How to avoid breakout?

[Freetochat]

I have to make some fencing, and need to put a rounded top on the uprights. I have a template and was going to do the job on a spindle moulder. Can anyone please advise how I can avoid breakout?

This pictureshows what I have to do.

Thanks

 

[matt]

I've never used a spindle moulder but suspect you could prevent problems by using some sacrificial timber clamped either side. Sounds like a long a fiddly job. Shame you can go for points - I cut mine on mass on the table saw - job done for about 20m of fence in no time at all.

 

[Freetochat]

I've never used a spindle moulder but suspect you could prevent problems by using some sacrificial timber clamped either side. Sounds like a long a fiddly job. Shame you can go for points - I cut mine on mass on the table saw - job done for about 20m of fence in no time at all.

Thanks for that. If it were my choice, I'd make the same as you.

 

[Steve Maskery]

Ho many do yo have to do? I'd bandsaw and sand for just a few, or bandsaw and spindle (well, I'd probably do it on the router table, actually) using a template jig:

Take a flat piece of MDF and round one corner to exactly half the rounded end.

Fit a support fence with a couple of toggle clamps

Fit a flush trim bit to the RT (or set the SM to flush trim)

Fit a notched single-point fence to the bandsaw.

Load the workpiece into the jig, bandsaw the waste against the single-point fence.

Flush-trim on the RT.

Flip the workpiece in the jig and repeat.

Once set up, it would be very efficient just flitting between machines, assuming, of course, that you don't have to move one to get at the other. There would be no breakout this way as you are never cutting against the grain.

HTH
Steve

 

[Night Train]

The last time I had to do something similar, make a load of rounded ends on some boards.

First I carefully shaped two by hand and band saw as templates.
I then chopped the corners off on all the stock using a mitre saw and then stacked the load of pieces together with a template at each end.
I then skew planed across the grain of all the pieces together using the templates as guides to keep the profile the even.

It was a quick and accurate method when there is no spindle moulder of router table to use.

But as Steve says, on a machine, do one side and then flip over to do the other side working with the grain both ways round.

 

[Freetochat]

Ho many do yo have to do? I'd bandsaw and sand for just a few, or bandsaw and spindle (well, I'd probably do it on the router table, actually) using a template jig:

Take a flat piece of MDF and round one corner to exactly half the rounded end.

Fit a support fence with a couple of toggle clamps

Fit a flush trim bit to the RT (or set the SM to flush trim)

Fit a notched single-point fence to the bandsaw.

Load the workpiece into the jig, bandsaw the waste against the single-point fence.

Flush-trim on the RT.

Flip the workpiece in the jig and repeat.

Once set up, it would be very efficient just flitting between machines, assuming, of course, that you don't have to move one to get at the other. There would be no breakout this way as you are never cutting against the grain.

HTH
Steve

Thanks Steve. I have about 300 to do. Hence using a spindle with a trimming ring. I had thought about making a jig for the bandsaw, but was unsure of doing a 75mm diameter cut that didn't need too much finishing.

I think I'll make a jig for doing a radius on a spindle first, and see how that works.

 

[moz]

If you have a sliding table on the spindle, you could do this a different way by using a cutter such as No. 14 on this page:

http://www.whitehill-tools.com/Cutters.aspx

Stack the pieces edge downwards and clamp them together. The last piece is a spelch board. Obviously not all 300 at once!

John

 

[OPJ]

It sounds as though you're looking for a better finish than what you would ordinarily get from a bandsaw blade... With a sharp, fine-pitched blade though (and a couple of spares! :wink you could build yourself a simple pivoting jig and do the lot on one machine.

Think of a circle-cutting bandsaw jig and you'll get the idea... That's how we used to do them in a previous job - until they bought in a bandsaw which had been "engineered" to pivot around the wood; meaning you could round-top an 8" square post without buggering your back or needing a spare pair of hands! 8)

 

[Freetochat]

If you have a sliding table on the spindle, you could do this a different way by using a cutter such as No. 14 on this page:

http://www.whitehill-tools.com/Cutters.aspx

Stack the pieces edge downwards and clamp them together. The last piece is a spelch board. Obviously not all 300 at once!

John

Thanks for the info. It sounds a good idea, but I can't locate the cutter from the link.

 

[moz]

My mistake. Select 'limiter' then 'limiter 96x55 aluminium 050A00050', just to illustrate the sort of shape. Obviously you would need something like a 96 x 100 block to profile your 75mm wide pieces.

John

 

[Freetochat]

My mistake. Select 'limiter' then 'limiter 96x55 aluminium 050A00050', just to illustrate the sort of shape. Obviously you would need something like a 96 x 100 block to profile your 75mm wide pieces.

John

Thanks for the tip. For speed this is the way to go. Wealden do a 50mm profile cutter with a 35mm radius. (No. 048). By setting this cutter at 45deg, it will do the whole job in two passes.

Thanks John.