Worm Gear Setup

[Bill Adamsen]

What old common tool or implement might have had a 90° gear with a worm drive? I'm trying to fabricate something and looking for a "parts" source I can get cheap without feeling badly about it.

[Dan Cameron]

What old common tool or implement might have had a 90° gear with a worm drive? I'm trying to fabricate something and looking for a "parts" source I can get cheap without feeling badly about it.

How about a hand drill ?

[Malcolm McLeod]

Most obvious is worm-drive circular saws. I've no idea of your size or Hp requirements, but maybe bevel gears from auto differential, or look at old farm equipment?

Also, take a look at Vex Robotics. They and other hobbyist robotics kit builders offer a fairly wide variety of small gear train components that might fit your requirements.

[ian maybury]

Stock gears from engineering supply places can be pretty cheap - and have the advantages of being new, and of their ususally being a choice of specs available...

[Morey St. Denis]

Depends somewhat on the power you are looking to develop and desired gearing ratio / shaft output speed... Assuming you might also want a working electric motor attached? At the high end of performance power tools you have the old reliable worm drive saws. Not just the renowned left-blade circular saws of Skil / Bosch; Makita, Ridgid & DeWalt also offer similar hypoid geared left-blade circular saws. In the middle to fractional HP output range you've got the portable angle grinders both 7" & 4.5" - 5.0" compact hand-held sizes.

I'm clear on your need for a 90 degree output shaft; bevel gears can also accomplish this at more modest reduction ratios and may not always require sealed gear-case lubrication that usually accompanies worm gearing. Think kitchen blenders / mixers or old manual crank hand drills. Worm drives offer extremely high reduction ratios enabling high torque output, but with the added requirement of extreme high pressure lubricants, often within a sealed gear-case. Offering midrange power around unity to fractional HP, with output speeds ~ 6,000 rpm, many conventional tile wet saws also now use adapted angle grinders. With your power requirements and shaft rpm goal firmly in mind, you might look for used tools of these sorts in working condition; also check Harbor Freight for economy angle grinders. With people often opting to dispose of or upgrade household appliances requiring only the most basic repair of a timer, switch, sensor, or flexible transfer coupling; could be on the lookout for a used laundry washing machine if this might also suit your goals in terms of size, power and gearbox output rpm.

[Malcolm McLeod]

Maybe windshield wiper gearbox/motor?

[Bruce Page]

Check out Pic Design (http://www.pic-design.com/) they have several choices as long as you're not trying to build a tractor PTO. ;)

[Earl McLain]

Radial arm saw, but definitely limited to hand cranking i would think. My intent is to one day move my drill press crank to the front of the table. I got a pair by dismantling the remnants of a Craftsman "bounty" saw. Half inch bore as i recall.

earl

[Chris Parks]

What old common tool or implement might have had a 90° gear with a worm drive? I'm trying to fabricate something and looking for a "parts" source I can get cheap without feeling badly about it.

The table height mechanism on a Hammer A3 combination machine has a worm drive.

[Bruce Wrenn]

Check out "Boston Gear." Most likely they will have something to fill your needs.

[Bill Adamsen]

Bruce & Bruce, thanks for those leads. PIC is right here in CT. I looked initially at my Unisaw worm and thought - that could work nicely - and even better if it were double the throw (90° instead of just 45°). Half a car flywheel would be perfect ... though cutting it in half might be challenging and the teeth are unlikely to have the same diametral pitch and thread (most flywheels I've seen are straight cut). What would be perfect would be just an edge of teeth I could weld onto a plate.

[Morey St. Denis]

As it's become apparent that you do not require even a full revolution of the output gear & shaft, believe more appropriate terminology may be worm drive pinion & rack gearing... Quite similar to automotive rack & pinion steering gear, if a linear "rack" component could be pivoted, hinged or otherwise gravity or spring loaded against the hand-cranked pinion, it may likely accomplish your needs more economically than a full circular, helical-toothed driven gear. Much like the table height adjustment mechanism of a drill press, mill or surface grinder, which can often be just rack & pinion. More costly helical tooth hobbing & precision grinding buys the advantage that these typically cannot be back-driven with the steeper reduction ratios..