Not so prefact knots Help???

[7miles]

Ok,
I built this really nice jig for the band saw to do multi jobs.

Cutting Knot is one job...It seem to work really well. However I can't seem to get my knots even. A few picture blow should help to see whats going on. One side of the knot seems to be larger then the other.

As you can see I have done 3 and I'm getting the same problem.

The first one is made from credit card....really a krogers card and the wood I'm not really sure.

pic 1 side 1

pic 2 side 2

The next one I have the same problem....blank is maple with a walnut knot. The jig that I built also cuts the thin piece of walnut at .042 is what these piece happen to be. But I have the same problem.
pic 1 side 1

pic 2 side 2

I really think my problem lies in my drilling, but not really sure.
Any suggestions would be appreciated.
[?][?][?][?]


Thanks
Dale

 

[jhs494]

That is not a bad job on the knot. I think that your drilling is not centered. Not sure how you drill, but if you have a chuck for the lathe it, IMHO, is far superior to keeping the hole in the center.

 

[LostintheWoods]

You're on the right track--the two variables which will affect the accuracy of your knot are: first, the kerf thickness (thickness of the cut produced by the saw blade) has to be EXACTLY equal to the thickness of the wood used for the knot; and secondly, the blank has to be drilled EXACTLY on center. If you can accomplish both of these, your knot will come out the way you want it to. BTW, your knots are looking pretty good from here, too.

 

[stevers]

I think Joe hit it, the knots could be right on and the drilling off center makes them appear to be off.

 

[leehljp]

In order to keep your knots centered you need to make sure that the blank stays square as you glue it back together. IF it is out of square a tad, it will affect the alignment for drilling.

Two ways to drill: 1. perfectly squared and centered DP; 2. On the lathe. I personally get more consistent precision centering on my lathe easier than I do on my DP.

 

[R2]

Those knots are pretty reasonable. I think you might not be drilling dead centre.

 

[GaryMGg]

Originally posted by leehljp

In order to keep your knots centered you need to make sure that the blank stays square <s>as you glue it back together</s>....

And the best way to do that is to NOT cut it apart.
Cut almost all the way through, insert the slice that'll be part of the knot, clean up as necessary and make the next cut. But, don't cut all the way through.
That doesn't look like your problem to me -- it merely looks like the drilling is off a hair. They're looking good.

 

[leehljp]

Originally posted by GaryMGg

Originally posted by leehljp

In order to keep your knots centered you need to make sure that the blank stays square <s>as you glue it back together</s>....

And the best way to do that is to NOT cut it apart.
Cut almost all the way through, insert the slice that'll be part of the knot, clean up as necessary and make the next cut. But, don't cut all the way through.
That doesn't look like your problem to me -- it merely looks like the drilling is off a hair. They're looking good.

YOU ARE RIGHT! I am a slow adapter. Not cut all the way through is BEST.

 

[Freethinker]

Originally posted by GaryMGg
And the best way to do that is to NOT cut it apart.
Cut almost all the way through, insert the slice that'll be part of the knot, clean up as necessary and make the next cut. But, don't cut all the way through.

Good advice......except that cutting a slot that is only the thickness of a credit card is a problem for me.

I can make a perfect (i.e, symmetrical) Celtic Knot when doing it on my table saw, but am limited by the thickness (the thinnest being 1/8 inch) of the 10" table saw blade.

When tried on the band saw, I have difficulty making the cut be exactly the same degree (45 degrees in my case) on each successive cut. The blade wants to pull (just very slightly, but enough to notice in the final product) to one side a bit.

What's the solution to that problem?

 

[Jarheaded]

I like the way your knots are. They give it a handmade look and not the mass produced look.

 

[Poppy]

Get yourself a 7 1/2" Freud Diablo blade if you can find one and Dewalt also makes one very similar to the Diablo, thse blades will give you a 1/16th kerf.

Originally posted by Freethinker

Originally posted by GaryMGg
And the best way to do that is to NOT cut it apart.
Cut almost all the way through, insert the slice that'll be part of the knot, clean up as necessary and make the next cut. But, don't cut all the way through.

Good advice......except that cutting a slot that is only the thickness of a credit card is a problem for me.

I can make a perfect (i.e, symmetrical) Celtic Knot when doing it on my table saw, but am limited by the thickness (the thinnest being 1/8 inch) of the 10" table saw blade.

When tried on the band saw, I have difficulty making the cut be exactly the same degree (45 degrees in my case) on each successive cut. The blade wants to pull (just very slightly, but enough to notice in the final product) to one side a bit.

What's the solution to that problem?

 

[VisExp]

I agree with Poppy. I use a WWII for 99% of the work on my table saw. It is a thin kerf and is actually 3/32". I also have a diablo circular saw blade which has a kerf of 1/16". You lose in the depth of the wood that you are able to cut but this is not a problem when cutting a pen blank. I have a sled on my saw which is 5/8" thick and the circular saw still extends past that more than enough to cut even the thickest of pen blanks.

You can pick up the Freud diablo circular saw blade at Home Depot or Lowes. Only $10 or $15.

The only problem with not cutting all the way through is that most saw blades are ATB and so you will not get a square cut. If this is in the section of the blank that is going to be turned away then it is not a problem.

Does anyone know where I can get a flat tooth grind (FTG) blade with a kerf of 1/16"?

 

[7miles]

Thanks for the advice guy. I did not cut all the way thru on these knots. To me it seems to be the only way to go. I like not having to line every thing back up.

Well off to work I go. I'm back in the shop tonight, to take another shot at it. I think I will fix my problem at the drill press. I hope anyways [][]

Thanks

 

[GaryMGg]

Does anyone know where I can get a flat tooth grind (FTG) blade with a kerf of 1/16"?

I'll have to see if there's still any marking on the blade I'm using. It's a HSS plywood blade and appears to be flat ground with no set. It's really old so I may not be able to locate it's source.

 

[Rick_G]

Check your blanks as well, if they are not perfectly square when you drill down the center it doesn't line up with the center of the knot.