LumberJocks

Cutting Curves

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by Martini1 posted 04-07-2019 08:59 PM 487 views 0 times favorited 12 replies Add to Favorites Watch
View Martini1's profile

Martini1

7 posts in 225 days


04-07-2019 08:59 PM

Topic tags/keywords: question bandsaw router sander sanding shaping

Looking for advice on cutting curves and cleaning them up. The general process I was planning on doing is to start with making a template using cheap thin plywood or MDF. To cut the template I plan to get it close with the band saw and the next step is where I have questions. Should I complete the final shaping of the template with a spindle sander or rasp? I have neither tool and am looking into purchasing one. What is faster/easier?

Once the template is complete I plan to use that to draw my lines on my piece of wood. Once again I will cut my wood as close as possible with the bandsaw. More questions: – Do I use the template as a guide for my router? If so, use hold downs to keep the template in place on the wood or double sided tape. – Do I not bother with router and use a wood rasp or spindle sander to get close to the line?

Should I be in the market for a wood rasp, spindle sander or both?


12 replies so far

View bruc101's profile

bruc101

1337 posts in 3903 days


#1 posted 04-07-2019 09:30 PM

We very seldom use plywood or MDF to make templates with, just us. We make our templates out of a hardboard bought at any big box store. It holds an edge and last longer than plywood or MDF for our templates.

We band saw close to the edge and then use an orbital sander to smooth it and take it down to the lines. Sometimes we also have to do some hand sanding on it.

Good luck on your projects.

-- Bruce Free Plans https://traditionalwoodworking.org

View jerryminer's profile

jerryminer

951 posts in 1802 days


#2 posted 04-07-2019 09:31 PM

You’re on the right track here. Yes, make a template first out of thin material (I like mdf because it is easy to shape and consistent in density, but plywood works too).

Shape the template to final size. You can shape by hand if you cut pretty close with the band saw. I often use a cut-off section as a sanding block to smooth the curve. Better than a spindle sander, IMHO, because you won’t get the divots that are possible with the spindle sander.

Trace the template onto the stock and rough-cut with the band saw.

Attach the template to the work (double-stick tape or brads or hot-melt glue, or…) and rout to shape. Done.

What are you making?

-- Jerry, making sawdust professionally since 1976

View wuddoc's profile

wuddoc

344 posts in 4079 days


#3 posted 04-07-2019 09:38 PM

We use an oscillating spindle sander with various diameters and grits for concave curves. A 1” by 30” strip sander with various grits for convex curves.

Attaching template to project wood piece we use double sided tape.

you tube has several videos under “cutting curves on wood with a template”

-- Wuddoc

View gwilki's profile

gwilki

293 posts in 1834 days


#4 posted 04-08-2019 12:54 PM

You’ve not said how long your curve is or how big the piece is, so I’ll mention that a router trammel may do the trick for you.

-- Grant Wilkinson, Ottawa ON

View bondogaposis's profile

bondogaposis

5368 posts in 2712 days


#5 posted 04-08-2019 01:18 PM

I use 1/4” MDF for templates shape them on a spindle sander and by hand with a rasp and sandpaper. Then attach template to project piece w/ double sided tape. One of the handiest things for doing this is custom shaped sanding blocks and pressure sensitive sandpaper.

-- Bondo Gaposis

View Sludgeguy's profile

Sludgeguy

56 posts in 483 days


#6 posted 04-08-2019 02:01 PM

I use 1/4” plywood for the template and the white double-sided “turners tape” to secure the template to the workpiece when I use a router. Sometimes I just get close with the bandsaw and finish it up with a spindle sander on the drill press.
You can buy pre-made template a Rockler.

View Aj2's profile

Aj2

2202 posts in 2159 days


#7 posted 04-08-2019 04:42 PM

When I make templates for my curved laminations screw the first one to pattern. Sometimes two sided tape will move. After I get the first one done I keep stacking and cutting with a flush trim bit. I used to glue them as I go with nails now I just as I keep stacking them.
I bet no knows what the hell im taking about. :)
Plywood forms I make can be up to 5 inches thick.

-- Aj

View Martini1's profile

Martini1

7 posts in 225 days


#8 posted 04-08-2019 05:07 PM

Thanks for the advice everyone. I am building a cherry spice rack right now. I also have a dresser top I was planning on putting a slight curve on.

View CaptainKlutz's profile

CaptainKlutz

1226 posts in 1855 days


#9 posted 04-08-2019 05:24 PM

How to cut/dress curves depends on situation?

IME – wood rasp is best for used for complex 3D curves in multiple directions are same time. It’s more of carving tool? Spindle sander does not shape complex 3D curves very well, and would not be used for same purpose.
Why not consider a spoke shave?

- flat panels – use router
Make template, mark shape, cut close on band saw, mount template with tape, clean up with router bit with bearing, and hand sand to finish.

- complex legs or small pieces – Use spoke shave.
Use any template, cut close on band saw, use spoke shave to clean up curves, hand sand.

IMHO – Using spoke shave and hand sanding is faster than trying to use a spindle sander and matching shapes.

Also – If working only outside edge of circle; a block plane or belt sander can be used to shave the rough band saw cut down to the line

YMMV

-- I'm an engineer not a woodworker, but I can randomly find useful tools and furniture inside a pile of lumber!

View Andybb's profile

Andybb

1886 posts in 964 days


#10 posted 04-08-2019 06:35 PM

The spindle sander is certainly faster than a rasp. YMMV. They are cheap at Harbor Freight. I suggest cheap because a SS is something that you (I) rarely use but when you need it it’s nice to have.

Double sided tape is untrustworthy (ask me how I know) so I suggest a brad or pin nail or a small screw.

Hardboard or MDF depending on what I have on hand.

-- Andy - Seattle USA

View DS's profile

DS

3141 posts in 2781 days


#11 posted 04-08-2019 08:32 PM

If you have a CAD program, you can print the Curve 1:1 on a printer – sometimes on more than 1 page – and paste this pattern on the front of your work piece as a guide for cutting.

If you also happen to have a CNC router;
  • Draw the curve in CAD.
  • Apply a tool path to the curve in CAM
  • Output G-code to the CNC Router
  • Press Start
  • Light Sanding
  • Apply Finish

If you don’t don’t happen to have CAD, or a CNC router, there are lots of other good suggestions above.

(I couldn’t help myself—sorry.)

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

View oldnovice's profile

oldnovice

7475 posts in 3728 days


#12 posted 04-09-2019 02:36 AM

I use either 1/8” or 1/4” hardboard for my templates for the reason given by bruc101 above. It holds its edge better that MDF and the edges are smother that plywood. The 1/8” thickness is easier to trim manually!

Before I got my CNC I used templates for all my routing work!
I don’t have a bandsaw or scroll saw so I used a coping saw, rasp, and sandpaper to get to the desired size.
I run a test with the template and make adjustment to finalize it.
I also made some “modular” templates that can be used indivually or together for different cuts.

I just tossed a whole bunch of templates because they were not going to used anymore.

-- "I never met a board I didn't like!"

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com