Kraton Full. Send. - an EXB Build Thread

[ABabyEater]

Just use a sharp blade or pick and pull them off. They are pressed in.

Pretty much this. I used a dental pick with a 90° bend in the end. Be careful with the seals, as they are often super thin sheet metal with a rubber coating. Work the tip into the bearing around the edge of the seal, unseating it from the bearing applying slight pressure away from the bearing, and gently slide it around the edge until it pops loose. To reinsert it, line it up and just press. My thumb fits over almost all the bearings (except the inner hub bearings), and I have found just squeezing will usually push the seal back in pretty evenly.

 

[L3phturn]

Just use a sharp blade or pick and pull them off. They are pressed in.

I was concerned that messing with them would end up attracting more dirt - but I suppose with the shields pressed back in it's not a problem. What bearings come stock with the EXB? Should I take those apart and grease them before I run, or just run it until I need to replace them and then go through this step?

I noticed the upgraded 3S lineup is coming with rubber sealed bearings. Probably not ceramic, but I don't think I would go ceramic unless racing. For bashing shouldn't a well greased and sealed steel bearing be enough? Do the ceramic bearings last longer or just roll a little easier?

Well I don't have to wait for parts like the diff rebuild I need to do for my EXB. It's in the box still but I plan to rebuild/shim/fluid the diffs before I run it. I guess I might as well clean and grease the bearings too. Taking the time to check this whole kit over and and do preventative work before it every runs I suspect will pay dividends down the road.

 

[Adawg]

Ok thanks. I tired using a small screwdriver but I think I need a pick so I don’t damage it. I’ll try on a old one. Pretty disappointed the new better exb bearings lasted shorter then anything I’ve experienced bearing wise

 

[ABabyEater]

I was concerned that messing with them would end up attracting more dirt - but I suppose with the shields pressed back in it's not a problem. What bearings come stock with the EXB? Should I take those apart and grease them before I run, or just run it until I need to replace them and then go through this step?

They do come with rubber shielded bearings. Likely steel. With it being a roller, not a RTR car, I would likely still pop the seals and check to make sure they are greased even with the stock bearings. I have not yet checked the steering posts to see if they are still running brass bushings, but if they are, even if you choose to not upgrade the bearing anywhere else, I would get some for there.

I noticed the upgraded 3S lineup is coming with rubber sealed bearings. Probably not ceramic, but I don't think I would go ceramic unless racing. For bashing shouldn't a well greased and sealed steel bearing be enough? Do the ceramic bearings last longer or just roll a little easier?

There are a couple types of ceramic bearings, the most common of which have ceramic coated balls, cages, raceways, or any combination of the three. These are usually in the $70-$80 range for a set. True fully ceramic bearings are upwards of $100 each!

Steel bearings are good for the average basher, and imo sealed steels are plenty good for 6S, but ceramic do offer some benefits. For one, they are waaaay smoother. Rubber seals will always drag more than unsealed bearings, but they do this to, well, seal the bearing from dirt and debris. Even with seals, ceramic bearings are noticeably smoother than steels. This means less power loss, less strain on the motor, less heat, and less wear. The impact vs cost value is up to the individual, but for me personally, I am already going full potato, might as well go with ceramic.

I will say that typically, even sealed steel bearings are seen as disposable, whereas a set of ceramics is pretty expensive, and when they start to get gritty or crunchy, I will likely clean them out and re-lube them instead of throwing them out.

 

[jondilly1974]

I run rubber sealed bearings for months and then toss them. They are $25 a set and are consumables imo. Part of the hobby. I didn’t do anything to my stock EXB bearings but will inspect them on my first tear down and evaluate them then. If they look good still, I will clean and grease them and keep running them. If I see any signs of rust, they go in the trash. If they gave grit inside, they go in the trash.

 

[SrC]

I was concerned that messing with them would end up attracting more dirt - but I suppose with the shields pressed back in it's not a problem. What bearings come stock with the EXB? Should I take those apart and grease them before I run, or just run it until I need to replace them and then go through this step?

