sur> ely a precision ground shaft should be the exact size, ie., 5mm?
Depends on what tollerance they shaft has been ground to, this is
signified by a lower case "h" followed by a number, Silver steel for
example is usually ground to h6 this would give a location/clearance fit
with your H7 reamer. For the fit you want then the shaft needs to be k6
or n6 which are light interfearance fits.
please forgive my ignorance of probably accepted machining principles.
is the machinist, but I am looking for ideas etc that will lighten
It seems I am trying to do a Similar thing to yourself but at lower
Speeds 10,000 to 20,000 rpm with 10 cm diameter x 1.2cm discs initially
made from nylon ( to check feasibility) then machined aluminium. I am
still at the ideas phase. though will prob
start work In next week or so.looking to push fit discs to a couple of
graupner turbo 820s with max rpm 24000.or poss use a prop adapter.
I am very interested in how your project turned out,
how you balanced your discs/was this necessary? (i assume so with 50k
what's the diameter of your discs
I am especially interested in how you fixed the discs to the
shaft/geometry of your discs/were they solid discs etc
you mention socket cap screws are these better than grub screws
or any experience that you have had with your project
this is what I am trying to build ( initially 2 Contra rotating discs)
I followed the advice given in this thread: ream at low rpm, feed in
and when it bottoms out, switch off the machine and then
withdraw the reamer.
This now gives perfectly acceptable results on most
motors, except for those
with shafts which are very undersized - many
I also found that a new, sharp reamer seems to ream a smaller hole than
older, not-so-sharp reamer. You can order any size reamer you want, I
very useful site:
I'm turning small diameter couplings (< 12.7mm) at high rpm - your
need to be very well balanced. We balance small model
propellers using a
magnetic balancer, this is simply a length of 1/8" or
3/16" ground steel rod
with precision ground points on each end
suspended between two magnets. The
heavy blade falls to the bottom and
material is removed from this blade until
each blade is as near as
dammit equal in weight - crude, but effective. You
could do something
similar to balance your discs, or you might need to look at
balancing, similar to how a car wheel and tyre is balanced.
Socket set screws are just grub screws that you tighten with a hex
instead of a screwdriver - same thing, different driver.
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