Kyosoho USA-1 Nitro Rebuild

[Monkey Wrench]

My first kit monster truck, back in the '90's was/is a Kyosho USA-1 Nitro.

I still have my original truck, but came upon one here on the marketplace for a good price and snatched it up.

Came with an OS .21 engine so gummed up not sure I can resurrect it, but the rest just seems to need some TLC.

Following pictures show I've removed, cleaned and rebuilt the rear end. Have the center diff out and soaking. Considering either polishing or powder costing the pan (welcome suggestions here).

All ideas and tips welcome!

 

[Greywolf74]

Id polish it over powder coating myself. Powder coat is just gonna get dinged up and chipped eventually.

 

[Monkey Wrench]

OK, have everything off the chasis and have been soaking it in decreased and about ready to polish. I've never polished this much aluminum at once, so asking for tips on doing so.

I've polished smaller parts using my Dremel and Mother's Aluminum Polish, but figure trying to use a Dremel will take forever and Mother's isn't cheap, so want to make the most of it.

I do have a bench grinder I can put polishing wheels on, but it dances on my work bench when I crank it up. I could use it in the garage on the stand, but I'd need to move my.Miata out to bolt the stand to the floor and I don't want to have my Miata sitting outside in this weather (chilly and rainy).

Are there polishing attachments for a grinder? Haven't looked yet, bit thought I'd throw it out here. Any other suggestions? Figure I need something with higher RPM's than my drill, though my corded drill seems to spin pretty good.

Any suggestions welcomed and thanks in advance!

 

[Greywolf74]

I know @WickedFog knows a thing or two about polishing. I'm sure he can give you some advice.

 

[WickedFog]

Polishing aluminum is a bit of a process. I start out with somewhere between 400 to 800 grit, depending on how many blems there are, or how textured the piece is.

From there, work your way down to about 1500 grit, going from 800, to 1000, to 1200, then 1500. Stay in straight lines. Using sanding blocks on flat areas will yield the best results, and only hand sand in the contours. You won't see it until the finishing polish, but the use of any power tools will leave divets and such that won't show until you get the mirror finish on.

Once you get to 1500 grit, you should start to see a blurry reflection. You can continue with finer grits, but if you have a buffing wheel on a benchtop grinder, you can go straght to jewelers rouge on the wheel.

You can get rouge at Walmart, or auto paint supply stores.
https://www.walmart.com/ip/Enkay-15...UrtD4_dwVT4KVyREcawxbnQfgdvrABXkaAmekEALw_wcB

A little warning about buffing wheels... never let the top edge of your piece enter the wheel. The fibers will grab it and turn it into a missle that will be going fast enough to penetrate a complete wall, through one side and out the other. Ask me how I know

Polishing may seem like a lot of work, but once you get going, it's not bad. And the reward makes it all worth it. I actually enjoyed polishing aluminum... (not my work, but this is like what I did)

 

[Monkey Wrench]

Polishing aluminum is a bit of a process. I start out with somewhere between 400 to 800 grit, depending on how many blems there are, or how textured the piece is.

From there, work your way down to about 1500 grit, going from 800, to 1000, to 1200, then 1500. Stay in straight lines. Using sanding blocks on flat areas will yield the best results, and only hand sand in the contours. You won't see it until the finishing polish, but the use of any power tools will leave divets and such that won't show until you get the mirror finish on.

Once you get to 1500 grit, you should start to see a blurry reflection. You can continue with finer grits, but if you have a buffing wheel on a benchtop grinder, you can go straght to jewelers rouge on the wheel.
View attachment 157806
View attachment 157807

You can get rouge at Walmart, or auto paint supply stores.
https://www.walmart.com/ip/Enkay-15...UrtD4_dwVT4KVyREcawxbnQfgdvrABXkaAmekEALw_wcB

A little warning about buffing wheels... never let the top edge of your piece enter the wheel. The fibers will grab it and turn it into a missle that will be going fast enough to penetrate a complete wall, through one side and out the other. Ask me how I know

Polishing may seem like a lot of work, but once you get going, it's not bad. And the reward makes it all worth it. I actually enjoyed polishing aluminum... (not my work, but this is like what I did)
View attachment 157808

Thanks @wickedfogFor the tips! Here are a few pics of what i want to tackle.

