How to attach a rod to a grass trimmer crankshaft?
 

https://lh3.googleusercontent.com/-R...November272012

I sloppily removed the clutch contraption, apparently without
functional damage to the grass trimmer.

I need to attach a 1/4 inch aluminum rod to that threaded bolt
sticking out from the crankshaft. Looks like it uses an uncommon
5/16"-20 bolt.

Any common or easy to get small plastic or metal parts threaded
5/16"-20?

A workaround (see the picture)...

I suppose some plastic or aluminum could be stuck over the bolt
and glued onto the base. And then the trimmer could be started and
used like a lathe to cut a hole for the 1/4 inch aluminum rod that
it will drive. That assumes the base is sturdy enough to twist the
rod. If so, maybe the bolt could be cut off to reduce the depth of
the additional material.

Apparently the shiny metal piece stuck on the black plastic is
used for timing the engine. With the opposite side of that metal
piece being there for a counterbalance. That's my guess.

Thanks.

How to attach a rod to a grass trimmer crankshaft?
 

On Wednesday, November 28, 2012 12:05:23 AM UTC-5, John Doe wrote:
https://lh3.googleusercontent.com/-R...November272012



I sloppily removed the clutch contraption, apparently without

functional damage to the grass trimmer.



I need to attach a 1/4 inch aluminum rod to that threaded bolt

sticking out from the crankshaft. Looks like it uses an uncommon

5/16"-20 bolt.



Any common or easy to get small plastic or metal parts threaded

5/16"-20?



A workaround (see the picture)...



I suppose some plastic or aluminum could be stuck over the bolt

and glued onto the base. And then the trimmer could be started and

used like a lathe to cut a hole for the 1/4 inch aluminum rod that

it will drive. That assumes the base is sturdy enough to twist the

rod. If so, maybe the bolt could be cut off to reduce the depth of

the additional material.



Apparently the shiny metal piece stuck on the black plastic is

used for timing the engine. With the opposite side of that metal

piece being there for a counterbalance. That's my guess.



Thanks.

http://www1.mscdirect.com/cgi/NNSRIT...-SearchResults

How to attach a rod to a grass trimmer crankshaft?
 

On Tue, 27 Nov 2012 22:19:41 -0800 (PST), rangerssuck
wrote:

On Wednesday, November 28, 2012 12:05:23 AM UTC-5, John Doe wrote:
https://lh3.googleusercontent.com/-R...November272012


I need to attach a 1/4 inch aluminum rod to that threaded bolt

sticking out from the crankshaft. Looks like it uses an uncommon

5/16"-20 bolt.




http://www1.mscdirect.com/cgi/NNSRIT...-SearchResults

It's almost certainly an M8 thread. The standard M8 pitch is 1.25mm.
5/16 = 7.94mm
20 TPI = 1.27 mm

--
Ned Simmons

How to attach a rod to a grass trimmer crankshaft?
 

Ned Simmons news nedsim.com wrote:

It's almost certainly an M8 thread. The standard M8 pitch is
1.25mm.
5/16 = 7.94mm
20 TPI = 1.27 mm

Right, I'm just looking at the wrong standards, thanks.

How to attach a rod to a grass trimmer crankshaft?
 

Inexpensive 1/2 inch socket

M8 1.25 nut (fits near perfectly into the socket)

5/16" bolt head

Stick the bolt head (bolt part) into a $1000 metal lathe (or a $60
drill press) and tap for the 1/4 inch aluminum rod. Cut off any
excess bolt part that still hanging on. Thread it.

Thread the end of the 1/4 inch aluminum rod. Stick it through the
socket. Screw the bolt head onto it. Pull it back into the socket
opposite the business end.

Screw the M8 nut onto the grass trimmer crankshaft bolt. Stick the
socket head over it and glue it. The only radial pressure will be
very slight.

--









John Doe jdoe usenetlove.invalid wrote:

https://lh3.googleusercontent.com/-R...November272012

I sloppily removed the clutch contraption, apparently without
functional damage to the grass trimmer.

I need to attach a 1/4 inch aluminum rod to that threaded bolt
sticking out from the crankshaft. Looks like it uses an uncommon
5/16"-20 bolt.

Any common or easy to get small plastic or metal parts threaded
5/16"-20?

A workaround (see the picture)...

I suppose some plastic or aluminum could be stuck over the bolt
and glued onto the base. And then the trimmer could be started and
used like a lathe to cut a hole for the 1/4 inch aluminum rod that
it will drive. That assumes the base is sturdy enough to twist the
rod. If so, maybe the bolt could be cut off to reduce the depth of
the additional material.

Apparently the shiny metal piece stuck on the black plastic is
used for timing the engine. With the opposite side of that metal
piece being there for a counterbalance. That's my guess.

Thanks.