4-Tec conversion

[lincpimp]

Ok, so I decided to actually convert this turd. After fooling with it a bit I got all of the belts to run smoothly and it actually feels good when rolling. Maybe not as bad as I thought...

So I took an old rcm revo mount and modded it to fit the chassis. Had to drill 1 hole in the chassis, but it is a bit scratched so I really do not care. The previous owner had already cut down the upper deck and side mounts, so I cleaned them up a bit and put it back together. By the looks of it I will have enough room to run a 6s 2100 maxamps lipo. I can cut and mod it a bit more to get addl clearance for the lipo.

Here are a few pics, lighting was weird, so some of the pics are dark.

[magman]

Looks good...it should really go

[lincpimp]

Tried a few other lipos, even the big 4500 30c 6s! The pair of 2170 3s packs should handle a decent load, as I run them in my 1/8 buggy.

[lincpimp]

Originally Posted by magman

Looks good...it should really go

Thanks, I ran the numbers on the calc, here are the 5s results:

Differential Ratio: 1
Transmission Ratio: 1.7
Other Ratio: 1
Spur Tooth Count: 41
Pinion Tooth Count: 20
Total Voltage: 18.5
Motor KV: 1638
Tire Diameter (inches): 2.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 2.05 : 1
Total Ratio: 3.485 : 1
Tire Circumference (inches): 7.85 inches (199.49 mm)
Total Motor Speed: 30303 RPM
Vehicle Speed: 64.67 mph (103.88 km/h)

I will see how this works with the maxamps 2100 cells wired up as 5s. They are not bad cells, but I do not know if they can push out 750 watts...

I may swap the bk9920 out for a quark 125b and run 6s with the fp 2170 lipos. Here is the setup on 6s:

Differential Ratio: 1
Transmission Ratio: 1.7
Other Ratio: 1
Spur Tooth Count: 41
Pinion Tooth Count: 20
Total Voltage: 22.2
Motor KV: 1638
Tire Diameter (inches): 2.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 2.05 : 1
Total Ratio: 3.485 : 1
Tire Circumference (inches): 7.85 inches (199.49 mm)
Total Motor Speed: 36363.6 RPM
Vehicle Speed: 77.61 mph (124.66 km/h)

And I can push the gearing up to a 25t pinion:

Differential Ratio: 1
Transmission Ratio: 1.7
Other Ratio: 1
Spur Tooth Count: 41
Pinion Tooth Count: 25
Total Voltage: 22.2
Motor KV: 1638
Tire Diameter (inches): 2.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 1.64 : 1
Total Ratio: 2.788 : 1
Tire Circumference (inches): 7.85 inches (199.49 mm)
Total Motor Speed: 36363.6 RPM
Vehicle Speed: 97.01 mph (155.83 km/h)

Not sure what kind of battery setup I will need to get that kind of speed. I doubt the 15l will handle it either.

I do have an aveox 2000kv motor, 1512 size. I am sure that it with a decent 90+ amp capable per cell 6s pack will do 100mph. I will have to whip up a 3200 30c 6s lipo, and use a MMM. This will be down the road, if the platform can even handle 80+mph.

Differential Ratio: 1
Transmission Ratio: 1.7
Other Ratio: 1
Spur Tooth Count: 41
Pinion Tooth Count: 25
Total Voltage: 22.2
Motor KV: 2000
Tire Diameter (inches): 2.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 1.64 : 1
Total Ratio: 2.788 : 1
Tire Circumference (inches): 7.85 inches (199.49 mm)
Total Motor Speed: 44400 RPM
Vehicle Speed: 118.44 mph (190.26 km/h)

[jhautz]

OK... This might be a dumb question, but dont they already make 1/10 touring cars that are designed for electric? Why go thru the effort of doing a converion for one. Of course I guess if you have and and have nothing better to do.

Seems kinda like converting a Tmaxx to me.



No offense meant, just wondering.

[OZ-RUSTLER]

Originally Posted by jhautz

OK... This might be a dumb question, but dont they already make 1/10 touring cars that are designed for electric? Why go thru the effort of doing a converion for one. Of course I guess if you have and and have nothing better to do.

Seems kinda like converting a Tmaxx to me.



No offense meant, just wondering.

Im assuming your talking about the Traxxas 4-Tec electric. They dont adapt very well to brushless, where as the nitro has been proven to handle 70mph+.

Nice work Lincpimp

[lincpimp]

Originally Posted by jhautz

OK... This might be a dumb question, but dont they already make 1/10 touring cars that are designed for electric? Why go thru the effort of doing a converion for one. Of course I guess if you have and and have nothing better to do.

Seems kinda like converting a Tmaxx to me.



No offense meant, just wondering.

Very true Jeff. I only have this as i bought it in a lot of other stuff, and have been unable to sell it. The electric version is crap too. Worst tc next to something duratrash...

Originally Posted by OZ-RUSTLER

Im assuming your talking about the Traxxas 4-Tec electric. They dont adapt very well to brushless, where as the nitro has been proven to handle 70mph+.

Nice work Lincpimp

Thanks, I am sure that a tc4 would be a better platform ,but this is something different. I have a feeling that it will handle a crash better than an electric tc... Kinda heavy with the al chassis and thich plastic bits!

[BL_RV0]

Looks good pimp. You need to pm me back!!

[BrianG]

Linc, looks good so far. The way you have your batteries was the method I initially wanted to do, but some people don't have nearly the lipo choices that you do!

I'm sure you'll be done far before I am because I still have to special order the "SE" Medusa motor (still undecided if I want a 50mm or 60mm motor), the ESC (MM and BEC), and fabricate the parts I need.

[lincpimp]

Originally Posted by BrianG

Linc, looks good so far. The way you have your batteries was the method I initially wanted to do, but some people don't have nearly the lipo choices that you do!

I'm sure you'll be done far before I am because I still have to special order the "SE" Medusa motor (still undecided if I want a 50mm or 60mm motor), the ESC (MM and BEC), and fabricate the parts I need.

I do have a few lipos hanging around...

I hoe to finish it by the end of the week, or at least get it rolling... If it performs well up to 65 or so I will go all out... I also need to get my top speed tamiya back out and prep it for 100+mph runs... Time for some ceramic bearings...

Good luck on your build Brian, what speed do you want to get out of it?

[BrianG]

I'm not looking for anything crazy, just around 50-60. Just for around the house or maybe a vacant parking lot.

[lincpimp]

Originally Posted by BrianG

I'm not looking for anything crazy, just around 50-60. Just for around the house or maybe a vacant parking lot.

Ok, the 50mm motor will be plenty for that... But you might as well get the 60mm, right

[BrianG]

Yeah, that's what I was thinking. Being belt driven, there's a fair bit of drag just from the drivetrain. And if I decide to go faster, the extra torque will pull a taller gearing easier.

Besides, I did some more work tonight and I really have to get a 60mm motor now...

[lincpimp]

Originally Posted by BrianG

Yeah, that's what I was thinking. Being belt driven, there's a fair bit of drag just from the drivetrain. And if I decide to go faster, the extra torque will pull a taller gearing easier.

Besides, I did some more work tonight and I really have to get a 60mm motor now...

Why, did you add a bunch of weight? I agree with you on the drag issue. I cannot imagine that any belt car could be smoother than a shaft driven one... Maybe I have not experienced a pro level belt car yet. The tamiya 4wd tc that I had setup for speed runs was so smooth you it felt like it did not have diffs in it. It would barely slow down during off power coasting...

[BrianG]

No weight (well, a little), but I need the extra length for wire clearance...