RC Truck and Construction

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- - china kat (https://www.rctruckandconstruction.com/showthread.php?t=10137)

You're lucky that you've gotten the unsprayed undercarriage.
The black undercarriage looks good on the internet pictures but in reality it is spraying work worthless because the paint falls off.
The black undercarriage is sprayed without prior degreasing, sanding or base coat.

Before you take on the real job remember that the undercarriage is not suitable for heavy duty.
After the undercarriage from my Kat was pretty twisted I have completely taken the undercarriage apart and reconstructed it with the addition of a lot of solid aluminum.

I can tell you much more about the Kat undercarriage but it is much more fun when you discovered it yourself and tell us about it.

Quote:

Originally Posted by RCP57 (Post 124461)

what are your impressions on the track drive motors? The speed looks good but do you think they are really torquey?
My excavator is over 50lbs though

Don't!
They are not suitable for heavy duty.

http://i60.tinypic.com/2mxo6s1.jpg

that undercarage is steel or at least that's what the magnet tells me.. but go

Oh no! Did the shaft break off inside the worm gear?

Inside, twice.
The second time I discovered that the worm was glued or shrunk on the axle.

Quote:

Originally Posted by bigford (Post 124559)

that undercarage is steel or at least that's what the magnet tells me.. but go

Yep, the nuts and bolts are made of steel 😉 or maybe they do something with the complaints and make the undercarriage stronger now.

I do not want to be too negative about this because their service is very good.
After I had reported the problems they sent me a complete new undercarriage.
No discussion and did not have to pay anything.

well buster was right about the paint the fingerprints under the black paint was
enough for me to mess with the cover. small pie tin and some lacquer thinner
and the paint was gone who knew you can glue aluminum
http://i1335.photobucket.com/albums/...psetr8eyml.jpg
http://i1335.photobucket.com/albums/...pshffae9vs.jpg

more and more i look at this makes me scared and also waiting to see what you do with it

ok after two days of looking at lipos and chargers I still have no idea what to get
I was told to get a 11.1v lipo with as high of a capacity you can find/afford

so you tell me what battery or batteries and charger and what ever else lipo crap I need please.. i'm a nimh kinda guy and this lipo stuff is as odd to me as the chine kats instructions

http://i1357.photobucket.com/albums/...pszq5jw267.jpg

I've had my share of chargers and I can't stress to purchase the best charger you can to start with, you wouldn't regret it. I've had this one for 4 years, since purchasing I quit looking. I use a 24v power source as I charge some of my packs at 20 amps.

http://i1357.photobucket.com/albums/...psboyjs5ow.jpg

Some of the larger packs I have, time for monthly maintenance. The part on left is a battery gauge , part on right is a blinky balancer. It can balance a pack by just plugging into the balance plug, also a battery gauge.

Some of the best high end performing batteries out there, (in my opinion, and many others)
http://dinogylipos.com/?no_mobile_theme
The basic go to for a lot of people
http://www.hobbyking.com/hobbyking/store/index.asp. Don't expect any customer service.

Long but very informative thread about lipos.
http://www.rcgroups.com/forums/showthread.php?t=1577989

They ran not any more dangerous than any other battery when used / charged / discharged properly. Simple common sense like don't throw a 9volt (or really any battery) un protected into the trash, something could cross terminals a cause that magic effect of fire. Biggest thing with lipos is do NOT try to overcharge them , that will cook them and surroundings. Don't damage them as they may become unstable and swell. Don't ask them to preform more than they are capable of. That will lessen their life and cause them to swell. A lot is covered on rc groups threads. Lipos can't be beat for their size a capacity to deliver.

Milliamperes (mah) is basically the size of gas tank
C rating is basically how fast it can empty the tank. Usually this number is grossly inflated.
C rating for charging is how fast you can fill the tank. Usually 1-5 c rating is pretty safe. Some say 20 c but that's 100 amps on a 5000 mah battery, no one makes a 100 amp charger that a hobbiest can purchase.

A little reading and common sense and you will be fine, my biggest advise it the charger, purchase a high quality charger. And there are only about 8-12 actual battery manufactuers worldwide that sell the kinds we use, a lot of rebranding, I use to know the major manufacturers and who was using who's batteries rebranded but lost track of companies as they don't want to share that info :). Kind of like tire manufacturers- only a handful of actual manufactuers but hundreds of brands.

And I'm by far an expert, just personal experience and trusted information from others. :)

well the dx9 showed up last nite WOW!!
alot of reading to do,but real cool

https://www.youtube.com/watch?v=9ftk6o0JHG0
https://www.youtube.com/watch?v=wxjFv7uS8DE
messing with the kat not sure what the problem with the cylinders is!!!

You could check if the servo is moving the valve max in both directions. Or there can be internal leakage in cylinder, or valve, so it don't get enough pressure?

Thanks for the info on batteries, Cooper. Seeing all your batteries , I am certainly glad I just got 4 Lipo's and 2 models, and 1 for the transmitter to keep track of at once;)

About the 'common sence battery balancer'..doesn't most/all newer LiPo chargers have this function of balancing, built in?

rimrock it feels like the inside of the cylindrer is rough
or there is a stutter. i was thinking low voltage?? only
running 8.4 nimh right now.

Quote:

Originally Posted by bigford (Post 124971)

rimrock it feels like the inside of the cylindrer is rough
or there is a stutter. i was thinking low voltage?? only
running 8.4 nimh right now.

There is a certain resistance in the such cylinders and hoses, so a certain pressure is needed to move things. The pump needs 11-12V I would guess, so just 8.4 V can cause things to move slow. Would try using more voltage first, and then possible check the cylinder more close, if it's easy to move in and out by hand with hoses disconnected, check it for possible dents on outer surface.

Looks to me like if there is air in the system.

Quote:

Originally Posted by Buster (Post 124974)

Looks to me like if there is air in the system.

That's a typical problem, yes. To little oil, pump partly sucking air. Another issue can be too thick oil. If one test with e.g thickness 32 oil used for full size equipment, it will feel like honey in the hoses...(but I would think thin type for models is used here, which would have thickness number 15-20 or so)

I've got the Kat myself out of curiosity, and I knew there would be a challenge of rebuild it. I've got friends that have the Eagle XL4200, and it's a lot of work making them go properly to. It's crazy to think about that one spend like $2-3000 on a piece of equipment, and then there is like 100 hours of fiddling around to make things work!;) Most people are tired of this crap!;) When one buy a cheap chineese powertool, like a drill, at $20, it's just to connect it to the grid, and start doing the job at once (very usually) We have been on the Moon, and we have been remote operated vehicles on Mars, COME ON!, it's 2015, give us a $2500 1/14 hydraulic excavator that works, out of the box! Just connect the battery, and GO! ;) (And then Rimrock woke up from dreamland, as the potatoes boiled on the stove.)

upgraded all parts on the kat to get it working better then at cabin fever

https://youtu.be/VHVPZy1YL-8 now were digging!!!!

ok so after messing with the kats valve body trying to get neutral
and not finding it or oil is passing the seals in the cylinder I give up
i'll order a different valve body and see what happens. the two ar9020 rx
that were ordered a month before cabin fever showed up in my mail box
that Saturday so now all functions work

Good to here it's working better and not just a trailer queen!!