Liftoff (FW) build diary

**Liftoff** · 17th August 2012, 18:28

I've finally got most of the parts I need for the build so I thought I'll follow most of you and keep you updated on this build diary - at the same time any advice and comments are more than welcome as I'm no expert in this field!

So some details first - Liftoff shall be a LP flipper track driven by two motors. Details Below:

Drive type: Tracks
Motors: X2 Makita 6347D
Esc: Sabertooth 2x60
Armor: HDPE (plus steel if weight permits

)
Weapon: LP flipper Co2 63mm bore cylinder

Pneumatic system parts mostly available and assembled, remaining is the cylinder which will be machined locally.
Will post some photos soonish.. :wink:

**Liftoff** · 1st May 2013, 18:38

Been abroad for some weeks so I had to abandon the build for a while... Now that I'm back home I can go about putting the pneumatics together and hopefully give it a test some time soon.
I'm replacing most components from the previous set up which had an empty weight of 3.7kg. The new set up weighs in at 2.6kg, that's a weight saving of 1.1kg, not bad eh!

Flow should improve as well - I'm using a different type of QEV which I had to modify to fit in limited space available (basically I had to plug the inlet and drill/tap a 1/8bsp inlet at the side) The smallest restriction from buffer to the ram will be 11mm as compared to 8mm of the previous setup - that should in theory help as well...

Some photos of old vs new QEV, old weighs 310gr, new weighs 120gr

20130501_202804.jpg

And connections from buffer tank to ram

20130501_203140.jpg

**Liftoff** · 10th May 2013, 20:50

Did some testing this evening, and I'm happy with the results. Pressurised the system to 5 bar (need to buy myself a proper compessor for higher pressures

). Was a bit concerned whether the 5/2 way valve would work properly, its miniscule compared to the rest of the system was worrying me! but I confirmed that it does not affect in anyway the flow through the system.
I can now turn my attention to the rest of the build.
Video in action

**Liftoff** · 31st May 2013, 09:14

A small update, been busy building the track drive these last days and finally most parts for it are ready, what remains to do is the tensioners holder and the tracks themselves. But before I order the tracks I want to get some different material samples to evaluate for best grip.

It was quite a headache to design and build, but it looks like this system will perform better than the old one...hope I can test it soon!
Here are some pictures of the progress so far.... questions and comments are welcome!

**Liftoff** · 2nd July 2013, 12:16

Been quite some time since last update and not much was happening either...was too busy at work...but now that I'm on holidays will try to give it a good push.So yesterday and today I spent the day on it trying to get the track drive in order.

And immediately bumped into the first problem! Put all the bits together, motors wheels track, and tensioners and tried to adjust the allignment, but the bearing on the motor gearbox is too flimsy! The motor shaft to which the drive wheel is mounted wobbles too much and as soon as I increased tension on the track, it jumped off the wheel and the gearbox jammed

I had the impression that the GR02 gearbox with the addional external bearing support would be up to the job, but it seems the wheel overhang is too much, even for this modification!

So had to go to the drawing board again to figure out a solution....and spent the morning filing and hacking at a new fitting to support the wheel at the far end... hopefully it will work, will see tomorrow!

**Liftoff** · 5th July 2013, 21:53

Update: One of the track drives is almost finished and assembled, it looks promising as rotating the track by hand it feels free so I'm hoping allignment is fine...but only when I hook it to a battery will I know the real result!
It's late now so that's for tomorrow morning.... fingers crossed!

20130705_153404.jpg 20130705_153452493630461.jpg

**webby** · 5th July 2013, 22:29

That looks great! Interested to see how it performs and how it grips/ slides, more inventive than wheels lol

**Liftoff** · 6th July 2013, 08:36

more inventive than wheels lol

true, but its also a bigger headache than wheels!

So as planned this morning I rigged the motor to a 6v battery and gave it a go...and immediately it threw the track off the wheel!

an hour later I managed to adjust the bloody thing to finally hold the track in place.

I'm not 100% convinced, I'm afraid that when both tracks are in place and try to steer the thing, it will throw the tracks off... the Hdpe base does not help much as it flexes a lot, installing the outer bulkhead should help stiffen the whole thing up, I hope!!

So this is how it looks while turning freely: