edited December 2014 in KAP Gear Sources
I was personally surprised finding good quality helical gears in waste TONER cartridges (office printers, copying machines), many and with good chances of choosing a proper ratio,...

WORM-GEAR are available from car rear wiper or electric up-down movement of car windows,...

Gears bought from SHOPS are cheap and suited for purpose,... it's not for the money,... but the chance of giving a new life and in the sky to pieces considered rubbish,.. it' s a pleasure

examples are in :

SMAC from Italy


  • Nice post SMAC and great tips for finding gears.
  • Thanks SMAC - great money saver!
  • Thanks you have just reminded me I have an old multifunction printer/copier/scanner in my junk pile to disassemble.
  • I'm a big fan of puling apart old appliances / etc to recycle the parts, and my kids (especially my 7 year old daughter) love it too.
    I don't recall where the gears on my current rig come from - possibly out of an old laser printer or similar ;-)
  • Here is one

    The pic is dated March 2002, one of the first on my web site!

    Some of these gears make interesting tops to play with.
  • edited March 2015

    Much thanks to SMAC for pointing this out. Yet to fly but full of magenta cartridge needed replacing so I re-purposed the old one...


    Can't wait to see how well they do, the drive shaft introduces 'waggle' to the drive so I may loose mesh after a while.
  • I'm still blown that you can get helical gears that way. Cripes those are nice!

  • Tom,

    Any idea how long I can expect nylon gears like this to hold up? HP cartridges run for something like 100 hours ( that's a pure guess- it may well be much less) Pan gears take a real pasting on my rigs so I'm keen to keep spares in sight. These might be the answer...

  • I think they will last for ever. The gears in the servos are much much smaller and still have an unbelievable long life.
  • edited March 2015
    "The gears in the servos are much much smaller and still have an unbelievable long life."

    Ha! I have stripped so many now I have lost count..I have got to the point where I use metal gear ones wherever possible!

    In general I wreck one for every rig I build as I figure out the tilt balance. True once balanced they do last well- they are properly aligned in a gear box. Suspension on the pan axle (especially a thin one like an M3bolt) seems to force things out of alignment far too easily, I use a top and bottom 'bearing' and that still seems to want to move. Any more metal in there and I'd be building more gearbox than rig!

    The big KAPshop gears from Peter are nice as the big teeth will let you get away with all manner of alignment abuse- these dinky helical ones feature tiny teeth....we shall see.

  • They're about the same pitch as the ones I have on my pan gears. I think mine are made from acetal, but they've stood up to years of my being mean to them.

    Helicals, on the whole, tend to fare a little better just because the load is distributed along their length and because they don't take a sudden spike in load as a tooth engages. If they're in an enclosed gearbox and don't get too abused, they really should last practically forever. Exposed to the elements as KAP gear trains tend to be, they might take more damage from grit and the like.

    Bill, in your article you say the larger gear needs a guide to go on the M3 pan axle. Do you have a feel for how well the servo discs and nylocks are going to work? If that stack does start to slip, don't give up on the nylocks or the gears just yet. They may need a more solid core inside the gear to be able to apply the pressure you need to keep it from slipping. If it becomes an issue, you may be able to press a nylon shaft spacer into service. (I'm guessing this isn't an issue, though.)

  • Tom,

    The packing was needed to keep the open end of the big gear from slopping about on the axle.

    The servo disc was a lucky fit, really snug and it threaded itself onto the bolt, filling the hollow end perfectly it didn't even need glue. At the other end (bottom) there is a problem. The gear has a weird 3 lobed recess which didn't look like it would turn easily against the rig top, even with a washer, so I used another servo disc to similar effect to the top, but filed down to fit- the nylocs crushed the whole plastic sandwich tight and so far it's holding well. I needed to make up the height to meet the drive gear and the bottom disc acts as both washer and spacer.

    The most likely cause of failure will be the gears 'lean' apart and slip when the axle is forced by pendulum swing, despite having a top and bottom bearing it can move enough to get the driven to skid over the drive on bench 'testing'.

    If the howling gale abates I'll be able to do something more useful than rig twiddling and find out how it works when the 360 micro turns up.

  • That all made sense. Here's hoping your weather clears soon!

    This morning I got skunked for the umpteenth time in a row. I'm going back in about half an hour with freshly formatted cards, charged batteries, and some cleaned up bridles to try again. If the weather holds I'll try to send some of it your way so you can test the gears in the air.

  • edited March 2015
    Having spent far too much time worrying about how the gears would do I grabbed a gap in the relentless Bft 5 and flew the rig in the other wind we have here: 'light variable' under a Jones 8'rok.


    Got some nice results...but clogged the lens on wet grass at launch.


    ...and thanks again SMAC!

  • Absolutely LOVE this tip! I'm going to become quiet the gear head.
  • Thanks to all contributors for comments added

    thanks in particular to Billblake for his effort in use and nice - kind documents added (too much honour for a little thing,..)

    but the original great surprise is that these GEARS are of good quality and good material

    SMAC from Italy
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