Prop Saver - Correct size

[coupe1942]

In looking over the prop savers listed with Hobby Zone, I do not see any that is actually 4mm in size. I thought that was the size needed, but my local HZ store only had the EFLM1914, which is smaller at 3.17mm. The sales guy could not find one in a 4mm size and claimed this one could be drilled out. However, in looking at it, there is not much metal left there to hone or enlarge by drilling. I was hoping to stay with HZ, as they have a local shop near me. I wanted to pick up a prop saver prior to taking flight with my Cub. Again, will the EFLM1914 work at all or is there actually one made specifically for the Cub. If so, where to I obtain one.

Thanks... 

[flydiver]

Harder to come by. Be aware once you get 100W plus you are pushing the safety limit of these things unless you are particular about how they fit and are fastened. You seem like the type maybe, so, first read this:
www.rcgroups.com/forums/showthread.php?t=1419378
Jack pushes well past 100W but he's REALLY good at this. He's a great motor rewinder too. Very smart and helpful guy.

Then go buy:
www.hobbypeople.net/index.php/maxx-prop-saver-4mm-motor-shaft-w-2-screws.html
www.fancyfoam.com/index.php?main_page=product_info&products_id=217
www.valuehobby.com/4mm-prop-saver.html
I can't vouch for the quality of any of them. I like the look of the Value Hobby one though. The other 2 look the same but my not be in operation.

These things are not as straightforward as it would first seem. FIT is important! The higher the power, the more important. Just because it fits the shaft doesn't mean it will fit the prop well. When I first started using one I didn't know much about them. When I made a sharp turn the prop would dislodge but not come off. Then it would start beating the beejeezus out of the cowl. > turn off the power and dead stick in. Scared me the first few times. It has the potential for flying off in the spectator area should the plane do some abrupt move if not properly fit and secured.
There is just about no standards in props, prop holes, prop adapters, and the like. It's one of the problem areas of this sport that often annoys me. I got a bunch of different ones from Hobby King once. Cheap. Most were crap.

[coupe1942]

Thanks for the info. I am ordering a couple of them and will see how they work out when they arrive. I appreciate the advise.

[toff]

Something else to consider as well....at the higher end of power/ RPM's, prop balance becomes really important. Prop savers use rubber 'O' rings to hold the prop on the saver. Over time, this 'O' ring will fail. I can say that having a prop come off, at 6000 rpm, is quite a shock, especially if doing a static test. Think loud bang and ninja throwing star combined. I only use prop savers on slow fly planes now, like the GWS slow stick and similar.