant.

The board I'm trialling this on has its' outermost binding inserts 50cm apart. My favoured stance is 50cm as well. The screws mounting the hinge to the plastic plate are 6cm behind the rear outermost binding insert point of the snowboard so I've used a 6 x 4cm mounting screw pattern to try balance the rotational forces from the plate once it's in use. All the bolts you can see are 6mm metric stainless steel 304 or 316 alloy.

The hinge is custom, home made, aluminium, and 18 cm wide. A local company makes an extrusion for making the hinges, 3mm thick plate (photo). It allows me to fabricate a hinge of any size I wish. The plastic sleeves that go inside the extrusion, between the hinge leaves, are also supplied by the same company. The single hinge pin is 5mm 304 alloy stainless steel, with a metric thread cut in the last few mm, and 5mm Nyloc metric nuts on the ends. The hinge needed to be slightly more than 1 cm above the board to prevent the hinge body from bottoming out on the board hence the second layer of aluminium beneath the hinge plate.

The plate with bindings attached will screwed through the 4 holes in the folded up leaves. Stainless machine screws will go through the holes to T-nuts, mounted flush in the upper surface of the plate.

The cuts in the surface of the UHMWPE are there to increase the ability of the plastic to curve with the snowboard. UHMWPE this thick is pretty stiff!

This unit demonstrates the hinge mechanism. The front unit, designed but yet to be built, will show the sliding mechanism, which has been separated from the hinge and utilises the very low friction qualities of the UHMWPE.

I'm still thinking away about possibilities/ materials for the actual plate.

Rigid vs. cambered & flexible.

Full bindings vs. just heel and toes pieces

Interested to read others comments and thoughts.

DISCLAIMER: I'm aware that I'm doing this at my own risk and I don't recommend you try this at home. What you get up to in the privacy of your own workshop is your own affair!

SunSurfer

[Shred Gruumer]

And its on!!! ready set go...

Funny how quickly things show up ... lets say.. like at the ECES.. and SES... and so on..

its official!! on your mark get set ....go!!:)

[b0ardski]

I like the idea of just toe/heel blocks to save weight, as any flexibility comes from the plate to board interface.

[tahoetrencher]

of the p-tex toe blocks? Have you compromised it with the the scoring?

This looks promising!

[Corey]

How deep do the slots go? My main concern is that if they're pretty deep the inserts closest to the hinge will see the majority of the load. To make matters worse it's a bending load where the plate is trying to peel up off the board. I'd prefer to have the hinge between the binding holes and skip the slots altogether. That will alter the flex pattern slightly, but no more than any other 4x4 binding does.

Cool idea in general, I'm anxious to see updates and how you do the slider mechanism.

[LeGogoussier]

Interesting.

I would suggest beefing up the p-tex along the green lines to avoid it ripping from the weak points at the corners (red lines), where shear forces will be concentrated. Also, ensure the screws into the p-tex (circled) are T-nutted underneath (not just screwed into plastic).

[bjvircks]

so... did I capture your design concept in this sketch? some of the detail dropped out when I reduced and compressed but the core concepts should be understandable.

[bjvircks]

Back in 1902 in USA there was a race to develop heavier than air flight. Samuel Langley was a world renowned scientist, inventor and engineer. He had at his disposal the best talent in the US for machinists, craftsman, researchers, etc that big money could buy. He and his large team repeatedly failed to create a working aircraft. At the same time a couple of poor uneducated bicycle mechanics who knew almost nothing of 'traditional science' just did things their own way. Wilber and Orville Wright and succeeded where the best experts did not.

I'm anxiously watching where your work on this goes.

[lonbordin]

Back in 1902 in USA there was a race to develop heavier than air flight. Samuel Langley was a world renowned scientist, inventor and engineer. He had at his disposal the best talent in the US for machinists, craftsman, researchers, etc that big money could buy. He and his large team repeatedly failed to create a working aircraft. At the same time a couple of poor uneducated bicycle mechanics who knew almost nothing of 'traditional science' just did things their own way. Wilber and Orville Wright and succeeded where the best experts did not.

I'm anxiously watching where your work on this goes.

While I completely want to support the "homebuilder" (Go Sunsufer Go!) I can not in good conscience let the remarks about the Wright Brothers go uncommented as they are disingenuous. The Wright brother's availed themselves of the science of the day and were in no way "uneducated".

I encourage a reading of their wiki page: http://en.wikipedia.org/wiki/Wright_brothers

Peace.

bjvircks I really appreciate your posts, BTW.

[bobdea]

While I completely want to support the "homebuilder" (Go Sunsufer Go!) I can not in good conscience let the remarks about the Wright Brothers go uncommented as they are disingenuous. The Wright brother's availed themselves of the science of the day and were in no way "uneducated".

I encourage a reading of their wiki page: http://en.wikipedia.org/wiki/Wright_brothers

Peace.

I agree.

[bjvircks]

OK... let's split hairs.

Neither got a high school diploma or went to college or university. While in those days they would have been considered 'educated' they were not formally trained in science, technology and critical thought. They were looked down on with distain by the established big name researchers of the day.

My point was and still is... they taught themselves, and in doing so they bested the 'experts' of the day.

Often when I am mentoring new engineeers I need to step back and let them find their own way rather than crushing them with 'this is the way to do this' guidance.

As a side note... The Wright family lived for a brief time in Cedar Rapids, Iowa (where I am). The toy feather helicopter incident occured here and we use this as a way to try to claim a little bit of the 'first flight' fame.

[lonbordin]

Why the brothers did not get their high school diploma is due to the families move not their capacity. Wilbur was planning to go to Yale before that accident that removed many of his teeth.

