Testing Sharpness of, and Setting, Planer Blades

I have a Gilbro Workmate Combination Saw Bench Jointer, and would welcome some advice on the Planer Blades,

The unit is almost as old as I am, and like me, did not come with any instructions.

Firstly, are there any simple (like me) tests to determine if the blades are sharp or not

Secondly, The Blades are not set evenly. Both the Infeed and outfeed beds are adjustable, and I can use a straightedge extending from the outfeed bed over the cutterhead as a means of setting each of the three blades to the same height, but what I need to know is how much the blades should extend beyond the diameter of the cutterhead cylinder/barrel.

Thanks

Dan

G'day Dan,

You'll soon find out if the blades are blunt when you run a bit of timber over it, it'll make a racket, you'll feel the cutters vibrate through the work and the timber will be burnished. If you look at the edge in the light, you should not see a silver line, an indication it is blunt. A sharp blade should also take a scraping off your fingernail.
To set your cutters, first set the in and outfeed tables true with the use of a straight edge with the planer set at '0'. Then take a straight batten of timber and place it so it spans from the infeed to outfeed table, and make a mark on it that lines up with a reference on the table. Adjust the blades so that when you turn the cylinder over, the batten is moved about 3-4mm no more. Do that at both ends of each blade and make sure they all move the batten the same amount.
Make adjustments with the power off
Cheers
Michael

Hi and thanks Michael,

I think the blades might be reasonably sharp as they do not burn the wood, but I will get someone with better eyesight than I have (which is just about anyone without a white cane or seeing eye dog) to have a look in the light for the silver line as you suggest.

With regard to setting the cutter blade heights, what do you mean by a "0" setting ?.
Might that be setting up the infeed and outfeed beds to be in the same line as the outer circumference of the cutter head cylinder ?

I have a Ryobi Thicknesser, and the cutter blade guage supplied with that is set to achieve a cutter blade height 1.5mm above the cutter cylinder radius,

The Gilbro Workmate unit I have is approximately 50 years old, and I do not know if current blade height settings would apply to older planers.

Thanks and regards

Dan

Set the infeed and outfeed table to the same height. Mine has a depth indicator, so I set mine to 0.

Cheers
Michael

Hi again Michael,

I suspect that your planer may only provide for height adjustment of the infeed bed, with the height of the outfeed bed being fixed at a preset height above the radius of the cutterhrad cylinder, whereas my planer has adjustable heights on both infeed and outfeed beds, and no guage to show how they are set relative to each other.

Is it possible for you to take a measure betwwn the underside of your straightedge and the outer circumference of the cuttelrblade cylinder when the infeed is set to "0" depthe ?

Thanks and regards

Dan

Hi Dan, Yes my jointer only adjusts the infeed table, as I thought all did. I don't know why you would need to adjust the outfeed table(apart from a means to fine tune), nor why the distance from the outer edge of the cutter cylinder to the infeed table in the '0' position is important, but it is 2mm in my Luna machine.
Perhaps someone else can help, sorry.:C

Cheers
Michael

Hi and thanks again Michael,

I have not had much experience with planers, and I wouldn't have thought there was any benefit from being able to adjust the height of the Outfeed Table, but since mine is adjustable, and the beds and blades seem all out of adjustment, I need to start by setting the height of both the blades and the outfeed table relative to the outer circumference of the Cutterhead cylinder.

2 mm seems like a good start point, so unless anyone has any other suggestions, I will start with 2 mm.

Thanks for your time and trouble Michael,

Regards

Dan

No worries, good luck!

Cheers
Michael