Nyper build thread

[Nikolai]

Finished the upper tabs. Had to strip it down to the bare frame again to get access for welding them.

These are .063 as well. Probably could have used .040 for all of them but .063 is more forgiving to my welding ability.

Raised the tabs until the sheet cleared the set screws in the lock collar.

All these are for really is to keep the sheet level so fabricating the piece around the headers is easier and it won’t have any downward pressure on it.

Bolted the header in to check clearance which there is plenty of.

I think next I am going to make tabs for the upper sheet and then finish making the enclosure pieces up front.

I’m also going to add a 1/2” x .035 tube to each side. The fuel tank will be secured to the 3/4 tubes and they flex a little more than I would like. Adding a 1/2” tube will take all the flex out and make sure the fuel tank doesn’t see any stress on the welds. Tube with blue tape is the one I’m going to add.

 

[Nikolai]

Summer is coming but still trying to pick away at the things I need to get done before sandblasting and paint.

Got the 1/2” tubes (with blue tape) tacked in place on each side. Added 0.13 lbs for both. Should take all the flex out for supporting the gas tank.

Instead of having to fabricate and weld a ton of tiny tabs I decided I will just secure the upper 7075 sheet with aircraft sheet metal screws right to the tubes. They hold well, even in .035 wall. I’m going to use 19 #4x1/4 screws. I’ll seal the threads with something on final assembly. It’s only a 3/32 hole so if I want later down the road I can drill them out slightly and use -4 cherry max rivets. I’ll have the screws on Monday and will finish mounting it.

After that is done I need to fabricate the remaining skid plate tabs and then I’ll finish weld everything and do the running board screws.

 

[Nikolai]

Got the remaining 6 skid plate tabs made from .063 and tacked in place. Total weight was 0.16 lbs for all 6 tabs which is well under what I wanted. I will install 6mm rivnuts after painting.

I’m not sure what I am doing for a skid plate. I was thinking 1/8 aluminum to keep it easy but also considering carbon fiber to keep the weight down. Maybe carbon fiber with the some ribs in the center to keep it from bowing up.

 

[Nikolai]

Made some more progress. Got the frame 100% welded again. Welded the 1/2” tubes, turbo hanger, header bracket and skidplate tabs.

Got the front enclosure piece finished. Had to trim for the bearing holder.

I also got the top sheet cleaned up and it’s 100% done. Drilled and tapped 19 holes for 4-40 machine screws.

The header bracket is lower than the frame tubes which is why it took 19 screws to pull the sheet up tight against the tubes so snow doesn’t get in. 3.5” spacing was about the max I could go.

Only 9 grams for 19 screws. A lot lighter than multiple tabs would have been and way less work. These are 4-40 x 1/4 aircraft machine screws.

The front piece is 1.0 lb and the top piece is 1.07 lbs so I’m good on my weight target so far.

I trimmed the HDPE side panel I had made to end at the new 1/2” tube. I’m not dead set on it, just wanted to get it installed and post a pic. That’s about as small as I can make it and still keep my boot out of the track. The stuff is light, that piece is 0.42 lbs.

Inside shot. I’ll probably cut a piece of .040 aluminum to block off the front triangle that’s open right now.

I don’t know what to think of the HDPE. It’s not attractive to me but it’s relatively cheap, super easy to work with, lightweight and snow won’t stick to it. I also like that I can install it after the drivetrain and and track are in which makes that much easier.

 

[sxr70001]

You do excellent work! Looking good.

 

[Nikolai]

I need some opinions on how ugly the HDPE is? I’ve been looking at pictures of when I had the rear suspension and track in and the access is good enough(with skid & track already installed) I could do screws from the backside into the 1x1/2 rectangle so the only zip ties would be around the bottom 1” tube which wouldn’t be very visible. I would tap 8-32 threads and use the washer head aircraft screws. Blue tape pieces would be screw locations on the backside, on the top I would weld 3 small tabs(silver sharpie) and probably use aluminum pop rivets.

Commit to the HDPE or scrap it and use a different material? I need to get this part figured out soon.

 

[earthling]

I need some opinions on how ugly the HDPE is? I’ve been looking at pictures of when I had the rear suspension and track in and the access is good enough(with skid & track already installed) I could do screws from the backside into the 1x1/2 rectangle so the only zip ties would be around the bottom 1” tube which wouldn’t be very visible. I would tap 8-32 threads and use the washer head aircraft screws. Blue tape pieces would be screw locations on the backside, on the top I would weld 3 small tabs(silver sharpie) and probably use aluminum pop rivets.
View attachment 178526
View attachment 178527

Commit to the HDPE or scrap it and use a different material? I need to get this part figured out soon.

