Very confused ... HELP

[ardsranger]

sorry for to post very close to the same but more i read more i get lost.
I have read several post on this site

Ok im looking at
these

Product Line: Hi-Lead®
Major Diameter: 1/2" (in.)
Threads Per Inch: 6 (Threads/in.)
Number of Starts: 2
Lead: .333 (in./rev.)
Effective Threads Per Inch: 3 (Effective TPI)
Hand: Right Hand

Product Line: Hi-Lead®
Major Diameter: 1/2" (in.)
Threads Per Inch: 8 (Threads/in.)
Number of Starts: 2
Lead: .250 (in./rev.)
Effective Threads Per Inch: 4 (Effective TPI)
Hand: Right Hand

Product Line: Hi-Lead®
Major Diameter: 1/2" (in.)
Threads Per Inch: 10 (Threads/in.)
Number of Starts: 2
Lead: .200 (in./rev.)
Effective Threads Per Inch: 5 (Effective TPI)
Hand: Left Hand

Product Line: Hi-Lead®
Major Diameter: 1/2" (in.)
Threads Per Inch: 8 (Threads/in.)
Number of Starts: 4
Lead: .500 (in./rev.)
Effective Threads Per Inch: 2 (Effective TPI)
Hand: Right Hand

any suggestion on which of these to use
my mill is 495 in steppers
on smc bearings / rails

cutting plastics

i want to increase the speed but will it 'LOAD UP' the motors alot if i go to higher TPI?

size of the table is 30" by 33"

as in previous post. my current screw is all thread 12 TPI using a 2 " aluminum block threaded all 2 inches.

i would love some input want to order very soon.

my current use able TPI for cutting is about 38 , rapid is 55 ish inch per minute


like to get cut speed to 85 to 100 and rapid to about 130+ inch per minute

thank you for your help bob

[grahamshere]

Hi again, ok the 8 tpi 4 start .500 will be you fastest hi lead you asked about. it will be 2 turn per inch of travel. You still get good resolution. But you also have to think about your drivers. Also you said you are working with plastic, delrin (spelling) I think you said, why not make your own nuts. you can use a piece of the lead screw to make a tap with.delrin would be better than metal I think. less wear on your screws. I think Roton sell's the plastic ones as well. I've been using nylon on mine and still has no slop. Graham