Mini T Update

[StrechM]

My Mini T project is getting closer to completion. Here is what's been done so far;
Mamba KV 6800
Thunder Power 3 cell lipo packs, 1-1320 and 1-730mAh
Losi oil shock set
Hitec DCX FM RX
MIP Ball diff
Losi slipper clutch with top shaft assembly
Trinity 4 pinion bag, 14t installed
Hitec HS-55 servo
Losi Hitec servo saver
Deans plugs
Bearings
Dynamite Vision Ultra Lipo charger
The first mistake that was made was buying the Kokam 1500mAh lipo batts, they will not fit. I returned them for the more compact Thunder Power version then modded the battery hold down to accommodate any thickness.
The second mistake was listening to Hitec and purchasing the HFS-03MM Rx. So far I have not been able to get it to work with my Hitec Tx although it may be the user.
The third mistake was purchasing the Lunsford clear gear cover and chubby screw set. The screws will not fit the Mamba motor and the Losi slipper setup includes a clear cover that is superior to Lunsford's fit.
As for the test yesterday afternoon... The Mamba setup is still running in its default mode but... man o man is this truck fast! It appears that it will hold it's own against any nitro that I've owned as far as acceleration goes. At half speed it'll wheelie all the way over onto its lid.
The weak turnbuckles are going to have to be replaced with ti. A 1/2 dozen cart wheels down the street folded one of the rears like a paper clip.
The stock tires and wheels need to be replaced with something more appropriate. Not sure which ones yet.
My first thought was to install an alloy spur but after reading several threads on the boards, no one seems to use them because they destroy the pinions. No problem yet with using the plastic spur.
I'll take some pics when it's completed and post.

 

[spyhunter48]

how much you have in it now and i like to see pics curtis

 

[StrechM]

how much you have in it now and i like to see pics curtis

Approximately $470 not including the charger.

It is very slow during the Holiday season at work. Knowing this I brought the car with me today. I've been trying to figure out the programing, brakes, timing advance, etc.
So far I've managed to lunched it off of my desk at wot while thinking that it was in the programing mode. As it peeled out across my desk it shot loose paperwork all over the place then hit the window about 6' away!

My electric rc IQ feels like 79.

 

[Candyman]

Man, I would have love to see that. Not only the Mini squealing like crazy and papers shooting off the desk, but the look on your face as you figure out what the hell is happening and how you're gonna stop this thing from destroying your office...

 

[Lightning1]

Sounds like its going to be a flyer... :smoke: It will be good to see some pics..
Cheers Andy

 

[Rolex]

I mentioned to you in an earlier thread, two guys at the LHS that are into a MiniT smack down war. Each has over $600 invested. Give me another day or so to find out which wheels and tires they are running. Their handling is awsome.

 

[StrechM]

It's almost 100% dialed in now.
The Losi Mini-T Mini-Smasher Tires with Foams on the rear helped out for type of testing that I have been doing. They are approx. 15% larger size than the stock tires and appear to last considerably longer. The original rears were almost bald after about 20-25 minutes of run time (on the street). Also added to the hopups was an RPM wide bumper for a little extra protection.

These little trucks are wickedly quick, much quicker than any nitro rc that I have owned or driven for that matter. My testing found that the Thunder Power 3 cell 730mAh battery is one of the best because it is so lightweight. The Mamba's performance is a mini powerhouse, smooth and very, very responsive to the trigger.

To give you an idea of what I'm referring to;
I set the timing advance setting at the extreme (4th level) with a fully charged 3 cell 730mAh lipo battery. I kept the stock gear sizes using a 14t Trinity metal pinion with a 60t plastic spur gear from the Losi slipper upgrade kit.

On the street I could not apply more than approximately 1/2 throttle before it reaches more than 1/2 half of its top speed or it will wheelie onto its lid. At 2/3rds of its top speed it will still wheelie straight up (or wheelie onto its lid sometimes) when I nail the throttle the rest of the way down. Castle Creation's published statement about the power of the Mamba is more than likely an under statement of the actual facts.

I'll try to document this via a movie at some point.

 

[robmob]

Is this the pack you are using?

What kind of runtime can you get out of it?

I sure would like to see a pic of your set-up. I am thinking of going brushless on my mini-t.

 

[StrechM]

Is this the pack you are using?

What kind of runtime can you get out of it?

I sure would like to see a pic of your set-up. I am thinking of going brushless on my mini-t.

Yes the 3 cell 730 and the 3 cell 1320 mAh pack.
The 1320 mAh pack will not fit without modification to the battery hold down. The 3 cell 730 pack will need velcro or a spacer to keep in place. As far as run times go I have not timed any of them. Maybe 7+ minutes for the 730 and 10+ minutes for the 1320 mAh pack before the power starts to drop off (I'm guessing). I did pick up a second 730 pack which gives me 2-730's and one 1320 for plenty of run time.
You have to understand that I'm running this setup in the extreme power setting mode that uses the maximum current draw.
Sunday morning I stopped buy this site to see just how fast that it would go. There was not enough room to run it at wot to max speed and still get it to stop safely.
Part of the problem is the KV 6800's power. I cannot give it more than about half throttle until it reaches at least 2/3rds or more of its speed (with the tires warmed up) without it popping wheelies.
There were several pics taken last night and I'll post them as soon as there is enough time.

