Buying a randon gear

[leen...]

Hi All,

When I started rejuvenating the hedge trimmer attachment it was sticking. Long story short, one of the metal gears inside has an area where the teeth have worn down and not catching the rod that is turning it. Not sure how this has happened since most of it is perfectly fine - assume at some point the blades were stuck at this location and the driving gear worn them down.

Looking at the Ryobi website and doing some googling, parts for it (AHF03) are discontinued so can't get a replacement. How viable is it to buy a generic one online? It is one of those types where the teeth are at 45 degrees to enable small diameter driving gear that is spins in a vertical plane to turn to larger diameter gear that needs replacing in a horizontal plane (if you see what I mean). Any idea what these are called as googling I can't find anything that looks like this.

Thanks

Lee.

[newshound]

It's a bevel gear. The teeth are likely to be a standard size (pitch or module), another variable is the number of teeth, the final one is the angle (not necessarily 45 degrees, but the two must add up to 90).

But the OD and ID of the boss, and the type of fixing (pin, key, screw, spline) will have been chosen by the designer. These *may* have standard dimensions but more likely they will be manufactured to fit other design constraints.

If you are lucky you might get something on-line that is adaptable. A good model-maker might be able to help, if you can find one.

Radiospares have a range, though for some obscure reason they call them mitre gears.

[williamwright]

Throw the thing away.

Bill

[Brian Gaff (Sofa]

Crown wheel or gear, unless its a bevelled angled gear set of course, in which case you need the pair. Brian

[Brian Gaff (Sofa]

That was my first thought too,its a bit like an old car we used to have with teeth missing on the flywheel so the starter would jam one time in 10, and somebody had to hit it with a mallet.

Of course to some the fact that the rest of it is OK would be seen as a challenge. I would imagine in this case you would also need to know what the gears are made from as well as other parameters, mentioned since you will have to replace both as that damage to one would indicate at least some damage to the other one, unless it was cheap plastic rubbish. Brian

[Chris Bacon]

Do googling to see if somene (lawnmowerspares, mower magic?) have old stock.

Buy a used one for £20 and cannibalise it.

See if the part is common to other brands or models.

Stick it in a shed and think about it for a few years.

[Animal]

Or 3d print one. But my preferred suggestion is the bin.