Starting Point

[zoll]

Team xtreme sorted me out with a couple from a job he was doing not sure he will have any more though im affriad ><

[xtreme]

Ill see what I can find for you.

[zoll]

If not these might do?

[elobire]

ok thanks.
i was thinking about using the centre of a bike wheel, the only concern i had about that is that i would need to weld a plate to it to bolt the axe on too.
EDIT: searched around, and found someone who sold some cheaper ones.
http://shop.ebay.co.uk/webtradersonline ... 581&_pgn=2

[zoll]

elobire, can I ask what welder you have and how your getting on with it as I'm looking to buy one. Think ive decided on a mig not sure what model though

[elobire]

i have a gassless mig welder, it was about £120. i dont really know the make/model, but i can find out tommorow.
im not doing too well with it anyway, all i can produce at the moment are messly welds which cant hold together well. im still getting used to it though, as i havnt used a welder before.

[zoll]

Exams finally out the way back on with some building...

Dont like the chain setup so am going for a gear reduction using the following parts from technobots
Steel Spur Gear MOD 1.5 12 Tooth - Part No: 4715-012
Tbot Steel Spur Gear MOD 1.5 60 Tooth - Part No: 4715-060
Tbot Steel Spur Gear MOD 1.5 12 Tooth - Part No: 4715-012
Steel Spur Gear MOD 1.5 36 Tooth - Part No: 4715-036
which i believe will give me a 15:1 reduction?

How easy would it be attach this motor to this gear? I think the shaft diameter is 8mm as is the bore in the gear so would i just be able to screw it straight on or is it not that simple?

[RogueTwoRobots]

In theory, it should be that simple. With an 8mm shaft and an 8mm bore, you could just slide it onto the shaft of the motor and secure it using a couple of grub screws drilled and tapped through the boss so that they're pressing onto the shaft of the motor when tightened.

That would hold it on but whether it would be enough to keep it there, with the forces that would be going through the axe mechanism, I cannot say (although hopefully someone else can)

[zoll]

Yeah was thinking that also thought about getting someone to put a touch of weld on the end.

Also can anyone see any problems with that combination of gears?

[Metal Demons]

You might want to think about some bigger gears - mod 2 or 2.5, ideally the biggest you can fit in within reason. 1.5 isn't terribly strong when you're considering that you'll be violently stalling the system, possibly reversing direction while moving the axe at high speed if you mess up a bit with the timing, that kind of thing. You might end up breaking a tooth.

On an 8mm shaft, you may get away with grubscrews and red (the strongest) loctite, but you'd be better off with a keyway in the shaft and gear (might be a bit small for that) and a machine key, shaft and gear with a flat side to the hole / hex shaft and hub / whatever, or another method of torque transfer. Grubscrews shouldn't be used to transfer significant torque, that's not their job.