*Open source purpose built snowmachine design thread*

[roo]

Originally posted by KAARLONEN
Would it be ok if we talk purpose built snowmachine as a whole, not just the engine?
Something like:
*Open source purpose built snowmachine design thread*
If you could do a purpose built snowmachine how would you do it?

Thank you KAARLONEN.
This thread is an awesome idea!

 

[roo]

Posted originally by KAARLONEN

> 1049cc yammi with boost, CVT, all cf construction, multiple fuel cells around the frame to get more volume and weight distribution like in fighter planes.
Projected weight 168kg ~ 370lbs.
Designed with Inventor.

EDIT:
Would it be ok if we talk purpose built snowmachine as a whole, not just the engine?
Something like:
*Open source purpose built snowmachine design thread*
If you could do a purpose built snowmachine how would you do it?

My point would be to get those great ideas presented elsewhere in this forum and guys behind them in same place. There are many threads about custon built bike/machines here so if we throw ideas into grinder hopefully output is pieces of blueprint for ultimate? working purpose built snowmachine. I'm sure there are more than few tinkerers here with ideas.

That picture I posted is something I've been planning since J&L Snowhawk posted his original *CVT snowbike* idea couple of years ago.
I really liked the concept and outside of the box engine placement.
That built kicked my design into gear and that is what I have now.

I have done one purpose built single ski snow machine some ten years ago, it had sled engine and CVT but it was bulky and had too many too complicated new ideas in it. Layout was about same as sleds but with only one ski. I got it running but it was more of a learning experience than working prototype.

Now I think it time for round 2.0.
Some more specs:
Track 153 3" cut down to 12" with KMH-motion 2.0 suspension (DIY) .
Yammi genesis 1049cc with MCX 270kit + CVT.
Construction CF/kevlar as much as possible.
Frame is continous optimized form of two plates with varying thickness. All mass and hi-stress points are close together and fork does not need hi-strength support because impact forces are delivered through A-arm to the center of the frame. Makes the frame small, light, stiff and strong.
Fuel is in small connected composite cells around the structure where there is leftover volume. It distributes weight around and lower that normal single tank.
Otherwise it is just normal tech arranged in new form.

 

[roo]

Originally posted by KAARLONEN

Like this? Simple A-arm front suspension with hollow carbon sliders.
Also my motor of choice. Centered mass and enough power

 

[roo]

Research links

I will try to edit this post in order to keep all reference links (informative links to other websites, forums etc.) that are posted in this thread in one place.

Retrofit hawk suspension
http://backcountryrebels.com/showthread.php?t=33148

J&L snowhawk
"New prototype"
http://backcountryrebels.com/showthread.php?t=33089

J&L snowhawk
2016-17 builds
http://backcountryrebels.com/showthread.php?t=34349

Grr
Garuda- king of the birds
http://backcountryrebels.com/showthread.php?t=33217

TLKD
phoenix project
http://backcountryrebels.com/showthread.php?t=30436

Steve sampson
"I might not make it"
http://backcountryrebels.com/showthread.php?t=13515

Sweden turbo
Next gen 3 snowbike, home build project
https://www.snowest.com/forum/showthread.php?t=407962

Swedenturbo
Gen two snowbike, home build project
https://www.snowest.com/forum/showthread.php?t=359272

J&l snowhawk
Cvt snowbike
https://www.snowest.com/forum/showthread.php?t=405813

Sheetmetalfab
Mid engine purpose built
https://www.snowest.com/forum/showthread.php?t=376728&page=2

Egesledder
Finally, a Snowbike Exhaust Cooker! (And complete custom CVT bike)
https://www.snowest.com/forum/showthread.php?t=422998

 

[roo]

Share cad files

I have used grabcad workbench to share cad files in the past.
https://grabcad.com
Seems to work pretty well. If anyone has a better idea where to share technical drawings feel free to chime in. We could also just list the member and you could pm them.
If you post links to cad drawings in this thread i will try to edit this post to keep all the links in the same place.

 

[roo]

Retroft hawk suspension.

I am willing to share all information with the exception of detailed drawings of parts that i am considering for production.

