Outcast Broken A-arm / Anything else I should upgrade?

[Sheed85]

Broke my Outcast 8s Arm doing a fantasticly failed back flip. Already ordered RPM full set front & rears. Anything else I should be considering upgrading while I have them out to be replaced?

This was my maiden voyage and I am in love with this 1/5 outcast. It handles amazing and takes a beating. Call me impressed Arrma, all 3 vehicles I have have all been super durable and only breakages I've experienced are driver error related (still a newbie ...haha), but in the end just Super fun. Thanks for your time Arrma nation!

Also how much travel should this Spur gear have on this shaft? It almost moves across the entire smaller (Pinion? Gear)

 

[SrC]

I am not allowed to comment. I don't own an 8s model.
But I do see many break the Arms with 8s rigs. I would always have spares on hand. It's an 8s thing???
Just replace with Stocker Arms, and keep rolling. You are still learning. Your driver skills will develope better. Quickly upgrading is just a band-aid approach to less than adequate driving.
Upgrading to RPM arms for example may not be the way to go. Being all too flexible. And the RPM arms don't have Droop Screw provisioning.
And don't bother with alloy upgrade arms.

Verify all the above with @djrahbee, he is the resident 8s expert. Many others here as well.

I have my own theories in regards to 8s models...... but at the risk of being flamed, take my small advice with a grain of salt.
Good luck.

 

[Sheed85]

I am not allowed to comment. I don't own an 8s model.
But I do see many break the Arms with 8s rigs. I would always have spares on hand. It's an 8s thing???
Just replace with Stocker Arms, and keep rolling. You are still learning. Your driver skills will develope better. Quickly upgrading is just a band-aid approach to less than adequate driving.
Upgrading to RPM arms for example may not be the way to go. Being all too flexible. And the RPM arms don't have Droop Screw provisioning.
And don't bother with alloy upgrade arms.

Verify all the above with @djrahbee, he is the resident 8s expert. Many others here as well.

I have my own theories in regards to 8s models...... but at the risk of being flamed, take my small advice with a grain of salt.
Good luck.

Thanks for your input and help hopefully someone can chime in regarding rpm arms before I put them on.

I can see exactly how the arm broke, slammed into the F chassis where it protrudes (only due to bad landing). I was shocked how many near perfect jumps were performed with both my typhon and outcast before this break. My confidence rose a little too quick. Haha (sorry I try to stay humble but I'm actually not that bad at driving scale or 1:1)

 

[SrC]

8s is a 30+ pound "Expert Level" beast. Way Less room for error when driving it. You are not the first to have broken arms very early on. Sometimes they can break with a perfect landing. Many have lowered the shocks oil to a lower CST/weight, (a thinner oil) I believe 30w.
You need @djrahbee , the resident expert, to confirm this. I am not the expert 8s guy.
Don't attempt to drive it and have it respond like a 6s rig at half its weight. It's just the physics of mass, weight and velocity, that gets you every time.
Sending it really high, any rig, always has its risks no matter what you do. Govern yourself accordingly.

 

[Ray87]

I have recently got a kraton 8s and so far haven't broken the arms, have jumped it many times now with bad landings etc, stock arms seems durable to me so far, but i broke the rear shock rod, would have this as spare or just go with the m2c rod in metal, they sell them without the shaft direct fit for stock.

Cheap easy upgrade, also running 35wt oil in the shock since i heard many use it to prevent damages, the stock 40wt seems a bit too much.

Then you want to fully pack the center diff with 20mill diff oil or maby go all the way and use silicone airplugs. This truck as new only have a light coat on the gears and front tire balloon so much and get too much power to the front. You want the center diff stiffer for wheelies and more air control

 

[Sheed85]

I have recently got a kraton 8s and so far haven't broken the arms, have jumped it many times now with bad landings etc, stock arms seems durable to me so far, but i broke the rear shock rod, would have this as spare or just go with the m2c rod in metal, they sell them without the shaft direct fit for stock.

Cheap easy upgrade, also running 35wt oil in the shock since i heard many use it to prevent damages, the stock 40wt seems a bit too much.

Then you want to fully pack the center diff with 20mill diff oil or maby go all the way and use silicone airplugs. This truck as new only have a light coat on the gears and front tire balloon so much and get too much power to the front. You want the center diff stiffer for wheelies and more air control

Was wondering about the diffs, think I'll take a peek inside. Would you check all 3 or just the center?

