Which is Better 269oz or 425oz motors?

[P.Passuello]

I will shortly start building a Solsylva router and am looking at purchasing one of the Xylotex motor kits to power it. The price difference between the 269oz and 425oz motors is minimal so I need to decide which motors I will buy. I have seen on this site a mention that using motors too big for the job is bad for the motors but this claim I have been unable to find anywhere else on the internet. I believe that the maximum usable speed of the 425oz motor is lower than the 269oz but I could overcome this problem with larger leadscrew if rpm is not too low.

Has anyone used the 425 oz motors on the Solsylva router and what speed has been achieved?
What usable rpm could I expect from a 269oz motor?
What usable rpm could I expect from a 425oz motor?
What is your opinion?

Thanks

[H500]

The best way to decide is to look at the torque vs rpm curve for the motors. To put it simply, the one with the higher torq X rpm number is the better one.

[P.Passuello]

Originally Posted by H500 The best way to decide is to look at the torque vs rpm curve for the motors. To put it simply, the one with the higher torq X rpm number is the better one.

Thank you for your reply
Unfortunately Xylotex advise they have no such curves for these motors. I will see what I can dig up.

cheers

[phantomcow2]

Check Keling, I believe their motors are the exact same ones that Xylotex sells but a different name:
http://www.kelinginc.net/SMotorstock.html
They have torque curves. The 425oz-in motors drop torque fast.