Saturday, March 12, 2011

Flycutter: Milling the tool slot

I've been thinking of my homemade flycutter-yet-to-be a lot lately. The day job kept me rather busy with late night appointments. With my showflat duty scheduled on Sunday (tomorrow), I've some time today in the shop while my elder daughter was having her tuition.
The mill was re-assembled after I failed to take out the slop in the table. The task today: mill the slot for the 1/4" left hand and if time permits, finish up the slot for the set screws.
To prepare for today's session, I redo the pocketing feature in bobcad to use a 4mm endmill and crank up the speed a little yesterday night.
These are what bobcad suggested:
Spindle speed: slightly less than 1200rpm
Feeds: 580mm/min
I set the DOC at 0.05mm per pass as recommended by Tang Kee, our guru of the Sherline list, Singapore chapter. I crank up the speed to about 1600rpm after the first pass, adjusting to the sound from the cut. The entire operation took 1hr 20mins. Painfully slow for such small depth. In-between each pass, chips were cleared with bottled compress air (1/2 a bottle was used and it cost SGD15 per bottle...). I don't like to power on the compressor due to it's loud noise when filling up. Maybe I should try to sell it off and get the Silentaire. But it cost more than SGD1,000 to acquire...

This is where I left off from the previous nerves racking session

I decided to follow Sherline's design to have the slot offsetted from the centerline

The slot done, 1hr and 20mins later...

Test fit with the brazed on carbide tip left hand tool from Sherline

The fit isn't good. Tool couldn't sit all the way in the slot

 No time left for me to do the other slot for the set screws. Still have to clean up this one to allow the tool to seat properly.

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