Biscuit joining question.

[archpa]

Hi,

I have recently bought a biscuit cutter for my router and tried out a test joint. The slot seems to big for the biscuit, and I was wondering if that's normal, or if my cutter is too wide, or the biscuits unusually thin...

Slot created by cutter: 4.3mm
Biscuit thickness 3.5mm

That's nearly 1mm gap! I know they are supposed to expand, but surly not that much. So which is it? the biscuit or the cutter?

I also measure the cutter blade and it's 3.9mm. Is it surprising that the resultant slot is 4.3mm in pine? Could the cutters be out of alignment and causing it to cut .4mm wider than one cutter? (It is a cheap cutter, I have to confess)

Cheers

Paul

 

[Philly]

Paul
They should be a reasonably snug fit in the slots-sounds like maybe the bit is out of true....My cheap ferm biscuit jointer used to do the same. I finally coughed up for a Lamello and finally I get slots that are "right"-when you watch Norm using biscuits he always has a hammer to hand to tap them in and get the joint together!
Maybe you should return the bit?
Hope this helps
Philly

 

[Neil]

Paul,

A couple of weeks back, Noely and I did a side-by-side comparison between his superb Porter-Cable (much better than Philly's Lamello ) and my cheap Ferm - the slots cut by the PC measured 4mm, and the Ferm 4.1mm. My biscuits were a tight, snug fit in the 4mm slots, so I would say that the biscuits must measure close to 4mm themselves, yours maybe sound a bit thinner than I would have expected? :? Maybe mine are a bit swollen, but if so I can't understand why the PC would be set up to cut 4mm slots...

4.3mm sounds too big anyway, just the extra 0.1mm slop in the slots from my Ferm results in noticable 'biscuit wobble'

Cheers,
Neil

<edited for typos :roll:>

 

[archpa]

Neil,

Thanks for that - that's very interesting. So it sounds like I need to get a new cutter and a new set of biscuits!

 

[Newbie_Neil]

Hi Paul

Sorry if this sounds very basic, but are you using the same size cut as your biscuit?

Cheers
Neil

 

[jasonB]

The size of the biscuit determines the depth of cut, they all fit a nominal 4mm slot but if the router cutter is running out then if using No20's the wobble will be greater.

How thick is the timber, if the arbour is a long way out of the collet to set the slot into thick timber this will also cause more wobble.

Jason

 

[Anonymous]

Paul

I found exactly this about 4 years ago. I bought a Trend cutter and the biscuits were very loose in the slots. I used a stone to reduce the thickness of the slot by working the edges of the TC teeth. Never got to be as good as I wanted

With my Freud biscuit jointer, there is a no slop at all

 

[Argee]

Standard cutters are 4mm. Biscuits are supposed to be an interference fit in that slot, but some poor quality versions are just rubbish - no consistency in size or quality.

Cutting with a biscuit jointer makes it easy to cut perpendicular to the edge, providing the fence is robust and the cutter is used with a firm, steadying grip.

Using a router-mounted cutter, it is not anywhere near as easy to get a perpendicular cut - the slightest rocking motion (not easy to spot, never mind control) will lead to an oversize slot.

Run-out is a possibility, however unlikely. Nothing beats a Lamello.

Ray.

 

[devonwoody]

Stick two biscuits together and then sand them down to the correct thickness :lol:

Only trying to help :x

 

[Anonymous]

Do they have to be the same sort or can you use a bourbon and a custard cream?

 

[Dewy]

I bought a cheap Ferm one from Screwfix and had problems to start until I got used to holding it correctly.
I had just been holding the tool with one hand which meant it was not always firmly down and then the slot was widening as I pulled it out.
Since keeping my left thi=umb firmly down on the fence the slots improved no end.

 

[Bean]

Do they have to be the same sort or can you use a bourbon and a custard cream?

I believ you can, But under no circumstances must you join Hobnobs to rich teas for the obvoius reasons

Bean

 

[Dr. Thrax]

So what make of biscuits (Non-edible ) does everyone recommend ?

 

[Argee]

Lamello or Freud

Ray.

 

[llangatwgnedd]

Tanseli
no problem with them and my Axminster BJ

 

[gwaithcoed]

So what make of biscuits (Non-edible ) does everyone recommend

Tanseli,Lamello, Freud, Trend, I've used them all at some time, never had any problems, main thing is to always keep them in sealed packs. I keep mine in the cupboard where the gas boiler is sited

Cheers Alan

 

[Bean]

Now then SP I have an axminster and some Tanseli biccies, I have almost always got a loose fit with an oversize slot. I have put this down to technique and or run out on the BJ. Have you ever measured the run out??

Bean

 

[llangatwgnedd]

HI Bean
I get a nice push fit with mine and even on a a dry assembly not one biscuit falls out.

How do I go about measuring the run out ?

 

[Bean]

I'm thinking of using a DTI on the blade tips, with the BJ clamped to the bench.
I will have a play later and see what I get.

Bean

 

[Anonymous]

Used to buy 100 pack at £4.95 but have now found that Trend now do a 1000 pack for £22.00. That`s what I call a Saving !!