I don't know if the material used in a 3D  printer is capable of standing up to the forces in gearing.    Someone else may know more about what is available for that.

On the other hand the following is source for gearing, chains, and sprockets.   You do have to know the dimensions for the gear you want.   It is called "Servolink"

http://servolink.com/default.asp

Try Stock Drive Products if the consumer RC car/robotics sites don't offer anything suitable.

SPSF has the answer. If you search on 10T gear on ebay there are many but to be sure just go to a Hobby Shop that specializes in RC cars so you can compare size. As long as the bore is the same or smaller you can drill it out to fit.

Pete

Brass is a lousy gear material.  Bronze or engineering plastic is what you want.

Try https://nwsl.com/

They help other forum members with new gears for the nuclear reactor. If you give them the gear specs they might be able to make you a new gear.

Joe

The short answer on 3D printing it, is yes... in carbon fiber, steel and a host of other metals and/or advanced plastics (metal additive manufacturing).  Those 3D printers are *not* cheap.

Here's a cheap Metal 3D printer @ $250,000.00

https://www.aniwaa.com/product...s/aurora-labs-rmp-1/

Dennis, I don't think any 3D design and printing of a gear that will hold up is in the practical price range, that's most likely a non-starter. I'd consider either finding one already made from the sources previous listed, or maybe find someone with a mill that's itching to see if he can make a gear.   Delrin is another material that is strong enough for the task, we used to make high precision aircraft instrument gears out of it.  I'm a sucker for automation, and it was fun to go into the machine shop and watch the CNC machine mill out gears and gearplates.

@bob2 posted:

Brass is a lousy gear material.  Bronze or engineering plastic is what you want.

I suspect the gear makers already know this.  Many people talk about brass gears when what they're really seeing is bronze gears.

FormLabs makes a Glass-filled Rigid 4000 Resin that prints with a smooth, polished finish and is ideal for stiff and strong parts that can withstand minimal deflection. Rigid 4000 Resin is general load-bearing applications. I dont have any because of the cost.

I have a sample made that can be used to remove bolts.

As to gearing, Rhino 6 has a gear-app that makes all types of gear models, I have made some with it. You just import the type of gear, the diameter and the number of teeth and it computes the gear size and makes the model to print.  It's a little tricker that that.

Again, I have used the gear app but see this its a lot easier https://vimeo.com/105038261

@Dennis-LaRock posted:

The short answer on 3D printing it, is yes... in carbon fiber, steel and a host of other metals and/or advanced plastics (metal additive manufacturing).  Those 3D printers are *not* cheap.

Here's a cheap Metal 3D printer @ $250,000.00

https://www.aniwaa.com/product...s/aurora-labs-rmp-1/

Thats what Shapeways is good for

I draw stuff all the time, print a test shot in PLA and if I like it but need something better, I'll just shapeways it and they can use a $250K printer and make me a final copy.

If you can spec match that gear with something off the shelf, it'll definitely be cheaper tham printing a one off. That said, if you need to print it, shapeways can do bronze. Its lost wax cast, so you get a solid bronze copy of a 3D printed pattern. Ive done brass detail parts this way and they come out quite nice.

.STL file attached.  This gear has 10 teeth is 0.23" diameter, 0.21" height, with a 0.08" hole for the drive shaft. However I cannot guarantee it will work in your application. It looks good!

Making correct gears requires a more detailed sizing of teeth,  see below

@bob2 posted:

Brass is a lousy gear material.  Bronze or engineering plastic is what you want.

@gunrunnerjohn posted:

I suspect the gear makers already know this.  Many people talk about brass gears when what they're really seeing is bronze gears.

Brass, bronze, steel, acetal resins....they're all good when used properly.

I'm not among those who might argue with the expertise of NorthWest Short Line, the gear people in our hobby.  Improper design in the first place...and lack of proper gear lubrication probably a close second...is more often the reason gear drives fail.  Re materials, their rule-of-thumb as stated in their website is...

"Improperly selected materials (most commonly a brass worm driving a brass wormgear - ie. Same materials - wear out rate will be very high, usually whether lubricated or not). Driving gear should be harder material than driven gear."

It's not a brass problem.  It's whether the use of brass in a gear train sequence is appropriate or not.

NWSL further states...

