K_Willis' PTI Goliath Rock Crawler Build-up

[K_Willis]

OK so my TLT needed a playmate. And while another TLT was tempting, I decided to go with something different. Enter, the PTI Goliath. After a few months of patiently waiting for them to come into stock, I had one on the way.

Building Materials List
PTI Goliath Rock crawler kit
Mamba 25 speed control with castle Link for setup
Eflite park 400 outrunner 920Kv
Futaba S3305 Servo

[john alardin]

It's good to see diff. rigs out there. I'm feeling the brushless system. If you need any brushless stuff, talk to Johnrobholmes, he really knows his stuff. What else were you planning on doing to it? I heard the axles weren't all that great, but that the tranny is better for crawling than the one on the TLT. Keep us updated. As far as the diff, it is the same as the TC3, so a spool for a TC3 can be used on the Goliath.

[K_Willis]

Building the axles went fairly smoothly. Anyone who has built a set of PTI axles probably knows that the way the cantilever links attach to the axle is a little hookey, but other than that I was rather impressed at how they went together. I had heard that there was a lot of slop in the way the diffs sat in the axles, and most people were required to shim up the ring gear to keep it from stripping. I had also heard that PTI had tightened the tolerances on their molds to improve this and this seems to be the case. My diffs had no side to side play whatsoever and meshed very well with the pinion gear.

The transmission, and I use this term loosely, is little more than a spur gear that meshes directly with the pinion on the motor. Advantage, light weight. Disadvantage, not enough reduction. The truck comes stock with an 84 tooth spur and a 12 tooth pinion netting a 7:1 reduction. A pede tranny, with the same gear set, nets a 19.04:1 reduction. Me thinks we will be lacking some torque.

The chassis itself is very simple, very lightweight and well designed. Just a couple of horizontal rails that mount to the transmisson with mounting plates for the battery, and electronics.

[Nlee111]

Originally Posted by K_Willis

OK so my TLT needed a playmate. And while another TLT was tempting, I decided to go with something different. Enter, the PTI Goliath. After a few months of patiently waiting for them to come into stock, I had one on the way.

Building Materials List
PTI Goliath Rock crawler kit
Mamba 25 speed control with castle Link for setup
Eflite park 400 outrunner 920Kv

Nice! Let me know how she builds! I dig those things. Mine is almost done

[K_Willis]

Originally Posted by john alardin

What else were you planning on doing to it? I heard the axles weren't all that great, but that the tranny is better for crawling than the one on the TLT. Keep us updated. As far as the diff, it is the same as the TC3, so a spool for a TC3 can be used on the Goliath.

The Goliath Rock Crawler kit actually comes with the steel spools right out of the box, a nice improvement over the ball diffs from the MMT.

Plan to run it stock for awhile just to see how it performs... Then go from there. After just a short weekend of crawling, I would say with very little tweaking you could have a comp worthy rig.

[K_Willis]

Originally Posted by Nlee111

Nice! Let me know how she builds! I dig those things. Mine is almost done

Hehe... I couldn't resist... I picked mine up from the post office after work, brought it home and sat down and built... Didn't look at the clock till I was finished... 2am oooops...

[john alardin]

Hmm, sounds good 2 me. I might look into getting one later on. I like the tranny. It doesn't have all that belt-slip business like the TLT.

[Nlee111]

Originally Posted by K_Willis

Hehe... I couldn't resist... I picked mine up from the post office after work, brought it home and sat down and built... Didn't look at the clock till I was finished... 2am oooops...

You can see fresh pic and vid of mine, video is 2.2 non comp just for fun, in chit chat, and I just posted pics in newbie section under holw long is to long

[K_Willis]

With the chassis, tranny, and axles built, all there was left to do was attach the cantis and shocks, and the body mounts.

I have to give PTI two thumbs up for including such a sweet set of shocks with the kit. They are very nice, threaded all aluminum units that look quite the business. These shocks would be worth at least $40 if you had to buy them seperately, add to that the Imex Red rocks at $40 a set, and you have to wonder how much money PTI makes on this kit.

