Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 23

Thread: Compression bit selection

  1. #11
    Join Date
    Nov 2016
    Location
    New Mexico
    Posts
    88

    Default

    We cut 3/4" plywood with 1/2" straight fluted bits from Lowes ($17 each).
    We ramp with 5 passes at 60 ipm and 16k rpm.
    Great results!
    We are not creating edges which require superior finished cuts. More like rough cutting.
    Our most important shop tool is the pencil sharpener!

  2. #12
    Join Date
    Feb 2013
    Location
    River Fall WI
    Posts
    779

    Default

    Not to get off topic but what cnc are you running because you numbers sound way off.
    We run cheap cmt 1/4" downcuts (kids brake them to often to buy anything better) @ 4 ips with 2 passes 12000 rpms, and get nice edges.
    So 1/2" straight fluted bits for 5 passes at 60 ipm and 16k rpm seems really odd.
    Kyle Stapleton
    River Falls Renaissance Academy
    Math/Technology Education Teacher


    PRS Alpha 96x60 2.2 hp spindle, Double Air drills, 6" indexer, Fein 5 zone vac table
    Desktop w/spindle
    Potter Pen
    Aspire 8.5, Creo 3.0

  3. #13
    Join Date
    Nov 2016
    Location
    New Mexico
    Posts
    88

    Default

    ipm (inches per minute)

    Pretty darn fast (IMHO).
    Shopbot Desktop with router.

    We go through 10 sheets of 3/4" ply every month.
    Last edited by woodshop; 10-01-2019 at 11:53 AM. Reason: spelling
    Our most important shop tool is the pencil sharpener!

  4. #14
    Join Date
    Feb 2013
    Location
    River Fall WI
    Posts
    779

    Default

    Desktop... that is still a little off.
    Try a down cut 1/4" 2ips (180 ipm) @ 12000 rmps 3 or 4 passes. (This is what we use on our desktop)
    Kyle Stapleton
    River Falls Renaissance Academy
    Math/Technology Education Teacher


    PRS Alpha 96x60 2.2 hp spindle, Double Air drills, 6" indexer, Fein 5 zone vac table
    Desktop w/spindle
    Potter Pen
    Aspire 8.5, Creo 3.0

  5. #15
    Join Date
    Nov 2016
    Location
    New Mexico
    Posts
    88

    Default

    180 ipm is too fast for our comfort level.
    Don't want to tear up a $6k machine.
    Anything we cut in our shop ranges between 60-75 ipm's.
    We bid our jobs at 60 ipm's.
    Our most important shop tool is the pencil sharpener!

  6. #16
    Join Date
    May 2014
    Location
    MA
    Posts
    565

    Default

    I agree with Kyle, that's far too slow. You're leaving time on the table. 2-2.5ips is fine for a Desktop. You won't tear up that machine at all. If you cut too fast (which 2ips isn't even close to too fast) at worst you'll just stall the steppers. No damage will happen to the machine.

  7. #17
    Join Date
    Jan 2004
    Location
    Marietta GA
    Posts
    467

    Default

    Quote Originally Posted by EricSchimel View Post
    I agree with Kyle, that's far too slow. You're leaving time on the table. 2-2.5ips is fine for a Desktop. You won't tear up that machine at all. If you cut too fast (which 2ips isn't even close to too fast) at worst you'll just stall the steppers. No damage will happen to the machine.
    60ipm = 1 inch per second x 5 passes
    That's a glacial pace.
    You should easily be able to cut at 160-180ipm at 3-4 passes with those big box straight flute cutters. I do it on my older PRT with a PC router with no issues.
    I'd at least consider going to 100-120ipm (approx 1.7-2 inches per second) and cut it 4 passes.
    You will not tear up your machine, and you'll double your output (or better)

  8. #18
    Join Date
    Nov 2016
    Location
    New Mexico
    Posts
    88

    Default

    We get paid well at 60 ipm. (We see no economic benefit to going any faster than that.)

    We are cutting hard wood layered together with exterior grade glues using a half-inch cutter. (Hard wood, hard glue, big swath.)

    We hate those hidden surprises in today's sheet goods... knots!

    We don't need unsafe speeds in our shop or with our expensive equipment.

    In all honesty, we have learned that we don't need those higher feed rates to make money and being SAFE is extremely ECONOMICAL.
    Last edited by woodshop; 10-03-2019 at 04:37 AM. Reason: EDIT
    Our most important shop tool is the pencil sharpener!

  9. #19
    Join Date
    May 2014
    Location
    MA
    Posts
    565

    Default

    You can go faster safely, and if you do your bits will likely last longer so there's your economic benefit! . I often bid my production jobs at lower speeds and then as I get more experienced with the job/material I'm able to push feeds and speeds. That allows for a cushion of down time, and also has allowed me to re-invest in my shop and equipment.

  10. #20
    Join Date
    Nov 2016
    Location
    New Mexico
    Posts
    88

    Default

    ok, we'll give it a shot. Maybe try 100 ipm today. Thanks.
    Our most important shop tool is the pencil sharpener!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •