TMN wrote:

Hi

I am new to milling and have aquired an Harbour Freight type Asian Mill
/Drill with the following specs:

# Drill capacity: 1-1/4"
# Face mill capacity: 3"
# End mill capacity: 3/4"
# Swing: 15-7/8"
# Spindle stroke: 5"
# Column diameter: 4-1/2"
# Spindle speeds (RPM):
120-200-250-290-400-465-820-1090-1245-1520-1820-2500
# Spindle taper: R8
# Longitudinal table travel: 19-3/4"
# Cross table travel: 7-3/8"
# Table: 8-1/4" x 28-3/4"
# Motor: 1-1/2 HP, 110 volt, single phase
# Angle vise capacity: 3-1/2"
# Height: 43-1/2"
# Shipping weight: 706 lbs.

I have a mixture of plain shank and threaded shank end mills and slot
drills (some metric some imperial) that came with my second hand lathe.

I have decided to go with the ER collet chuck as opposed to R8 collets
because with 5 or so collets I can handle plain or threaded shank and
both metric or imperial.

I ordered an received an ER40 chuck with 5 collets but was a bit
shocked by the size of it - I am thinking that I should have rather got
the ER32 set. I orded the ER40 as I have a brand new 1 inch 6 flute
end mill and 3/4 inch slot drill that will only fit into the ER40
collet(25 - 26 mm) But it seems according to the specs that this
excedes the machines capabilties ????

Could you please give me some advice as to the best size ER collet
chuck for this machine for general home/ model enginerinf use.

regards
Tim

If I'm reading the specs right, it looks as if you got an RF30 or
equivalent.

The downside of almost all the collet chuck type end mill holders is
their physical size. Especially on limited headroom benchtop mills.

I'd like to suggest that you aquire at least a few R-8 collets too. Get
some sizes that will hold common end mills. The reason for this is that,
eventually, you will have work that requires all the space you can get ,
between head and table, and that ability to hold a cutter a few cm
further from the table top will be of value.

Cheers
Trevor Jones