Nylon or acetal gears to replace baltic birch known to work

[EmGo]

Sounded like the 10 was material costs - "I can get the acetal for $13, paying $10/set now" .... if that's finished product price, just run them on a router. Could get a decent small router and do them himself is probably best choice. 1/4" of 3/16" end mill would whoop right through those in plastic. In fact, whoever is doing it now could swap materials, probably.

 

[animal12]

Woodguy , is there a link to the product ?
thanks
animal

 

[technocrat]

Woodguy , is there a link to the product ?
thanks
animal

Little Proteus Power feeder

power feeder for woodworking

powerfeeder.alladd.com

 

[technocrat]

some cool incorporation of metal parts in 3d print that turned up in the additive machinery forum

 

[EmGo]

Debbie Downer Time : you can't even see the gears. And all the rest of it is made from plywood already. It works. People are happy. What will this accomplish ?

 

[memphisjed]

Debbie Downer Time : you can't even see the gears. And all the rest of it is made from plywood already. It works. People are happy. What will this accomplish ?

Perceived value (sales). Also, same stream, aesthetics. Tool aesthetics are a big deal- wood peckers even more so than metal workers. Lufkin and starret and empire all make combo squares, which do you like to use?
Bridge city tool hand planes are nicer to use than Stanley, not as nice as Fall River. Aesthetics are part of design.

Now- real gears can be smaller, less can get get desired reduction and have less noise. Real value.

Take the marks money.. err I mean client on.

 

[EmGo]

Perceived value (sales). Also, same stream, aesthetics.

Did you look at the video ? you can't see them. I can barely see the edges of one gear, maybe half of two teeth, in one or two shots. It's like silver plating the p-trap under your sink ....

 

[memphisjed]

Did you look at the video ? you can't see them. I can barely see the edges of one gear, maybe half of two teeth, in one or two shots. It's like silver plating the p-trap under your sink ....

Imagine how cool a steel blue grey tooth with a hint of bronze light flicker would look peeking thru skirt slit. Details.
Or go hyper clean with anodized al gear box the thickness of a phone with chamfered edge/ totally enclosed.
Plastic gears fit nowhere in the tool. Aesthetically and structurally they are sub par to the laser cut wooden ones. Never mind the plastic gear to axle interface which still has no elegant solution.

It’s a very clever concept of a tool now. It works apparently. It has sold enough and op believes enough in it to refine it to be better- not cheaper. Imagine if more mtb went this direction!

 

[Comatose]

I have to imagine part of what's pushing this redesign is Baltic birch plywood has gone up by a factor of about 4 due to Putin covering his neighbor's house. There's no great alternative for structural plywood.

 

[Houdini]

Just buy a laser cutter and cut then from the polymer.

 

[dgfoster]

So, here are the gears used in the machine as shown in a kit purchase option. What I do not understand is why off-the-shelf, cheap, widely available plastic gears could not be used. Purchased in quantity , they should be at a price point that makes this feasible.

Or why could 3-D printed gears not be used? Printing would be slow, but a decent machine could just keep cranking out gears hour after hour.

And as someone already suggested, casting them using a commercial casting product like Repro One from Freeman Supply would work and be fairly quick. Highly accurate reproductions with minimal (no?) post-finishing I think would be possible. Repro is very tough and sets fast. I have not used it for a gear set, so I should be cautious suggesting it. But my experience using it in making iron casting core molds indicates it would be strong enough.




Denis

 

[Houdini]

I use Smooth-On products for all my liquids, mostly for effects.
but they have some awesome industrial usages also, I have seen gears.
call them and they can tell you best scenario.

Smooth-On

I would injection mold them, but then again I do tooling so the mold would be free for me, other than materials.
Dupont Zytel/Hytrel Nylon 66 with 30% glass.

gears molded

EDIT:

And to answer the OP's actual question:
"I want to have them made from machined acetal or nylon, or injection molded from suitable material. All things being equal, which material and production method would be better, how should they be made, and how thick should they be to be comparable in strength to the plywood, or assure no failures?"

Injection molding is cheapest of the two in the long run, especially if your doing a lot of parts. Machining is the most expensive, but cheaper if your only doing a set amount of a small quantity over all.
Machining is more accurate than injection molding them, but its high accuracy is lost in this assembly context.

