Cutting coves


Recommended Posts

I’ve been trying to cut some coves, started out with small spindle gouge and got them basically the size I wanted, then decided to practice a little with a round carbide cutter. I do fine cutting down the left hand side of the cove but, every time I try cutting down the right hand side it catches and I get a bunch of tear out. Can’t figure out what I’m doing wrong. 

   Any thoughts?

Link to post
Share on other sites

If I understand you correctly you are having difficulty with the carbide tool.

Since we can't see what you're actually doing I'll hazard a guess.  Carbide turning tools are generally scrappers, not cutting tools.  So the tool needs to be flat on the tool rest, the handle horizontal and the edge contacting the work at the equater level.

If you angle the tool very much you'll get a catch.  Pushing the tool in too aggresively can give you a catch,too.

  • Like 2
Link to post
Share on other sites

Get used to turning from a variety of stances and hand positions.   But always be safe about it.  Tool on the rest before it touches the piece!  Ride the bevel into the cut. 

Take a good look at how your bevel and cutting edge is riding on the piece as it turns.  I can make a cut using my gouge that use (lets say) 1/8" of an inch of cutting edge, but the bevel is near perpendicualr to the piece, that gives me a scraping cut.  I can use the same exact 1/8" cutting edge, but ride the bevel on the piece and ease the edge into it, that will give me a nice clean cutting action.  Different types of cuts with different results using the exact same cutting edge. 

If you are getting clean cuts right handed, but having catches left handed, then study what you are doing right handed, and emulate that tool position with the other hand.  If you are getting catches, then you are presenting the edge to the piece incorrectly.   This can happen even with carbides, even though my comment is aimed at a chisel/gouge. 

I'm assuming you are trying to cut the cove in a true spindle, where the grain is running from head stock to tail stock.   If the grain isn't running in that direction, it's not a spindle.  There may be a direction where the grain is going to blow out regardless of your presentation.  The only real solution is to take lighter cuts.

Now, if it's a catch and a blow out, then it's a technique issue as I mentioned above.

Link to post
Share on other sites
9 hours ago, trz said:

It happens mostly when I’m presenting the tool to the work.

The tool must always, always be on the tool rest before it touches the wood, securely held in your grip.  Ease the tool forward and begin with a light cut, deepening as desired. 

BUT, before you even turn the lathe on:

The tool rest should be as close to the piece as the piece, and the tool will allow.   Set your tool rest to the closest it can be to the piece, while still having proper spacing for the tool you are using.  My carbide tool requires me to be back about 1/2" inch from the piece, or it may catch on the end of the collet, while If I'm doing a facing scraping cut with my bowl gouge, I prefer to be about 1/8" of an inch away.  Then manually spin the piece, confirming it does not strike anything and makes at least a couple full rotations.  

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.