Casement Operator Help

Thanks for posting. I suspect this is either the 39-388 or its opposite-handed counterpart, the 39-387. Review the diagram below and see if this type matches what you have. For a compatible crank handle, go with the 39-114L.

Dimensions for 39-388

I'm afraid I don't see the curve you're talking about. Referring to your photos, I don't see any particular detail that sticks out as disqualifying. Can you specify why exactly the 39-388 and 39-387 won't work?

Thanks for getting back to us, Bill. Unfortunately, we don't have a version of this operator with a gear arm that's shorter than 4-3/4". This appears to be the only size currently available. To be perfectly honest, I've never encountered a shorter version. It's rare that the gear arm length is the issue, usually it's the link arm. 

Either way, at this time the 39-388 and 39-387 remain the best and only replacement options we can supply for this design. I am sorry for the inconvenience. 

The 39-317 and 39-318 have another major difference, which is that the link arm is riveted below the gear arm, rather than above it like on the 39-387 and 39-388. That may not seem like a big difference but it does affect how the link arm aligns with the bracket it must connect to on the sash. If it can't connect to that bracket, it won't be able to function properly.