mini-x versions

sleepyb · #1 08-07-2002, 01:26 PM

was wondering, heard mentions of new vs. old version of the mini-x...
what exactly are the differences?

The Thunderer · #2 08-07-2002, 02:06 PM

Absolutely! I'd like to know too. I've got one that is the glitchiest thing ever... with an FM radio! I'm not sure if its the radio or something wrong with the car.

The thing that also concerns me is the plastic (clear plastic... fragile plastic?) gears at the rear shaft end point and the forward shaft end point. These guys scare me! The look to be easily broken.

I HOPE that this is not a new version...

Any insights Mini-X experts?

tinyrc · #3 08-07-2002, 03:12 PM

The old version was a fake/prototype version that was never intended for sale, and somehow HK retailers got a hold of some and sold them, and it made the Mini-X look bad as they were junk (since they were prototypes, not for consumer release). The proper Mini-X, which we stock here, is much tougher. It may look fragile because it's clear, but it is far stronger and thicker than for example a Mini-Z.

dgilpin · #4 08-07-2002, 08:13 PM

They look pretty cheesy, but seem to hold up fine, especially indoors. I cracked that front pinion gear pretty quick, so plan on making a foam bumper for the front. I was able to modify an 8-tooth mini-z gear to replace it. So order some spares. The motor runs way too hot (burns your fingers!) on 6 cells, and mine burned out, so get one of those, too if yours runs hot. I hope that one was just bad from the start.

The rest of the plastics are fine after two weeks of use, some out on the concrete driveway which is not very kind to it.

Mine is also very glitchy. I put alkalines in my mini-z transmitter instead of nimh. That helped a little (higher voltage). The 6-cell pack helps on the rx end a little, too, I think. I will try my T-maxx transmitter sometime.

I am running on lithium ion cells now, and that required a lot of plastic surgery, and relocating the rx toward the rear had the benefit of allowing me to pull the antenna wire up more, which also helped the range some. How about a longer wire?

tinyrc · #5 08-07-2002, 08:50 PM

Quote:

I am running on lithium ion cells now, and that required a lot of plastic surgery

Wow, cool, can you post some pics in a new thread about your LiIon conversion?!

dgilpin · #6 08-07-2002, 09:39 PM

I shouldn't stir up interest yet - the jury is still out on them. The cells I got were for an electric r/c airplane, and were pulled out of surplus cell phone battery packs.

Lithiums are more dangerous to work with, as I understand they can melt down if pushed too far. But after running them through a few charges seem ok on the x. My concerns are that they are about 8.4v fully charged - what will that do to the esc long term? It does not get warm, so I hope it is ok. The motor is another matter. I thought it would have hurt the esc and not the motor! But that is good because motors are cheap, and we may see modifieds some day.

The packs have a tiny circuit which limits current draw (2 or 3 amps) and shorts, so of course I removed that! So the cells may not last long (I paid $4 per pair - a pair is 8.4v - so I don't mind burning out a few). That allowed me to snap them into single AA holders from Radio Shack - one on each side. Since they are longer that AAA, I had to trim away the plastic on the front battery box, and move the rx and esc up higher. It is getting pretty ugly. But the AA holders are on their sides, so I can change batteries without romoving the body!

Two lithiums and the holders are still lighter than the 6-cell pack, and have about 850mah capacity. But the discharge curve is not as level as nimh, so the voltage drops while using. And you have to be very careful not to run them down too much or a cell can be damaged (that little circuit takes care of that by cutting out).

All that just to say it is not for the faint of heart, may be hard to obtain, and may damage your car. So let me get a new motor in this thing and continue testing before saying much more!

Pics will have to wait 'till I get a camera rigged up. Just imagine a fat AA cell on each side, the side and front plastic removed from the battery "box", and the esc and rx mounted over the batteries to avoid hitting the steering works.

There are some other mods, too. But nothing interesting.

tinyrc · #7 08-08-2002, 12:44 AM

Cool!

irc · #8 08-08-2002, 01:40 AM

The first mini x proto had a lot of binding in the gears. The newer version rolls much smother and drives nice. the plastic is very strong but the front pinion gear is the weak point. If your steering is glitching try twisting the short servo wire this always works. The motors do run hot and IM not sure why?

dgilpin · #9 08-10-2002, 03:09 PM

I got a new stock motor and put in bearings and two capacitors. I also twisted the servo and speed control cables from the receiver. Glitches are completely gone! I used to hold the car up and press the throttle - the esc LEDs flickered and the motor stuttered pretty bad. Not now!

Btman · #10 08-10-2002, 05:07 PM

Wow great tip about twisting the servo wires. I have not tried it yet because my car does not glitch too much. In fact it glitches less than my mini-z. I also noticed that the motor runs very hot on these cars. So far mine has not burned out since I got the car about 2 months ago. I don't know if the heat is due to the 4 wheel drive (even with bearings), the turns on the motor or what. Other than that the car has been very reliable and durable. Maybe there should be a heatsink finned aluminum motor bracket for these cars. I know modified motors on larger scale cars can be hot and heatsinks are available to help with the heat problem.

dgilpin · #11 08-10-2002, 08:33 PM

Definitely needs a heatsink, and I have been working on that. Just a wired-on piggyback heatsink gets hot, but its really just too much of a load for that little motor. How about a tiny fan blade on the long motor shaft? Probably not enough. We need a micro radiator up front!

tinyrc · #12 08-10-2002, 11:50 PM

I would really like to see what people can come up with in terms of a heat sink as the motor certainly does get hot. Keep us posted on your experiments.

usagi · #13 08-11-2002, 12:07 AM

There is a Mini-Xj version out here. Looing forward to getting this car in oct.

irc · #14 08-11-2002, 02:46 AM

I have used heat sinks made for the Z before on my X but it's not much help. I notified Xpress about the hot motor cuncerning us about 6 months ago and I was advised something would change in future cars but they did not say what? In the mean time they assured me it's ok to keep running the motor even when in gets hot?

baleisen · #15 08-11-2002, 10:04 AM

Lubricate the bearings and motor. That cut down some of my heat. BAE