Disdain? Perhaps due to the threat they posed.

Wilbur's letter to the Smithsonian to gather more information in their quest is further proof of their education. Remember this is 1899 and they have managed to educate themselves about Cayley and Penaud and knew to write the Smithsonian to gain more information. This is a feat unto itself.

Source:

http://siarchives.si.edu/history/exhibits/documents/wrightmay301899.htm

Cedar Rapids as first flight is classic.

BTW- Go Sunsurfer Go!

[bjvircks]

My point was and still is... they taught themselves, and in doing so they bested the 'experts' of the day.

I believe we are saying the same things and that we are in agreement... Capability is not always rooted in formal education.

Don't mess with us here in Cedar Rapids when it comest to aviation or aviation history, we take it very seriously. Every major airframer on the planet comes here for our help with avionics, weather radar, communications, collision avoidance, cabin systems.

[lonbordin]

Don't mess with us here in Cedar Rapids when it comest to aviation or aviation history, we take it very seriously. Every major airframer on the planet comes here for our help with avionics, weather radar, communications, collision avoidance, cabin systems.

Sooo that's why they call it flyover country.

[sfleck]

so... did I capture your design concept in this sketch? some of the detail dropped out when I reduced and compressed but the core concepts should be understandable.

Maybe I'm missing something here, but when I look at this diagram I feel like it's set up backwards. It looks as though this setup would allow the plate to flex without deflecting the board, but if the board flexed (tail going up in diagram) wouldn't that also flex the plate up? Feel like the hinge should go the other way.

Again, maybe I'm just misreading the diagram.

[lonbordin]

Maybe I'm missing something here, but when I look at this diagram I feel like it's set up backwards. It looks as though this setup would allow the plate to flex without deflecting the board, but if the board flexed (tail going up in diagram) wouldn't that also flex the plate up? Feel like the hinge should go the other way.

Again, maybe I'm just misreading the diagram.

I'm going to get in trouble if I dood it... I dood it.

Your right, the diagram is not correct. Look at the photo and the stomp pad for directional guidance.

[Jack M]

Great write-up, thanks! I agree with Corey Dyck though.

fyi, Vist has screws mounting directly into the plastic bars, no inserts or t-nuts. It's nice that way, you don't have to worry about cross-threading.

This is a great start, but it seems like the Apex canoe paddle also has an element of vertical suspension, in addition to the sliding axle. Not sure how important that is though, I think the biggest issue is what you're addressing.

I would definitely make the top plate rigid. It shouldn't need to flex while spanning the chord of the flexed board. Actually I think it would detract from the effect if it did flex.

[bjvircks]

Crap... so that is what that stuff is! For some reason I thought it was just scrap material laying around and dismissed it.

Corrected Sketch

[Mtrappy]

First of all in my opinion I dont think P-Tex for the mounting bracket is the best way to go especially with the cuts in it because I dont think it will be nearly strong enough. If you are trying to make it flex easier with the board then the cuts are on the wrong side of this P-Tex mount. They would need to be on the board side. Also same thing with the 3mm metal hinge, not strong enough. And could you please tell me how you are going to make a free floating plate out of this? I think it is sweet you are experimenting with this. I only have these questions because I spent all last summer making a plate of my own and most of this winter testing it.

[b0ardski]

we want pics trappy:biggthump

[leeho730]

Crap... so that is what that stuff is! For some reason I thought it was just scrap material laying around and dismissed it.

Corrected Sketch

Thank you! Everything is clear now...

By the way, it's nice to see another New Zealander, Sunsurfer!

I used to board in Turoa (I still have a life pass there) and Tukino, before I move to Australia. There're so few of us in NZ!

I used to work in the Army (Waiouru ATG) and the ski field was only 40 mins away. I remeber pulling sickies to go snowboarding Funny thing, everyone knew about that (including 2IC, a lt col) they didn't care! I miss being in the Army sometimes, I could get away with so many things ;)

Anyway it will be an interesting concept to try! I've also seen similar plate system somewhere. It supposely allows the board to flex more naturally...

[bjvircks]

Hey, Guys! If we swamp Sunsurfer with all of our 'conventional knowlege' and 'help' he will end up creating a carbon copy of what others have already made. Could we just let him have at it and only offer insight or opinion when he asks for it?

[Mtrappy]

I'm still thinking away about possibilities/ materials for the actual plate.

Rigid vs. cambered & flexible.

Full bindings vs. just heel and toes pieces

Interested to read others comments and thoughts.

SunSurfer

Looks to me like he did ask for opinions....... and I am just trying to same him some time and energy cause I know somethings that just plain wont work. But I am all for him coming up with something completely different that works. Would be awesome.

Boardski:

I can not share any photos at this time unfortunately. Sorry. But i know many of you have seen it around. ;)

[lowrider]

Difference between a soft plate and stiff plate is much like the difference between a plate and no plate. While a stiff plate gives a more resistive stance a soft plate allows you to stand a little more relaxed but with the same control as stiff. Plates are going to change the way boards are made. I can see it comming down to a combination of board design , plate design and hardware interface, hinge,slide whatever. It would be nice if we could agree to some standard for mounting hardware ie; insert pattern so all can participate and interchange components as we can with binding.

[bjvircks]

My appologies... SunSurfer did solicit our input. I know that I have a lot of things I see in his approach which I could comment on with regards to load path, torsional durability, material selection, etc. I'd just rather not say 'this didn't work' when he may well find a novel way to make it do better than an existing approach.

But I am all for him coming up with something completely different that works. Would be awesome.

absolutely