Hi Azalin
Well, it's not that simple of course.
First of all, what are the 5 mm pins made of? Ordinary mild steel? or maybe hardened HSS? Very different things.
What is the big gear wheel made of? Will it run dry or in an oil bath?
How thick is the big gear, and how thick is the support disk behind the big wheel? If the support disk is too thin it may flex or the pins could become loose and wobble.
5 mm is not very strong, but there are a lot of pins around the edge, so maybe that is OK for strength at the edge.
You have only 5 pins in the middle, and that is not so strong. Could you increase these to 6 or 8 mm?, or could you increase the number?
Anyhow, a lot of this will depend on what loads are going on the drive. If all it is doing is rotating slowly for positioning, no problems, but if you are spinning it at 2,000 RPM and putting 2 kW through it - very different!
Cheers
Roger