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All Replies on Need help ripping a Hexagon post from a 4x4

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View QuickTooth's profile

Need help ripping a Hexagon post from a 4x4

by QuickTooth
posted 08-26-2012 12:56 AM


16 replies so far

View exelectrician's profile

exelectrician

1711 posts in 1148 days


#1 posted 08-26-2012 01:18 AM

Lay it out in sketchup find the exact distance between the flats then saw off the opposite side so you have two parallel sides, thickness these two reference sides with your planer. Then saw the 30 degree sides on TS and clean up with the planer. Just my 2 cents worth.

-- Love thy neighbour as thyself

View MonteCristo's profile

MonteCristo

2098 posts in 909 days


#2 posted 08-26-2012 03:25 AM

I think exelectrician is pretty much got it. You want to use the fact that, assuming you’ve squared up your 4×4 to start that you already have 4 of the eight sides, and you only need to establish 2 of the remaining 4 because the last 2 are each parallel to one of the ones you just established and can be got using your planer. You might have to be a bit careful planing to get one of these last two sides, ie. make sure the thing doesn’t teeter on the side on the planer bed. Double side tape it to a wider piece if necessary to get stability.

-- Dwight - "Free legal advice available - contact Dewey, Cheetam & Howe""

View QuickTooth's profile

QuickTooth

8 posts in 1049 days


#3 posted 08-26-2012 01:12 PM

Thanks to both replies. Getting the fist 2 sides the right width and going from there seems like a good start. Figuring things our in sketchup is a good idea as well and I will play around with that here momentarily. However I think MonteCrisco was giving me advice for making an octagon with 8 sides and I am looking at making a 6 sided hexagon.

Just to be clear though. I wish I had an awesome shop with lots of tools but I am more one the art side than the woodworking side of things. So I have no planer at the moment. I have a decent Ridgid table saw and thats going to be about it for getting the cut down besides sanding it. It will be ok if its not dead flush. My main problem was getting the angles right.

Th

View Moron's profile

Moron

4704 posts in 2614 days


#4 posted 08-26-2012 03:01 PM

http://en.wikipedia.org/wiki/Hexagon

At the above link there is an animated procedure for laying out a hexagon.

Lay a sliding Tbevel on the angle, transfer angle to TS blade, use a test piece for sample cut and rip on the TS, clean up with a plane or scraper………done

-- "Good artists borrow, great artists steal”…..Picasso

View MNgary's profile

MNgary

235 posts in 1137 days


#5 posted 08-26-2012 03:16 PM

I think the crucial settings for you are going to be blade tilt and distance of the fence from the blade. Don’t get frustrated and, instead, just keep fine tuning both. The built-in blade angle indicator and fence distance tape will only give you a first approximation – not anywhere near accurate enough for your project. Even a hand held protractor and steel tape will only get you close to the final settings, in my opinion.

I would start by having a number (6 to 9) of 4 by 4 test pieces long enough to safely rip and exactly the same height/width as your final piece and then trial and error my way to the final settings. Also, it is essential your 4×4 be perfectly square with all four sides precisely the same dimension. If you only rip one-third of the way into each test piece you’ll have 12 to 18 attempts at establishing your final settings.

You may want to focus on getting the blade angle first because changing blade tilt will alter the distance from the fence.

-- I dream of the world where a duck can cross the road and no one asks why.

View woodsmithshop's profile

woodsmithshop

1178 posts in 2266 days


#6 posted 08-26-2012 03:35 PM

set the angle of the saw blade to 45 deg then set the rip fence to 2/3rds the width of your board away from the blade, for you that would be 2-11/16” make a test cut to make sure, you may have to fine tune this.

-- Smitty!!!

View Moron's profile

Moron

4704 posts in 2614 days


#7 posted 08-26-2012 03:42 PM

setting the blade to 45 degrees would create an octagon ?….Yes ? No ?

MNGary……..I concur with his advise

-- "Good artists borrow, great artists steal”…..Picasso

View JAGWAH's profile

JAGWAH

929 posts in 1804 days


#8 posted 08-26-2012 03:44 PM

Just a quick sketch based on a 3.5 square post. Post size should actualy be 3” x 3 1/2”

-- ~Just A Guy With A Hammer~

View waho6o9's profile

waho6o9

5197 posts in 1297 days


#9 posted 08-26-2012 03:55 PM

Here ya go, HTH

View casual1carpenter's profile

casual1carpenter

353 posts in 1196 days


#10 posted 08-26-2012 05:22 PM

QuickTooth, as the others have pointed out getting the 4×4 square and straight is your first priority. Might want to search LJ’s for “straight line rip jig”. It is my belief that you first need to get one side straight and flat, with minimal material removal. Then the second side is cut with that first cut down on the jig. Now you should have two surfaced sides that are straight and true, square to each other. Remove the jig and set your fence to the finished dimension, in your case 3.5” and set your one true square corner to the table and the fence, proceed with rip, rotate stock and make final rip.

