BumpyRoad's Twin Hammer build

[BumpyRoad]

Hi guys,
how's things? I am a RC fanatic based in Australia and I'been looking at this forum for a while now and getting inspired by so many awesome TH builds.
So I decided to get a kit and build my own and the idea is to build a Twin Hammers for speed. The buggy will have as low a COG as I can get and the front diff will be quite loose.
Originally I was looking at the GCM front end setup with the battery at the front, but then reading that the bell-crank steering kit from Sr.Irie, wasn't really available I ended up looking into the Scorched parts 3D printed components and I must say that from a build point of view I am very happy with them.
I also decided to install the dual rear-shocks so I tried to order the shock mounts from BlueMonkeyRC, but without success. So for the moment the TH has a single set of shocks at the rear. Looking into the BoomRacing shock hoop extenders as an option now. But if anyone has a better idea, please let me know.

I also got the upper rear links and trailing arms from Vanquish (again to replace the BMRC parts that I was really after)

For the electronics I went with the Castle Mamba X and the Castle Slate sensored 3800kV. The servo is a XPert 6601 (a bit less torque than the 7701, but a bit faster).

For the moment I'll use velcro straps for the battery: light and cheap option. Let's see how that holds up on the jumps.

After I am happy with the build and electronics setup I'll then work at making it look a lot more scale. But it needs to run well first.

Hope you like where it is at so far.

 

[smog]

Fun setup. Sensored, quick and balanced.

 

[Yeti.stealth]

I like the look of the scorched parts stuff!

 

[BumpyRoad]

Hi SMOG, yes: it should be fast and fun. And at the moment I geared it very high because I only have a 33 pinion gear handy...

Yeti.stealth: I ageee: the Scorched Parts components do look very good and feel very strong. I am keen to test them on a few run to see how they actually perform.

 

[nedmo]

Nice mate. What tricks did you do to get the king's rod ends to fit in the vanquish arms. I had to swap mine for some plastic ones

Sent from my Pixel using Tapatalk

 

[BumpyRoad]

Hi Nedmo!

Which plastic ball ends did you use?

I had to file the sides of the bottom ball end (the blue part) until it eventually fitted. And only on the rear-most hole. PITA if you ask me. I spent some time online and found that these, from the Short Course Truck shocks should fit, but obviously they are out of stock:

King Off-Road Short Course Racing Shocks Replacement Bottom Ball End

Then I used 3mm spacers made from slices of worn out Axial SCX-10 link ends that I had kept (never throw away anything ) to raise up the aluminium spring holder discs so they don't rub on the Vanquish arm.

The trick of the 3mm spacers helped solve another problem: since I use the rear anti-squat truss, the upper links used to bump into the ESC/Receiver holder when the rear shocks are fully compressed. But the 3mm spacers limit the run of the shocks and prevent the bumping.

 

[BumpyRoad]

This weekend I made quite a bit of progress: I painted the body panels and put together the cage. Here are a couple of quick shots of the roller with borrowed wheels. I have tried a few different type of wheels and I am now set on Pitbull Rock-Beasts with CI Deuce's wild single stage closed cell foams. I'll take some photos of this combo when I get to mount them on.
By the way the spare will go and is there now just for show. I'll probably cut the rearmost part of the cage as well and shorten it.

Apologies for the bad quality of the photos. I'll try a different camera next time.

 

[Yeti.stealth]

The Scorched parts front end is looking great, good to know it all fits under the body too. That things gunna fly!

 

[BumpyRoad]

Yeti.Stealth: it does fit. Although the room in the pan and generally around the buggy is super tight.

Here are some pictures with he electronics installed: you really have to get creative with wire routing.

 

[Dbx]

That is looking super cool. Makes mine look a bit tatty!

 

[BumpyRoad]

Thanks DBX,
It’s quite far from finished yet: I need to figure out how to fit the extra rear shocks and then test and tune it.
The parts you designed fit perfectly and feel very strong, very happy with them!

 

[BumpyRoad]

Hi guys, what’s up?
I completed the body of the TH and installed some broken-in (aka used ) Rock Beasts. Here’s what it looks like. Ready for a test drive.

 

[BumpyRoad]

Got to install the double shocks today. Originally I wanted to use the BMRC upper shock mounting system, which I bought but never got delivered :-( Theb I bought the boomracing Shock Hoop extension, which kinda fitted, but required cutting to fit under the cage and drilling to place the shocks where I wanted them.
In the end I just discovered that by drilling a hole in the shock tower I could nicely fit both shocks exactly how I wanted them.

Now I just need to find the time to go drive this buggy.

 

[rs10man]

sweet build, just got one recently myself, needing a power upgrade though

 

[BumpyRoad]

Hi all!
Some photos from the first real run of the TH.
The 3800kv motor is very fast even on 2S Lipos. I can’t imagine it being very controllable on 3S. Fun car to drive on dirt as the limited side grip reduces the chance of rolling it at speed. On more grippy surfaces it has still some tendency to roll.
The rock beasts 1.9 on CI Deuces Wild work really well with the Twin Hammers. Large enough, but not too much and the closed cell foams give the wheels enough rigidity at speed.
Still have some way to go to get it where I want it to be but getting there.
Cheers

 

[GR8 PMKN]

What weight oil, springs and piston size did you use front and back? I am building one now with the same front scorched parts front end. Need to order the rest.

 

[mgputer]

That's quite the setup. I'm on my 3rd twin hammers now. They are quite fun. I like the colors and shock set up you have. With the motor you have in there she must be fast.

Sent from my ZTE A2017U using Tapatalk

 

[BumpyRoad]

Hi guys,

@GR8 PMKN: I use Team Associated 32.5 oil both front and back and the default pistons in each shock.
I removed the internal spring in the rear twin shock. The King Shocks are a pain to bleed. It took me a few attempts to do that properly without springiness.
The springs are the default one for the 110mm at the rear (a bit too soft for speed) and the black ones at the front. I bought the spring set for the 80mm King shocks - if you do, pay attention at the compatibility as there are two versions (mine is the one with part no. Z-D0035) and buy the spring set for exactly that model.
Oh: the model of the 110mm shocks is Z-D0030.

@mgputer: Thanks! Yes, it is plenty fast and fun. Next frontier is the track. I want to see how close I can get it to some of the SC trucks and Truggies that race there. :ror:

 

[Barndog Racing]

Great looking build Bumpy!

 

[BumpyRoad]

@BarndogRacing Thanks a lot for the nice comment!