Still having issues with cutting consistent thin strips on table saw

Discussion in 'Segmented Turnings Forum' started by Ed Korsberg, Jul 6, 2019.

  1. Ed Korsberg

    Ed Korsberg PRO Member

    I have tried a couple of times to make this laminate pattern from thin (like 1/8 inch) strips of ripped wood but I am still having obvious tapering issues from end to end. The total length of the strips are about 3 feet in this case.

    As you know you first you cut a series of strips of various thickness and wood species, glue and clamp till dry. Then cut the laminate at an angle (in this case 30 degrees with width of 1 inch) and then glue and clamp again. There is another round of that process to follow but already the errors are excessive.

    In hindsight I should have assembled all the pieces (24) in their original orientation which would have minimized much of the mismatches. Thus if I take a piece from the thicker end and pair with a piece from the thinner end then the mismatch is glaring.

    But more to the point is how can cut a perfectly consistent thin strip on my table saw? I tried to align my saw (Dewalt DW944) as best I could. On a separate note I am considering getting a Sawstop contractor table saw after having my first and hopefully last table saw accident. Would a higher quality saw be more able to maintain a consistent cut? Various people offer opinions that not even a higher end saw would really make for a precision cut. I have looked into maybe making a thin strip cut jig but those are usually for lengths much less than 3 feet. I have a Grr-Gripper but never used yet. There seems to be an attachment for 1/8 strips and they also recommend getting 2 Grr-grippers for lengths greater than 16 inches.

    Basically I am having problems achieving results such that other more experienced members of this forum are achieving.


    Title: Imgur

    this is even a worse demonstration of it
    Title: Imgur
     
  2. mfisher

    mfisher Super Moderator Staff Member

    Hi Ed:
    I am lucky to belong to a wood club that has professional grade equipment. That said, the club has Sawstops and they are good saws (safer too). Getting perfect thin strips with no taper is a challenge. Having access to a joiner, planer and drum standers help in producing consistent thin strips.

    I generally cut my stock thicker than the final dimension. I take my stock and join one side and one edge. Then I can rip to desired width. Those strips are then run through a planer and drum sander to get the final thickness.

    If I was limited on space I would get a sawstop and a good drum sander.

    I use a Ggripper. It is a good push stick on steroids. It helps keep the stock against the fence and your hands away from the blade. You do need to check to make sure the blade goes through the tunnel and the blade is not set to high to cut the Ggripper.
     
    Jeff Miller likes this.
  3. Ed Korsberg

    Ed Korsberg PRO Member

    I have a planner and a drum sander. However I don't remember the details but the planner cannot go down to 1/8 inch. The drum sander could go thinner than the planner but I am not sure even that could do 1/8 inch.
     
  4. mfisher

    mfisher Super Moderator Staff Member

    Most planners or drum sanders won't go down to 0.125. You can use a carrier board of 0.5 or 0.75 thickness. I also glue a thin board on the end of the carrier board to help keep the boards I am planning from slipping off. The carrier board can also be used on a drum sander when sanding very thin material.

    The use of a carrier board allows you to plane down to almost nill thickness.
     
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  5. Ed Korsberg

    Ed Korsberg PRO Member

    This is very useful and I should be able to do this. I find it interesting that even those who have higher end table saws still resort to this technique of oversizing the cut on the table saw and then finishing the thickness via this carrier board and a planner/sander. But having said that I am still surprised that a tool like a table saw which is built to rip cut long linear and hopefully consistent stock is in fact not really that reliable. I have to believe it can be done but maybe it needs a combination of heavy cabinet saws, featherboards, grr-grippers, etc and a skilled operator.
     
  6. Ed Korsberg

    Ed Korsberg PRO Member

    Here is another issue I am facing.
    Using the LaminationPro software my repeating unit should be 2 inches for this pattern.
    But after the various cutting steps I ended up with this.
    Title: Imgur

    I measured the total distance for 9 segment and it as 18.25 inches instead of 18.00 as expected.
    Essentially my segment edge length is 18.25/9 = 2.0278 vs 2.0 inches long.
    Any ideas what could account for this error?
    As far as I know my first cut width was as close to 1.0 inches as I could make.
    Title: Imgur

    When I said I wanted a challenge I guess I got what I asked for.
    I have made 3 practice pieces all with various errors which I have shared in this forum.

    PS I am making a carrier board now for the next experiment and appreciate the help and feedback from more experienced people.
     
  7. Gary Beasley

    Gary Beasley PRO Member

    Are you doing any sanding before you glue up the strips? The calculations may have been including sanding waste between each glue up to get the proper dimensions. The only other factor I can think of would be accumulated glue thickness.
     