Note that it is important that your cut angle be set precisely, you are making a large height cut and a small deviation can be a big measurement on the squared stock. Also remember that the piece you are ripping needs to be long enough to process with the table saw safely. You can site search that here to.

When you do the 60 degree cuts remember that as you remove the 60 corner you flat base to table will diminish and you need to watch that it does not try to rotate on you.

Is you TS fence tall enough to catch that hex point if your stock climbs the blade because of inadequate hold down pressure and too fast of feed? Just saying, I’ve had similar happen in the past.

With what tooling you have available this is what I would do. I have no idea however if my posting was even necessary for you, but lots of people follow threads it may be something to think about for them.

View QuickTooth's profile

QuickTooth

8 posts in 1049 days


#11 posted 08-26-2012 07:15 PM

Wow! A wealth of information. Thank you all so very much. I think I have what I need to give it another go. Ill be trying this out tomorrow and will let you all know how it goes or what new problems I make for myself.

JAGWAH, awesome sketch that will come in handy no doubt. Thanks for taking the time.

View woodsmithshop's profile

woodsmithshop

1178 posts in 2266 days


#12 posted 08-26-2012 08:12 PM

ok, I had a brain fart, I was thinking octagon, I went back and reread the original post, it says hexagon.

yes, Moron, 45deg would create an octagon

-- Smitty!!!

View Sylvain's profile

Sylvain

574 posts in 1220 days


#13 posted 08-27-2012 01:46 PM

What about using a hand plane?

It can go rather quick.

-- Sylvain, Brussels, Belgium, Europe - The more I learn, the more there is to learn

View knockknock's profile

knockknock

245 posts in 893 days


#14 posted 08-28-2012 09:59 AM

Since no one else has mentioned a ripping sequence, here is my ‘Theory’ (I no longer have a table saw to test it).

Mark one side of the 4×4 as bottom (if you want you can draw your hexagon on the ends with a flat face on the bottom of the 4×4 and points to the sides).

Set the blade to rip a 60 degree angle off of the bottom corners (30 degree tilt from vertical).

Set the fence so the blade is tilting away from the fence.

Measure the width of the 4×4, the fence should be 3/4 of the width or less from the blade (base of cut). Note: you might want to double check my high school math.

Rip the left and right bottom corners off of the 4×4.

The bottom of your 4×4 should now resemble the bottom of a hexagon. What you have established is the bottom face and the bottom left/right corners of your hexagon.

For the next 3 rips, you want to have an established corner of your hexagon, running along the fence, by always rotating one face at a time in the same direction (cork screwing the waste off, because a hexagon does not fill a square).

If your blade tilts to the left and the fence is on the right, rotate one face counter-clockwise. So the bottom right corner of your hexagon is running along the fence, and rip the next slice off.

If your blade tilts to the right and the fence is on the left, rotate one face clockwise. So that the bottom left corner of your hexagon is running along the fence, and rip the next slice off.

Continue with the next 2 rips, by rotating one face in the same direction as before, with the next corner of the hexagon riding along the fence.

Hopefully, you now have your hexagon cross section.

View rance's profile

rance

4145 posts in 1881 days


#15 posted 09-02-2012 03:43 AM

Given your full situation, my guess is that you know what to do, you just can’t get the repeatable results you are after. 1) if you don’t have accurately squared lumber, you will have descrepencies in your final results(the hex disks). 2) I suggest you cut your post into, say, 18” lengths. This will be more forgiving of inaccuracies of not having a perfectly squared post when you begin.

Other aspects: If you cut one 60 deg. angle, then rotate the log around, you are more likely to have an error in the end. Try(as knockknock aludes to) working from your starting reference surface and working from BOTH sides.

= = = = = = = = = = = = = = = = = = = =

Suggested easiest solution:

Steps:
Rip to 3.5×3 1/32
Set Tablesaw to 60 deg. tilt
Set base of blade 2 5/8 from TS fence
Rip all 4 remaining sides

Notes:
1) Make it even easier by setting fence to 2 3/4” from the base of the blade and sneak up on the 2 5/8”.
2) Ignore my 1 33/64” measurement above. Just raise the blade a tad above centerline.

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

View Moron's profile

Moron

4704 posts in 2614 days


#16 posted 09-02-2012 05:15 AM

repeat

beauty fades

stupidity is forever

-- "Good artists borrow, great artists steal”…..Picasso

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