Weighting Tamiya M03 Mini for LiPo Cells
There are now several LiPo packs available that are shaped like a stick pack, so they will fit the Mini M-Chassis.
But! They are a LOT lighter than a pack of NiMhs. So much so, that most clubs that race minis now specify a minimum weight for all minis. It’s usually around 1350g.
This isn’t such a bad thing, as a LiPo mini without extra weight doesn’t handle very well anyway!
So, you need to add extra weight, usually in the order of around 200g. There are a few of ways of doing this.
1. Stick weights all over the place – ugly, but you can put them where you want to get the best handling. It’s up to you where you stick em.
2. Carefully put lead around the battery, and in front and rear bumpers – tidy, more concentrated weight where you want it. If you open up the chassis you’ll see a gap above the battery, you can put a strip of lead in there. It you take the bumpers off you’ll see they are hollow, you can fold some lead into those too. It’s very tempting to put lead in the large void at the back of the chassis, but that’s not really where you want to put it, the handling will be effected a lot.
3. Create lead packing strips to fit above and below LiPo – accurately imitates a NiMh pack, so handling isn’t changed whatever battery you use – and you can use either a NiMh or LiPo pack. Above the LiPo is usually a hollow, create a lead strip to fit into that hollow. Underneath the battery you can use a double thickness strip, it should hold in by friction. If you wrap the lead in tape it looks nicer, and can help you get the right thickness so the strip holds itself in. You can stick it to the LiPo if you wish, but then that LiPo can only be used in that car. The main advantage of this is the main extra weight is below the Lipo, and it actually ends up with a lower centre of gravity than with a NiMh.
The performance difference between NiMh and LiPo in an M03 is minimal, the voltage curve of a LiPo is a little better, so may be a bit stronger in the latter part of a race in comparison with NiMh.
How To Add a 40mm Cooling Fan to Tamiya M03 Mini
Small fans are often used on Radio Controlled Cars, for cooling speed controls, or motors.
I was running a 30mm 3 Racing fan on my Tamiya M03 Mini, and I recently ‘stuck my finger through it’. This is common occurence, where a misplaced finger causes the fan to break.
I had repaired it with superglue and it had been okay for a meeting or two.
In one run though, I felt I was down on power, and I reckon it’s cos the fan broke again, and end up looking like this…
Broken 3-Racing 30mm Fan
I think that was enough to jam it, and cause an increased power drain on the batteries, and hence a reduction in power to the motor, slowing the car.
Time to replace it, I wondered if there was a way of fitting a larger, 40mm fan in a similar place.
After some measuring, a failed attempt at a mounting bracket, I came up with a small bracket that mounts a 40mm fan above the motor.
40mm Fan and Bracket
The bracket is a simple piece of aluminium angle, with two M3 bolts securing it to the fan, and one M3 bolt securing it to the chassis.
Simple and neat. A 40mm fan is more effective and stronger than a 30mm fan.
Poor Man’s Dyno or Motor Checker
Poor Man’s Dyno or Motor Checker Video
I wanted to compare some motors, and wanted a simple way of reading RPM. So I needed an RPM counter of some sort. I thought about making one, but I quickly came across some on ebay.
I ordered one up, and it’s quite a bit bigger than I expected it to be, but that’s not a big deal.
It works very simply, you stick some reflective tape to whatever is rotating, and shine the laser on it. The reflective part needs to be less area than the non-reflective part. It then just counts the reflections and displays the RPM.
Brilliantly simple. Sure, it doesn’t check anything else, no torque measurements, or current measurements etc, but for a quick and dirty comparison it’s great.
It is of course important when checking motors to ensure that the voltage is similar on all of them. So use a fully charged race pack, and test them all at the same time, one after another.
I could even go so far as to test them under load, such as fitting them into a car and using the drivetrain as a load, as long as it’s the same conditions for each motor then it should be consistent and useful.
Tamiya M03 Mini Tyres
I struggled with tyres last night on my Tamiya M03 Mini, I was using S-grips on the front and M-grips on the back. Both were very well worn, and had been repeatedly glued, so the sidewalls were pretty coated in superglue.
Supergluing the sidewalls is a great technique to reduce the bite of a tyres, but when they start wearing, you don’t get enough grip from them at all!
I then tried a new set of Express tyres on the front, and they were TOO grippy, loads of turn in sure, but also grip roll, which isn’t really necessary.
I think it’s time for some new Tamiya Tyres… I’ll get a couple of pairs of each, and play around. The common forumala for indoors is M grips on the rear, and either ‘kits’ or S-grip on the front. Though, getting S-grips to work can be problematic – they can be too grippy. Hard foam inserts are fine, especially on the front. And perhaps they’ll make the M’s on the back wear more evenly?
Here’s the part numbers etc.
53254 M-CHASSIS 60D SUPER GRIP RADIAL TYRES(1 PAIR)
50683 M-CHASSIS 60D RADIAL TIRES(1 PAIR) **’kits’
50684 M-CHASSIS 60D M-GRIP RADIAL TIRES(1 PAIR)
53255 M-CHASSIS 60D INNER SPONGE HARD(4PCS.)
Connectors for Fans etc. on Radio Controlled Cars
I picked up some of the small 2mm ‘Corally’ type banana connectors, off of ebay [search for: 2mm gold connector], these are ideal for use connecting fans, UBECs, LiPo cut-offs, etc.
