Tormenta 2 - Build Diary

[mattsdragons]

Believe thats just the gearbox and the motor has yet too be secured in as it goes through the side wall

[Gabe01]

http://i1088.photobucket.com/albums/i32 ... 202/15.png

yes you're right, checked his CAD

[Ellis]

Yeah, the motor will go through the side. Not brilliant but, eh, again, it just can't be any smaller!

Yes we'll put something around the drive motor to protect it. When the chain is under tension it should clear quite nicely, but a bit of PVC won't go amiss. We didn't predict the magnetism of the motor being an issue, though! Surprisingly strong pull.

The motor is just a biggish 14.4v drill motor. It's 50mm in diameter as against to the drill motor size of about 36mm. The high resulting RPM of putting more like 20v through it is being turned down to 120rpm with no load, so there's a pretty big reduction. Hopefully it'll have the power. Actually occurred to me that if we can get the right pinion we could stick a Speed 900 in there!

[PJ-27]

The output shaft on most cheapy drill motors is usually very small, so the pinion gear is equally tiny. A Speed900 has a 6mm output shaft so you may struggle.

[Gabe01]

Sewer Snakes weapon motor is subject to a 75:1 reduction. I reckon if you test it early stages and it can lift 20 kg's (fast) the it will be effective. Its got to be fast and furious, if its to behave like Sewer Snakes.

[Ellis]

Sewer Snakes weapon motor is subject to a 75:1 reduction. I reckon if you test it early stages and it can lift 20 kg's (fast) the it will be effective. Its got to be fast and furious, if its to behave like Sewer Snakes.

That's the thing. The motor is by no means huge. Just compared a Speed 900 to the motor we have, a 900 is about a cm longer, and it weighs about 200g more. The output shaft on our motor is 5mm, I think.

It would probably be possible to do, actually. If we had to. Quite a lot of $$$ though.

We did some tests as you saw in the videos, and it didn't seem to struggle at all. It lifted about 5-6kg on a 7inch bar without the further 4:1 reduction on a bad battery when we first got the drill, which would suggest it'll do around 20kgs.

We shall see! We haven't completely ruled out buying a drive motor for a bigger robot as a way to do it. This will lift a FW, I'm quite confident of that, it's when it lifts itself+another machine (which will happen quite a lot I think) that we may struggle.

[PJ-27]

Matt Maxham the guy that built Sewer Snake is a really friendly guy. I emailed him a while back because I wanted to make a similar robot, but that's yet to happen.
I think he's also on this forum, but not very active.

I take it you've seen this vid?:

[Ellis]

Yes, I had seen it. I love how rugged it is. We're trying to do the same. Precision isn't our thang (in that we can't really have it, lol).

Been a while since we made progress, and MMM is suddenly REALLY SOON so we're going to try and crack on and finish now. We didn't do much tonight, made a Swiss-cheese style piece of HDPE with a total of 13 holes in it! Should do the trick though, it's to do with mounting the lifter motor.

We haven't gone ahead and finalised the lifter motor position yet as it's probably best to get the actual lifty bit built first. To do that we need scoop material. It's on a shallow angle so about 4mm steel would be great, but it may be impossible. Assuming we can source some locally, it may simple be too heavy. In which case 10mm HDPE might do. For the UK champs most likely not, but for MMM where I believe the competition won't be quite as lethal it could get us out of trouble. Better on the lifter motor too; lighter.

Mentioning that, the lifter gearbox is a 2-speed and so it has a sliding plastic ring gear inside. We fear it will fail, as we're over-volting and putting massive stresses through it. It's quite a complicated shape. It's similar to this: click - any idea if we could get such a thing made out of stronger material? And if so, where? If anyone can suggest a company we'll love you for ever and ever!

[PJ-27]

I believe one of the gearbox settings doesn't use that ring, but which one I can't remember...... Pretty sure it's the low range.
If you're using the high then don't worry about it. If you're using low then do....

[psycho_fling]

without knowledge and the access to the correct machines it would be hard to replicate that, and you wanted someone to do it say out of ali it is doable looking at that picture but looks very time consuming->expensive