SCAX-MT Grave Digger Monster Truck Build

[johnfm3]

Originally Posted by Stricklinator

Very nice truck you have built! It looks great. I agree that you should switch to open gears in the axles for this application. What servos are you upgrading to?


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I have recently purchased my first Savox servo, a 1231SG, which has done quite nicely in my Wraith. 388 oz of torque at 5v, it seems to be doing well. So I am thinking 2 of those should turn my Clod Buster Tires quite nicely. I am tossed on the whole open axle thing. I do understand the reasoning for going open axle as that would relieve alot of the stress of having to turn those big tires, and if it was a street rig, I would not think twice about doing it, but I think I am going look at upgrading my steering servo first.

Originally Posted by TrailDawg362

Very cool! With the original Clod wheels, what adapters did you use and were there any clearance issues with the AR60 knuckles?

These adapters seem to be home made. There has been no interference with the AR60 knuckles. As shown above, I am looking at new wheels from RC4WD, and I will be getting new adapters which I will hope install easily.


To All:
The only I still need to do is come up with a clean way to install the body using the existing side post holes Right now the body is just resting on the RC, and I have another body I use when I pull it out. Since I am the only one of my friends who owns a RC monster truck, this rig mainly remains a shelf queen.

[mx.stud]

holy crap man truck is looking awesome!! glad to see it went to a home that used it well, even if the chassis is the only thing left lmao

Great build man!!

[johnfm3]

Originally Posted by mx.stud

holy crap man truck is looking awesome!! glad to see it went to a home that used it well, even if the chassis is the only thing left lmao

Great build man!!

Are you the one who I bought the AX-10 setup from?

[mx.stud]

Originally Posted by johnfm3

Are you the one who I bought the AX-10 setup from?

Yes that would be me lol

[johnfm3]

Originally Posted by mx.stud

Yes that would be me lol

Dude. I actually used more of that rig than it looks like. The ESC and Receiver. The Links, Shocks, and chassis plates. I dont recall if the AX10 had a Axial tranny or the RC4wd tranny. But I installed a Wraith tranny with hardend gears.

As of recently, I am purchasing a new rig (Bruiser) and going to use this chance to upgrade the ESC to a Tekin FX-R and a new receiver to bind to a multi model (10 I think) transmitter. Parts I am going purchasing hiding from my wife while I buy the parts for the Bruiser... lol

Your AX-10 made this model possible. All I had to do is add the Wraith Axles and SCX-10 chassis plates. I am glad your are pleased with how its turning out.

By no means is it finished. And like I said above, for the most part its a shelf queen as I dont have anyone who owns something like this to run with. But with that body, I dont want to run it much anyways. Need another one to bash with... :-D (And I am sure my wife wishes I meant rc body)

[johnfm3]

Ok, so I am bringing this thread out from the depth of the grave.

Since purchasing the house and things are finally settling down, I am able to look at this build again. I did end up building a Tamyia Brusier and as a result I did end up purchasing a second FX-R ESC and hand wound 40 turn motor which was forced into my wraith due to damages which also included a the purchase of a Savox 388oz @ 5v steering servo.

Which brings me to my current post.
This monster truck build is still running 2s lipo with a Axial 27T motor. And for the most part I am happy with the speed and performance. But Steering has always been a problem for me. And so I am posting to get some opinions on Steering Servo's. The history above on the wraith will be come relevant soon.

So this rig was setup with front and rear steer using a servo reverser for the rear both hooked up to the steering channel. Unsure if that will change. Looking at Hi-Tec servo's since I own the programmer and can get rid of the reverser and reduce the latency. The current F/R servo's are Hi Tec 645MG (106oz @5v). While moving forward or reverse and trying to steer, only the trailing tires will turn. The servo connected to the leading tires can not move them. I have read that many people recommend the Hi Tec 7955TG with its 250os at 5v as a contender. What I am concerned about is that I have seen my 388 oz Savox at 5v have a problem with my Wraith 2.2 tires. And I am really wandering if a 1/5 scale servo such as something 500 oz is really required to move these big tires? Keep in mind that my axles are locked as stock wraith axles are. The other thing is, with this setup should I really consider a 3s lipo batter and a BEC setup for 6v?

Ideally, I would like to get rid of the servo reverser. And I can program one of the hi tec servo's to go counter clockwise so that my rig can turn correctly with little to not latency. Dual steering will come later. But will the 7955TG really turn those big tires with locked axles, or should I consider bigger such as a 500 oz Savox.

Thoughts?
John

[ussprinceton2004]

I have 2 HiTec 7955TG servos on my BigFoot 1 monster truck

[johnfm3]

Originally Posted by ussprinceton2004

I have 2 HiTec 7955TG servos on my BigFoot 1 monster truck

Ok, that is a nice MT. Are those tires as large as the ClodBusters? What about your axles? Are they locked up?

It looks like that thing moves around nicely. Most of the video was it on the pavement. Does it do as well dry steering on grass?

I have confirmed that the 7955TG's are programmable. So that's one bonus for them.

Thanks,
John

[johnfm3]

Originally Posted by ussprinceton2004

I have 2 HiTec 7955TG servos on my BigFoot 1 monster truck

After thought
Are you running 2s or 3s? What voltage do you have going to the servo's?

John

[johnfm3]

So the appeal of being able to program the Hi Tec 7955 so I can remove the reverser is a major consideration for purchasing those.

