Nordic Crawler Design Losi 2.2s/Sportsman chassis

[Tomy]

Hi everyone

I have been talking to a few Losi drivers over at the AX10 sections about a Losi specific version of this 2.2s / Sportsman chassis that I have been working together with at friend of mine called Douwe. Douwe has done most of the design work for the AX10 version and now I have spent some time to make it fit a Losi tranny as well.

Personally I have no experience with Losis. So I have been relying on the help of a few Losi drivers.

This is what I have got now. The chassis is only a prototype and therefore the material is polycarbonate. The final version will be cf. Also the bottom of the tranny would need to be modified or short spacers used as it is not flat, but this is just a mockup to show you how the tranny is positioned in the chassis.












There is room for a motor with a can at max 55mm long. I was told that a popular motor for the Losi is a Tekin brushless that has a 53mm long can.

Also I was recommended to position the tranny so that the transmission outputs are centered on the skid plate.

Please let me know what you think of it so far.

Thanks!

Tomi

[Tgreer]

I think that's a great start! I personally would rather see the driveline slightly off center, just to pull the motor in a little. Maybe somewhere between stock location and a tranny flip mod, if that makes sense to you!

[AlexG]

^^^ what he said

Plus adding a front upper link holes below the current one.

Edit: stand corrected about the upper links, the angles of your shot make's it hard to see.

[WAM]

Is this the "longer skid" you were considering, or the current skid with revised bolt pattern?

If you simply grind-flat the underside of the motor plate end (the bump), won't what's left still get into the rod-end? I wonder if we could redesign that lower bracket along the motor plate so that it still supported the spur gear but bolted onto the plate in better locations. Or a slick billet motor plate that didn't need the bracket.

[zeko]

That's looking sweet Tomi... If it fits a Tekin brushless, I'm in no matter what.. I'm dyeing For a new chassis for my losi.

[dentonmac]

Originally Posted by Tgreer

I think that's a great start! I personally would rather see the driveline slightly off center, just to pull the motor in a little. Maybe somewhere between stock location and a tranny flip mod, if that makes sense to you!

Originally Posted by AlexG

^^^ what he said

Curious...Reason?

I really like the center tranny mod. The amount of bend you can put in the lower links is amazing.

Thanks.

What is the width of the skid compared to stock? Looks like the LCC tranny will fit. Looks great.

[WAM]

Originally Posted by dentonmac

Curious...Reason?

I really like the center tranny mod. The amount of bend you can put in the lower links is amazing.

Thanks.

Yeah, but it's a compromise. I also prefer the centered tranny because worm gear resistance causes very large frictional losses when driveshafts have to run thru angles. It's much more important with a Losi than an AX10. But having the motor hung out there is obviously a negative. For a basher or bodiless I'd want a more inboard motor. But for a full-comp 2.2 Shafty I think the centered tranny is the way to go.

[Tgreer]

Yes, the tranny flip is better than stock position for sure, but I have ran the tranny flip for a long time now and it has it's downfalls! I get hung up, it took a long time to work the shocks so that it had even sidehilling ability on both sides, and it's still not equal. No matter the amount of tuning, it still favors one side more than the other, so by compromising and giving the driveshafts a slight offset,(just a little) to bring the motor in just a little more to better balance the chassis would go a long way, and with only a slight driveshaft offset, the worms would still have more free motion than stock! I think it's the best compromise for both the driveshaft and motor weight!

Originally Posted by WAM

Yeah, but it's a compromise. I also prefer the centered tranny because worm gear resistance causes very large frictional losses when driveshafts have to run thru angles. It's much more important with a Losi than an AX10. But having the motor hung out there is obviously a negative. For a basher or bodiless I'd want a more inboard motor. But for a full-comp 2.2 Shafty I think the centered tranny is the way to go.

[WAM]

As seen in the top photo, as you start moving things to the right, the corner of the motor plate (flathead screw) moves further into interference with the link rod-end. Move too far and you can no longer fit a third tranny/skid screw.

[Tgreer]

Originally Posted by WAM

As seen in the top photo, as you start moving things to the right, the corner of the motor plate (flathead screw) moves further into interference with the link rod-end. Move too far and you can no longer fit a third tranny/skid screw.

So move the lower link mounting point more forward on the chassis, making the front lowers a little shorter!

[huskerfan406]

I have the tekin 21.5t and think the design looks good for a sporty rig for my losi! I hope you get the chassis figured out! Looks great so far! I would like one too! Thanks for your time in designing this chassis!

[BDR]

Looks good Tomi

It is great to see a vendor listening and working with customers to get what they need err ahh want

Love the fact the sensor wire just fits in too, with that motor any way

[Tomy]

Thanks again for all the valuable input!

Regarding the tranny output position I believe we can do it both ways. I will need to adjust the skid plate just slightly and there will be room to adjust the tranny position sideways.

We can have two different skid plates or could probably even have mounting holes for both positions in the same skid plate, but that would leave us with three holes that need to be plugged somehow. I believe the more stylish option is to have two separate skid plate options.

The skid plate is now 72mm long. If I make it 75mm (thats a little less than 3") the tranny can move sideways. The skid plate could be made shorter in the front but to me it does not make much sense as the chassis plates will need to remain the same to make room for the motor.

How does the skid plate lenght compare to what you are using now?

[zeko]

Im still using A stock losi skid plate and it is roughly 72mm long.

[crelesy]

This is how I coped with the bend link problem at the rear.

Maybe a more centered point for mounting the lower links on the skid would be prefereble? Thatway you don't have to much axle swing when flexing. This is a strong advantage on the Losi.

If you follow the image's link to my album you can find some mesurements and serious mock up/trail and error there. (Its public) http://s1233.photobucket.com/albums/ff396/crelesy/LNC/

[crelesy]

O and as you may already know, I'm in for the Losi chassis ofcourse!

I'm having a comp next sunday here in Holland, I heard Douwe and AlexG will be there as well. I will bring a complete spare LCC wihte me. Maybe the 3 of us can figure something out and maybe Douwe can take some parts home fore measurments and ideas? ( he still has my LNC tranny )

Let's hope your chassis kick's the LCC back on track!

[dentonmac]

Originally Posted by Tgreer

Yes, the tranny flip is better than stock position for sure, but I have ran the tranny flip for a long time now and it has it's downfalls! I get hung up, it took a long time to work the shocks so that it had even sidehilling ability on both sides, and it's still not equal. No matter the amount of tuning, it still favors one side more than the other, so by compromising and giving the driveshafts a slight offset,(just a little) to bring the motor in just a little more to better balance the chassis would go a long way, and with only a slight driveshaft offset, the worms would still have more free motion than stock! I think it's the best compromise for both the driveshaft and motor weight!

Thanks for the explanation. I actually see what you mean. Great, now I have something ELSE to test/look at next time I go out.

Would it be possible to make the tranny mount holes in the skid long so you could 'slide' it from current location to center driveline? Just curious if I am missing something?

[WAM]

My Losi/Gatekeeper skid is 50 x 66 mm. I have pretty good confidence in both Gatekeeper and LCC suspension geometry. (And they're remarkably similar.) I'd be reluctant to start arbitrarily shortening arms or altering geometry without running the alternatives thru 4-link software analysis.

But of course you need to build what the majority want to buy.

[Tomy]

When you guys mount the Losi tranny on a flat skid plate, do you use short spacers between the skid plate and the tranny or do you trim the motor plate mounting tabs?

[Tgreer]

Originally Posted by Tomy

When you guys mount the Losi tranny on a flat skid plate, do you use short spacers between the skid plate and the tranny or do you trim the motor plate mounting tabs?

1/8" spacers!