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OSRC

I've got 3 unfinished trucks sitting on my workbench, as well as a crawler course I'm trying to relocate in the backyard, so what's one more project?

After tearing down 2 built trucks to build the Belly Dragger Sawback (with all the good parts) I had enough parts left over to build the second Sawback. Nothing too fancy, its mostly stock parts with a few twists here and there to keep it interesting. I had to resist my typical urges to cut up some aluminum and build a chassis.

Stock chassis with some flat black. I assembled it first, then painted so the color is consistent. I'm not a scale snob at all, but it makes a world of difference getting rid of the chrome.


My biggest beef with the GS01 chassis is the noise. The transmission sounds like I'm driving a blender through the woods. Compared to the SCX10II and especially the Ascender, the racket was driving me crazy. I tore down the trans and played with some 5mm shims to see if they made a difference. I found the counter gear was a bit chewed up...not sure why, looked like a molding issue ilo a debris issue. So I mixed and matched gears from 2 transmissions, played with some shims, and now the trans is amazingly quiet. Testing it on the workbench with 3v is smooth and almost silent. Amazing what a few shims can do.


Hung the rear axle on. Axle has brass inserts, Axial shocks with 40wt. oil and is set up with a large helper spring. The Sports body is a bit heavy, so the extra spring works out nice. I made an anti-wrap link when I initially built the kit and it seems to be working well. The springs have been on a few trail runs, and they look pretty good still.


Went a bit different up front - set up a 4 link ilo the leafs. It allowed me to push the front wheels out about 10mm or so...larger tires tended to rub the back of the fenders under compression and it never looked right to me. The geometry leaves a bit to be desired, but I think as a front axle, it'll work ok.


Took some messing around, but I got good caster angle, pinion angle, and a nice range of motion. Axle has brass inserts, and another SCX10 shock filled with 40wt. does the duties here too. Left the steering servo on the axle for now, though I have room for CMS later on if I decide to go that route.


And we're rolling with Sport bumpers and some Redcat Iroks stuffed with 4.5 soft DS foams and a bit of weight to offset that tall body. Tires feel GREAT....as good as any I've got on any truck. We'll see how they do though just testing around the basement I've got high expectations....


Wired up...running out of crawler stuff, so an silvercan will have to do. It's geared down with a 9t pinion, so should work out very well. (I have a 35t on the way) Battery can go up front or out back - starting with it up front for now.


Next up - bodywork. Can't ever go wrong with Tamiya copper.....

OSRC

And finished! That went quick. Sport cage added, and Hunter Dan is ready to explore. 1 less project on the bench!

Well, almost finished, forgot the bumper insert.



And a flex shot of course.. The front axle has much more travel then the leaf setup, and the rear is somewhat stiff. Should be a good setup.


Wheels look good to me, but I'm thinking a set of the new SSD slots would look even better on here.

JatoTheRipper

Those tires do look awesome. Should be a fun and capable rig for sure.

Tell Dan to take those sunglasses off. It only rains here on crawling days.

alexleblanc

great looking build - leafs out back and a 4 link up front is a pretty decent setup, I built a LWB bullhead/flatbed with Gmade leafs out back and 4 link up front and have been surprised how good of a setup it is.

jokersinsanity

I loved the gs01 chassis i had the sawback 1st gen and a komodo both took a beating only issues i had were the dogbones or front axles shafts whatever u call them and Driveshafts both easy fixes. Really wish someone would make a better trans for it and diff gears though never was a fan of the "tin can looking" gears and the lack of a metal trans gear upgrade.

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soze

Looks great. I really should get my Sawback out for a drive. I'll need to see if it needs shimming in the transmission as well.

OSRC

Thanks fellas, liking how this one came out.

Yup, been there. CVD's are in the front axle, and Wild Boars replaced the stock driveshafts.

jokersinsanity

Yea if i remember right the gmade long cvd kit was the best one i found for steering withour bindingSent from my LG-M703 using Tapatalk

OSRC

Got the Sawback done pretty much aside from a few odds and ends on the body and took it for a test run on my (under renovation) backyard course. Right away noticed the front suspension was way too soft, both in spring rate and oil.



So brought it back in and swapped out the springs for a bit stiffer ones and dumped out the 40wt. oil and went with 60wt. Packed it up in the truck and met up with some friends for a Sunday morning trail run. Ran my TRX-4 at the same time as a comparison truck.


Conditions were wet and a bit muddy making traction at a premium, but the tires did pretty good overall. Not in the same league as my Proline TSL's, but not bad at all. Hard to tell sometimes when they are wet constantly. Plan on adding some cuts to those big lugs to help them conform a bit better.


This line took me forever. Pics really don't give scale and depth, but it's a great little spot - the last piece of a very long hill climb. Had to kinda ride along the large rock and tiptoe your way up. The TRX4 basically walked up it with open diffs(!) though the Sawback struggled a lot. I got it up there eventually though.


Posing at the top of a long hill climb- a well earned rest!


The leaf rear/front link setup worked really well. The rear was very planted and set the entire truck well on climbs and sidehills while the front did most of the flexing. Never drove with this kind of setup, and it was fun for sure.


Mud coming... Didn't get it too muddy, but I was thankful for the TSL's today as we navigated up a small running creekbed. Perfect TSL terrain.


So now what? I think the front shocks could be a bit stiffer still, and the tires need a bit of attention. Also, it was a bit zippy with the 27t motor even geared way down. I have a 35t motor to swap in, and will do so. Amazingly, it ran 4+ hours on a 3000mah pack, even with the lowish turn motor. Otherwise, not sure what else to change. Great little truck, and has me thinking about redoing the spring under Sawback to a similiar setup.

2mtech

That's a great looking rig, can't believe I hadn't seen this one before. I'm with Shinchu, makes me want to get mine back out.

JatoTheRipper

That's an awesome photo!

My Bronco struggled up that section. I wish I had seen the line you took.

And those tars were as good as my KLRs if not better when things got wet and slickery.

soze

Ugh... damn photobucket. @OSRC, I'd like to see some pics of your shimming for the transmission to quiet it down if you still have it around somewhere.

OSRC

I do not, sorry. I allowed my PB account to expire since they wanted a few hundo to keep it alive. Wasn't much to see, i just picked up some 5mm shims in various widths and kept stacking until the gear got bound up, then took one back out. I remember using a few TRX fiber washers, one of the gears had a ton of play! Did that on all the internal gears. It helped for sure, but the trans was still on the loud side. It's the gear profile, it's just noisy! I did find it was quite sensitive to different pinions - 32p Tamiya pinions were the quietest IIRC.

I sold this rig a long time ago, and have since bought another, lightly used roller. I did not shim the trans though and it sounds like I dropped a ball bearing into a trash disposal. I have a Stealth trans here ready to drop in, far easier than the R1 gear mod for a it of OD, and will quiet things down.

soze

I'm about to go that route too. I plan to stick in a stealth as well. I'll be making a skid for it actually.