Material would be Nylon or Acetal, I have made a few gears from both, but mostly Nylon, even for extreme speeds and uses like a blender.

Injection molding the parts I would probably not leave them solid, but would thin them out in the center to save on plastic cost, reduce cycle times, reduce sinking and warping, molding needs uniform wall thickness.

Injection molding them as far as design, and getting it implemented is the most involved though. Unless you pay someone else to design and machine the mold and a molder to run it.

2 cents.

 

[EmGo]

So, here are the gears used in the machine as shown in a kit purchase option. What I do not understand is why off-the-shelf, cheap, widely available plastic gears could not be used. Purchased in quantity , they should be at a price point that makes this feasible.

Or why could 3-D printed gears not be used? Printing would be slow, but a decent machine could just keep cranking out gears hour after hour.

And as someone already suggested, casting them using a commercial casting product like Repro One from Freeman Supply would work and be fairly quick. Highly accurate reproductions with minimal (no?) post-finishing I think would be possible. Repro is very tough and sets fast.

I's like fluoride in the water, the subject of "teeth" seems to drive all the bats out of every belfry in town.

They are a half inch thick. Please point us to these "cheap, easily purchased" 4 mod, 12 mm face plastic gears with 9 teeth and 19 teeth. He's already got the thing designed and tested, don't think he wants to make an entirely new mechanism.

Why not use 3d printed gears ? Well, except that they'd take an hour and a half apiece and cost more and be less reliable, I guess no reason.

Or powder metal ! even better !

Hey, how about getting granite rounds, cutting it into slices with a diamond saw, then profiling the teeth with a waterjet then finish grinding the shape with custom diamond wheels ! Yeah, that'd be très cool !

wtf, over ? What's wrong with the way he's doing them now, on a router ?

Or even the conventional way, lathe and any sort of tooth cutting machine.

Mention teeth and you guys go wacko, like no one ever did this before. If you come up with any more cockamamie ideas we'll have to reserve you a place in Napa.

 

[Finegrain]

Here's my 2 cents ...

OP has a very unique and apparently successful product. It is marketed to, and appeals to woodworkers. It's made out of wood. Fabulous .

Machinists like ourselves are full of ideas on how to make it "better." No doubt it would be stronger, smaller, and more long-lasting with metal framework and real gears and shafts. But, those changes move it away from its core appeal.

One suggestion, that doesn't change the base appeal but is a significant improvement -- the Delta Unifeeder used a hex arrangement for its plastic drive gears:



You could retain your wood gears, but with this hex drive arrangement. Have proper machined shafts made from commodity hex stock.

How about a completely redesigned metal version? Keep it separate from the wood one and promote each one on its own merits, without pitting them against each other.

Regards.

Mike

 

[Houdini]

If you trust yourself with your CNC router.
order a mold, machine it, and have someone run it for you.
Aluminum off the shelf molds.

 

[Houdini]

I's like fluoride in the water,

Your killin me with the fluoride in the water

Now every time I scroll down and see it I start laughing.

 

[dgfoster]

Sounded like the 10 was material costs - "I can get the acetal for $13, paying $10/set now" .... if that's finished product price, just run them on a router. Could get a decent small router and do them himself is probably best choice. 1/4" of 3/16" end mill would whoop right through those in plastic. In fact, whoever is doing it now could swap materials, probably.

I'd like to see the proposed setup to reproduce the gears as shown. Making the tooth outer 2/3 is pretty trivial. Making the squarish inside corners may be a bit more challenging. Remember, this needs to be simple and fast. So, how exactly is that done with a router.

I's like fluoride in the water, the subject of "teeth" seems to drive all the bats out of every belfry in town.

They are a half inch thick. Please point us to these "cheap, easily purchased" 4 mod, 12 mm face plastic gears with 9 teeth and 19 teeth. He's already got the thing designed and tested, don't think he wants to make an entirely new mechanism.

Why not use 3d printed gears ? Well, except that they'd take an hour and a half apiece and cost more and be less reliable, I guess no reason.

Or powder metal ! even better !

Hey, how about getting granite rounds, cutting it into slices with a diamond saw, then profiling the teeth with a waterjet then finish grinding the shape with custom diamond wheels ! Yeah, that'd be très cool !

wtf, over ? What's wrong with the way he's doing them now, on a router ?

