Sawing / cutting turned wood on a lathe

[Trefor]

I've turned a pear shaped object on the lathe which is about 200mm long, fat at one end, thin at the outer. I needed to cut it up into slices, each about about 25mm thick. Trying to keep the cuts thin, neat and parallel I us a hacksaw with the wood on the lathe and turning slowly. This was ok at the thinner end, but at the thicker end, the cut ended up thicker end finished off being slightly domed. What should I have done?

 

[Phil Pascoe]

Used a parting tool.

 

[Linus]

Assuming your object is safely held in a chuck I would advise that you use a parting tool to obtain a parallel slice which you can finish with a saw once you approach the centre of the object if you prefer. Plenty of vids on YT i.e.

 

[Stigmorgan]

As above, a hacksaw blade has way too much flex hence the deviation in your cuts not to mention the risk of the saw being ripped from your hand, either use a parting tool or make up a jig to hold the piece and use a band saw if you have one.

 

[Trefor]

I needed the cuts to be as thin as possible so that the reassembled segments would retain the majority of the original shape. On-line videos are informative, I'll probably try my hand at making a thin paring tool ready for next time.

Thanks.

 

[Shan]

If want a really thin cut can you use a junior hacksaw? Or as others have mentioned a parting tool.

 

[Phil Pascoe]

You say fat at one end - what diameter?

 

[Fergie 307]

Might be worth looking at a metal working parting blade and mounting it in some way they can be very thin.

 

[Dave Moore]

Might be worth looking at a metal working parting blade and mounting it in some way they can be very thin.

Chris Stott marketed a thin parting tool years ago but you can make one from a redundant machine saw blade if you can get one from a friendly local machine shop or fabricators. I’m not sure if Sorby took over the marketing of them.
regards,
Dave

 

[cmoops2]

Use a Japanese Pull Saw - works a treat !

 

[Democritus]

What are you making?

 

[Thingybob]

Use a Japanese Pull Saw - works a treat !

Lathe in reverse

 

[mwinfrance]

What Stig said. ^^^

 

[Rodpr]

Lathe in reverse

I have a premonition of saw catching and being pulled out of your hand before hitting the bedways!

 

[Richard_C]

Here's my DIY thin parting tool. Had window fitters fitting windows last summer, using reciprocating saw to cut old frames out. I got a blunt blade from them. Shade over 1mm thick. Conventional wisdom is to chisel out a recess in one half of the handle, but I cut 3 slices on the Bandsaw, one the thickness of the blade, and cut round the blade with a stanley knife. Clamped up the sandwich and gave it a quick sand. Easy job on grinder to get the teeth off and shape the end. Doesn't hold edge for long but takes seconds to sharpen. A bit flexible so not a substitute for a proper tool but good for parting off when you want minimal waste, and for adding fine grooves to decorate a vessel.

 

[mwinfrance]

And despite them being "pozis" you even "clocked the screws..nice

I like the "protractory thing".

 

[Richard_C]

I like the "protractory thing".

It also serves as a drill gauge and - what I use it for - a centre finder for square and circular blanks. I remember it came sellotaped to the front cover of Practical Householder when I used to get the magazine, which was when I first became a householder and wanted to be practical. 1976 or thereabouts

 

[Fergie 307]

That's pretty much what I had in mind. Substitute your sabre saw blade for a 3/4 or 1" HSS metal parting blade and it will be more rigid and last for ages. They also have an angle so the cutting tip is wider than the blade, handy in avoiding the blade rubbing, especially in a deep cut, I imagine that would be particularly useful in wood.. But I'm a great fan of using what you have so fair play, might be worth considering for a MkII version when it wears out

 

[Richard_C]

Substitute your sabre saw blade for a 3/4 or 1" HSS metal parting blade

Yes, it would be better but this was available for free and right here so worth a go. You can reduce binding with this (and most plain sided) parting tools by a slight rotation around its longitudinal axis as it goes in, more of a rhythmic wobble than a twist. The cut ends up fractionally wider but it doesn't bind as much.

Mk2 when it wears out? I've estimated how much I've ground off in the last 4 months, worked out the shortest useable length before it needs replacing and done my sums. I would be overjoyed to need to make a Mk2 - it would mean I am still turning when I am 97 and a bit.

 

[Dave Moore]

Yes, it would be better but this was available for free and right here so worth a go. You can reduce binding with this (and most plain sided) parting tools by a slight rotation around its longitudinal axis as it goes in, more of a rhythmic wobble than a twist. The cut ends up fractionally wider but it doesn't bind as much.

Mk2 when it wears out? I've estimated how much I've ground off in the last 4 months, worked out the shortest useable length before it needs replacing and done my sums. I would be overjoyed to need to make a Mk2 - it would mean I am still turning when I am 97 and a bit.

Hi,
I trained with Chris Stott over 20 yrs ago which is where I first used his thin parting tool. To avoid jamming you move tool handle left to right to widen the cut slightly, as mentioned before an old machine saw blade from a steel saw works great. They vary in size but are about 40mm wide and about 2mm thick so are not as flexible as the sober saw blade but you are on the right lines.
Regards,
Dave