This is the suspension i built for my snowhawk.
I will make the cad drawings available in the next couple days.
It is a very simple design that has been tested for the last 3 seasons. It works very well and is extremely tough. Not one single part failure in 3 seasons and i have hammered on it going big on a machine that weighs 450 lbs.!
Link to bcr detailed build thread.
http://backcountryrebels.com/showthread.php?t=33148

 

[roo]

The drawing is of the first design which relied on shock bottom out bumpers to control the coupler arm.
The gen 2 design incorporated a mountain bike coilover and shortend bumpers that controlled the bottom and top out of the shock in the coupler arm.
I am in the process of designing a resin infused carbon fiber coupler arm that will use a pit bike fox air shock with a handlebar mounted charging and discharging push button valve to control pressure in the shock/ level of coupling the skid.
http://www.ridefox.com/2016/product.php?m=moto&t=shocks&p=3340

 

[roo]

Stoked!

I am obviously pretty excited about this idea.
I have been riding, wrenching and building single skies for going on eight years now. I solely own and operate a small shop in the pacific northwest, 3 axis cnc routing, plastic vacuum forming, composites and light fabrication.
Prior to that i was employed as an aerospace mold maker for a company that also made carbon fiber parts for recreational vehicles.

My work allows me quite a bit of free time to work on personal projects (sometimes the router can run all day unattended while i work on something else.) My wife loves it because i can get personal projects done without having to stay out in the shop late every night like before i was self employed.
I am currently working on concepts related to light weight parts and geometry. I will use my 800 hawk as a test platform. If the parts hold up on this pig they will definitely work well on a purpose built lightweight machine that i will start building in the near future.

I am willing to help people with questions they may have about the materials and processes that i am familiar with. I would love to see more unique innovative designs be brought to the table.
Hopefully this takes off and grows into a healthy database for diy builders. It would be really cool to combine the wealth of knowledge from our ever growing community into one area that has high exposure. Who knows maybe could lead to helping one of the large companies that already has the massive buying power needed to actually produce a purpose built single ski.
There are lots of tallented builders out there that are hopefully willing to share information.
If anyone knows of any existing drawings of suspension, bike kits, concepts etc. Please post some links.
If anyone is willing to share cad drawings or even napkin drawings lets get this thing rolling!
Cheers
Jeff
DGS

 

[Norma Stitz]

Great ideas. I wish you worked at mototrax.
How does the pit bike shock differ from the mtb shocks?

 

[Hbmtr]

I am obviously pretty excited about this idea.
I have been riding, wrenching and building single skies for going on eight years now. I solely own and operate a small shop in the pacific northwest, 3 axis cnc routing, plastic vacuum forming, composites and light fabrication.
Prior to that i was employed as an aerospace mold maker for a company that also made carbon fiber parts for recreational vehicles.

My work allows me quite a bit of free time to work on personal projects (sometimes the router can run all day unattended while i work on something else.) My wife loves it because i can get personal projects done without having to stay out in the shop late every night like before i was self employed.
I am currently working on concepts related to light weight parts and geometry. I will use my 800 hawk as a test platform. If the parts hold up on this pig they will definitely work well on a purpose built lightweight machine that i will start building in the near future.

I am willing to help people with questions they may have about the materials and processes that i am familiar with. I would love to see more unique innovative designs be brought to the table.
Hopefully this takes off and grows into a healthy database for diy builders. It would be really cool to combine the wealth of knowledge from our ever growing community into one area that has high exposure. Who knows maybe could lead to helping one of the large companies that already has the massive buying power needed to actually produce a purpose built single ski.
There are lots of tallented builders out there that are hopefully willing to share information.
If anyone knows of any existing drawings of suspension, bike kits, concepts etc. Please post some links.
If anyone is willing to share cad drawings or even napkin drawings lets get this thing rolling!
Cheers
Jeff
DGS

great thread jeff!

 

[roo]

Great ideas. I wish you worked at mototrax.
How does the pit bike shock differ from the mtb shocks?

The fox pit bike shock is burly, way tougher than a mtb. Shock.
Hiem joints instead of teflon lined DU bushings. the mtb. Shock i am running right now needs the bushings replaced atleast a couple times a season. Hiem joints allow for misalignment issues caused from flex, warping from welding etc. The mdf jigs i machined worked pretty well but definatly not perfect.
The pit bike shock also has the same ice scraper seals that fox uses in there snowmobile shocks. My design requires 3" of shock stroke.
Pit bike shock is way cheaper than a 3" stroke downhill mtn. Bike shock, by like 40%.

