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Old 03-14-2018, 12:24 AM   #1
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Talking Sawback time!

I've been wanting a leaf sprung Sawback for quite a while now, but there always seems to be something more important that's demanding my money (new motorcycle for the boy, sewer main replacement, root canal, etc.) I bought one of those cheap WPL B1 bobbed deuce toy grade "crawler"s hoping to get my leaf spring fix, but it was far from doing it for me. Well, I think the stars have aligned as I sold a fair amount of old stuff that had been sitting around AND the rest of my rc collection is (mostly) functional right now.

I'm planning to start with just the basics, kit, optional roll bar, motor, esc, and cheap servo. I'll be using my Radiolink radio, and most likely an $11 Towerpro MG958 servo, I'm for sure going with another WP1080 esc, and I'd like to use another HH Trailmaster Sport 550...

so question #1 is: will a 550 brushed motor directly bolt in, or be made to fit without major surgery?

question #2: what is the transmission reduction?

I've found that the axles use 32/14 (2.29:1), but I still haven't found the trans gearing. I'd just like to play around with the numbers myself before deciding between 21t or 27t for my motor, assuming a 550 fits. I'm hoping to place my order from RPP in the morning.

question #3: are the kit's screws made of butter, or will they suffice? I understand they are philips head.

question #4: is there anything that is a "must have" part for the initial build?

Looking forward to joining the club!
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Old 03-19-2018, 12:21 AM   #2
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Default Re: Sawback time!

Well I've spent the last few days skim reading EVERY thread in the Sawback sub-forum, so I went ahead and placed my order. Besides the kit, I've got 2 sets of brass axle weights, an R1 ring & pinion for the front, a stainless hardware kit, and a Holmes Hobbies Trailmaster Sport 27t 550 brushed motor to get me started. I was going to get the Gmade roll bar too, but I'm not even sure if I'll use the stock body yet, and the Scalerfab roll bar looks nicer for not too much more money anyway.

I do really like the stock body, and it could be a great scale version of my good friends '47 Ford GPW, but the reason I really wanted a leaf sprung truck was to start building a semi-scale replica of my own K5 Blazer. I know the Proline 1980 Blazer body meant for a Tmaxx fits pretty well, but let's be honest, 1980 was THE ugliest front clip of all the square body Chevy's. The RC4WD Blazer also looks like a match made in Heaven for this chassis, but I'd really prefer the '81-'88 quad headlight style body (mine is an '87.) That leaves the Vaterra '86 K5, which is HUGE, but it would be my first choice for a body. That would require stretching the frame, which I'm capable of, and I'm not against the idea. I kicked around the idea of modifying a Clodbuster body, but I don't think I'm ready to pull that off just yet.

I'll have to wait until next month to get the rest of my electronics, but that will give me time to think about the direction that I'd like to take this car.

I will for sure be making an anti-wrap bar that attaches at 2 vertically separated points at the axle, and is shackled at the skid plate, exactly as my 1:1.

I have 40" Yokohama Geolander MT's and 17" KMC XD222 beadlocks on my 1:1, so depending on which body I decide on, the stock Gmade tires might actually be a good choice! If I go with the Vaterra body, it's right at 1/9 scale of my stretched 112" wheelbase, and I already have a set of Chinese KMC 1.9"s and 4.4" RC4WD Trail Rider's that will work absolutely perfect!

A set of aluminum knuckles for a Tamiya DF03 look like a good way to convert to high steer, but I won't be able to mimic my 1:1's rear-mounted tie rod. I'm not planning to go to Chassis mounted steering, but will instead run the servo horn upwards to kinda get the "look"... with the draglink attached to the passenger side knuckle of course.

I'd like to do a shackle reversal on the front end too, but I did not come across a method that I liked, so that's something I'll have to play with.

I'm super excited to get started!
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Old 03-20-2018, 02:10 PM   #3
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Default Re: Sawback time!

Well this has escalated quickly! I just noticed yesterday that the Vaterra K5 body has been discontinued, time to $4!+ or get off the pot! A buddy texted me this morning about a 15% off anything on Ebay promo, so I swooped up a K5 body with the quickness.

So the deal has been sealed, I will be cutting up my brand new Sawback chassis and grafting in a piece to make the wheelbase (287mm) work with the Vaterra body (314mm)

Without having the kit or body in hand, I'm thinking that a rearward stretch might be best, adding all the additional length of frame just behind the skidplate. I know that will make the rear driveshaft more vulnerable, but I'm going to try to make the antiwrap bar so that it will take most of the hits, and that will give me a better forward weight bias.

