Been away for a while....

...but not out of the RC game completely.

For a number of reasons I haven't found (or maybe that should be haven't made) the time for my RC cars. Truth be told I'm having a bit of a break to see in what direction I want to go with it. I no longer work on my cars in the house and 'my' room has been turned back into a home office. I'm thinking that if I have to work outside anyway then I might as well get myself a big, smelly, oily 2 stroke RC again. We'll see though, if it does happen it won't be for at least 6 months.

Anyway, what I have been up to is helping a local high school with the 4x4 in Schools Technology Challenge. The challenge, in a nutshell, is to create a rock crawler to compete a number of tasks / obstacles within a set design spec.

As new comers to the competition the school were eligible to compete in the rookie class but as that didn't stretch much beyond making a new bodyshell the team decided they wanted to jump straight in to the deep end and take part in the full competition!

Here is a picture of the track at the Southern region finals that took part at Savoy Place, home of the IET in London.

As you can see, the track consists of a number of technical elements and despite only working on the car during their lunch breaks the car that the team created did a great job of getting around the course.

Based on a Losi Mini Rock crawler the team re created the chassis, designed and made their own suspension links and mounts, made their own wheels, upgraded the suspension and tyres, converted it to 4 wheel steering and even more adaptions.

Here is the teams main driver who managed to do 90% of the course on his own with no driving errors at all! With over 20 years experience of RC cars I couldn't have done a better job.

The team have made it through to the national finals in March so I'll be giving another update then as well as a full run down of what has been done to the car. Wish us luck!

And to think I used my one as a basher!

My old Tamiya FF-01 had a Volvo 850 shell that saw many hundreds of uses over the years. In the end it was battered, most of the paint had come off the front and it was partially held together with cable ties.

Therefore imagine my slightly gutted feeling when I saw what mint ones are going for these days ebay link SEVENTY NINE QUID inc P&P! Maybe the guy is a dreamer but still... damn!

FF-01 Build - Battery Holder Manufacture

As I've already mentioned the FF-01 came minus a couple of bits. I managed to order a body fitting kit from ebay to replace the missing rear body mounts. At the same time I also ordered a manual, probably come in handy for the £2.50 it cost me. This left me needing to sort the battery holder.

After a bit of Googling I realised that I wasn't going to be able to buy one so I would have to make my own!

I measured up the chassis and did some pencil sketches to get some ideas down and then went into my 3D CAD package of choice, Solidworks.

The part was dead simple to draw, although in hindsight I'd have done it slightly different, maybe a mk2 version is needed but more in that later! Here is what I came up with-

The idea was to get the part made up on our ABS rapid prototyping machine. For this I needed to create a wireframe vector model known as an STL. A couple of clicks later and this was done-

Feeding this into the Insight software that drives the rapid prototyping machine takes this wireframe model and breaks it down into 0.2mm layers (the thickness that the ABS plastic comes out at) and also works out the paths needed to be taken by the machine to lay down both the ABS model material and the support material that is removed after the build is complete.

The part took around 50 minutes to build. After it was removed from the machine it looked like this with the support material in place-

The part was quite robust and the support material quite easy to get to so I attacked it with a screwdriver rather than dissolving the support material away.

Time for a test fit!

Like a glove ;) All I need to do now is drill a hole in the centre shaft so I can get a body pin through. I could have added the hole to the model but it would have been filled with support material so I decided to just drill it out after.

So, the improvements I mentioned... I should have added a fillet to the join between the horizontal and vertical parts to improve the durability and remove a stress razor. Secondly I think the original had angled supports on one side. I'll see how my chosen battery fits and may do another version with these added.

Another project... I'm actually going to complete this one!

Well after deciding that my Touring/Drifter hybrid wasn't the best of ideas I got rid of the TC3 and decided to concentrate on that niggling idea of another FWD car.

I wanted the same layout as my Tamiya FF-01 (motor mounted in front of the front wheels) as I knew this made the thing handle like a dream. This left me with two options, a brand new FF-03 or hunt out a used FF-01 like I used to have.

I really can't afford a new FF-03 so when a MSUK forum member mentioned that they might have an FF-01 for sale I bit their hand off! The car is a rolling chassis, just needs rear body mounts which I know I can buy and a battery clip which I will attempt to make if I can't track one down! Here she is (photos from the seller)

I kept saying how I regretted giving away my old FF-01. Well now I'm not so sure it was a bad idea as this is a much tidier chassis to use as a base.