Or even the conventional way, lathe and any sort of tooth cutting machine.

Mention teeth and you guys go wacko, like no one ever did this before. If you come up with any more cockamamie ideas we'll have to reserve you a place in Napa.

Wow, that is quite a thoughtful answer.

Let's look at just one aspect. I am not going to take the time to do all the research for each option I listed, but I stand buy them. One thing that is easy for me to fact check is the 3-D printing option cost/time. For a common 2.5 inch dia by 1/2 inch thick gear printed on a Prusa XL with more than adequate resolution I usjt modeled them on my Prusa:

20 gears (actually a couple more could be done) on a single plate could be done in 11 hours while you sleep as opposed to eating sawdust while attending a router for how many hours? And how many gears do you get before that nice sharp carbide cutter starts to talk back? The material cost is just under 50 cents for first-rate PETG. PETG is tougher than birch any day.

I am not going to say the rest of that rather unpleasant response you made is equally fact-based. But I suspect it was.

Bottom line for those that don't like to read: 50 cents material cost per gear. 20 unattended in 11 hours. Not bad I'd say. In fact, I'd have them made days before a new order was shipped to me.

And one other note, maybe it would be good to simply stick to the facts of the situation without getting into all the "Cockamamie, reserve you a place in Napa" stuff. That clouds the issue (though it really does make the person saying it sound super smart?)

Denis

 

[Comatose]

So let's see. Two mold bases at $3k each, plus machining time, plus setup charges at an injection molded. $10k.

If the price difference between routing them in plywood and routing them in acetal is $3, that might turn a profit in 3000 pieces.

But now OP also has to learn mold design, shrink, sink, the nuances of whatever resin he's using, gating, ejector pins. Learning to build injection molds that work for 10,000 pieces is a half year project, at best. A half inch thick injection molded part is gonna need cooling, or the cycle time will make a $500 3d printer look fast. Did I mention that time on someone's injection molding machine isn't free either.

And at the end of a year of struggle, he ends up with an injection molded copy of a wood gear that was working perfectly fine.

Or he could spend the same year looking for a $3 cheaper per part plastic supplier, which probably takes five phone calls and one business lunch.

 

[Comatose]

I'd like to see the proposed setup to reproduce the gears as shown. Making the tooth outer 2/3 is pretty trivial. Making the squarish inside corners may be a bit more challenging. Remember, this needs to be simple and fast. So, how exactly is that done with a router.

20 gears (actually a couple more could be done) on a single plate could be done in 11 hours while you sleep as opposed to eating sawdust while attending a router for how many hours? And how many gears do you get before that nice sharp carbide cutter starts to talk back? The material cost is just under 50 cents for first-rate PETG. PETG is tougher than birch any day.

Easy there! I think it's safe to say that everyone else is talking a CNC router. Which is obviously how the wood gears are being make now.

On my pretty mediocre router, one set would take about fifteen minutes, and I could run an entire 4x8 panel's worth unattended.

Also, don't disrespect birch. The Spruce Goose was made of birch, and that was the largest airplane in the world for about 50 years. Baltic is an amazing material. Just a bit awkward to source right now.

 

[memphisjed]

Here's my 2 cents ...

OP has a very unique and apparently successful product. It is marketed to, and appeals to woodworkers. It's made out of wood. Fabulous .

Machinists like ourselves are full of ideas on how to make it "better." No doubt it would be stronger, smaller, and more long-lasting with metal framework and real gears and shafts. But, those changes move it away from its core appeal.

One suggestion, that doesn't change the base appeal but is a significant improvement -- the Delta Unifeeder used a hex arrangement for its plastic drive gears:

View attachment 428821

You could retain your wood gears, but with this hex drive arrangement. Have proper machined shafts made from commodity hex stock.

How about a completely redesigned metal version? Keep it separate from the wood one and promote each one on its own merits, without pitting them against each other.

Regards.

Mike

Good answer.
Bite your tongue calling all us machinist. I am a few things, machinist ain’t one.

Stop it with the plastic gears. Op is looking for pro grade option. Plastic gears have a place. Cheap wall clocks, legos, and valentines diaramas.