I figure that it will be best to build up the kit as a slider first, then go from there. I've got no less than a dozen other rc's in regular circulation, so I plan to take my time with this one to hopefully do my 1:1 some justice.
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Old 03-20-2018, 02:19 PM   #4
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Default Re: Sawback time!

The Sawback is an awesome truck. You'll love it. Welcome to the Leaf Spring Mafia!

Buy the Sawback, the WP 1080 and a sealed can brushed motor. You don't need a 550. I can't remember, offhand, if a 550 will fit.
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Old 03-20-2018, 02:37 PM   #5
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Default Re: Sawback time!

I came across several threads in here with guys running a Titan 12t 550 (surprisingly, no mention of a Titan 21t) so I went ahead with a 550. This will make 3 cars with HH 27t 550's and WP1080's for me, it's kind of my go-to combo as of lately. It looks like if there were to be any interference from the longer can, my frame stretch would alleviate it. Either way, I'm committed now, so I'll make it work!
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Old 03-20-2018, 02:48 PM   #6
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Default Re: Sawback time!

Quote:
Originally Posted by TheLetterJ View Post
I came across several threads in here with guys running a Titan 12t 550 (surprisingly, no mention of a Titan 21t) so I went ahead with a 550. This will make 3 cars with HH 27t 550's and WP1080's for me, it's kind of my go-to combo as of lately. It looks like if there were to be any interference from the longer can, my frame stretch would alleviate it. Either way, I'm committed now, so I'll make it work!
I think the 550 will fit a stock Sawback without modification. It might interfere with the body, but the chassis should be fine.

One one of my Sawbacks, dubbed the Sawbeast, I flipped the trans so the motor faces front. Even a 540 runs into the electronics tray and body.
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Old 03-28-2018, 02:28 AM   #7
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Default Re: Sawback time!

I started building this evening. I decided to mostly build according to the instructions initially, just for the sake of mock up. The axles went together very nicely and have some good heft to them with the brass tubes installed. I got the transmission and most of the chassis done too, but I'll have to put in a bit more time tomorrow to finish it up.

I think I'm going to follow OSRC's lead from his "belly dragger" build, and make a one piece flat skid/boat sides attached to the outside of the chassis with angle aluminum, or the stock side supports turned up side down. I'm shooting for 3" under the belly at ride height, so I'll see where the flat skid puts me once I've got it built as a roller with my slightly taller tires under it. I wasn't planning on making an entire new chassis like OSRC did, so I'll explore some options with the spring hangers if the flat skid isn't enough.

Even with the soon to be stretched wheelbase, I'm anticipating the driveshafts will need extra attention as my 1:1 that I'm trying to dimensionally replicate needed a stupid-expensive 42 CV to work with the clocked t-case and a substantial amount of wheel travel. There's no way I'll get as much vertical or articulated travel (to scale) as my 1:1 on this build, so maybe I'll get away with some Traxxas shafts... I'll find out soon enough!

I'm really liking this kit so far.
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Old 04-03-2018, 07:02 AM   #8
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Default Re: Sawback time!

I don't know if you laid the knife to it yet, but it might be easier to get a different grille for the proline body than to stretch the chassis. That K5 body will probably be very easy to re-sell as time goes on. Some things can't be undone. I really liked the sawback, but this is one of the major reasons I went with the ascender.
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Old 04-03-2018, 08:44 AM   #9
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Default Re: Sawback time!

The K5 is discontinued.

Definitely don't hack it up unless you're sure.
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Old 04-03-2018, 03:27 PM   #10
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Default Re: Sawback time!

I haven't cut the chassis yet, but I did start making the extensions. 1/2"x1/2"x1/16" box tube cut down the center isn't quite perfect, but damn close.

I did think it was weird that the Vaterra K5 body shows as discontinued on Horizon's site, but not the K5 Ascender RTR, nor kit. I know that it would be A LOT less work using the Proline body, but the Vaterra K5 was what I really wanted, and as a true square body fanatic, a '76-'80 K5 is not the same as '81-'88 (and '89-'91 with a grille swap) as they have a totally different front clip (not just the grille.) I'm not cutting up the body (much) and I'm not real concerned with my metal working abilities, so this project is a go. Worst case, a new set of Sawback rails is $30.

Progress has been slow as I've been trying to finish up the tile in my front bathroom, but I should be able to get back to the Sawback as soon as I get the grout and shower doors (currently in the middle of my garage, so no hot-work while they're out there) dealt with.

Still digging around for other build ideas, I've seen a lot of TF2's use the Tamiya Bruiser spring hangers and shackles as an easy bolt-on front shackle reversal, while gaining a little (1/8"ish) lift in the process. If I can track down those parts, I may give that a shot as well. I'f I go that route, I can file the front spring perches down a few degrees to get the pinion back where it needs to be...

