View Full Version : CNC??????

06-11-2007, 09:41 PM
I thought that CNC means smooth cuts, slim lines, quality work. I am ready to pull my prop, after this weekends trip and this is what I saw. Please tell me that this in not normal. I already ordered a new prop form Acme Props. Not to happy with this workmanship of OJ.

06-11-2007, 11:21 PM
I just put an OJ XMP on my Outback and it looked just like that. We operate a CNC facility that works with wood, and acrylic so it is hard to compare... I did not perceive it as a quality issue....just looked different than what came on mine originally from OJ and who knows, it may smooth out after hours of use (had 125 hrs prior to stump)

06-12-2007, 04:05 AM
Ah, CNC, aka Computerized Numerical Control. I'm afraid it won't smooth out over time, It just means the blades of the prop weren't cast in a mold, but were machine cut. The perceived advantage is the blades are more uniform on the cnc one.
hope this helps

06-12-2007, 09:27 AM
I was told that the OJ props were CNC When I pulled the one I bent, it did not look CNC to me. I have seen some CNC props and they do not look anything like this one. Well no worries, I already ordered my new prop. It should be here by the end of the week.

06-12-2007, 12:29 PM
All CNC props will look similar to that.

Both Acme and OJ make Cast props and CNC props - all the higher end models are CNC. The process makes a better ballanced, and more consistent prop. The minor surface marks from the milling look bad, but in the water they do very little, especially near the hub where you are poinging the camera. At the tips of the blades everything is smooth. The scuff marks you see are from a manual grinder that they use to smooth out any minor imperfections and also ballance the blades.

Find something else to worry about.



06-12-2007, 11:10 PM
I have an Acme 3 blade and the blade surfaces look pretty much the same. Not sure about the hub, but balance is the key. I am no expert, but I would be surprised if some irregularity around the hub would be an issue. But you should have a spare anyhow....

06-13-2007, 12:09 AM
I will be getting the old one fixed. The new Acme will be on the boat and the OJ will be in the bag for backup. I still need to purchase a prop puller. I found it at WestMarine.com. for about $70.00.

06-13-2007, 12:24 AM
I've had excellent success with the Cutter prop.