Cutting with grain

[Jaco]

Cutting finger joints in 23mm pine using the Polycut with its large table.
Cutting with the grain (ripping) the blade tends to follow it's own mind not leaving a straight cut.
The cross cutting section is spot-on on the line.
Normal #12 blade used and tension checked.
The oil nipples in the arms were topped up.

Yes, these finger joints can be cut using a jig on the table saw.
Ended up as firewood.

Anybody had similar experience cutting with the grain?
Cutting out patterns are not an issue.

The slight variation is not critical as any gaps are filled with own glue and dust mixture.
The joints are held together with glue and galvanised nails.

 

[Katomi woodsmith]

My band saw wanders all the time. I do all my important cuts with a hand saw,tenon saw
I only use band saw now for cutting blanks to near round ready to go on the lathe

 

[Jaco]

My band saw wanders all the time. I do all my important cuts with a hand saw,tenon saw
I only use band saw now for cutting blanks to near round ready to go on the lathe

Not having a bandsaw cant comment, but it does sound unusual as other woodies use it extensively for sawing and re-sawing and also veneers.

Maybe post a query on the General Woodworking?

 

[Jaco]

Ok, 40 cuts done, 10 per corner.

This is the fit after some tweaking with a No25 paint tin opener.

Does not look too shabby, ready for glue and nail.
Done in 3 passes:
One corner
Other corner
Join last side

The cutting is not that simple as the one board is 420mm long and the other 510mm and both 250mm wide, so standing is not that close to the blade.
(use my paunch as a steady rest! )

 

[scrimper]

Cutting along the grain is always a problem more so in softwood whether than using a scrollsaw or a band saw the only way to avoid wandering cuts is with a table saw - ideal for re-sawing but not for cutting dovetail of box joints.
I do quite a lot of box joints but what I generally do is do the 'with the grain' cuts I use a bandsaw with as wide a blade as possible and use the scroll saw for across the grain cuts.

 

[Jaco]

Agree with you

Only problem is ............................
I do not have a bandsaw!
A small one is no good and there is no space for a big one.

There is only one more box with 40 joins, I will persevere.
(I have already made 8 boxes like this.)

 

[MarkAW]

Have you accounted for kerf when marking/cutting the line?

You could also cut a bit wide and pair down with a chisel for precision.

Or knock up a fence to rest against (batten clamped to the table)

 

[Jacob]

All your lines need to be cut for precision, not just pencil, as the joints are all visible and you work back to them.
Your "finger" joint is known as a "box joint" and is really a simple precision machine joint.
What is a "Polycut"?
If you do it by hand you might as well do dovetails as the hand procedure would be exactly the same but making a better joint.
Have the boards slightly over length so you can plane the ends back for a perfect appearance.
Mark the shoulder lines both sides both pieces with strong cuts; cutting gauge or knife.
Mark the pin holes on first board, or just freehand them.
Cut the pins on first board and saw/chisel out the waste back to the cut line without going past it, undercutting slightly.
Mark the pins second board from the pinholes already cut on the first board and cut accordingly.
When the glue is dry, plane off the ends of the pins/tails.

 

[Jaco]

Have you accounted for kerf when marking/cutting the line?

You could also cut a bit wide and pair down with a chisel for precision.

Or knock up a fence to rest against (batten clamped to the table)

The kerf is only 0.5mm or .02" (blade thickness) so not an issue.

I have used a fence for another project some years ago, but these boards are 250mm wide.

I also use a 25mm chisel (sharp!) for cleaning and aligning the joints.

 

[pgrbff]

Cutting finger joints in 23mm pine using the Polycut with its large table.
Cutting with the grain (ripping) the blade tends to follow it's own mind not leaving a straight cut.
The cross cutting section is spot-on on the line.
Normal #12 blade used and tension checked.
The oil nipples in the arms were topped up.

Yes, these finger joints can be cut using a jig on the table saw.
Ended up as firewood.

Anybody had similar experience cutting with the grain?
Cutting out patterns are not an issue.

The slight variation is not critical as any gaps are filled with own glue and dust mixture.
The joints are held together with glue and galvanised nails.

View attachment 195205

What is a polycut?

 

[Jaco]

All your lines need to be cut for precision, not just pencil, as the joints are all visible and you work back to them.
Your "finger" joint is known as a "box joint" and is really a simple precision machine joint.
What is a "Polycut"?
If you do it by hand you might as well do dovetails as the hand procedure would be exactly the same but making a better joint.
Have the boards slightly over length so you can plane the ends back for a perfect appearance.
Mark the shoulder lines both sides both pieces with strong cuts; cutting gauge or knife.
Mark the pin holes on first board, or just freehand them.
Cut the pins on first board and saw/chisel out the waste back to the cut line without going past it, undercutting slightly.
Mark the pins second board from the pinholes already cut on the first board and cut accordingly.
When the glue is dry, plane off the ends of the pins/tails.

Thanks Jacob.
The 'polycut' is a Hegner scroll saw, the largest and heaviest that they make.

This is not a fine woodworking project but a bee brood box.
The bees don't mind the rough cuts as long as the joint is sealed.
The box gets smothered in Waksol (dark brown) and any gap variations are not visible.
Glued up one corner yesterday, next one this afternoon and last one tomorrow.

Here is the box corner in 'traction'.

 

[Jaco]

What is a polycut?

The 'polycut' is a Hegner scroll saw, the largest and heaviest that they make.

https://www.yandles.co.uk/scrollsaw...PKVPF0Kdd9wwLNa5ZUu_vwWJ4xqlTaJTndEWy7YoLG4Vd

 

[MarkAW]

The kerf is only 0.5mm

0.5mm + 0.5mm on the other side = 1mm, which is a lot in a joint. Though it was more a rhetorical question.

 

[Jaco]

0.5mm + 0.5mm on the other side = 1mm, which is a lot in a joint. Though it was more a rhetorical question.

Yes agree, and would be noticeable when doing fine woodworking D-tails or joints.

The only big issue here is that the corners must be 90 degrees to accommodate the frames.
I have only destroyed 1 box where the corners were out by 20mm, still not sure what went wrong, wrong .................
Once glued and nailed - no second chance.

 

[Katomi woodsmith]

When I cut joints like those I cut smaller on the cut outs and over size on the pegs to allow for saw kerf
Finished with paper 240 grit to bring to finished size
For a different look I left my pegs long ... think old style log cabin so the pegs over hang the end of the joint

 

[ajs]

I would experiment with the tension, with a heavy blade such as a #12 you need a lot of tension on the blade, it is not a question of plucking with your fingernail and listening for the "ting" - instead try pressing the side of the blade with moderate finger pressure - saw off of course. If it deflects more than 1/8”, ideally 1/16”, you need more tension.

I was using my Diamond scroll saw a few weeks back to cut box and tenon and mortice joints in 3x2 CLS for a bench in my new shed. Had exactly the issue you describe - fine for cross cut but wanders when ripping - until cranking up the tension. That was a full three or four extra turns of the rear tensioning knob over the "ting" point. I did at first worry about breaking something the tension was that high, but I figured it's construction is such I probably wouldn't be able to hand tighten the knob to actually cause damage. Blades seem to cope and actually last better.