Still thinking about driveshafts, is there an easy way to make (or buy) a double cardan type driveshaft? I'd like to roll both pinions up to get them out of the rocks, and more closely match my 1:1, but I'd like to use the correct type of driveshaft for the job. I've thought of all sorts of things including welding 2 yokes back to back, to get it done, but if there's an easier way, I'm all ears. I haven't had luck finding that type of 5mm joint on ebay/etc... yet.
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Old 04-03-2018, 03:31 PM   #11
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Default Re: Sawback time!

Just caught this thread. Congrats on the purchase!

I made 2 chassis when I hacked up mine, the second one moves the front axle 1" forward (like a modded 1:1 jeep would have done, and tons of room for a winch too). It's good to have options... I didn't see how I could stretch the WB with the stock chassis...the leaf hangers are already almost at the end. If I had to go back and redo it, I would have added the stretch at the rear to keep more front weight bias.

Post up some pics as you build! I need some incentive to get mine finished...
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Old 04-03-2018, 03:37 PM   #12
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Default Re: Sawback time!

I'm adding the length (27mm, unless I change my mind again and decide to go a little longer) right in the middle. Since I'll be making a new flat skid (totally copying your idea OSRC) I'll be able to mount the trans in the same position relative to the front axle, with all the added length behind the trans.
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Old 04-08-2018, 03:11 AM   #13
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Default Re: Sawback time!

No build progress to speak of, but I did sell one of my other crawlers to free up some cash... to buy more rc crawler parts!

I set the K5 body on top of my 4.4" Trail Rider tires and just couldn't get over how small they looked. At 1/9 scale, they should have looked exactly like my 40"s on my 1:1... but they didn't. Then I found my error. I had divided my actual wheelbase (112") by the Ascender K5's (12.36") to get 1/9, when I meant to divide the K5's factory original wheelbase (106.5") by the Ascender body's 12.36 to get 8.6:1.

With my new found 8.6:1 scale, I needed to rethink a few things. First up were the tires. I needed 4.65" tires (still 1.9"s) so I broadened my search to include 4.65"-4.75". I couldn't find any bigger versions of my Yokohama Geolander MT's than what I already had. I could have gone with a different "V" tread like the Baja Claw, or Pitbull Growlers, but the Baja Claws seem a bit overused in the rc world, and I just couldn't fall in love with the Growlers with their tight tread pattern and bulbous look. Next consideration was the RC4WD Irok, the size was perfect, and I know they'd work well in my usual terrain, but I ultimately ruled them out because they are not a tire that I would run in real life. I really wanted to try out RC4WD's new(ish) X2S3 compound Goodyear MT/R, but I know the wildly asymetrical tread pattern would have driven me nuts.

I settled on the 4.75" RC4WD Compass which is a good looking copy of a Toyo Open Country MT. I know they are not the latest/greatest tire in the rc world, but they should still be decent scale tires. I've run those in the past on my 1:1's and that is what my spare is for my 1:1 K5, so it still fits this build well.

Since my tires were no longer a 100% match, I figured it would be alright to mix up the wheels a tiny bit too. I bought another set of Chinese KMC XD222's, but went with a black set this time. I'll switch outer rings with my other set of raw aluminum XD222's, add some scale bolts, and have two good looking sets of wheels. Once I test fit them to determine hub size, I'm planning on getting either another set of SSD brake rotor hubs of the correct size, or possibly some brake rotor weights (since there are no knuckle weights out there for this truck, at least not when using the Tamiya DF03 knuckles.)
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Old 05-05-2018, 03:27 AM   #14
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Default Re: Sawback time!

If you've happened across my Foff Wraith "build" thread, you likely could tell that I have rc/project ADD

Squirrel!

I bought 5 packs of SSD 2mm scale bolts and a new Wiha driver to finish up my wheels. I bought 4 beef patties and rattle can chromed them, then set them on a scotchbrite pad and gave them a good twist for some realistic wear, I know I don't have calipers, but I'm sure the rc God's can forgive me. The overall width with 600 hubs (without beef patties) was perfect, so I'm going to run 475 hubs to compensate for the thickness of the beef patties. I also bought a pair of RC4WD 1/8 scale Warn hubs, still need to order the Locked Up RC rear full float hubs, then my wheels will be done.

I took a deep breath yesterday and cut 1 frame rail in half with my portaband (left the other intact for now as a reference for square.) I have my 30mm extension mocked up using a magnet, but I'm going to make a jig out of a piece of angle to bolt/hold everything in place while I braze it, and make sure that both rails end up identical. I'm still thinking about tilting the ends of the frame rails down a little at the tips, essentially flattening out the drop at the belly some (instead of meeting the extension piece squarely, I could file the ends at a very slight angle where they'll meet) to cheat a little bit more height out of this thing, maybe 1/8"-1/4"?

