A new knife grinder

[Von Gruff]

I have always enjoyed making my own knives and lately it seems I have been doing more than I ever thought I would, with some now going to others, so it started to seem as if my little handyman grinder attachment was not quite up to what may be required of it. I have seen the really nice 72 inch (expensive) grinders that the guys have on the knife makers forums but being somewhat of a do it myself tightwad I wondered if I could cobble something together that would be just as effective.
Aboiut 40 years ago I bought a little dyco saw bench that I gave to my father when I moved up to a better model and when he died I got it back and having no use for a small saw bench I converted it to a sander.
The large drive pulley was replaced with a small one and with the two bench top bearings in place, I got a length of shaft and a larger pulley to slow the output down. To mae the drum I got a piece of 3/4 play and cut a circle then a number ofthers with only an inch in from the outer dia to make the drum. It worked very well but it no longer gets much use so decided to use it for the base of the new grrinder.


With the drum off and the top cleared it looks to be a good place to start

[Von Gruff]

In a dedicated effort to save money I decided to make the drive wheel from hardwood as I had some Jarah in the rack.

A 11/16 slice

Through the thicknesser to bring it back to 3/8 and sawn to 4 1/4 in wide then cut into 4 1/4 in lengths

With the pieces laid with the long grain alternating, they were glued up cramped

The thick (and hard) block needed carefull cutting to get a good 4 in circle which will become the drive wheel

I didn't get a pic but a plate was cut and drilled for the 1/2 end on the shaft it will run on and bolted to the drive wheel. It is down at the garrage for the guy to weld the plate to the shaft and turn the drive block to a true to the shaft round and then I can crown it when when it back on the grinder base.

[Von Gruff]

I found a really good set of plans that will allow me to make something very close to this one here.\


I got a great deal if information from this web page
http://dcknives.blogspot.co.nz/p/2-x...t-grinder.html

Things will have to sit for a bit as I need to get into the city to pick up some steel and for the other needed wheels and and some 72in belts to arrive.

[Blackwater]

Nice work, VG! Love to see folks doing things themselves. Reminds me of the old 'smiths that put together the old PA & KY rifles so long ago with little to nothing to go on. I have Dillin's book, wiht good pics of some of the old rifling and other machines, and they were all built of wood with very little metal used because there simply was very little of it TO use. "Where there's a will, there's a way."

When it comes to grinding knives, though, I'm afraid I got spoiled. Used a Burr-King. MUCH quieter than a Square Wheel and I like the quick adjustments and very rapid availability of either flat or wheel grinding. I guess I never should have touched one of those?

But in th end, it's really not the equipment, but the craftsman in question that matters most. Each of the old riflemakers in the PA/KY era had their followers and advocates. Sam Hawken surely had the notoriety, but many others were involved as well. Variety really IS the "spice of life."

[Von Gruff]

It all comes down to the available dollars in hand and with next to none of those I revert back to the old adage that has been the cornerstone of most of my little projects when wants outrun income and that is "how can I make one of those"?
I have been lurking on a couple of knife forums for a while and seeing some of the best of the grinders going for up to $3000 and even the cheaper end of the ready builts or kit grinder is spending money that could be saved for those things I cant do.
I have a friend who is a full time knife maker and seeing his equipment and the ease with which he has fabricated some of his grinders (he has four that are permanent set-ups) makes it a no brainer for me to do this one. While it may not match the top of the line models it will still do all I will ever need with much more versatility than the little 2x36 that has sufficed up till now.

[BigEyeBob]

A bloke has to do what he has to do .

[nekshot]

You remind me of my dad as he was a master benchman with wood. He left me with a lot of his small speciality tools he made and boxes upon boxes of wood fasteners many of them brass. I was the only son that had woodworking in my blood but he was a perfectionist and I made mistakes as a teen and that separated us in the shop.

[Reg]

Brilliant Sir, just plain brilliant !!!

[W.R.Buchanan]

I made mine in 1984 while working for a company here in Ventura. I was making knives on the side and needed a real grinder and didn't have $1200 for a Burr-king. I bought the main wheel and Idler assembly and fabbed the rest from scrounged parts. The bearings came off a food grade conveyor that was scrapped and have ran perfectly ever since with greasing about every 15 years. I have a Flat Belt Attachment, and a Hollow Grinding Jig that allows repeatable blade contours.

I still use it nearly every day for various grinding jobs in the shop and I used it last night to shape a Front Sight Blade for the Springfield I shot today. I get to do that job again as that blade went winging on shot #17 today.

So far in 30 years only the belts (2x72) and the on/off switch have been changed.

Randy

[Von Gruff]

Looks good Randy. Many different iteration of these have been made in numerous home workshops and work perfectly well.

[Von Gruff]

After a good look in my shed I found some 2x2 box steel that would work for the main stands and with trip to the garrage for some welding was able to do a mock-up .

[Tnfalconer]

How are you planning to control belt tension? Spring inside the square tubing behind the platen? That think looks great so far. Especially since you have found most of the parts laying around house.

