Thread: Nobody can sharpen my 3/8" jointer blades - what to do?

Originally Posted by rsser

Apologies for the redundant advice in that case.

Don't think H&F carry the Veritas jig; try Carbatec.

In your shoes I'd also be researching whether after-market TCT or HSS blades were available. Maybe make a trip down to the local saw doctor?

In any case, you have the basis of a solution. If you want to persist with it, go for those high quality abrasive films mentioned in the 2nd link. They're very good.

Certainly no apologies necessary, I take all advice on board. I have been to all of the saw doctors in Brisbane and someone also recommended a company in Sydney too, none of them could do it as they are not wide enough. I will have a look at the link for the abrasive films as I am just using the Bunnies stuff at the moment,

Cheers

Col

Bunnies stuff down my way causes more problems than it solves. They used to stock decent quality wet 'n dry. No longer.

Good luck.

Since you have the cutterhead out of the machine take the cutterhead to Hare and Forbes and ask them for a knife. I think you are trying to match knives that have been ground down from 5/8 stock and are nearly used up.

Just ring around some machine shops asking if they have a surface grinder and get a quote.

If you are really stuck, we have a makino grinder at work. It would be a simple job on the magnetic table.

Have you tried this mob - Contact_Leuco_Australia, any aharpening shop thet has a knife grinder with a magnetic chuck should be able to grind them, can you post a picture of the cutter head with the knife in it, so we can have a look at better asess your situation

Originally Posted by China

Have you tried this mob - Contact_Leuco_Australia, any aharpening shop thet has a knife grinder with a magnetic chuck should be able to grind them, can you post a picture of the cutter head with the knife in it, so we can have a look at better asess your situation

Hi China

I have a few pics on page 1 of this thread, 7th post down, the cutter has blue paint on the end and is backwards in the picture but you will get the idea. Thanks for the link, I will shoot them off an email to see what they think.
Someone must be able to do it, they did it 50 years ago when the machine was made

Col

Ok Silly me I remember looking at the photo's, after having a good look and a think about it, here are my thoughts as mentioned above the knife is mounted in the cutter block in the wrong place and back the front, I printed the picture and cut the knife out and placed it in the correct postion, in doing so I have come to the conclusion that the knives you have are not the the correct items and should be of thicker stock and should be wider but this would depend on how many times they have been sharpened, I suggest you take the cutter block to Leuco or another competent saw doctor and have them supply a set of knives to suit.

Originally Posted by China

I have come to the conclusion that the knives you have are not the the correct items and should be of thicker stock and should be wider but this would depend on how many times they have been sharpened, I suggest you take the cutter block to Leuco or another competent saw doctor and have them supply a set of knives to suit.

Hi China

I don't think that I could fit too much thicker knives in, not the next size up anyway. The blades are a tight fit with the nuts backed off all the way at the moment.

The smallest blades any of the saw doctors can make me are 15mm wide, which is almost 50% (5mm) wider than what they are now, which is a fair bit I reckon. I have no way of really knowing what size the originals were, I just assumed the fact I could buy the right size stock HSS at 1/16 * 3/8 they were right.

I don't see much of a problem of fitting wider blades, as there is enough clearance in the housing. The only issue I can see it that the cutting knives will be at a larger overall diameter and therefore be at a slower speed at the knives. There would also be more centrifugal force on the cutter head with the extra weight and larger circumference. Of course this wouldn't be a problem if they are meant to be wider and thicker.

I can only give it a go I suppose.

Cheers

Col

the large circumference of the knives would cause them to cut faster. Larger diameter same rpm. It would be easier to have the gibs modified or the screws to allow for thicker knives so you don't have to go through this again with another set of knives

Originally Posted by msiemsen

the large circumference of the knives would cause them to cut faster. Larger diameter same rpm. It would be easier to have the gibs modified or the screws to allow for thicker knives so you don't have to go through this again with another set of knives

Hi

I have to disagree, I think the larger the circumference of the head, the longer it would take to make one revolution and longer would mean slower. It sounds right in my head anyway, but I could be wrong.

Cheers

Col

The motor and pulleys spin at a constant RPM, so RPM of the head doesn't change. Each revolution therefore takes exactly the same time. If the circumference increases at the same RPM, then the velocity of any point on the circumference is higher.

Originally Posted by petersemple

The motor and pulleys spin at a constant RPM, so RPM of the head doesn't change. Each revolution therefore takes exactly the same time. If the circumference increases at the same RPM, then the velocity of any point on the circumference is higher.

I was dead certain I was right but I stand corrected you guys are right. Obviously if the blade has to cover more distance in the same amount of time it has to do it quicker - doh

Col