"For best gear life, the gears should be dissimilar materials with the driving gear harder. This is particularly important for high speed and/or high load interfaces such as worm to wormgear and less important in low speed situations such as idler gears between axles. Acetal is the generic name for the engineering plastic trade named Delrin (DuPont) and Celcon (Celanese). NWSL acetal gears are machined from stable, aged material to avoid the shrinkage and cracking problems inherent in inexpensive moulded plastic gears. Gears can be machined in material of your choice with appropriate handling and difficulty charges (ie. gears in bronze usually require a 50% surcharge compared to brass because of added machining time and tool wear)."

...the last sentence perhaps reflecting why bronze gears may not be as OEM-prevalent or arbitrarily applied in the model railroad industry as you might suspect.

There's a lot of information on NWSL's new website (Menu: "Old Catalog Pages") about gearing design, materials, lubrication, causes of failure, etc., etc..  Again, who am I to argue with those for whom this has been a successful vocation?

TEHO/FWIW, always.

------------------

More directly to the OP's original inquiry, though, here is a link to NWSL's website showing their current 10-tooth (number of teeth is critical) spur gears, 2mm bore, availability/prices...

NWSL Link

You might send an email to NWSL to have them confirm which might be applicable to your situation.

KD

Here are a couple of ideas.

1.  Have someone with a 3D printer print you a dozen or so gears using the toughest resin they have.  I doubt that the pylon drive train delivers much torque.   Since the original gear is plastic this might be the quickest, easiest, and cheapest approach.

2,  This company, like Shapeways, will laser cut you a gear out of what ever material you desire.  https://www.ponoko.com/ I don't know if such a small gear is within their capabilities.

Jan

A lot of interesting advice above - but I bet it would be cheaper and faster to buy a used pylon and canabalize the parts you need

If you convert your dimensions to metric you can find a number of gears for RC cars, as SPSF said in his first response.  Try searching for a 10T 2mm shaft.

this could be laser cut from 1/4" thick acrylic  the actual thickness is about .216" it would take about  10min if you need the engraved top.

Dennis, I took Alan's STL file and printed it using the finest settings on my machine and this is what I got after 8 minutes

The gear is so small with detail that this is the best I can do and my printer is pretty good. Doubt if this would work but I could mail it to you to play around with if interested.

Email me with any questions if you want.

That should work perfectly.

How about we just go buy an RC car gear for three bucks.

That's one UGLY gear!

Check McMasterCarr. Their customer support might be able to help you ID the gear if you're not familiar with how they're called out.

A gear that small would be a doozy to print because of the fine detail but it could probably happen.

This ugly gear shows the limit of the equipment used, if I can't get a good sample on the Prusa 3D printer then we look at another process. This is a good exercise in deciding what is the best equipment that might be on hand to do this kind of a job.  Failure is a necessary part of success. "No failures means your not working, too many failures, your not working for me"

This still leaves Dennis with needing a gear that will do the job. He could go out looking for a comparable gear to work which is a great suggestion.  At the same time wouldn't it also be nice to know that you could make this and many other parts similar to it especially if you might already have the equipment.

The question was "I didn't know if the gear could be reproduced using 3D printing or whether that procedures would yield a gear strong enough."

So I would say the answer is no, not by this printing process, too much minute detail in a tiny part, but am sure there is a process which could do it.  As far as being strong enough I would want a material that would last in normal operation and not so hard as to ruin the drive gear if something causes excessive strain.

I have someone who is going to look into another process, might be SLA if nothing else other than to prove it can produce an acceptable gear.

In the meantime Dennis I hope you can find something to get this working for Christmas.

update:

This gear was printed with an inexpensive  "QIDI TECH Shadow 5.5 S 3D Resin Printer"

This resin gear came out pretty good, next step is to use a resin that will give the toughness required and this of course assumes the design of the gear we started with is close enough to the original.

this gear measures .220 dia x .20 lg with a thru hole of .075

Thank you all for the help and advice!  I am in contact with Ray and we will try the gear he produced!  I will let you know how it works.

I did ordered some brass and copper gears from China and we will see if they fit.

Thanks again for ALL of input. That is what makes this forum great!

Dennis

Hope you get it fixed!! Let us know!

I received the 3-D-printed gear from Ray the other day.  Upon inspection, I drilled the thru-hole out a small fraction (not enough apparently ).  While tapping the gear on the knurled shaft, it split into two pieces.  Bummer!  I guess I shouldn't have used a sledge hammer!

