ServoCity has a large offering of gear sets available for sale: 

https://www.servocity.com/servo-gear-sets/

Thank you for your response, I've checked out this website but it doesn't have the specific gears that I need. Do you know any specific gears that can attach to a twenty-five-tooth servo?

Are you talking about the gear that goes inside the servo or something that connects to the servo horn?

I think you'll need to actually contact ez-robot through customer support, not their store. You'll have to write a message using their Contact Us form and ask if you can purchase the replacement servo gears.

Thank you DJ Sures for your response.
So, if I understood you correctly, for a gear that connects to the servo horn, contact them directly?

Oh - so you want a gear that connects to the servo horn? Not an actual gear that goes inside?

Just to clarify, do you need one of these?

Servo Gear) 



or 

Servo Horn) 


or

U Bracket) 

Oh yes, sorry for the confusion. I need some servo horns, potentially more of those depicted or even if there are any alternative options.

Sweet - i can tell you what... there will be A LOT available through ez-robot if you reach out on their Contact Us page. I know they don't have them on ez-robot's website, but with a request from a paying customer, i suspect they'll get added quickly

Otherwise, check out places like ebay or allibaba because you can get them for cheap in a HUGE lot if you're okay with waiting. Things like that are usually a lot cheaper when you're okay with waiting... and waiting...

Just to confirm, I am looking for gears of this type that are able to connect to an EZ-robot servo and act as a servo horn. Preferably in plastic though.

Ah okay. I’ve never come across anything like that before. So don’t think ezrobot will be able to help. 

You’d think something like that already exists out there as a kit. Wonder if anyone here has seen that? A mechano type kit that worked with servos would be super awesome. Never come across it before but maybe it does exist hmm

That's alright, thank you for your help. Hopefully I find something.

There's always the winch style gears from servo City but they are pricy: https://www.servocity.com/servo-gearboxes/

Otherwise, I'd suggest checking out the inMoov project, the shoulder section has a high torque, servo-driven,  3D printable worm gear.

Alternatively, you could TinkerCAD to design and 3D print gears that are mountable on common servo horns, which shouldn't be too difficult.

*Edit: Yet another solution could be to laser cut acrylic or Delrin gears that mount on servo horns. There are 2D gear generator programs out there that can make this quite easy. I have a laser cutter if you need some assistance, but I'm unsure how far away from each other we are. *Lol, looks like we are a world away Australia is a bit far

Thanks so much, that's a great idea of attaching to servo horns already. Which programs can make these 2D gears? I'm not sure if I'll need it due to the first suggestion being so achievable but thank you very much for the offer.

Here's one that exports to SVG: Gear Generator

Sweet, thank you very much.

Thank you for your help