Squirrel!
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Old 05-05-2018, 07:07 AM   #15
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Default Re: Sawback time!

Well, you're committed now!

Bout time for some pics....
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Old 06-04-2018, 07:14 PM   #16
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So I thought I'd try brazing the chassis using MAPP gas, no bueno. Works fine for the tiny stuff, but I just couldn't keep the heat up.

I went to my Dad's house to use his oxy/acetylene rig (which he just about never uses), and almost immediately ran out of oxygen. Took the cylinder to Praxair for an exchange and had to pay for a hydro test since the last one on my Dad's bottle was 38 years ago! Got the new bottle set up and watched the needle on the gauge climb even with the regulator backed all the way off, so now the regulator needs a rebuild. Got the kit ordered, but have yet to get it reassembled. Always something, right?

RPP sent me an email that the Bruiser shackles were back in stock, but I was still holding out for the Bruiser spring hangers to come back in stock too. Well I got that email, so I ordered up the shackles and spring hangers last night... and a Savox 2290 servo! The 2290 isn't going in here, but I will be using the JX 46kg servo, that the 2290 is replacing, in the Sawback. I had stripped the steel gears in the jx after just a couple weeks, but I plan to replace the gears with those from a Holmes HV500v1 as soon as they're back in stock, since Mr. Holmes sounds confident that they'll fit. I know it's overkill in the torque department, but I'm hoping it will be understressed and more reliable in the lighter (hopefully!), smaller tire'd, less abuse prone Sawback.

Picked up a second can of Tamiya PS1 white paint too, since there's no way one can would get full coverage of the giant Vaterra K5 body. I'd like to paint the chrome trim with a Molotow liquid chrome paint marker, but I'm concerned that it may have trouble adhering to the lexan? I really don't want to screw up this body, what says the peanut gallery?

I also came across a set of 3d metal emblems for this body that I think I need in my life, on rcmodelx.com. Added to my wish list.
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Old 08-26-2018, 02:49 AM   #17
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Default Re: Sawback time!

I finally did it. I finished the chassis. I made a really simple jig by drilling 2 holes in a piece of angle aluminum which I bolted the shock towers to, and used a magnet to hold the extension piece in line with the 2 cut halves of the frame. I gave up on the brazing idea, and just went for it with the MIG welder. To my surprise, I was able to get it done without any hiccups or blowing through! I used a flap/sanding disc to smooth out the welds on the outside, and a small cutoff wheel on the die grinder to clean up the inside. The jig insured that both frame halves were exactly the same when all was said and done.

I painted the belly section of the frame using more Krylon "chrome" , which is not even close to the original finish, but much less obvious than if I'd painted it black. It will all be hidden once the new boat-sided belly skid is made/installed. I then installed the Bruiser front spring hangers, which required drilling one extra hole in each frame rail, and then installed Bruiser shackles at the rear of the front springs with the closed side of the shackles towards the front, and the upper shackle pivot going straight through an existing hole in the frame. With Sawback hangers and Bruiser shackles in the rear, the rear suspension is 1/8" taller than the front. It would sit perfectly level using Bruiser/Bruiser hanger/shackle at the front, and Sawback/Sawback hanger/shackle at the rear.

I then finished tapering the leaf spring eyes, inserted my nitro fuel tubing spring bushings, and joined the axles/springs with the chassis/hangers. Now that it's sitting on its own weight/wheels, I set the Vaterra K5 body on top of it. The 30mm stretch put the wheelbase right where I wanted it, with the axles just a smidge closer to the ends of the body vs centered in the wheel wells, just like my 1:1. I'm pretty pleased with how all of that has turned out so far.

I guess the next order of business is to start on the boatsides/skid, making a template out of card stock before cutting it from 1/8" aluminum sheet. I'll play around with transmission placement, as I want it as far forward as possible, but I need to stay mindful of the front driveline angle. I may spin the trans 180 to get the front output a bit further back, and the 550 motor further forward. Then it'll be on to body mounts.

We'll see how long I stay motivated this time, but at least it's actually bolted together permanent-like now.
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Old 08-26-2018, 08:52 AM   #18
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Default Re: Sawback time!

Glad you finally shot those distracting squirrels and got moving forward, but SURELY some pictures are mandatory here!!
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Old 08-26-2018, 12:36 PM   #19
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Default Re: Sawback time!

Do I not only tell a story, but paint a beautiful picture as well?
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Old 08-26-2018, 01:48 PM   #20
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Quote:
Originally Posted by TheLetterJ View Post
Do I not only tell a story, but paint a beautiful picture as well?
No.

A picture is worth a thousand words, no?
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