# X 2 Mill Belt Drive Alternative



## velocette (Sep 30, 2011)

Hi this is a "What I Did not a How I Did It" post 

Stripped out All gears and counter shaft from mill head and replaced bearings With Taper Roller Bearings 30206
30 X 62 X 17.25. Grind down 1.5 mm from inner race. Fabricated brass shim shields .25 mm thick = 16 mm Height (same as original ball bearing)

Fabricate and Fit "Poly Vee Pulleys calculated to give 1200 rpm 1900 rpm and 3500 rpm 
Drill and tap top of gear box to fit 12 mm aluminium mounting plate 

Removed torsion spring mechanism and fitted Longer rack to give 205 mm travel.

Fitted "Air Spring" to counter weight of mill head 24 kg rated.

Added rev counter from diesel engine 96 tooth disc and ABS wheel sensor from a Volvo as pickup 12 volt DC powered.

Made and fitted stiffener for column Thanks to all who submitted their ideas to "Home Model Engine Machinist."

The results are remarkable "Self Praise Again." No grumbling gears or power wasted making them spin
 Added photos of Belt Drive


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## B-RAD (Oct 2, 2011)

More pics!! :big:

I'd like to see your column support..


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## velocette (Sep 8, 2012)

Hi an update to the saga of the X2 Mini Mill Belt drive.

Fitted a 1.25 hp tread mill motor and "Minarik" Motor Control instead of .5 hp original motor.

This allows me to be able to use a 16 mm end mill cutting caste iron 2 mm deep @ 600 RPM  60 mm min traverse.

Using the mid range pulleys that give a maximum speed of 1800 RPM.

The improvement in power output is very pleasing with a low speed torque that the original motor never had

Been a bit naughty and set the Motor maximum speed to 5500 from 4700 to give me 3200 RPM spindle speed on High this will only be used on small milling cutters.

The "New" motor would not fit to the Existing mounting so the yoke for the "Air Spring" was discarded and new one machined out of piece of cast iron.

With a bit of thought this could be made "Adjustable" to give MORE "Z" Axis travel from 205 mm (Max Stroke on Air Spring)
to 285 mm plus.

Adjustment is by loosening the clamping screws on the yoke and sliding it  up or down the two 20 mm columns 

Will attempt to tell the story with a few pictures showing Set on Low and Set on High with the motor mount as well.

 New belt drive added to cope with the extra power.  Extended Hand Wheel  to clear Larger pulley

Guard was omitted for clarity 


Eric


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