Machinists - Looking for a small job ?

[theoldwizard1]

The OD measures 1.226". The ID measures 0.492" (1/2?). 0.370" thick. It has 28 straight cut teeth. I have not measured the keyway yet.

The original was probably made out of powdered metal. Lots of torque going through this gear.

 

[theoldwizard1]

Can a water jet cut teeth this small ?

 

[The Cobbler]

If no one on here reaches out, I would suggest Keith Rucker @ vintage machinery.org on you Tube . I think he mentioned ion one of his videos about an online gear supplier as well that stocks all sorts of common stuff

 

[LopezBart]

bore is likely 12.5 mm. Is this metric?

 

[larry_g]

Linn Gear Co.

Linn Gear manufactures stock and custom sprockets, gears and other mechanical power transmission components for industrial applications.

www.linngear.com

You really need to identify the pitch and pressure angle. metric or standard. Then go to the above site and see if they have a standard off the shelf gear that can then be bored and keyed to the shaft you need it to fit on. That is probably the best route that I could suggest unless you find a willing person to make if for you. You could also give out the information of what this gear comes off of. That information may help in tracking down basic information of the gear. I'm guessing that the manufacture is NLA.

If the gear is not that precision then you could contact Send cut send to cut it for you. A friend uses them a lot and is amazed at what they can do. He has had gears cut for small instruments.

lg
no neat sig line

 

[tool_scrounge]

Linn Gear Co.

Linn Gear manufactures stock and custom sprockets, gears and other mechanical power transmission components for industrial applications.

www.linngear.com

If the gear is not that precision then you could contact Send cut send to cut it for you. A friend uses them a lot and is amazed at what they can do. He has had gears cut for small instruments.

lg
no neat sig line

I use sendcutsend and they can be a great value. But when cutting 0.25” or thicker there is a noticeable taper on the cut surface. So if I need to mount to the cut surface. I need to face it off square on a mill if I want perpendicular parts. This is probably an issue for thick gears.

 

[Firebrick43]

You can find a gear blank from someone like Boston gear or Martin much cheaper than having a whole gear machined

Their gears are Hobbed or skived and are going to be stronger and longer wearing than gears made on a milling machine with an indexer/rotary table with and an involute cutter

They usually have an undersize hole so the machinist only has to bore the center out and broach the keyway

https://www.bostongear.com/ecatalog?page=search&cid=spur_gears_02

https://www.martinsprocket.com/docs//catalogs/power%20transmission/4_gear%20catalog/gear-catalog.pdf

I couldn’t imagine one of them not having the correct blank for a simple spur gear.

If you don’t have the measuring equipment you can enter what you think you have into a gear calculator program, have it output to dxf and print in 1:1 scale. Then you can put the original gear on top of the print to check.


Gear generator

 

[RoninB4]

Why would you think this gear is made from PM? Gears of all sorts have been made for decades before PM was ever an option.

As for using a water jet, the tolerances for a gear will be tighter than most water jets can achieve in the state most shops keep them in. Furthermore, the thickness of the gear would likely cause it to be tapered (draft) and that's not acceptable for a gear subject to high torque.

Firebrick43 had the best advice about checking Boston Gear or Martin. Most shops I've worked at used either and I'd be surprised if one of them didn't have an off the shelf solution. A straight cut spur gear may look like a simple job but cutting gears is not as simple as it looks.

 

[theoldwizard1]

bore is likely 12.5 mm. Is this metric?

I don't think so !

You could also give out the information of what this gear comes off of. That information may help in tracking down basic information of the gear.

It is from a late 70s/early 80s Craftsman (made by DeWalt) drill, model No. 900.27121

 

[theoldwizard1]

Why would you think this gear is made from PM? Gears of all sorts have been made for decades before PM was ever an option.

Because the faces of the crack look like PM ! Could it be cast iron ?

 

[alfadan]

The above options are easiest. You'll be seeing some numbers like 14 1/2 pressure angle or 20. I'd wager its a 14 1/2.

My expertise extends to replacing a single gear one time! I used a catalog gear from Boston Gear. If you get no other options I'd try my hand at doing it.

 

[DocsMachine]

Because the faces of the crack look like PM ! Could it be cast iron?

-70's/80's Craftsman? All but guaranteed it's cast iron.

As the others have said, very likely you can find an off-the-shelf gear like that- there's absolutely nothing unusual about it.

McMaster-Carr has a selection of gears, too. Not as extensive as Boston or Martin, but for something fairly simple like that, they might have what you're looking for.

Doc.