[Skeeno]

One thing to help the diffs is to run screws all the way through the axle next to the pinion and secure on the other side with a locknut. This will help keep the halves from separating which leads to skipping and stripping teeth.

You can also use a ziptie or hoseclamp around the axle where the cantis are mounted. This will keep the halves together at that spot.

I had to grind longer slots in my spools to limit binding at full steering lock.

[Nlee111]

Originally Posted by K_Willis

With the chassis, tranny, and axles built, all there was left to do was attach the cantis and shocks, and the body mounts.

I have to give PTI two thumbs up for including such a sweet set of shocks with the kit. They are very nice, threaded all aluminum units that look quite the business. These shocks would be worth at least $40 if you had to buy them seperately, add to that the Imex Red rocks at $40 a set, and you have to wonder how much money PTI makes on this kit.

Looks good man. Let me knoe how that outrunner does, I had to use a gd-600

[K_Willis]

With the stock links and dog bones as long as I could make them, and the cantis as short as I could make them, I was able to end up with a wheelbase just under 11". I'll probably extend this out at some point, but since there are no competitions around me, I'm fine with the shorter wheelbase, it gives me a tighter turning radius anyway.

Initial test runs with the park 400 and the red rocks tell me I am way overgeared so I have placed an order for an airplane reduction box, with a 2.9 to one reduction to open up some gearing options. Things were a little bit better with 2.2 moabs, but the little outrunner was still having issues starting up in any sort of a bind. So just to get a few test runs on the truck, I decided to pull out my stock TLT tires which seemed to be a pretty good match for the stock gearing.

And of coarse here we see the mandatory articulation shot.

[K_Willis]

A shot out on the trail with my TLT.

[K_Willis]

Originally Posted by Skeeno

One thing to help the diffs is to run screws all the way through the axle next to the pinion and secure on the other side with a locknut. This will help keep the halves from separating which leads to skipping and stripping teeth.

You can also use a ziptie or hoseclamp around the axle where the cantis are mounted. This will keep the halves together at that spot.

I had to grind longer slots in my spools to limit binding at full steering lock.

I sometimes hang around one18th, so I had seen that mod. Just need to track down some longer screws. Already did the zip ties around the axles.

I think it was in one of your posts that I had read that you thought PTI had revised their molds for the axle cases. Mine definately seem like a tight fit. My ring and pinion were actually meshed a little too tightly on my initial run, but it seems to be running a lot more smoothly now.

You started with a MMT, and added TC3 spools later correct? I haven't noticed the dogbones binding at full lock, but I will definately keep an eye on it, perhaps the Rock Crawler kit spools don't have this issue?

Originally Posted by Nlee

Looks good man. Let me knoe how that outrunner does, I had to use a gd-600.

I am definately going to need some more reduction. It's just too quick as it is, and the park 400 is only 2 ounces and lacking a little in the power department. I managed to track down an airplane reduction box, that doesn't have the nub on the front of it like the GD-600 and it appears also has a 3.2mm output shaft. So it may be a drop in replacement, with no machining required. I'll post up some pics when it gets here.

I also have my eye on another possibility for an outrunner. 28mm stator, 3.2 mm shaft and 25 mm bolt spacing. Keeping this one a secret for now, I want to be the first one using one in a crawler . Just wish I had seen it before I ordered the park 400. :-(

[Nlee111]

Originally Posted by K_Willis

I sometimes hang around one18th, so I had seen that mod. Just need to track down some longer screws. Already did the zip ties around the axles.

I think it was in one of your posts that I had read that you thought PTI had revised their molds for the axle cases. Mine definately seem like a tight fit. My ring and pinion were actually meshed a little too tightly on my initial run, but it seems to be running a lot more smoothly now.

