MAHLE RTI BRC550 - Manual (Page 22)

Page 20
VIII. Changing Spindle Speed
All drum cutting and most rotor cutting should be done at 110 RPM or the slow speed setting as
shown in Figure 4. (This 110 RPM is faster than the slow and medium setting of most competitor’s
lathes.) For advanced level operation, cutting rotors with less than 10" (255 mm) the BRC500/550
is designed to allow for an extra fast 220 RPM fast setting. The faster speed will produce a better
surface finish, but tool life will be reduced. To change the belt position and spindle speed, first
loosen the Allen type lock screw on the pulley arm and then loosen and move the pulley arm stop
adjustment screw to the right. Change the belt position, tighten and move the pulley arm stop
adjustment screw to the left, locking the pulley arm by finally re-tightening the Allen type lock screw
on the pulley arm. Be sure both the narrow primary belt and the wider secondary belts are both
tight and do not slip. There should be about 1/16 “ (1 mm) of movement in the belt when
approximately 10 pounds (5 Kg) of force is applied in the middle of the belt. The belt should not be
too tight. This is evident if more than 20 pounds (10 Kg) of force is required to deflect the belt or
chain 1/16" (1 mm)
IX. Adjusting Chain
The BRC500/550 uses a special roller chain for the final drive of the spindle so that the full 1 HP
of the spindle motor can be used, with no vibration and no slippage. This chain may require
adjustment during the life of the lathe. The correct tension will result in the chain deflecting from
at least 1/16" (1 mm) to a maximum of 1/4" (6 mm) when approximately 10 pounds (5 Kg) of force
is applied to the middle of the chain. Too much play may result in vibration and excess noise. To
adjust the chain, the top center pulley has an eccentric cam. To make the adjustment, the control
box must be removed to gain access to the lock nut for the eccentric cam. Re-check the tension
of the middle belt.
X. Changing Cutting Tips
RTI’s Positive Rake Cutting Tips have three corners. There is a top and bottom. The tips will only
work when the top is up. When viewed from the side, the top is evident based on the fact that the
taper should from the top edge to the bottom with the top edge protruding more. The cutting tip
edge on each corner is worn and should be changed when the surface finish no longer meets
requirements or when the corner is chipped or damaged. When one corner is worn, simply loosen
the tip, turn it 120 degress and re-install (See Figure 3).
XI. General Maintenance
There is no suggested maintenance to the BRC500/550 other than: 1) Keep the entire lathe,
especially the slideways, clean, removing cutting chips with the cleaning brush supplied after each
use; 2) Clean and lube the slideways as noted in the Initial Set Up Section at least once per week;
3) Check belt and chain tension at least once per week; and 4) Lube the two feed screws and drive
chain with a moly based grease, as needed.
XII. Technical Support
For the life of the BRC500/BRC550, you are entitled to free over the phone technical support.
Please call if you have any questions. Our number is 800-486-2321 or 717-840-0678 (Extension
259). If we are not immediately available due to extra heavy phone traffic, we will call you back the
same day. (8 AM to 6 PM ET). We look forward to speaking to you. We are happy to hear from our
customers.