 

[SrC]

Might as well do all 3. Absolutely. Start with all 3 fresh diffs.

 

[Ray87]

Was wondering about the diffs, think I'll take a peek inside. Would you check all 3 or just the center?

As SRC said all 3, always good to check, i filled mine with 100k rear and front as the manual said, fill just above the pins in the middle front and rear, for the center just pack it as full as you can, i had to run mine and then open the center again to completly fill it full.

 

[Sheed85]

Are EXB arms and turnbuckle direct fit to the BLX?

 

[RCbuzz]

Are EXB arms and turnbuckle direct fit to the BLX?
View attachment 315202

They are, arms are the same, turnbuckles slightly beefier.

I have heard boiling the stock arms for 3minutes makes them slightly more flexible (I plan to try it).

I just run the stock arms, as @SrC mentioned the RPM arms have no droop adjustment. I hear they are durable though.

Side note, I always thought that the droop screws put too much pressure on the diff case but their function is useful.

And yes the side to side play in the spur gear is totally normal.

If you are looking to make the RTR shocks last longer you can see what we did here: https://www.arrmaforum.com/threads/shock-bend-kraton-8s.19642/post-758402

 

[PeighDay]

View attachment 315059
Also how much travel should this Spur gear have on this shaft? It almost moves across the entire smaller (Pinion? Gear)

Mine does the same exact thing. Haven’t had any issues with it.

I would ditch those motor mount screws though as they are notorious for stripping.

 

[Moirae]

I think you're better off with the stock arms personally. Don't rpm arms bend too much causing driveshafts to bend? I swear I read that on here somewhere. It might have been m2c website.

 

[Sheed85]

I think you're better off with the stock arms personally. Don't rpm arms bend too much causing driveshafts to bend? I swear I read that on here somewhere. It might have been m2c website.

Ended up getting a full set with tie rods off ebay brand new and returned the RPM, after looking at it closer I would fear exactly this! Thank you!

 

[Moirae]

Ended up getting a full set with tie rods off ebay brand new and returned the RPM, after looking at it closer I would fear exactly this! Thank you!

I still have a brand new pair sitting here for a year because I found out too late after I bought them with the truck.

 

[Sheed85]

I still have a brand new pair sitting here for a year because I found out too late after I bought them with the truck.

Now I know where to find a discounted set if I ever need a set.

 

[Dubbl-A]

Boiling the Arms is a good idea.
I was always cracking the front arms on my Senton 6s where the pillow balls went in. Boiled a fresh set of arms and it hasn't happened again!

 

[PeighDay]

Boiling the Arms is a good idea.
I was always cracking the front arms on my Senton 6s where the pillow balls went in. Boiled a fresh set of arms and it hasn't happened again!

How long do you let them boil for?

 

[SrC]

I still have a brand new pair sitting here for a year because I found out too late after I bought them with the truck.

Since you have the RPM's on the side already.... Just as an experiment I would try the RPM's when or if you break the stockers. Observe for yourself. Your mileage may vary?? IDK. With the Arrma 6s rigs, I find at the rear is where too much flexing becomes a problem. At the front, the upper and lower RPM's seem ok. But the RPMs tend to deform and stretch out after a while for "some of us".
RPM arms are pure Nylon, so they flex more before they will snap. But generally I prefer stiff arms.. RPM arms tend to work best with my smaller 1/10 scale RC's.
I cant see how boiling the Stock arms will do anything for flexibility. They are "composite" Plastic. Not Nylon. I tried that already.
The supposed WD40 trick also did not work for me. I think that is just a placebo. Some do it just because the next guy did. Just makes it shiny new looking and attracts dirt.

RPM says you can boil their pure nylon parts. Because they are nylon.
>>>Many years back, RPM nylon parts only came in "white", so many would dye them in boiling Clothes dye.. doing various colors. Or usually black. The white Nylon Parts always got dirty looking.
So it was a thing to color them. The boilng water thing came about because of this. The "nylon" parts became more flexible, as a side benefit when dyeing them. I learned this at the track, and from the various RC Mags. It was and still is a thing.
There was no Internet back when in the late 80's.