LDM

My Feedback: (15)

Purchased a beautiful prop three blade from Troy built models 17-8 three blade.
Purchased a 12mm fox reemer to enlarge the hole
So thinking I did everything right I started to gemtly and precisely turn the reemer. Thinking I did the perfect job I sit the prop on my electric motor and it sits on an a angle .
To my shock while turning the reemer I must have pressured the cut off from front to back .
So thinking I just blew $65 bucks , I did the next best stupid thing , I filled the hole with fiberglass reinforced 60 min expoxy and retapped with a drill bit vs the Fox reemer .
Now the prop sits perfectly but when visually looking at the front guild circle it's appears perfect , but the rear hold still looks off , yet it's sits perfect on the motor shaft .
Any suggestions ? Measuring seems dead on but the we are talking such small measurements that it's difficult to see with the nacked eye?
Is my prop ruined and how do you prevent this , I really waited and patiently thought my process was correct .
Even the reemer went for 8 to 10 up to 12 mm in slow turns for accuracy

F4u5

My Feedback: (81)

Your prop will be fine for test running. I would fire up the engine at low idle and check for tracking and vibration. Run the prop up to about 1/2 throttle and check for vibration; check the tracking from the front and side again. You can go all the way to full throttle and check again, but if good at 1/2 throttle, you are fine, in my opinion. At any time serious vibration is found, shut the engine down so the prop does not come apart or tear your engine from its' mount.

For tracking, check from the front and side of the prop, at a safe distance. If the prop is off, you will see the blades wander for and aft from the side view and/or see the prop arc become oblong (see the arc jumping up and down).

I recommend getting a step drill bit for reaming props. The reamers are OK for the small engines, small props, with ledd of a hub to cut thru. However, on the larger hubs, this can easily happen, and has happened, to people other than you. A setp bit ona drill press is the best way to go. They are not cheap, at around @1+ bucks, but well worth it. You can get them in standard, numbered or metric bits.

http://www.northerntool.com/shop/too...k=All&Ntt=step bit&Nty=1&D=step bit&Ntx=mode matchallpartial&Dx=mode matchallpartial&cmnosearch=PPC&cm_ven=google_PPC&cm_cat=PowerTools&cm_pla=generic&cm_ite=step bit&mkwid=sXrHo4nnk&pcrid=15585390551&mt=b

Jeff

LDM

My Feedback: (15)

Thanks Jeff , great info and advice , I wil proceed with all your suggestions and see what I find .
By the way your from my favorite hobby shop state , Hobby Warehouse and big sky hobby ! Great shops !

alanc

Beg borrow or steal a Dubro balancer, before you run it, as mentioned, step reamer is the best thing if you do not have a vertical drill

LDM

My Feedback: (15)

thank Alanc, I do have a drill press and a prop balancer , I am also going to test a marker on a set point and spin the prob to see if the blasds are pass the marker evenly

SCALECRAFT

My Feedback: (13)

Make sure the step drill bit you find has enough "step" between the step sections to penetrate the entire prop hub section. Short steps will not work.

Also, if you have an electric motor that can handle that prop, the electric motor will simplify balance/alignment since it is not vibrating.

And STAND CLEAR!!!!!!!!!!!!!!!

Good luck Lou.

Steve

Ron101

My Feedback: (22)

I just chuck my step reamer up in my drill press and put the pulleys to slow....
they come out great

pimmnz

Check which end of the hole is in the centre. Easy to do with a measuring stick. Taper ream from the opposite side of the hub to within 1/4" of the central hole. Fit the prop to the shaft and allow the the rear part of the hub to fit flat to the prop driver. This is the best way to fit any prop so that it tracks straight to the hub and there is no bending force on the prop shaft. Next time, ensure that you use the rear face of the hub as your centre, trim the blade tips to match, taper ream from the front as described, then balance. This makes sure that the hub is flat to the driver face, the shaft is straight, and the prop properly torqued over the full diameter of the hub/prop washer.
Evan, WB #12.

LDM

My Feedback: (15)

Hey Steve , thanks for the advice , yes its an eletric for my 79" P40 .
The Fox reemer was stepped in 8 to 10 to 12 , being right handed I started the process and was very careful in turning and eyeing my process .
The back hold was the one that appeared off when looking at the scibed cirle that is in the prop from the factory .
I knew as soon as I placed the prop on the shaft that I had made an error.
I immeditly thought well if the prop is trash I might as well experiement with getting the hole straight . So that is why I filled with 60 glass reinforced expoxy (that part seems to have work really well ) .
Ok , so from this point on seems that after I test the prop , my future is getting the step tools, drilling from the back side and following the rest of the advice !.
I did one small test today because I spent most of my free time flying . The test was to set the prop on the shaft and allow it to touch the wall as i slowly turned the prop , I was precise in this test , as precise as possible (no power applied ) just hand spinning .
Each prop seem true when approaching the wall , it was all or nothing , they either all cleared or all rubbed at the exact same point with same visual friction .
Tommorow night I will try my prop under power and look for the things stated above ,
Thanks
Lou and Happy 4th