Wobble saws

[Giff]

Has anyone any experience with or opinions on using a wobble saw on a spindle for grooving ? Thanks Geoff

 

[Beau]

Hi Geoff

Got one and it's very handy. Big variation in groove size for a small outlay. On the downside the bottom of the groove is rough and in a slight ark so if doing haunched tenons say on a door where they would show it needs cleaning up. Also you can get some breakout to the sides as they don't have any scribe cutters like on a tenoning head. Cant remember the brand but got it from Axminster (could be Omas)

 

[Mike Jordan]

They are very handy for grooves of all sizes, as mentioned the base of the groove is not totally flat, but this is rarely a drawback. Breakout can be greatly reduced if you use a spelch board and ensure that the saw is sharp.

 

[Jacob]

Mine's unbranded. Very useful. Fast, accurate, quiet, safe, easily adjusted, no break out of any sort (maybe different brands are worse?). The "arc" of the bottom of the channel has a large radius (equal to the radius of the blade) nearly flat, which makes it totally unobtrusive in yer typical slot.

 

[mbartlett99]

I haven't had chance to use it yet but bought one of these - http://www.ebay.co.uk/itm/HM-Verstellnu ... nlyiMkeR9g . Arrived pretty quickly and looks ok - just need the time to use it.

 

[Giff]

Thanks for the advice...I have always thought they may be a poor alternative to a dedicated slotting disc but the replies are really useful.Thanks M for the Ebay link as well. Geoff

 

[Jacob]

Thanks for the advice...I have always thought they may be a poor alternative to a dedicated slotting disc but the replies are really useful.Thanks M for the Ebay link as well. Geoff

Actually probably a better alternative to the slotting disc. The wobble saw is mostly spinning free in the slot with very little risk of kickback or other hazard. It doesn't actually wobble in any sense - it's always balanced. They hum a bit (quietly) as they do displace a lot of air - but no vibration or actual wobble.
The biggest hazard is the large teeth invisible when spinning fast - so always use 2 push sticks and/or other protection to keep your fingers well away.

 

[PAC1]

Geoff, a wobble saw is better than the disc but not as good a the micro or shim adjustable groover that have dedicated nicking cutters. My experience is the wobble saw is a good industrial groover which is good at cutting grooves along the grain. I do not agree that there is no breakout with a wobble saw, my experience is there is breakout. Given the direction of travel of the blade it has to be a risk at the very least. For high class work I use the shim adjustable groover with dedicated nickers to prevent any breakout.

 

[pollys13]

bought one of these - http://www.ebay.co.uk/itm/HM-Verstellnu ... nlyiMkeR9g . Arrived pretty quickly and looks ok - just need the time to use it.

Saw that site a while back at the time he also sold other interesting spindle stuff at good prices, and good quality. Wish exchange rate was better. Can find stuff on German Ebay, use Google translate.

 

[Jacob]

Geoff, a wobble saw is better than the disc but not as good a the micro or shim adjustable groover that have dedicated nicking cutters. My experience is the wobble saw is a good industrial groover which is good at cutting grooves along the grain. I do not agree that there is no breakout with a wobble saw, my experience is there is breakout. Given the direction of travel of the blade it has to be a risk at the very least. For high class work I use the shim adjustable groover with dedicated nickers to prevent any breakout.

You may well be right about cross grain - I've never tried using mine that way,* not least because of the difficulty of setting it up. But not a prob along the grain.

*PS I might have a go to see what happens.

PPS not sure what difference a nicker would make as compared to a very sharp tooth. They both have to cut into the wood and emerge out of it in a similar fashion.

 

[heimlaga]

I do also use my two wobble saws quite a bit. One of them actually has a pair of scribe cutters.

The downside with wobble saws is that they are dudfficult so set for exactly the width you want. Usually you end up test cutting 3 or 4 times before the width is spot on.
A wooble saw must always be used with a rather low RPM otherwise it will start flattening itself out due to the centrifugal force. That is a downside in some industrial uses where high feed speed is important.

 

[Jacob]

I do also use my two wobble saws quite a bit. One of them actually has a pair of scribe cutters.

The downside with wobble saws is that they are dudfficult so set for exactly the width you want. Usually you end up test cutting 3 or 4 times before the width is spot on.

Mines got a setting scale on it marked in 1/8"s which seems to be spot on.[/quote]
A wooble saw must always be used with a rather low RPM otherwise it will start flattening itself out due to the centrifugal force. That is a downside in some industrial uses where high feed speed is important.[/quote]Mines OK at my machine max speed 7000rpm

 

[Giff]

Sorry if this is a stupid question but I have never used one...... Does the blade actually "wobble" up and down to cut the groove. Are there any balance issues with vibration ? I was also unsure about accuracy so I will check if there are calibration marks on the one I am looking at as Jacob's.

 

[Jacob]

Sorry if this is a stupid question but I have never used one...... Does the blade actually "wobble" up and down to cut the groove. Are there any balance issues with vibration ? I was also unsure about accuracy so I will check if there are calibration marks on the one I am looking at as Jacob's.

It's tilted sideways to make a wider cut so it stays in balance, there is no wobbling or vibration. In any case it's only a slight tilt - typical max cut is 3/4" wide slot so the blade is only a few degrees off square.
It hums a bit - it does displace a lot of air when it's set for a wide cut.
It used to be done with "wobble washers" and an ordinary saw blade but this is deprecated. The modern wobbler is a purpose built unit and much better.
I see there could be probs at very high speeds as Heimlaga points out, but not for your typical small workshop speeds.