Post by: kenboonejr on October 03, 2021, 06:24:49 PM
#1 How do you cut a nice steady curve for starters?
Then #2, I would think you have to sand both pieces before gluing an accent stripe in and how do you ensure it's a tight fit?
Then finally #3 if you are doing another curve, would you cut out the first curve, put your accent stripe in place and then glue it all back, drop it in the heat box, and once that has cured then cut your next curve and add the next accent stripe and then throw that back in the heat box again? and if so is there any effect of having the first part go into the heat box a second time?
Just saying.. I'm thinking on my next one I would like to try a curved striped but not exactly sure how to go about doing it.
Thanks!
Post by: Mad Max on October 03, 2021, 06:54:52 PM
You need a pattern sander with a bearing or rub collar.
Mine is a rub collar (at the bottom) flush with the sanding belt.
(https://i.imgur.com/JSwsIeu.jpg)
Some 3/4" plywood
You can use a router and a router attachment to make circles for a simple radius
Let's say a 12" Outside Radius on 1 piece of plywood and a 12-1/8" insider radius on a 2nd piece of plywood for a 1/8" stripe.
Double side tape both pieces of the riser block to the patterns and pattern sand them.
Yes you would do 1 curve and glueup then the second curve and glueup.
For something like this you need someone with a CNC to make your patterns.
(https://i.imgur.com/cPQcLQv.jpg)
Here are a pair to make 2 different curves for a 1/8" stripe
(https://i.imgur.com/9Kn1697.jpg)
Post by: Crooked Stic on October 03, 2021, 09:10:52 PM
Post by: Mad Max on October 03, 2021, 09:52:14 PM
and get plenty of 60 grit sanding sleeves
Make sure and get the BIG one
https://www.stewmac.com/luthier-tools-and-supplies/tools-by-job/tools-for-sanding/robo-sander-flush-trim-sander/
Post by: Shredd on October 03, 2021, 11:21:45 PM
For the crescent accent just run the curved wedge through the saw with the same radius jig...
You need a fairly smooth cutting blade... After you make your curved cuts just run them over your sander with a very consistent and light touch... Use the saw marks as your guide... If your sanding is not consistent the saw marks will let you know... Don't sand smooth... Just leave enough saw marks on that shows that you sanded consistent... You are never gonna see .001 to .003" deep saw marks from the edge... Sand with the cut you made don't try to true it up to 90*... If you do you are looking for trouble and you will probably get gaps...
If you decide to go with fatter accent, lets say 1"... You will have to cut the radius of one of the riser pcs 1" smaller or larger radius than the other pc. so they fit together properly...
[ You are not allowed to view attachments ]
[ You are not allowed to view attachments ]
Post by: kenboonejr on October 04, 2021, 10:20:00 AM
@Mad Max - that looks good but don't think I am going to try and tackle anything that I need to have cut on a CNC at this point. I like the way it looks like you have two patterns wrapped up in just those 2 pieces. That was some pretty good thinking there!
@Shredd - Yea I was wondering if you just did 1 cut if that would work or not and I guess that depends really on the shape of the curve. I suppose that works if doing a consistent arc, but if your curve changes like starts to curve in more near the bottom kind of thing, you would definitely have to have another pattern.
Thanks guys!
Post by: Shredd on October 04, 2021, 02:14:43 PM
I done at least 40 bows this way using this method... You need a smooth cutting saw blade though and a light consistent touch while sanding... I only use a pattern sander for the back side of one of my risers to fit my form... It's not a radius on that riser...
You can even make sanding blocks the same radius as the cut on the riser and sand by hand... :thumbsup:
Post by: kenboonejr on October 04, 2021, 10:05:53 PM
Thank you guys!
Post by: oldandslow on October 10, 2021, 06:44:19 PM
That's cool. I think I am going to try it on my next bow!
Thank you guys!
Google woodslicer bandsaw blade...cuts so very nice.
Post by: Mad Max on October 10, 2021, 07:36:41 PM
Google woodslicer bandsaw blade...cuts so very nice.
[/quote]
That's all I use
Post by: kenboonejr on October 10, 2021, 07:42:01 PM
Thanks,
Post by: oldandslow on October 10, 2021, 09:12:22 PM
So i googled it and it says it is a resaw blade. Can you use that for the curves as well? 1/2" blade?
Thanks,
Absolutely...wide curves cut nicely. Using a jig will require little sanding
Post by: kenboonejr on October 11, 2021, 09:06:20 PM
Post by: Walt Francis on October 22, 2021, 12:42:31 AM
You can use a Robo-Sander Flush Trim Sander
and get plenty of 60 grit sanding sleeves
Make sure and get the BIG one
https://www.stewmac.com/luthier-tools-and-supplies/tools-by-job/tools-for-sanding/robo-sander-flush-trim-sander/
They make 60 grit metal sanding sleeve for the Robo-Sander that cleans up fairly well with a sanding belt eraser/cleaner. The one I bought 8-10 years ago still works fine after a few dozen bows. Some of my risers have a few curves, below is the bow I built for last years Tradgang bow trade:
Post by: kenboonejr on October 22, 2021, 10:02:41 AM
Post by: 4 point on October 22, 2021, 09:00:13 PM