Planer / Jointer Knife Sharpening Jig

[transatlantic]

I thought this series was pretty cool, and thought others would to. I don't actually own a Planer/Jointer, but was mostly wartching out of interest. The film abrasive is new to me, so I think I might try it at some point. I also thought the microscope stuff was very cool too.

https://www.youtube.com/playlist?list=P ... Am5EDx9UOt

 

[stuartpaul]

Neat jig. At $150 that's a good price. Mind you by the time it gets over here it'll be £200 plus! I'll have to wait for the Rutlands version

Also, why do some youtubers talk so much? A 10 minute vid could have been done in half the time!

 

[transatlantic]

Neat jig. At $150 that's a good price. Mind you by the time it gets over here it'll be £200 plus!

It seems fairly straight forward to make, and I don't see why it would need to be CNC milled to get good precision.

Also, why do some youtubers talk so much? A 10 minute vid could have been done in half the time!

I don't mind the talking, but I did find he would say the same thing in several of the parts. I also find the whole splitting of the content into parts rather annoying, there really is no need. I believe it comes about from the old youtube rules, or perhaps its so that they get more views for their ads?

but I agree, could have been condenced into one shorter, to the point video.

 

[custard]

The 3M Gold Stikit self adhesive abrasive rolls that he uses are brilliant! I've never seen them for sale in this country (only the 3M 150mm diameter self adhesive discs) but I used to bring them back with me from the US when I worked there. I stick them to small blocks of ply or MDF and use them as super hard sanding blocks (that won't dub over edges), for getting right into corners, and on shaped blocks as profile sanders.

Not cheap but if you ever come across any I can really recommend it, well worth stuffing a couple of rolls in your return luggage if you ever take a holiday in the US.

 

[Steve Maskery]

Cheapskate version Here

 

[cedarwood]

This is what I use to sharpen my planer knives, it also comes with a small slider for hand planes and chisels and a holder to sharpen drill bits (but not used that yet) plus a dressing stone, cost was about £250 shipped from germany or a chap in Austria.
It is also very heavy I don't move it about much.

 

[stuartpaul]

Cheapskate version Here

Actually Steve, would that work 'inverted'? If similar abrasive were used would your jig be capable of being moved over it? Wonder if that would make it easier to hone better angles as there'd be better contact.

Wos reckon?

 

[Steve Maskery]

Yes it works fine upside down.

 

[yetloh]

Neat jig. At $150 that's a good price. Mind you by the time it gets over here it'll be £200 plus!

That's a lot of sharpenings by my local industrial sharpening outfit.

Jim

 

[Steve Maskery]

I no longer have the jig that appears in the video, so this thread has spurred me to make another.

The weakness of the original was always the clamping. The first one was not very secure, and even the one that worked well required the use of a screwdriver, so I thought we could do better.

This one is just two saw cuts at 42 degrees from the broad face, which is 48 degrees off vertical. As a TS only goes to 45 deg it means running the wood on its edge. That results in 42 deg from the flat which is 2 deg more than the grind. That way I hone just the very outer edge.

Ideally the cut is made with a 1/8" kerf, flat-top-grind, rip blade. All my blades were stolen, and I have replaced them with thin-kerf ones. I like the thin-kerf ones, but it does mean that I had to jiggle the fence over by half a mil or so to widen the kerf, and then the bottom of the groove needed a bit of a tickle to get the corner clean and square.

Then 4 magnets are set at just the right height to hold the knives in place. Had they been a snug fit I could have just shoved them in, but they were loose, so a bit of DS tape saw to that.

Because the magnets were so close together I found that as I pushed one in, the other popped up. That's why in each pair, one is face up and one is face down.

I've actually made two today, one for me and one for a mate. I originally put the magnets further apart and tried to screw them (they are countersunk) but the screws came through to the slot. By moving them closer together there is room for a short screw, but even my shortest were too long, so I stuck with the DS tape (ha-ha).

The block is about 6mm shorter than the knives, so I can lever them out easily, and the magnets offer just enough hold that the knives don't drop out, whilst keeping them securely in place.

It works perfectly and there is no tooling or clamping to bother with.

