Setting Surface Planer Knives So All The Same Height

[pollys13]

This topic might be of help to anyone struggling to set their planer knives to the same height.
I thought having them all the same height was crucial to getting a good result.

" I tried one last time earlier today. I lowered the outfeed table so could get the ruler to move by 4mm.
Knife three moves the ruler by 4mm, knife two by 6mm and knife one by 2mm. I didn't bother to check the movement at the other end of the block as would have had the same inconsistent results. "

Axminster engineer replied,

" The difference in height of the blades is amplified in the distance the straight edge moves across the bed.
I mentioned in my previous email the scale you are working to (0.10mm is roughly 5mm of travel) therefore;
1mm of travel on the straight edge is about 0.02mm so the height above the outfeed table you have is around 0.04, 0.08 and 0.12mm. This will work fine, the material will grow or shrink a lot more than that depending on the weather.
Setting the machine this precisely is a bit like setting your car tyres so the O of Goodyear lines up with the valve for balancing purposes, not necessary. "

So, there you go

 

[squib]

Not being crucial for getting a good result doesn't take into account good workshop practice and also by not setting the blades accurately you will create wear unevenly on the blades.
This can cause noise and after a few sharpens can also cause imbalance ( if all blades are not ground exactly even).
The first few times setting planer blades can seem slow and complicated but soon becomes easier and such a pleasure using a set of sharp knives.
If you need to draw parallels to setting the blade heights different or skewed ,I think it is like setting your pressures differently and saying it's only a bit and won't affect the top speed

 

[k4wils]

Even when I had a Felder with disposable blades which supposedly didn’t need setting I would always check and adjust using a dial gauge from the outfeed table. That way you can be sure the blades are parallel with the table. Perhaps a bit finicky but it’s nice to know you are starting a job accurately rather than building inaccuracy in from the beginning.

 

[Mark Begbie]

I got a pair of inexpensive knife setting gauges for my Kity / Axminster planer. It was a nightmare. I'd set the blades, tighten, test and adjust. However, the adjustment was all over the place with no repeatability. In the end I took the blade lift springs out, singe the gauges are magnetic. Hey presto, super repeatable setting and success.