I noticed the upgraded 3S lineup is coming with rubber sealed bearings. Probably not ceramic, but I don't think I would go ceramic unless racing. For bashing shouldn't a well greased and sealed steel bearing be enough? Do the ceramic bearings last longer or just roll a little easier?

Well I don't have to wait for parts like the diff rebuild I need to do for my EXB. It's in the box still but I plan to rebuild/shim/fluid the diffs before I run it. I guess I might as well clean and grease the bearings too. Taking the time to check this whole kit over and and do preventative work before it every runs I suspect will pay dividends down the road.

EXB bearings are Sealed Rubber Coated metal (removable). The stock RTR bearings are permanently Pressed in Metal Shielded (not removable) hence not rebuildable.

 

[ABabyEater]

Agreed. Steels are disposable. I would still check them before running for the first time, but then again, even if I was putting fully stock 6S electronics in the EXB, I would still do a full teardown and inspection before driving. Remember people, this is not an RTR car.

 

[SrC]

A fresh Exacto blade for seal removal. Watch your fingers!! If the seals get bent. Flatten them out as best you can before re-installing, or the bearing cage will rub the seal. No good.
Only fill the bearing with approx. 1/3 grease. If overfilled, the seals will pop off and the cage will let go and all the balls fall out while bashing.
Also, I don't advise mixing the OE grease with another. Not all greases work well together and the mix will break down. So cleaning a new bearing of OE grease is primary first. You cant be lazy about this. Or just leave the OE grease in there if there is even any at all.
I have received so many bearings that were dry with NO lube. I inspect all my bearings. It doesn't matter the brand. I always find dry or barely lubed bearings. Without inspecting them and addressing that, the bearing will probably be the first to fail much sooner than later. You will chalk it up to a bad crash or whatever that bricked the bearing when in reality it was dry from manufacturing.
These are very cheap bearings in the big scope of things and little QC is evident, no matter the brand! ?‍

Edit: I use the RPM's Bearing Blaster for Cleaning my bearings. They make a large and small one. I couldn't be without it. Its been around for like 25 years. Most don't know about this. Thought I would mention it. Its so inexpensive. A must have if you maintain your bearings. But many just replace bearings and don't go the extra step. I get it.
BTW, never spin your bearings when dry after they are cleaned! The BB gall very easily when dry!

 

[ABabyEater]

Not all greases work well together and the mix will break down.

A very true point I knew, but didn't think about. At the very least, I will report back on how well behaved the Phil's grease is. Luckily ceramics are often recoverable since the ceramic polishes the races instead of straight breaking them down and cracking them like steel. At that point I'll try out the 1up oil.

 

[SrC]

A very true point I knew, but didn't think about. At the very least, I will report back on how well behaved the Phil's grease is. Luckily ceramics are often recoverable since the ceramic polishes the races instead of straight breaking them down and cracking them like steel. At that point I'll try out the 1up oil.

I use Phils grease on my Bicycles...my other Hobby. Are you into cycling also?? Phils is a known good bike lube also. But I find it expensive as a designer lube.
Been using Super Lube with my RC gear. Its way more cost effective. But Phils is great also.

Edit: if using Hybrid Ceramic bearings, its a sin to use any grease. Oil is the way to go. Grease negates the attributes of a HS Ceramic bearing

 

[ABabyEater]

I use Phils grease on my Bicycles...my other Hobby. Are you into cycling also?? Phils is a known good bike lube also. But I find it expensive as a designer lube.
Been using Super Lube with my RC gear. Its way more cost effective. But Phils is great also.

I don't. @Pat_ranch and I work together on all this stuff, and we found it buried in his garage from his cycling days. We were both surprised to see how well regarded it is even today considering how old it is.

If I was on the other side of the local pass, I would be doing much more of this in my dad's shop where we have rebuilt several real people sized cars together, and would be using much more appropriate lubes, adhesives, etc.