In the olden days this would have been the basis of a magazine article...

 

[memzey]

That's interesting Steve. Don't 100% understand how you got to the 48* though. Did you rip the edges 3* off square before milling the grooves?

 

[Steve Maskery]

No. The groove has to be cut at 42 deg off the horizontal, which is 48 deg off the vertical. But the saw tilts only 45 deg off vertical.
So to get the 42 deg workpiece has to be presented on edge.

The edges all remain square, of course.

If this were a magazine article I'd have done more WIPs and a diagram, but it isn't!

 

[stuartpaul]

Thanks for posting this Steve. Nice and easy to do!

 

[memzey]

Aahh gotcha. Thanks for clarifying. It seems to be a good and convenient means of honing dull or lightly chipped knives as opposed to sending them out for a full re-grind. Do you think this does away with the need to send them out or do you still re-grind every few hones or say when the 42 deg bevel has extended right across the edge?

 

[Steve Maskery]

It depends how bad they get. If some silly person puts a coupe of nails through it when they are brand new as happened at the Community Workshop last week, then they really need either a regrind or a lot of elbow grease. We didn't have a spare set (the spare set had just be put on the day before) so it fell to me to sort it out. After all, it was my jig...
It took me the rest of the day. The offender left sharpish, but did apologise this week.

I've never honed a pair so much that the 42 deg goes right across. Sort of defeats the object in a way, but even if I did, it wouldn't matter, as it is just a clearance angle. The cutting angle is set by the cutter block, in the same way that a standard plane's cutting angle is set by the frog.

 

[yetloh]

Nice idea Steve, but have you any ideas for poor s*ds like me who don't have the luxury of a table saw?

Jim

 

[Steve Maskery]

Yes indeed. It's more work, but this would be perfectly doable as a laminate, built up in the same way that I built up the one in the film. Bandsaw the various section, hand plane them and then glue them together,.

 

[yetloh]

Thanks Steve,

I'll have another look at the film.

Jim

 

[Steve Maskery]

I've taken delivery of a new toy, it's a little microscope that fits to my mobile phone.

These are the knives that are currently in my machine. They are cutting quite nicely, actually, but there is a little damage:

Whereas this is what the newly honed edge looks like:

The horizontal scratches are from the original grinding, but you can see that they peter out at the edge, because they have been polished away. I like them like that!

 

[Jacob]

I no longer have the jig that appears in the video, so this thread has spurred me to make another.

The weakness of the original was always the clamping. The first one was not very secure, and even the one that worked well required the use of a screwdriver, so I thought we could do better.

This one is just two saw cuts at 42 degrees from the broad face, which is 48 degrees off vertical. As a TS only goes to 45 deg it means running the wood on its edge. That results in 42 deg from the flat which is 2 deg more than the grind. That way I hone just the very outer edge.

Ideally the cut is made with a 1/8" kerf, flat-top-grind, rip blade. All my blades were stolen, and I have replaced them with thin-kerf ones. I like the thin-kerf ones, but it does mean that I had to jiggle the fence over by half a mil or so to widen the kerf, and then the bottom of the groove needed a bit of a tickle to get the corner clean and square.

Then 4 magnets are set at just the right height to hold the knives in place. Had they been a snug fit I could have just shoved them in, but they were loose, so a bit of DS tape saw to that.

Because the magnets were so close together I found that as I pushed one in, the other popped up. That's why in each pair, one is face up and one is face down.

I've actually made two today, one for me and one for a mate. I originally put the magnets further apart and tried to screw them (they are countersunk) but the screws came through to the slot. By moving them closer together there is room for a short screw, but even my shortest were too long, so I stuck with the DS tape (ha-ha).

The block is about 6mm shorter than the knives, so I can lever them out easily, and the magnets offer just enough hold that the knives don't drop out, whilst keeping them securely in place.

It works perfectly and there is no tooling or clamping to bother with.







In the olden days this would have been the basis of a magazine article...

The B&D version (similar but metal) has the bit between the blades as an insert held down by knurled bolts and working as a clamp. Easier and simpler than magnets. But if they are just a push fit they'll stay in place anyway if you use the thing blades down on your wet n dry (wet in a pool)