Liftoff (FW) build diary

[Liftoff]

Thanks :wink: The wheels I planned to use are twin 73x20mm banebots to give me a with of 40mm.
Like this:
http://www.technobotsonline.com/banebot ... re-30.html

But the drive system will be different from what's in the drawings... I'm still obsessed with having it track driven!
I know it was a real pain to set it up and it was not the most efficient drive system at all - but I designed a new set up which hopefully should work...the steady bearing on the gimson motors will come in handy for this!
Will post a couple of drawings tomorrow...

[Liftoff]

As promised - the tracked drive system design. Running track drives for these last 4 years on different machines always gave us trouble - but I have to admit the early ones were quite rudimentary systems
Main problems were : excessive side load on the motors as they were not supported at the far end, causing the motor to heat up and draw a lot of current. Another issue was track alignment, without proper precision engineering the track would try to slide off the wheels and rub against the sides.

In this new design the drive wheel is supported at both ends, that should take load off the motors. Alignment of the track is achieved by adjusting the forward idle roller. The fwd roller is mounted on shock absorbers which can be adjusted to move fwd or aft. This should hopefully keep everything aligned and tensioned . Both wheels are flanged to help prevent the track coming off...

The pics: :wink:


Tracked drive system V.04





Drive wheel and attachment to GR02 motor - exploded view





Drive wheel and GR02 assembly

[Eventorizon]

That looks awesome! I have been wanting to fit tracks to one of my machines for a while, I might just have to nick that idea And again, great CAD! An exploded drawing in Sketch-up!

[Liftoff]

Good! I'd only be too happy to know my work was useful to someone else! I really learnt a lot from this place.


I've always run our machines on tracks and I like it to stay that way - but having said that, it does not mean its superior to other types of drive. I actually think its got more disadvantages than advantages...mainly being: increased weight, complicated (more things to go wrong) and believe it or not , less traction! The main advantage is its ability to move over uneven surfaces, that is - it difficult to get stuck.

Thanks for the compliments on the drawings...but as I said, once you get used to it, its quite simple...will try to upload some of the components just in case someone would like to use them

[PJ-27]

I said a few times in the past we should have a cache on here of everyone's SketchUp components. Saves everyone making the GR02!

[Revsmin]

I've already done the GR-01s, and I'm working on other components. Search for them in the workshop.

[Liftoff]

Maybe we should open a new topic and make a sticky....then all post and link their components there...
I've uploaded the sabertooth esc... don't think I need to upload the GR02 now

[Ellis]

I put a GR02 up there and have loads of other components that could go.

[Liftoff]

So I've dismembered Liftoff and got it to a shell again in preparation for the rebuild - one thing is bothering me tho. When I first put it all together I used normal chipboard wood screws to join the HDPE parts together - now I'm not convinced they'll re tighten as much as they used to do.

I had read somewhere on the forum that you could use wood inserts for better results. Now I've had a look on ebay and found what I need, just want to know what size you recommend, I'm using 10mm HDPE so the insert must fit within the thickness...

These are what I was looking at these two, both fit within the thickness, but the screw size is different

http://www.ebay.co.uk/itm/M3x12mm-Slott ... 3f0c4473b0

or

http://www.ebay.co.uk/itm/M4-x-10mm-Unh ... 4169c14f67

[plargen]

I've used the m4 1s before and they seem pretty good at holding the first bot together dropped it a few time and it stayed in 1 piece