Brodak do some fancy alloy I C spinners . Can Supply UNCUT .
To cut I meaure center of blade front at about 1/4 less than spinner dia. ( to allow for taper ) from backplate ( parrallel to Shaft ) .
Centerpunh at 180 degrees ( masking tape will help penlines & prevent scratches .)
Drill 1/8 in. hole ea side . Stick 1/8 steel thru and measure ( check ) centrality , a knife blade whittles the alloy easy , if your doing it at 11 pm in the dark etc , and are off .
So get the L E holes satisfactory & round , finish drill to 1/4 dia ( or similar ).
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Pin back thru ( a rod or tube , Out with the virneer ( Shifting Spanner
) and mark back blade width at the spinner dia. plus say 1/8 Max . from FRONT of Hole .
Another mark about 45 deg. down & back . ( same Dimn. as hole hight , back ) from front underside oh hole .
Grabed the Circle Template & scribed large rad. aft intersecting the 1/4 hole Fr. Edge ,
another , or stright - under front 1/4 hole to 40 - 45 Deg. Slash ( front underside blade ) mark .
Chop with razor saw judiciously inside line . stop just short of 1/4 hole . 1/64th .
Out with the big half round file .
Of Course Three Blades you looking at 120 Deg , and will have to match circumfretially . Mark a line around circuferance at L E hole center hight . or center top & bottom ( 3 )
Virneer measure between Equal on All , the crucial take time set up key .
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Fluked it spot on Fri. on 2 " spinner , with scrapeing to lines . with 11 x 5 T F & 11 x 6 old T F roudnded props fitting marvellously .
Just edges in over the prop , one side at a time .
About the Third Brodak uncut Ive Cut , so wasnt entirely providential , tho the errors in the first 1/8 dia. holes, balanced to match , dialed it in just right .
Take the time to triple check the 180 degree bit Ea Time , is the deciseive part . ( a rat tail files good , but go easy , its soft as butter .
Getting Equal Fwd is easier , but must be exact . The Cross Bar thru the initial holes ( a longish one ) and its trueing exact to hight & same distance to Ea Side , when at Fwd Edge of Holes , is the KEY .
Once there , its ' Equal Each Side . With offsets to starboard rather than port , when your useing Left Hand Props .
Just put the plane in the boot , so ' a picture ' another day . But its a right hand prop , unless I take it in a mirror .
Practise on a junk one or plastic , marking out , if they bother you . Once mastered your unlikely to ruin one .
Hold Between Wooden Blocks in your vice . And dont crush it outa shape . minor displacements ease true with thumb pressure , when it shifts sawing it , under L E back cuts .