You started with a MMT, and added TC3 spools later correct? I haven't noticed the dogbones binding at full lock, but I will definately keep an eye on it, perhaps the Rock Crawler kit spools don't have this issue?






I am definately going to need some more reduction. It's just too quick as it is, and the park 400 is only 2 ounces and lacking a little in the power department. I managed to track down an airplane reduction box, that doesn't have the nub on the front of it like the GD-600 and it appears also has a 3.2mm output shaft. So it may be a drop in replacement, with no machining required. I'll post up some pics when it gets here.

I also have my eye on another possibility for an outrunner. 28mm stator, 3.2 mm shaft and 25 mm bolt spacing. Keeping this one a secret for now, I want to be the first one using one in a crawler . Just wish I had seen it before I ordered the park 400. :-(

Rock on! umm, your secret just got out at any rate good build man. my links are just at 12.75in so Im a bit too long, and it causes some problems at that size anyway. I might try bent lower links, and drop her a quarter inch.

[K_Willis]

Originally Posted by Nlee111

Rock on! umm, your secret just got out at any rate good build man. my links are just at 12.75in so Im a bit too long, and it causes some problems at that size anyway. I might try bent lower links, and drop her a quarter inch.

I'll have to go over and take a look at your build. Not using the stock links I take it? I love this little truck. I have been tweaking my TLT for nearly 2 years, and it's quite a shock to see that this truck performs nearly as well straight out of the box. With a 6 cell 2/3a pack 2.2 moabs and the stock "Fodge" body, the truck weights under 3 pounds read to run, while my TLT is well over 5. Once all the snow melts off the rocks here, I'm betting she'll climb like a goat.

[Nlee111]

Originally Posted by K_Willis

I'll have to go over and take a look at your build. Not using the stock links I take it? I love this little truck. I have been tweaking my TLT for nearly 2 years, and it's quite a shock to see that this truck performs nearly as well straight out of the box. With a 6 cell 2/3a pack 2.2 moabs and the stock "Fodge" body, the truck weights under 3 pounds read to run, while my TLT is well over 5. Once all the snow melts off the rocks here, I'm betting she'll climb like a goat.

Most of my build is on 18th, but I made all my progress over here, the best pics are near the end of members rides, and the new ones in how long is too long, just added links few days ago., Im running a Novak crawler and esc, moab's, MSD 2.2 beadlocks, revo canti's, a spektrum ar6000 reciever, and of coruse the gd-600

[K_B]

These trucks are inherently light. Mine also weighed in at 3 lbs. ready to run. You may wanna add some weight in the tires. I found that at 3 lbs, the truck just ain't quite putting enough pressure on the tires.

Here's a dumb question. What lube are you using on your diff gears?

[K_Willis]

Originally Posted by K_B

These trucks are inherently light. Mine also weighed in at 3 lbs. ready to run. You may wanna add some weight in the tires. I found that at 3 lbs, the truck just ain't quite putting enough pressure on the tires.

Here's a dumb question. What lube are you using on your diff gears?

I have thought about running weight in my tires, (I don't run any in my TLT either), but out where I am there are no comps, so I'm not really super concerned with getting that extra little bit of performance.

My main concern is parts breakage. Out in the middle of nowhere it takes forever for parts to come in, so I prefer to run my rigs as lights as possible. My TLT is nearly 2 years old, and I am still on the original ring & pinion, diff shafts, axle casings and knuckles. *knocks on wood* My rig has taken some pretty big tumbles, and I still haven't broken anything. I attribute this to not having all that extra weight way out on the axle ends.

I use bearing grease for boat trailers in all my rigs axles. The stuff is made to be dunked in the water and protect your wheel bearings, so it seemed like a good idea for this application to. I pack as much as I possibly can into the diff case, it definately adds a little extra drag to my axles, but I think it's worth it for the protection I get considering my trucks see so much water. Yes it's kinda a mess if you have to pull your axles apart to work on them, but I'm used to working on my 1:1, so it seems pretty minor to me.