 

[rocksnstumps]

You can find a gear blank from someone like Boston gear or Martin much cheaper than having a whole gear machined

Their gears are Hobbed or skived and are going to be stronger and longer wearing than gears made on a milling machine with an indexer/rotary table with and an involute cutter

They usually have an undersize hole so the machinist only has to bore the center out and broach the keyway

https://www.bostongear.com/ecatalog?page=search&cid=spur_gears_02

https://www.martinsprocket.com/docs//catalogs/power%20transmission/4_gear%20catalog/gear-catalog.pdf

I couldn’t imagine one of them not having the correct blank for a simple spur gear.

If you don’t have the measuring equipment you can enter what you think you have into a gear calculator program, have it output to dxf and print in 1:1 scale. Then you can put the original gear on top of the print to check.


Gear generator

^^This. Was going to mention those exact two sources and found this reply already. We used those companies a lot back in the day when we designed our converting equipment in house. Will likely still have to find a machinist to match your bore and keyway. Maybe they even offer those services these days, doesn't hurt to ask

 

[MichaelP]

Buying a new drill will be less expensive than having the gear cut by custom order.

 

[BillK]

Does this look like the correct part ? Maybe start searching e-bay etc or calling some tool dealers and see if someone has one old stock.

https://www.toolpartspro.com/dewalt-parts/dewalt-d116-04-type-1-parts/dewalt-445265-00-gear-pinion

 

[imagineer]

Can a water jet cut teeth this small ?

Yes, easily. Even our old, well used WardJets can hold +/-.020"

 

[RoninB4]

Yes, easily. Even our old, well used WardJets can hold +/-.020"

-A .040 spread on gear engagement? If we add in the draft from cutting a thick section it may/will be more. Sure it's possible but doesn't sound like good results.

 

[theoldwizard1]

Does this look like the correct part ? Maybe start searching e-bay etc or calling some tool dealers and see if someone has one old stock.

https://www.toolpartspro.com/dewalt-parts/dewalt-d116-04-type-1-parts/dewalt-445265-00-gear-pinion

That is what it meshes into.

Could be https://www.ebay.com/itm/204943037362

 

[86turbodsl]

Buying a new drill will be less expensive than having the gear cut by custom order.

This! I had some gears made custom for an expensive machine tool that was already EOL. It was near 3K if i remember correctly.

If it doesn't have a mate at Boston or one of the others, it'll be waaaay cheaper to just get a new drill.

 

[Beerhippie]

I think that's called a "small part, big job".

 

[dr_clyde]

Why would you think this gear is made from PM? Gears of all sorts have been made for decades before PM was ever an option.

As for using a water jet, the tolerances for a gear will be tighter than most water jets can achieve in the state most shops keep them in. Furthermore, the thickness of the gear would likely cause it to be tapered (draft) and that's not acceptable for a gear subject to high torque.

Firebrick43 had the best advice about checking Boston Gear or Martin. Most shops I've worked at used either and I'd be surprised if one of them didn't have an off the shelf solution. A straight cut spur gear may look like a simple job but cutting gears is not as simple as it looks.

Depends on the jet, to be honest. Flow has a nice tilting stream feature that compensates for the taper and the cuts are very precise, even in thicker steel.

I would bet a competent waterjet operator with a taper-compensated head could hold .005" without breaking a sweat. I've welded 3"+ thick steel plates that have had features cut in them on the waterjet to within .005" and it wasn't proclaimed to be a big deal.

If this was me, I'd replace the drill. Cheaper than getting a gear made by a long shot. If I was serious about replacing the gear and a hob wasn't available, I'd get it wire EDM cut. The wire shop at my day job cuts a LOT of gears, and for a one-off is the way to go if the geometry can work with wire. But, we're looking at a few hundred dollars to make a gear in a drill that would cost half that to replace.

 

[theoldwizard1]

Well, I purchased a gear for $10. Correct OD, ID, gear pitch and key way. 99% certain is is also PM.

It has a shoulder that needs to be ground down. Bore a shallow hole in a 2x4 slightly smaller than than the OD and press the gear in. A few passes with the grinder and I should be good.

 

[The Cobbler]

nice! hope it all works out for you

 

[RoninB4]

I would bet a competent waterjet operator with a taper-compensated head could hold .005" without breaking a sweat. I've welded 3"+ thick steel plates that have had features cut in them on the waterjet to within .005" and it wasn't proclaimed to be a big deal.

-I've only been out of the shop for a few years and things are already changing faster than I can keep up with, the thread on 3D printing is also educating me. I'd like to thank you for updating me on what's possible. Retirement has me in one shop downstairs and I don't get to keep informed about machinery I can't afford.