Perhaps the gears that I ordered from China will stand up to the task.

I really appreciate the efforts of Alan and Ray for attempting to help me here!

I will update you when the gears arrive from overseas.

Dennis

Dennis,

maybe as a last ditch effort, give this route a try

https://ogrforum.ogaugerr.com/...poxy-saved-christmas

Just clean the gear and shaft well to remove grease.

I'm liking the experimentation, experience and knowledge being gained here.  Just think... nobody would have a PRR T1 if there was no quest for the future.

Dennis

Epoxy sounds good, is that still possible?

@wmcwood posted:

Dennis,

maybe as a last ditch effort, give this route a try

https://ogrforum.ogaugerr.com/...poxy-saved-christmas

Just clean the gear and shaft well to remove grease.

This should work, even better if Dennis’s is metal. Use JB Weld, the original long set version as its twice as strong as the 5 minute. Don’t disturb it for 24 hours. When its in place clamp lightly to try and close the crack a bit but not crush the gear.

Pete

If you are trying to buy gears, it really helps to know the profile. Metric gear teeth go by 'M's (M0.6, M1, like that). Standard sizes run by 'pitch' (24 pitch, 32, 48, etc). Not interchangeable between metric and standard.

There are sites where you can measure the gear, submit overall diameter, how many teeth, and it will tell you what size gear you have in your hand.

Brass gears are fine if the mating gear is steel. Nylon is durable with a steel(or nylon) mating gear. Most other plastics won't hold up.

The UV resin 3D printer material is pretty delicate, some of the tougher materials used in FDM printers (filament) is tougher, but as you saw, the resolution is not there for such a small part.

If you are going to replace this gear try and buy the gear that it mates to as well (not at all familiar with this accessory).

Jim

Both the original gear and the replacement gear are plastic.  I hadn't thought of epoxy!  It is certainly something to try at this point.

Stay tuned ... !

As the revised title reads, I got the North Pole Pylon working again!  I took one of the brass gears that arrived the other day, drilled out the 2 mm thru-hole with a #47 drill bit and tapped it onto the knurled portion of the shaft.  Reassembled the accessory and Santa rides again!

The pictures below are he original gear, the 3-D printed attempt, and the brass gear on the shaft.  The 2nd photo is the fit of the gear against the motor shaft - perfect!

Thanks again to Alan and Ray and all those rooting for a solution.  Have a Merry Christmas!

@dennish any chance you know what size that brass one was or how to order one just like it? i have the EXACT same issue as you and have been looking for replacement parts for 6 or 7 years now.

instanttim That was a while ago !  Let me look and see if I have a gear.  I am sure I do.  Just have to look in my gear parts container drawer.  Can you refresh my memory on the size of the gear?  Number of teeth?  That will help me identify it quicker.  I can look it up also.  Dennis

@instanttim  Try Ebay. (link removed per OGR TOS)

The specs on the gear are 0.5 modulus, 5 mm height, 6 mm diameter, and 2 mm hole.  As I see in an earlier post, I drilled it out with a #47 drill bit.

Thanks @dennish for the info. I ordered both some brass and plastic cogs meeting those specs, which i confirmed by measuring my own as well. I'm looking forward to my pylon being animated again!🤞🏻

To make this very simple. Ordered these as per below ebay link, I believe $ 10 for 10 incl. shipping. Installed and fixed 3 pylons. Thanks to Dennis Heban for all his help.

LINK DELETED per OGR TOS....no EBAY LINKS!!!!

@instanttim posted:

Thanks @dennish for the info. I ordered both some brass and plastic cogs meeting those specs, which i confirmed by measuring my own as well. I'm looking forward to my pylon being animated again!🤞🏻

Were you successful?

Wow that was a lot of work to make a gear that is readily available on Amazon, lol.   Plastic Pinion gears are known for cracking because they are pressed on the shafts and can eventually split.   I have had many devices besides trains that were powered by motors with small pinion gears that split and fixed them by simply buying the plastic gear packs on Amazon.  They contain a whole bunch of styles and sizes and so far, they have always had one that matched (size, hole diameter, number of teeth).   Yes, sometimes you have to buy a couple different packs, but they are like 5 dollars each.

@gunrunnerjohn posted:

Were you successful?

Sadly I haven't gotten around to trying yet. All the parts are just sitting there waiting for a day without more important chores.