CAD CAM EDM DRO - Yahoo Group Archive

[CAD_CAM_EDM_DRO] ServoTiming belt selection

Posted by Les Watts
on 2001-02-18 10:14:45 UTC
Well I have spent part of today selecting timing belts as I want
to get them ordered first thing tommorrow. I can have the machine actually
moving as soon as I get the belts and pulleys.
I will have to bore some of the pulleys but no big deal.

I am using the modified curvilinear GT-2 belts due to their
supposed improved registration and lower backlash compared
to a trapezoidal timing belt.

I found the GT-2 3 mm belts 9mm wide will jump teeth
at 640 oz in with about a 1" pulley with rec
omended tension.

GT-2 5 mm will jump teeth at 4800 oz in with similar setup.

2 mm jumps at only 128 oz in so is not a consideration.


As previously set up 3 mm gives a max position error of .012".

2 mm gives max position error of .0002"!

5 mm is not listed.

This is from the Stock Drive Products web site at:
http://www.sdp-si.com/herb/spk/sdp-si/D260/D260cat.htm#S10

I think They may have a decimal place off somewhere in the
positional accuracy data. 3mm 60 times poorer than 2mm??!!

I could not access the gates rubber design program to check this. Does
anyone have their cd so I could get a verification
of these numbers?

I am using 2:1 reduction with a 1" small pulley to insure
at least 6 tooth engagement. Width is 9mm to 15 mm but
I think jump torque is a weak function of width.Suprisingly it is shown as a
very weak function of tension. It may be a strong function of positional
accuracy though.

Center to Center distance is about 5".

Thanks,

Les


Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html

Discussion Thread

Les Watts 2001-02-18 10:14:45 UTC [CAD_CAM_EDM_DRO] ServoTiming belt selection