I would be most concerned about the HDPE attachment options. Zip ties get brittle when cold, at minimum make sure you are using ones rated for cold (-40f). Were you planning on extending the HDPE more towards the rear?

WRT cosmetics, it depends on what the options are. I like the idea of HDPE for all the reasons you state (snow won't stick) but its not a great looking material, its a better liner than it is a cover if you know what I mean. Are you sure you are going to be able to get at those screw heads from the backside after the track is in place? I would think about a thru-hole there at the tape marks to a barrel nut on the backside or something like that on those flat tube sections. Just a thought. Me... I would likely want a single sheet all the way back to the side tailpiece triangle. With the tube frame painted, it would all more or less blend together, while showing off the tube construction. Will it look like a mass produced sled, no, but that is the point, might as well embrace it.

What is the plan for boot traction?

 

[zx4ever]

I would commit to the hdpe it is a durable product and lite and it will advance your project as it is easy to use. I used it on my old tube tunnel I used 1/8” and riveted it on and it still is holding up wheel 10000 km later. I would use 1 whole piece from front to rear of tunnel it’s stronger and easier to attach to frame

 

[Nikolai]

I would be most concerned about the HDPE attachment options. Zip ties get brittle when cold, at minimum make sure you are using ones rated for cold (-40f). Were you planning on extending the HDPE more towards the rear?

WRT cosmetics, it depends on what the options are. I like the idea of HDPE for all the reasons you state (snow won't stick) but its not a great looking material, its a better liner than it is a cover if you know what I mean. Are you sure you are going to be able to get at those screw heads from the backside after the track is in place? I would think about a thru-hole there at the tape marks to a barrel nut on the backside or something like that on those flat tube sections. Just a thought. Me... I would likely want a single sheet all the way back to the side tailpiece triangle. With the tube frame painted, it would all more or less blend together, while showing off the tube construction. Will it look like a mass produced sled, no, but that is the point, might as well embrace it.

What is the plan for boot traction?

1. I wasn’t going to extend it more to the rear because on the other side of the tunnel where it would end in the same spot is the turbo exhaust. So any further back on that side it’s going to melt HDPE and I’d have to switch to aluminum or make carbon fiber panels that could hold up to the heat. I’ll take a pic with the header and turbo in.

2. There is room to get screws in from the back. The tips of the paddles are below the screw locations.

3. Boot traction is going to be screws tack welded. I have Kold Kutter tire screws I removed the shanks on with my lathe and I’m tack welding the heads on. Waiting to get the side panels done before I put them on.

 

[Nikolai]

I would commit to the hdpe it is a durable product and lite and it will advance your project as it is easy to use. I used it on my old tube tunnel I used 1/8” and riveted it on and it still is holding up wheel 10000 km later. I would use 1 whole piece from front to rear of tunnel it’s stronger and easier to attach to frame

That looks great! I can’t run one piece of HDPE on the other side due to turbo exhaust. Will post a picture today.

 

[Nikolai]

Here’s what I have to work with on the exhaust side. There’s about 1-1/2” from the edge of the exhaust to where the side panel would be if I ran it all the way back.

If I stick with HDPE and ran it all the way back I guess I could cut a vee out of it the same shape as the exhaust for heat clearance and then all you would see from the side is the portion of exhaust below the frame tube?

 

[earthling]

I would still rather 'hold' a barrel nut on the backside and torque the screws from the outside. It looks like there is just enough room there to install some torx or other shallow head screws from the backside but I hate lining up threads blindly.

We used those on the boat for hard to reach places to hold similar material to HDPE. Used a hole punch on the cover, slip these through a hole in the tubing, tighten from the outside. There are a million variants.

Whatever material you end up using, I would try to find a way to run it all the way to the tail.

 

[Nikolai]

I would still rather 'hold' a barrel nut on the backside and torque the screws from the outside. It looks like there is just enough room there to install some torx or other shallow head screws from the backside but I hate lining up threads blindly.

View attachment 178534View attachment 178535

We used those on the boat for hard to reach places to hold similar material to HDPE. Used a hole punch on the cover, slip these through a hole in the tubing, tighten from the outside. There are a million variants.

Whatever material you end up using, I would try to find a way to run it all the way to the tail.

Those would work well, maybe I’ll see if I can find some smaller diameter aluminum ones.

My other thought was to just weld in some small 1/4 x .035 tubes to keep my boots out of the track and not even panel the tunnel, just leave the entire thing open. The 1/4 tubes for both sides would only be .2 lbs. then only close off the section behind the chain case and clutch.

Something like this.

 

[Nikolai]

One more. Could just do a small .040 aluminum plate for the boot area and leave the rest open. Aluminum would only need a couple fasteners. I this one is my favorite so far. Could powder coat the aluminum to keep snow from sticking.

 

[earthling]

Won't the track just blow snow out every opening?