Pic on the top is the pan from the rebuild I am doing. One on the bottom is a spare I have laying around. I think I left the rebuild one in the decreased too long as it.now has a brownish patina. One on bottom is stock that hasn't been cleaned yet.

Think I can bring the rebuild pan back or is it too far gone?

 

[WickedFog]

Think I can bring the rebuild pan back or is it too far gone?

That patina should polish right out of it. Metal does not absorb chemicals like pourous materials, but it can sometimes penetrate a few tenths (.0001") of the surface, which should polish away pretty easily.

 

[Monkey Wrench]

Working on the front end this evening and wanted to show before and after shots of the front dog bones.

I know I learned this trick here, just can't remember from who, though.

I polished the ends that go through the hubs using my Dremel and Mothers Mag and Aluminum polish.

This truck uses bushings rather than bearings, so this gives it a nice, smooth surface. Just too bad you can't see it!

Before

Compare

After

That patina should polish right out of it. Metal does not absorb chemicals like pourous materials, but it can sometimes penetrate a few tenths (.0001") of the surface, which should polish away pretty easily.

I dabbled a bit with some 220 and you're right, it comes off.

Are you wet or dry sanding?

 

[WickedFog]

Are you wet or dry sanding?

Use WD40 to keep your paper clean. Sorry, I should have mentioned that earlier.

 

[Monkey Wrench]

Use WD40 to keep your paper clean. Sorry, I should have mentioned that earlier.

Thanks!

 

[WickedFog]

Thanks!

No problemo. Post pics as you go. Another little tip... sand with the same grit til you've removed all the lines from previous grit. And when you think you are ready to go to a finer grit, hit everything one more time with the current grit. It sucks to start on a finer grit, and end up having to step back to clean up an area you missed, and ruin any sanding you just did.

 

[Monkey Wrench]

Will do! Need to get fresh paper then I'll start on it! Appreciate the tips!

 

[WickedFog]

Will do! Need to get fresh paper then I'll start on it! Appreciate the tips!

Go with 3m wet/dry. Best stuff for polishing. I used to use emery cloth as well for the coarser stuff.

 

[Monkey Wrench]

Well, here it is! Pretty much finished. I mulled polishing the pan, going back and forth, but decided to wait on fully polishing it for now because I do want to bash it and I think I might cry if I polished it all up only to ding it up!

It's bone stock as there a few hop ups for this old rig these days. Did replace the servos with HI Tec servos (yeah, I know they're old, but hey, they still work) and Spectrum RX.

Need to figure out the fuel tank, though. I need a nipple that I can attach fuel lines to both sides so I can make a fuel pick-up line for the tank. If anyone has ideas, will appreciate them!

Just need to find an engine for it, then we're off!

 

[WickedFog]

Looking good! Ain't a thing wrong with old Hitec servos. They are probably better than a lot of new servos!

Do you already have a body for it?

If later on you want to put a decent finish on the pan without a ton of work, get the red 3M Scotchbrite pads. Scrub the chassis in straight lines, going completely from front to back without stopping. Long, full strokes will leave that purdy brushed finish.

 

[Monkey Wrench]

Looking good! Ain't a thing wrong with old Hitec servos. They are probably better than a lot of new servos!

Do you already have a body for it?

If later on you want to put a decent finish on the pan without a ton of work, get the red 3M Scotchbrite pads. Scrub the chassis in straight lines, going completely from front to back without stopping. Long, full strokes will leave that purdy brushed finish.
View attachment 158032

Will do! Get those at auto parts store or something like Lowes?

 

[Greywolf74]

Need to figure out the fuel tank, though. I need a nipple that I can attach fuel lines to both sides so I can make a fuel pick-up line for the tank. If anyone has ideas, will appreciate them!

Soemthing like one of these?

LINK 1
LINK 2

 

[WickedFog]

Will do! Get those at auto parts store or something like Lowes?

Yeah, possibly. You can buy it on Amazon too. Walmart may even have it. Any place that sells auto paint should have it for sure.

 

[Monkey Wrench]

Soemthing like one of these?

LINK 1
LINK 2

Yeah, that's what I'm thinking. Ideally, something that screws together since I have to put it through the tank, but I think I may be able to make one of those work.

 

[Greywolf74]

Yeah, that's what I'm thinking. Ideally, something that screws together since I have to put it through the tank, but I think I may be able to make one of those work.

The one in link 2 does screw together