Originally Posted by RONALDO_UK
Hi - thanks for the advice and welcome plus a geography lesson (I looked you up - I've heard of Columbus, Ohio but couldn't place it exactly!). I'm inclined to think it might be the new prop and saver and possibly bad adjustment when I replaced shaft. Some "obvious" things are only obvious after you're told! When nut at end of shaft is tightened (how tight?), I saw info that said go by sound of motor which is probably a good guide? The tail is all new so there's no tape and only a smidge of glue. I'm surprised you didn't mention the spinner? - I presume this is for aerodynamics and I would imagine leaving it off makes some difference?? Fuselage is fine and I don't think motor has moved but goodness knows how you check motor with any accuracy (just by eye?). There's a defined velcro strip for battery so it can only be varied a few mm. In the past I've generally put it as far forward as poss. I might get an original prop replacement and try it without the saver (plus spinner). Thanks again.
These little guys weigh such a small amount that any tiny change can make a big difference, especially when located at the extreme ends of the airframe. Could well be the prop saver as you say. I am having trouble picturing what prop saver you are using based on your description of the end nut etc.
At the speed these planes travel at I would not think the spinner or lack thereof makes much difference from an aerodynamic standpoint, it might impact the weight and balance but I suspect the prop saver set up more than makes up for that.
If the prop saver works well and you want to stay with it, you may find that you end up treating the velcro position "not as a rule, but more of a guideline or suggestion" . On my old micro SU-26 I ended up enlarging the battery compartment probably a good 1/2 inch rearward and added a little velcro to get the CG to a spot the plane flies well. On the micro P51 I opened the battery slot forward to get the 150maH batteries to fit. Had both out this evening and had a good time flying both along with the 4 Site) - small field and absolutely no wind. Only had a hour or so but was a great time
I assume you are in UK- where?