In my e-savage I had two fans and a UBEC I wanted to connect direct to the battery voltage. I connect two wires, one to each of the +ve and -ve on the Deans battery connectors, and run them to where I want the sockets of for the accessories.
Then, I soldered three of the 2mm sockets in a small triangle, and onto one of the power wires. So 6 2mm sockets in total, 3 +ve, 3 -ve. Heatshrink around each triangle of three, gives a nice neat 3-way socket.
On each fan/ubec I have a 2mm plug on the power wires, heatshrink them again and plug them into the socket.
It’s important that there is no bare connector showing, especially as the +ve and -ve are often positioned next to each other.
The Schumacher E-Manic Concept Car
Shared by simoncrabb
This looks like a direct E-Savage / Savage Flux / E-Revo / E-Maxx competitor…
“Schumacher have been working hard with various brushless motor/Speed control companies to best use those systems in many of our vehicles. The latest concept idea is the E-Manic. The E-Manic is a sensational 4wd ready to run 1/8th scale monster truck designed to accept high performance electric brushless systems. It can take up to 14.4v lipos and with a high performance brushless system such as the Castle Creations Mamba Max and new 2200 motor, the speed and acceleration is staggering. With a rugged suspension, and strong 4wd transmission it is designed to handle the roughest ground and most challenging obstacles. Its impressive speed and handling make the Manic an outstanding choice for any conditions. The fantastic Schumacher reputation for quality and support will make the Manic a favourite for all monster truck owners.”
[Our thanks go to Schumacher for this news]
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HPI E-Savage 14 Cells How To – Add 2 cells!
A really easy way to go quicker, just add an extra couple of cells! The standard E-Savage is powered by 12 NiMh cells (14.4v), in 2 stick packs of 6.
I had lots of stick packs, which I wanted to keep standard, as I use them in other vehicles, and I have a balancing tray for stick packs. I wanted to run 14 cells in the E-Savage, to make 16.8v, so thought of ways to add two more.
HPI E-Savage 14 Cells How To from rcLazy on Vimeo.
The standard speed control can handle 14 cells okay, and it has two plugs on it, but effectively two of the wires are joined in a loop, so you end up with 12 cells in serial. I figured I could add two more cells to the chain to make 14.
The VERY IMPORTANT thing to consider though, is that the 2 extra cells must be of a higher capacity than the 2 x 6 cell stick pack. This is so that the 2 cells don’t dump first, when you’d hardly notice it wilth 12 cells still powering the car, thus damaging the cells.
So I had pairs of cells of 4200, 4500 and 4500, and I got hold of another 4600 pack, so split it into 3 x 2 cell packs.
Then, I made up an adaptor to plug the 2 cell pack in series with one of the 6 cell packs. It doesn’t really matter which side, as they are treated in series by the speed control.
Then I charged up all 3 packs separately, the six cell packs on the standard dual output GT charger, and the 2 cell pack on my other (Graupner) NiMh charger.
A simple bracket was made for the 2 cell pack to sit in, secured with a velcro strap.
UPDATE:
HPI E-Savage 14 Cells How To UPDATE from rcLazy on Vimeo.
After making this video, I went to the forest and tried the car, and I wacked the 2-cell bracket on a rock and ripped it clean off. I think it was perhaps too low, and that servo tape was not strong enough to hold it.
So I have to go back to the drawing board and modify my design. I figured I needed a 3 sided bracket, higher up out of the way, and fixed more firmly.
Almost Enough Speed…
Did all my mini fiddling work? Yes, almost!
I raced tonight, and instead of being 3 or 4 laps down off the pace, I was only a lap down. I made the A, by the skin of my teeth, hurrah.
A little room for improvement though… I managed to trash the motor I was using whilst cleaning it, not sure what I did, so I was on motor 2, which wasn’t quite as quick in testing. So I’ll revisit the motors again and do some running in etc.
And, the track was very tricky, lots of chicanes etc, and I think my slow servo isn’t cutting it… I might have to try the fast Futaba one out of the touring car to see what difference it makes, if it’s noticeable I might have to get a quick servo for the mini.
Tyres, in the final I was struggling with understeer, fronts were Express, and bald, and rear M grips. I’ve got some new Express but not on rims, so I’ll mount them up and try them on the front, with a veriety of rears to see what’s working.
Springs, I’m running it pretty hard, I think I need to soften it up a bit to let it roll a bit, and hence grip a bit more. A couple of times I was getting the diff spinning up in a tight corner.
All in all, good stuff, and a little more room for improvement, I’d be frustrated if there was nothing left to try!
If you’re gonna race: help!
I’ve raced at and been involved in running many radio controlled car clubs over the last 20 years… One thing that hasn’t changed in that time is the lazy attitude of some racers!
Some racers seem to think that a club is providing a paid service. Nothing could be far from the truth, the club is invariably run by volunteers, and any race fees paid merely go towards venue rent, equipment, consumables etc. The race fees don’t cover the organisational effort too!
Countless meetings do you see people turn up and then sit down, or race then vanish before everything has been cleared away. There’s usually considerable amount of effort to set up the track and timing equipment, and then pack it all away again. And it’s usually done by the same few people time and time again. And it’s usually the same people who don’t lift a finger!
Do these racers think no-one has noticed?
It’s the same old story year after year.
IF YOU’RE GONNA RACE: HELP SETUP AND CLEAR AWAY!
Okay, I’m done on that, for now, but no doubt it’ll get on my nerves again in a few weeks or months time.
What can be done to make racers help?
Buy Lazy Things !
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