[Von Gruff]

I have a small gas strut to keep the belt tensioned. I got some more steel today with the two tool arms (I will need more for some other set-ups later) and the adjuster arm then a foot of 4x1/4 plate to hold the angle iron platen and the idler wheels and a length of 4x3/8 for the tool rest





I need a few bolts but the tracking adjuster is done



Then I changed the use of an old target stand I made some years back (it is no longer used) and with a little cutting off of various bits and adding some box section short pieces it will make an ideal tool head stand

[W.R.Buchanan]

Garry: Your drive pulley needs to have a crown on it and be adjustable side to side to allow for belt tracking. Belt Tracking is necessary so that you can hang one edge of the belt over the side of your main pulley, or in your case the Flat Platen so that you can radius the back edge of the blade bevels. You need to be able to change the tracking easily so that you can bias the belt to one side or the other quickly to do this part of the blade grind. Also the tracking will change as the belt wears or heats up during use.

On a Flat Belt grinder like you are making, you have to do the tracking adjustment at the drive pulley because you can't really do it on the upper or lower idlers as they are generally fixed.

Not sure if you're aware of these fine points but thought I'd make them known so you didn't back yourself into a corner if you didn't know.

I can guarantee that the belt WILL NOT track right on it's own no matter how good your alignment is. It has to be adjustable as no two belts are the same and just using one side of the belt more than the other will stretch it and change the tracking as it heats up.

This is the same theory as a Band Saw's wheels needing to be adjustable for tracking, or a conveyor belt. Making fences to guide the belt doesn't work as it only wears the fence and as the belt heats up from that friction it only makes it worse until the belt finally fails.

Also I assume you are making this thing to use 2X72" belts? They are the most common and have the widest variety of grits and types of any belt size.

The drive pulley's crown only needs to be a small amount like 1/8" high in the center and it can be cone shaped on either side resulting in a high center. The belt will follow the crown. Typically on conveyors the drive pulley is crowned and the idler is flat or I've seen both crowned on conveyors that are really long.

In the pic showing my Idler assembly you can see how the thing both allows for belt tracking and acts as Spring Loaded Tensioner. To make gross adjustments you can see that the entire carriage that the Idler assy. is mounted to will travel on the 2x2 upright.

Anyway it looks like your machine will turn out fine as long as you can figure out a way to adjust the drive end for tracking.

Just to clarify,,, I have to adjust belt tracking on mine virtually every time I use the machine. It changes with the heat of the Day as well as with usage!

Randy

[Von Gruff]

I have been using a smaller (2x36) grinder for over 35 years and belt sanders since the 60's so am well aware of the tracking needs of belt grinders
If you have a look at my second post Randy, I mentioned that I will be crowning the drive wheel and my last post, you will see that I have a tracking adjuster which will be a crowned wheel. I have done a lot of reserch on these grinders and the link I made earlier in my thread to the set of plans with a couple of pics from the link should indicate that I have looked into this quite well before commencing on the build. Being on a couple of bladesmiths forums I have also read a great deal on the good and bad point of the various designs.
It is being built round the 72in belts (again as mentioned at the start of the thread) and I have a selection being sent along with the the crowned adjuster and idler wheels I need.

[W.R.Buchanan]

So you're good to go,,, Glad to hear that. I, like most, don't always read all of a thread especially when there's pictures to look at.

More concerned that you end up with a good final product. So many just dive in and don't pay attention to the details.

Looking forward to seeing it running.

Randy

[knifemaker]

For your 2X72" sanding belts, check out the "Supergrit.com" web site. Great prices on sanding belts and they carry many other abrasive items. I can order on Friday, and have the belts delivered on Tuesday, sometimes Monday.

[Von Gruff]

For your 2X72" sanding belts, check out the "Supergrit.com" web site. Great prices on sanding belts and they carry many other abrasive items. I can order on Friday, and have the belts delivered on Tuesday, sometimes Monday.

I got my first selection coming from these guys as I got some of the wheels etc from them as well.
http://usaknifemaker.com/

I will put your link in my folder Thanks.

[Von Gruff]

Been a busy day and have it all to a stage now that it just needs the drive wheel turned and the wheels to arrive from the US so in a couple of weeks I should be able to get it tunred on. The tool rest will not get welded on till the wheels arrive so I can center the rest against the belt
This is how it sits for now though.

I will drill out the holes for the idler wheels when they arrive

The handle of an old gate valve made for a good tracking adjuster wheel and a length of pipe flatened and welded to the bolt head will allow for tightening up on the two sliding tool heads.
Here I am holding the tensioner down against the gas ram stroke

With it released it shows I have a goodly amount of travel

Then there is the tracking aduster screwed all the way out to track one way

And all the way in to track the other

[floydboy]

Great thread. Please continue to post pics as you proceed. I like to dabble in knife making and have got to the point I want a grinder that will do a better job. Like you I don't need or want the best but would love to have something like this to play with.