  8. Ed Korsberg

    Ed Korsberg PRO Member

    no sanding. I cut the strips to what I hoped would be a consistent thickness across the entire length and then glue and clamp them. However I have already learned several tricks from this forum and others. The next time I will try overcutting the thickness and then use a carrier board to then reduce thickness on a planer or drum sander. Not sure if the planer or sander would be better for this step. In addition since my lamination needs to be fairly long, like 40 inches, rather than trying to cut 1 long strip of that length (which I can't do easily since some boards are only 3 feet long) I will cut shorter lengths and I think when these are glued up into a laminate it will be fine.
     
  9. mfisher

    mfisher Super Moderator Staff Member

    Ed:
    Maybe I am confused on your issue. I am going to regress a bit. First you need to design your vessel using WTP or SP. From the design of the vessel you will know what diameter the featured ring will be, the number of segments and the segment edge length required to make that diameter ring.

    In LP adjusting the "set first cut width" determines the repeating unit width.
    ex" 1" cut width gives a repeating unit of 2 inches
    ex: 1 1/8 cut width gives a repeating unit of 2.25 inches

    You need to adjust the first cut width to get as close to the segment edge length you need for your vessel.
    It may be helpful for you to post your WTP file and LP file so we can see what is going on.
     
  10. Ed Korsberg

    Ed Korsberg PRO Member

    Thank you for the update. I think I do understand the principles. As far as I can recall my first cut width was 1.00 inches. However since my resulting repeating unit seems to 2.0278 inches then by extension it would seem my first cut width was really 1.013 inches wide instead of 1.00 inches. that little bit of a difference really adds up after many cuts.
     
  11. Ed Korsberg

    Ed Korsberg PRO Member

    I just learned of a table saw accessory called a 'power feeder'. A cabinet maker friend told me he has them on both his table saw and planers. He said if he feeds work through the saw by hand it ends up not being a consistent cut. But when he uses the power feeder every cut is consistent.
    I wonder if people in this forum have such tools in their shop.
    I still think the planer carrier board idea is workable and is what I will try next.
     
  12. mfisher

    mfisher Super Moderator Staff Member

  13. Glenn McCarron

    Glenn McCarron PRO Member

    Check out this DIY power feeder.
     
  14. Arlin Eastman

    Arlin Eastman Member

    Ed

    If you have a planner and or drum sander make a sled to put the strips on and use double backed tape to hold the ends down while it goes thru the process.

    That is the way I do it and have 3 lengths of sled. When I finished making the sled I put it thru the planner or my double drum sander to get it all even and down to 1/8" on the front and back edges.
     
    Ed Korsberg likes this.
  15. Ed Korsberg

    Ed Korsberg PRO Member

    Yes I intend on trying this on my next attempt. 3 practice runs have all failed to produce a repeatable pattern I would be willing to use. When I show my friends the pieces their first reaction is 'oh that looks good' but then I have them look again more closely and it is then very obvious. What material do you use for a sled? MDF? Basically would like to go to home depot and simply buy something modestly low cost that is flat from the get go rather than try and create some flattening jig with a router.
     
  16. Gary Beasley

    Gary Beasley PRO Member

    Mdf has the advantage of being more dimensionally stable as long as you keep it out of puddles of water. The melamine surface you can get on it, especially on both sides, is slick and easy to clean. It should do well as a sled. Don't go too low on the cutter, it will be tough on the blades if it hits the sled.
     
  17. Arlin Eastman

    Arlin Eastman Member

    I use melamine for the bottom and use oak on the ends.

    On the bottom of the sled I also use 6 oak 3/4"x3/4" strips so there is something to grab onto.
     
  18. Frank Smith

    Frank Smith Member

    Hmm...I wrote this reply yesterday but must have failed to click post...

    The main thing the power feeder is doing in this scenario is consistently keeping the board against the fence. You should be able to accomplish that with a good pushstick (maybe a Grr-ripper as Mark Fisher suggested) and good technique. Two Power feeders are a pretty expensive way to accomplish this but adjusted properly they would get the job done!
     
  19. Jeff Miller

    Jeff Miller Moderator

    Make sure you are measuring perpendicular to the saw cuts and not the distance from blade to fence or stop. If the first segment is not 1.0 inches wide, then each cut magnifies the problem. I use a waste piece of wood to get the measurement as perfect as possible before using the laminate.
     
  20. Ed Korsberg

    Ed Korsberg PRO Member

    So on this latest experiment I tried the suggestions of using a carrier board and then planing/sanding the strips to a flat consistent thickness. So far it is looking much better but am only at the stage of gluing up the chevron pattern. However in all the attempts I have made the width of the board during the generation 1 chevron cutting is slightly wider than what the software states. I have cut the strips to what I hope is a precise measurement. In this case the software claims the board width should be 2.82 inches but the actual is 3.06
    I have made 4 practice attempts so far (yes 3 failures before that) and each time my actual width is larger than what the software claims

    Title: Imgur
    Title: Imgur
     

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