Plan is to get the radio gear and brushless ESC and motor in there. Then get the battery clip made, everything else will have to wait until I release a few quid out of my RS4 parts which are failing to shift on MSUK. I might just have to bite the bullet and get them on ebay to see the back of them.

As for a shell... I'm not sure yet! All I do know is that it will have LED's and this time round I'm going to try a connection between the body posts and the body itself to get power to them. Not sure if this will work or not but it will be good if I can do it as I will be able to mount the batteries for the LED's on the chassis.

Finally... what about the drifter idea? Well, I will come back to it but from a different angle. How does a tail happy Rally/Drifter hybrid with a D-Box (or in my case a cheap piezo gyro!) sound? Lets get this one finished first anyhow ;-)

Slash castor block broken again!

Well my glued up castor clock didn't last long! This time it was my own foot that I hit rather than a post! Only a small knock though so obviously the plastic didn't take to gluing very well. Having said that if I had known that the part was only £3.09 I'd have just ordered one anyway!

I did look into uprated parts but the only ones available were aluminium ones at £17.99. I'd rather keep breaking  cheap and easy to replace castor blocks than move the damage to something else in the event of an impact.

I ordered them from Modelsport so I should get them in just a few days.

RC Driving 101

When driving your RC car from the other side of a car park, after thinking "I must avoid those bollards" DON'T then proceed to drive flat out into one of them! Doh!

Car in question was the Slash which came out of it quite well really with a snapped C hub which I have simply super glued back together.

Waiting for the glue to dry...

Before that little... incident I was really pleased with the extra speed that the gearing change had. Much more like the pace I was expecting from it! The downside was that while getting used to the extra speed I was grip rolling loads which has put two small cracks in the shell near the back of the roof. Oh well, it isn't a proper Slash without a knackered body!

For now I have just put some duct tape on the inside of the shell to try and stop it spreading.

As for the HoBao, well I remembered to take the right handset this time but found that neither servo would move, all they did was glitch when the power was turned on. The new steering servo turned out to be a duffer but that didn't explain why the throttle servo didn't work. Strangely at home it seemed ok after swapping on my spare battery pack out of the RS4. I've charged the AAA's from the HoBao and I'll just have to keep an eye on it I guess.

Buy cheap, buy twice!

Well, I guess my post title is a little unfair. Basically when swapping a pinion on the Slash my 1.5mm hex driver sheared off.

Where has my tip gone?

There it is! (in the end of the grub screw!)

I think I must have cross threaded it because when I tried a normal (and rather flimsy) allen key on it the thing wouldn't budge.

On another note... the reason I was fiddling with it in the first place? I thought it was about time to try out the optional pinion and spur which allow for greater top speed. I'll see how it goes tonight when I take it out to the Park & Ride car park.

TC3... sold!

I decided I couldn't wait to build a storming FWD monster so I have decided to move the TC3 on to a new home. Already sold via the Modelsport forum so I'll be keeping an eye out for the right FWD chassis.

Loved it, Loathed it!

So while breaking my (second!) RS4 for parts I was thinking that my cars fall into two distinct categories (well, with one exception!) I either loved them, loathed them... or they are my Traxxas Slash which is just... meh!

So how do they sit, well from where it all began when I was a nipper to current day, here is how they scored!-

Tamiya Thunder Shot - Loved it
Tamiya Boomerang - Loved it
Tamiya FF-01 - Loved it
Kyosho Ultima RB - Loathed it
Tamiya TL-01 - Loathed it
HPI RS4 Evo (x2!) - Loathed them 
Tamiya TT-01D - Loved it 
Kingmotor Baja - Loved it to drive but it was a PITA so it scores a... Loathed it
HoBao Hyper 12 - Love it
Traxxas Slash - Meh!

So only 1 of 4 nitros hit the spot or 1of 5 internal combustion cars and 4 of 5 Tamiyas were among my best cars.

Interestingly this makes my recent decision to put together a collection of electric Tamiyas together less crazy than it might seem... oops... did I just say that out load?! Better watch this space to see what will be making its way in and out of my collection over the next few months.

Bye Bye RS4

Well I slept on it and I think the RS4 has to go. I've simply never been happy with the car, the rally conversion needs more work than I planned (single speed conversion etc.) and well... I've already got my TC3 project on the go and a few others that I'd like to do sooner rather than later.

I'll keep a fair amount of the car (suspension etc.) as spares and may use these bits to Frankenstein something up in the future. Bespoke bits will end up on ebay and this has solved my issue of where to source a radio for the TC3 at least ;)