 

[SrC]

Super Lube oil and grease work fine with each other, I've experimented with 1/3 SL grease and A drop of SL oil. With great results FWIW. (Steel BB)

 

[Adawg]

The exb still has brass bushings for steering FYI. The regular Jim’s rubber sealed bearing set is 18 the stainless is 31 and the ceramic hybrid is 80. I’m trying the stainless this time and we’ll see how it is.

 

[ABabyEater]

Super Lube oil and grease work fine with each other, I've experimented with 1/3 SL grease and A drop of SL oil. With great results FWIW. (Steel BB)

Good to know! I will likely be discussing much of what is being done on this build with my dad, as he is a literal rocket scientist and used to build 2 stroke race motorcycles. He likely has some good insight on much of the mechanisms and workings of many different parts of the car, from bearings and lubricants, to toe and camber angle, and beyond.

 

[SrC]

Stainless is not generally as smooth and fast as standard smoother Chromium. Stainless is used for running in water. Chromium will rust in water immediately. And they become bricked super fast no matter what. I find stainless no more or less durable than Chromium under load. Stainless is even softer metal! Just that SS BBs will not rust in water. They still need to be maintained the same as all BB's. Maybe more so with SS since wear is much faster. My thoughts.

The exb still has brass bushings for steering FYI. The regular Jim’s rubber sealed bearing set is 18 the stainless is 31 and the ceramic hybrid is 80. I’m trying the stainless this time and we’ll see how it is.

Brass bushings at the ST Bell crank....still to this day. I just don't get it????? In an EXB?? They didn't listen well enough?? ?‍ Arrma/HH trying to save 3 Nickels??? That reminds me of Tamiya Crap. Did Arrma think brass oilite bushings would go unnoticed? ?‍

 

[L3phturn]

The exb still has brass bushings for steering FYI. The regular Jim’s rubber sealed bearing set is 18 the stainless is 31 and the ceramic hybrid is 80. I’m trying the stainless this time and we’ll see how it is.

Does the bearing kit include bearings to replace the steering bushings or do I need to get those separately?

 

[ABabyEater]

Does the bearing kit include bearings to replace the steering bushings or do I need to get those separately?

The Fast Eddy's kit does. I am not sure about other manufacturers. In my last post with pics I point out which bearings go where

 

[SrC]

A very true point I knew, but didn't think about. At the very least, I will report back on how well behaved the Phil's grease is. Luckily ceramics are often recoverable since the ceramic polishes the races instead of straight breaking them down and cracking them like steel. At that point I'll try out the 1up oil.

Hybrid ceramics have ceramic balls and chromium steel races. The ceramic Balls are harder than the the steel races and actually wear the races down. So they are not truly maintenance free like a Full ceramic bearing is by comparison. Full ceramics are 100% ceramic Balls and Races and are not cost effective for RC use. You wont find them. But I just thought I would mention that about Hybrid ceramic Bearings. I don't use them much in RC. (except my TA vintage Pan Car)But my custom bicycles builds have Hybrid ceramics. One of my derailleurs jockey wheels uses the $full ceramics$. Overkill IMHO. But Full ceramics can be run dry. And they even handle heat much better and of course cant rust. FWIW.

 

[ABabyEater]

Aah, I see. Thank you for the clarification!

 

[ABabyEater]

More progress tonight!

Finished setting the new hub carrier bearings, as well as setting M2C pillow ball retainers.

With the 2028 putting out so much power, I figured the lest flex in the alignment of the spur, the better. An aluminum mount should help.

Spool time!

50T Pinion and a 36T Spur. Hopefully the 2028 will put out the torque needed... Rumor has it some people are putting 2028s in Arrma 1/8 scale cars at 1:2 gearing, so we'll see.

I had to grind down the shroud over the stupidly large pinion to make it fit in the car, but it does now fit!

And since there was some interest last night, what I finished off the night with. I am more of a Rye guy, and local is even better.



I will likely have to put the build on hold until the M2C diff output shafts are back in stock, as well as the wire sleeve I ordered to show up, but I do have a few smaller things I can upgrade at the moment - shock upgrades, droop screws, etc.