Took 2 days but managed to attach a steel blade to my line trimmer :)

[xxxx_guy]

Been on this forum a while however haven't done much with my lathe and mill.
I have a line trimmer, however the grass had grown so long that I decided to try fit a steel blade for it.
Made the attachment shown out of 50mm diameter aluminium bar.
It threads onto a M8 thread protruding from the base of the cutter. Holes are drilled to allow me to use a angle grinder wrench to tighten. A lock-nut secures it further.
Major issues is that my workshop is a mess, this greatly increased the time needed to find tools. Will be trying to tidy and organise it more.
Had to find somewhere that sells 6.8mm drill bits to allow the taping, 6.5mm wasn't good enough. Cut up fingers trying to hold outside of part whilst tapping, so learnt to use a clamp for this.
The opposite side of the fitment (not shown) has a stalk that fits in the hole for the blade to centre it. The stalk is 1.9mm long whilst the store bought blade is 2.0mm thick, such that the stalk doesn't transmit axial loads onto the blade. There is then a small cavity such that only the outside few millimetres of the fitment contacts the blade to transfer rotational forces (torque) to the blade.
Have tried use it and so far so good.

 

[markba633csi]

Be sure to keep body parts away while using!

 

[Eddyde]

Looks good. Please post more pictures if you can.

 

[RaisedByWolves]

Wear boots!

 

[homebrewed]

Wear boots!

With steel toecaps. I've found the add-on toecaps are pretty terrible, comfort-wise. Properly-sized boots with integral toecaps are OK.

FWIW, one of the most-injured parts of the body when using a chainsaw are the toes. I came close once....

 

[xxxx_guy]

Have attached a few more photos!

Photo 1: Line trimmer head and M8 bolt to attach to
Photo 2: Store bought blade, home made attachment and angle grinder wrench
Photo 3. Back of home made attachment. Stalk in middle to keep blade centred. Hollowed out to put bearing pressures further out on blade
Photo 4: Front of home made attachment. Hole drilled and bored to seat lock nut and fit socket to tighten/loosen lock nut. Tapped M8 hole to fit attachment onto line trimmer head.

And will use steel toe caps to protect feet when using.

 

[fixit]

I made an adapter and used a 7 1/2 inch dull skill saw carbide tipped saw blade. I can cut small trees with it.

fixit

 

[brino]

I made one similar and it worked great..... for a few hours.....

Then on disassembly autopsy I discovered that the multi-strand, twisted flexible drive shaft they used inside the curved down tube simply wasn't up to the torque required for the saw blade.

YMMV
Brian