Obtaining a smooth rocker curve

robg · Post by **robg** » Wed Dec 12, 2007 11:59 am

Does anybody have any experience/suggestions for obtaining a smooth rocker curve? I am in the midst of making the SS rocking horse (12 days left before it has to be finished!) and I started working on the rails last night.

So far, it appears that patience and a drum sander is the key, but I thought I should check for any tips that people might have. I already know to finish them clamped together for a uniform curve of course. I am working on getting them to a smooth radius, dealing with band saw imperfections and eliminating the flat spot I just HAD to put in on the bottom of the curve.

drewa · Post by **drewa** » Wed Dec 12, 2007 12:36 pm

The underside of the belt sander. It is unsupported in back and will give a fair curve. But watch out for dust in your face.

I would, however use the disc sander. If you have a scribed line. Set up the disc sander and sand to the line. You should, with a steady hand, be able to sand the line and just touch up with some hand sanding.

Or you could make a jig for a router with a follower bearing. You chose.

Unfortunately you will have to be patient.

Be good,

Drew

Ed in Tampa · Post by **Ed in Tampa** » Wed Dec 12, 2007 12:56 pm

robg wrote:Does anybody have any experience/suggestions for obtaining a smooth rocker curve? I am in the midst of making the SS rocking horse (12 days left before it has to be finished!) and I started working on the rails last night.

So far, it appears that patience and a drum sander is the key, but I thought I should check for any tips that people might have. I already know to finish them clamped together for a uniform curve of course. I am working on getting them to a smooth radius, dealing with band saw imperfections and eliminating the flat spot I just HAD to put in on the bottom of the curve.

When I built my rocking horse I had pretty much the problem you are having. If was to do it again I would build a plywood pattern.
I would cut the arc in ply using a circle cutting jig and my bandsaw but I would cut the bottom arc leaving the wood attached to the ply up to the piviot. Next I would use double sided adhesive and attach my wood to the ply pattern, thus using the pattern with center point cut the arc on the bandsaw and the circle cutting attachment.

Once I got the bottom arc cut I would then use my conical sander to sand the bottom using the pattern as a compass. After final sanding I would then cut out the top side of the rocker.

If you wanted you could use a router to cut the bottom arc using a compass attachment.
Ed

reible · Post by **reible** » Wed Dec 12, 2007 1:46 pm

Hi,

This operation begs to be done on either a router table or with the OPR but since you have by now gone past the point deciding how to make the part I'll skip that part and move on to a good way of sanding these.

You will need to make a pattern out of either 1/4" plywood or hardboard. You do this because it is much easier to work with the thinner wood and you need to make the pattern as close to perfect as you can. At this thickness I would get close then switch to hand sanding to just touch the line.

Now go to page 228 in the current PTWFE and read the heading Pattern Drum Sanding. Now follow the instuctions and you will have a nice easy way to finish your project.

Save the pattern in case you want to make a second or third one some time in the future...

It is worth making jigs even if they only get used once.

Hope you get some pictures to share with us once the project is done, I'm sure it will be great.

Ed

robg · Post by **robg** » Wed Dec 12, 2007 2:01 pm

Thanks for the advice. You have given me some new thoughts . . .

Perhaps I will make a pattern out of plywood and run the rail through the router to that pattern and then touch it up with the drum sander and by hand. Or even sand to it on the disc sander (although that seems to leave more room for error).

Ed in Tampa · Post by **Ed in Tampa** » Wed Dec 12, 2007 2:19 pm

[ATTACH]656[/ATTACH]

Here is a picture of my daughter introducing my granddaughter who is now 20 to her new horse named Stripe. Stripe has been ridden by 6 garandchildren. Stripe has fared better than me through all these years. He was a plan found in Woodsmith, his mane and tail made from yarn and the saddle, bridle from leather and plastic eyes all came from the kit Woodsmith offered.

I was looking through some old pictures and came across this one, couldn't resist posting it.
Ed

robg · Post by **robg** » Wed Dec 12, 2007 2:51 pm

Awesome Ed. The only thing missing is easily seen some era specific clothing that would date the picture.

RobertTaylor · Post by **RobertTaylor** » Wed Dec 12, 2007 3:10 pm

great job ed. keep doing awsome work. bob

a1gutterman · Post by **a1gutterman** » Wed Dec 12, 2007 8:07 pm

Nice! Nice ducks too, Ed. He He He

john · Post by **john** » Wed Dec 12, 2007 8:13 pm

Robg:

I have made several horses of the same SS patern. I made a template from 1/4" plywood for most pieces and cut them on the bandsaw. In the case of the rockers, I then clamped them together, put them in my Workmate, and mostly hand sanded to get them even.

Ed:

Nice job on the horse! I hope you had as much fun building it as the kids have riding .

John