The one advantage of the mtb bike shock is you have a lockout lever on the shock. This is basically allowing you to almost close down the compression damping. But as a safety if you take a hard enough hit it will blow through the lockout instead of blowing up your shock. I am also involved in the mtb. Bike industry and some of my contacts are a little skeptical about how long their shocks will hold up in this application. Most all brands with high end air shocks also offer a handle bar mounted switch which through a cable connects to the lockout lever on the shock which would allow you to couple and un couple your suspension on the fly. There is an aftermarket kit to install this same concept on a specific sled suspension, (not recalling which suspension). Theirry also incorporated this design into his phoenix project.http://backcountryrebels.com/showthread.php?t=30436&page=2

The difference being fully coupled in deep snow is absolutely amazing. Being fully coupled on hard pack and bumpy roads is incredibly scary.

I plan on being able to change the pressure in the shock on the fly. Not quite as good as a lockout but it should still have a similar effect. Having a tougher shock is more important to me. I am really hard on these machines.

 

[NEWDUCK]

Honestly for this season I pretty much own what I want in a snow-one-skied machine. Only thing I truly hate is the 700 Polaris engine. Has zero bottom end. Top end and midrange its a beast.

Heated bars,Dirt bike seat, TS ski, Chain drive, 151x13.25x2 track(could use 2.5),Holz rear skid that makes this thing pop up on the snow everywhere. Weight at 485 with 10 gallons of fuel.

But If I ever get around to it and if we are talking dreams it would be this chassis with a Big bore 925 cat engine in it with a 155x3 track

 

[LoudHandle]

How many degrees of steering is needed?

Sleds have about 60 degrees each way (centered to stops), 120 degrees total.

Do the one skis require the Same? More? Less?

Working on some CAD designs and possibly considering producing some parts is the basis for the inquiry. Thanks

 

[roo]

Sleds have about 60 degrees each way (centered to stops), 120 degrees total.

Do the one skis require the Same? More? Less?

Working on some CAD designs and possibly considering producing some parts is the basis for the inquiry. Thanks

I can tell you the hawk and bikes seem to both be pretty good in my opinion.

I can measure the hawk and get you some numbers.
Also my cr and my ktm if you want those also.

 

[roo]

I can tell you the hawk and bikes seem to both be pretty good in my opinion.

I can measure the hawk and get you some numbers.
Also my cr and my ktm if you want those also.

Maybe someone else could help you with the bike measurements or maybe even look it up.
My bikes are buried in the corner for the winter.

 

[LoudHandle]

I can tell you the hawk and bikes seem to both be pretty good in my opinion.

I can measure the hawk and get you some numbers.
Also my cr and my ktm if you want those also.

When it is convenient for you, thanks. I'll try and check bike on the specs.

 

[roo]

Degrees of steering

Sleds have about 60 degrees each way (centered to stops), 120 degrees total.

Do the one skis require the Same? More? Less?

Working on some CAD designs and possibly considering producing some parts is the basis for the inquiry. Thanks

If you are calling center zero this would be 31-33 deg. Each way. Because of my added bump stops i am limited to 31 deg. I would say it is plus a deg. Or 2 in stock form. I think bikes turn farther.

Cheers

 

[roo]

Oh ya picture!

 

[roo]

Honestly for this season I pretty much own what I want in a snow-one-skied machine. Only thing I truly hate is the 700 Polaris engine. Has zero bottom end. Top end and midrange its a beast.

Heated bars,Dirt bike seat, TS ski, Chain drive, 151x13.25x2 track(could use 2.5),Holz rear skid that makes this thing pop up on the snow everywhere. Weight at 485 with 10 gallons of fuel.

But If I ever get around to it and if we are talking dreams it would be this chassis with a Big bore 925 cat engine in it with a 155x3 track

Nice build!
Did you fab the tube chassis?
I am also pretty happy with my ride.
Other than minor geometry changes and a serious jenny craig program the hawk fits my riding style really well.
I really dont think there can be a do all purpose built.
But i guess there is nothing to say there cant be different models for different styles. Just like there are in every other motorsport industry.

Big reason i cant argue hawk vs. Bike two completly different machines. If i was in a better financial position i would deffinatly have both!!!

 

[roo]

Honestly for this season I pretty much own what I want in a snow-one-skied machine. Only thing I truly hate is the 700 Polaris engine. Has zero bottom end. Top end and midrange its a beast.

Heated bars,Dirt bike seat, TS ski, Chain drive, 151x13.25x2 track(could use 2.5),Holz rear skid that makes this thing pop up on the snow everywhere. Weight at 485 with 10 gallons of fuel.

But If I ever get around to it and if we are talking dreams it would be this chassis with a Big bore 925 cat engine in it with a 155x3 track

485# - 10 gallons of fuel @ 6.2 lbs/gal.= 423# dry
Is this without bodywork?