 

[lykan]

Hey Stretch.. I really appreciate all this info, I am sure there are plenty more lurking about like me waiting to see your next installment.

Is the KV 6800 a brushless motor? I am thinking I might be recieving a mini-t from X-mas, and I'm not sure if I want to invest the money to go brushless.

I am more concerned about run time than power, because it seems like if you do it right you can power these things to the moon. On a conservative setting how long do you think your Li-po will last?

 

[StrechM]

lykan,
Yes its a brushless motor and I have no real clue how long a lipo would last set in the max effeciency setting. Probably for quite a while.
Here are Castle Creations published specs for the one that I purchased:
6800 Kv Competition Package:
Stock gearing Mini-T
3 cell Lipo = 50mph
2 cell Lipo, or 8 cells = 40mph
6 cells = 27mph
Most likely, the best 6 cell all-purpose racing setup. Good runtimes and
speed. A little hot for racing w/more than 6 cells, but still VERY capable
of ridiculous bashing speed runs on 8 cells, or 3s Lipos.

Go to: www.castlecreations.com for more info. Fllow the Mamba link.
Go here for complete recomendations. http://www.castlecreations.com/documents/MambaSetups.pdf
Go here for the manual: http://www.castlecreations.com/documents/Mamba25 User Guide.pdf

 

[StrechM]

Here you go.

This is what was left over plus two rear tires and wheels.

 

[FastEddy]

Holly Guacamole!!!!!!

 

[lykan]

so how does it handle? the weight distro looks like it's a little heavy in the rear.. is this pretty much for onroad.. or do you do a bit of offroad bashing too?

Eiter way it looks like a damned sweet setup to me.

 

[StrechM]

It handles well with a light trigger finger. No offroading yet.
I'm trying to come up with a new rx mount/battery hold down that will allow me to keep using the 1320mAh lipo without using a makeshift small balsa block that was cut to hold the batteries forward (forgot to install it for the pics). If I cannot come up with a satisfactory solution then I will go with the 730mAh lipos only which will allow me to mount the lipo and the rx side by side on the lower chassis then put only the esc on top of an unmodified top plate. That would give it a lower cg but less run time. If any of you have ideas or a solution to this please feel free to share.
After giving consideration to the nature of lipo batteries a decision was made to dremmel off the 4 small sharp tabs at each corner of the inside of the battery compartment. It appears that in a crash that they were sharp enough to cut into a cell.
Next will be the rear cvds, then where to mount the on/off switch, possibly a smaller inside antenna and paint the new Crowd Pleazer body etc.
It's a mini rocket ship in the making.

 

[msly]

That is very cool. Imbroken and I got all wrapped into the mini RC scene. We both had very expensive Micro's for all of about 2 mins... Man I took a beating on that when i sold it. I tell you when I first saw the Mini-T I really wanted one bad but was nervous I was about to drop another 5 C Notes into a toy LOL.

I did not even have mine fully tricked out and damm it was fast. But not very controlable at high roughneck speeds..... Deep down I still want a tricked out Mini T though

sLY

 

[lykan]

Have you looked around, or put any thought into a modified or aftermarket chassis? It would be nice if you could find one 1-2" longer..

Here's an idea for ya.
Take the hard styrofoam board they use for electric planes (the 4x8 sheets that' used for house insulation) and cut a nice square donut shaped battery spacer. It would take the place or your balsa, absorb more impact, and you could cut it to almost any configuration. It's also stiff enough to be used to mount the esc/rx on top of, and can be sliced for thickness..

What I am kind of looking for is a quick fix for my r/c habit somethign I cna play with and then stick on the shelf when I'm done.. I am thinking a mini-t with larger than average tires, and the weak spots fixed up..maybe a nice long run time li-po battery etc. Something I could take out and not have to worry about fuel, a big place to run, or the noise that just antagonizes my neighbors heheh

I love your mini-t it looks like a blast. If I were to make something similar I would probably keep it in efficient mode..I am teetering between a mini-t or a venom mini giant.. The only thing that worries me is that a high powered micro that I am prone to obliterate.. if the power is there I'll use it lol...

 

[StrechM]

I ordered an 18T (but changed my mind and let someone else have it at the lhs) and opted for an M18 after X-Mas.

msly, Honestly I was getting bored to death with the same old thing over and over again. It will give me a couple of new challenges for winter projects. These are a lot of fun.

lykan, I like your thoughts on the foam. Really I have not broken any parts. Just bent up the turnbuckles bfore going with the ti. They are a lot stronger than I first imagined them to be.

 

[StrechM]

Update on the hopups.

I've opted to use the smaller of the lipo cells that will allow for me to mount the rx and batts on the lower chassis and mount the esc only on an unmodified top portion of the chassis. This should help considerably with the weight distribution by allowing me to move the batts to the far forward position.

The issue that I was having getting the 03-MM Hitec rx to work was because it is a single conversion receiver. The Hitec Aggressor CRX is a dual conversion tx and I was trying to use a dual conversion crystal. Problem solved by adding one Hitec single conversion crystal. Pics will follow when I can find the time.

The M-18 will be in tonight....next!