I have ran the SA-1231sg on my wraith and with 440oz at 6v, its been suggested that those should break steering linkage with out a thought. And these large tires should not be a problem.
Savox SA1231SG Digital Servo

The concern I have is my desire to get rid of the servo reverser. Currently I am running a Traxas 2ch radio, though that will be changed to my new 20 model Tatic TTX 650 air craft Tx. I need to look into mixing and see if its possible to do so I can rear steer with a separate channel.

John

[ussprinceton2004]

Originally Posted by johnfm3

Ok, that is a nice MT. Are those tires as large as the ClodBusters? What about your axles? Are they locked up?

It looks like that thing moves around nicely. Most of the video was it on the pavement. Does it do as well dry steering on grass?

I have confirmed that the 7955TG's are programmable. So that's one bonus for them.

Thanks,
John

Originally Posted by johnfm3

After thought
Are you running 2s or 3s? What voltage do you have going to the servo's?

John

Originally Posted by johnfm3

So the appeal of being able to program the Hi Tec 7955 so I can remove the reverser is a major consideration for purchasing those.

I have ran the SA-1231sg on my wraith and with 440oz at 6v, its been suggested that those should break steering linkage with out a thought. And these large tires should not be a problem.
Savox SA1231SG Digital Servo

The concern I have is my desire to get rid of the servo reverser. Currently I am running a Traxas 2ch radio, though that will be changed to my new 20 model Tatic TTX 650 air craft Tx. I need to look into mixing and see if its possible to do so I can rear steer with a separate channel.

John

Those are the Wheely King tires. not as big as the ClodBuster, but pretty big. My axles are locked. I was using 2S in that video. I have a Futaba 4PLS as my transmitter.

[johnfm3]

Originally Posted by ussprinceton2004

Those are the Wheely King tires. not as big as the ClodBuster, but pretty big. My axles are locked. I was using 2S in that video. I have a Futaba 4PLS as my transmitter.

Many thanks for the response. I think what I will be going with is the HiTec, and if I end up having to pull those for the savox, they can go to my other rigs such as my 1.9 SCX-10.

[johnfm3]

Choices Choices,
I was getting ready to buy my Servo's this weekend when RC4wd sent me a email notifying me of the availability of the Aluminum Universal Monster Truck Beadlock wheels. Need less to say, I didn't buy servo's. And I pushed my budget to the edge to get these wheels (and needed hub adapters) now instead of waiting till the weekend.

Here is a image from the rc4wd web site.


I will get another image posted when I get them installed on my rig.

John

[johnfm3]

Some new updates.
The Truck is in the shop getting some finishing work done. I decided to ask the shop to help with the mounting of the body.

Meanwhile, my rc4wd clod wheels are being delivered today. For tires, after much looking around I decided on the Pro-Line Destroyer tires. If anyone has any suggestions for NEW original clod tires, I would be stoked. I am must be looking for the wrong thing.



In any case, hopefully in the next few weeks I will have this thing back on the road.

Thanks
John

[johnfm3]

OMG... These things are huge.

Did you ever buy something, and then when you got it really wander if it was the right purchase... lol

Yeah, I think my Monster truck is going to break.

Packaging shows 7 pounds of weight.





I am not so certain my plastic axial wraith axles will hold up. Further more I believe I am going to have to step up the steering servo's to over 400 oz.

Thoughts?

John

[johnfm3]

Here they are...
I got the tires mounted on the wheels. I am pretty stoked. Still worried about weight and needed upgrades. But I will just ride that out and replace as I go along.



I am so stoked :-)

[johnfm3]

So an update on the truck, as it appears I had not stated this above...

The truck itself is at a RC shop getting some work done. I am too nervous to touch that body, and I have given 1 guy permission to get that body supported on the chassis. I trust his work. We will be using the existing side holes for mounting. But the body will require some trimming in the rear to clear the chassis. The other added benefit is, the chassis will retain the stock vertical body mounting post as well so when I take the show body off, I can have a basher body which can be top mounted.

Need to work with the shop to come up with a creative (stock looking) electronics box.

And the final thing I need to look at is suspension. I may want to re work the suspension some. First I will try some new Wraith Shocks and see how it sits. Then may need to move to some custom bent links.

More things to come.

[350TacoZilla]

those wheels and tires look good together, though I do believe you will be going through a set of plastic knuckles on the axles lol.

[johnfm3]

Originally Posted by 350TacoZilla

those wheels and tires look good together, though I do believe you will be going through a set of plastic knuckles on the axles lol.

Yeah, I suspect that as well. Currently looking at burly tube or beef tubes as metal inserts to the plastic axle housings. And then purchasing aluminum C-Hubs and Knuckles.

In doing all this, I will probably clock the pinion up by one tooth on the c hub.

For now, I will be running it as is and note how long it last. Then updating this thread for reference.

John

[johnfm3]

Ok, so I am running 2 Savox SA-1230SG servo's for my front and rear steering (of course 1 each axle)...
Weight(g): 79.0
Speed(@4.8V sec/60): .20
Torque(@4.8V oz-in): 416.6
Speed(@6.0V sec/60): .16
Torque(@6.0V oz-in): 500.0
Gear: Unique Steel
Bearing: 2BB
Case: Full Aluminum

I am running them at the default 5v setting of my 10A CC BEC.

I am still dealing with lack of steering. Only the trailing axle steers correctly.

Its been suggested that I consider running a 20A BEC at 6V. I don't know how much current these servo's use at 6V, and I am not sure if a 10A BEC will be enough to handle 2 servo's, the receiver, and possible LED Head/Tail lights.

Any Ideas?

John