Another home built grinder

V

Von Gruff

Joined
Nov 24, 2014
Messages
115
Seeing pleasanthill's recent wip thread on building his grinder I though I would post the one I built for myself. More as a means of showing that other ways and means for those who may be wanting to build one as well. I had posted it on another forum that dosent have the expertise that resides here but though it may prove to benefit some.

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 make 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


 
This part will have the experts guffawing but it works and very well at that so I am happy with it (and dollars better off into the bargin)

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.
 
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 .

 
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

 
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

 
Have had some good progress with a couple of hours at the engineers yesterday. He turned the heavy collar of the end of the shaft and lengthened the turned portion to take the drive wheel, then turned and threaded the other end to take the disc grinder and leather strop.
With a bit of welding done it is at the stage now that it just requires the wheels and a couple of more bolts to be ready to go.

The disc grinder and with it being 375mm (14 3/4 in) in dia with a 40 grit disc it will be a great asset


The smaller disc (doubled 3/4 ply) has a leather strap glued round the edge and loaded with green stropping compound and having already tried it on a knife I am really pleased with how it works.



On the belt side, there is the platen plate that needs the two idler wheels to complete. The tracking wheel is also needed but these should all be here in a week.



The 300mm (12 in) contact wheel



The small wheel just needs the idler wheel for the lower position and I will have the means to grind the finger curve on the front of the knife handles.



The tool head stand will get a length of 3x2 (75x50) fixed on the top with short lengths of 3 in (75mm) down pipe screwed to it to hold the variety of belts

 
While waiting for some other bits I made a little knife clamp


A length of 2x2 box, a couple of short lengths of 1 1/2x1/4, a hinge, 2 pins, 2 nuts and bolts and a bit of shoe leather were all that was needed.





The leather clad gripping arms on top of the box to show how they work


Great for either end of the knife whether vertical



or horozontal


And of course it is invaluable for polishing (or any other work) on the blade

 
Most of the wheels and a few of the belts I had been waiting for arrived so there was a little more progress on the grinder today.
It did take a little while to set up to make sure all the wheels were in the same plane from the edge of the base and thata required a spacing with washers to get it all right but eventually I ran the belt and it tracked true so I was a bit pleased. It is actually running in this pic and runs quiet and smooth. Very pleased indeed.



Having it running true I crowned the drive wheel the simplets way by glueing a 1/4 in strip light leather round the center point of where the belt ran then covering it with another strip of 7/8 in to effect a rudimentary crown that does work well.


Getting the platen plate wheels sorted was next but that now tracks to the same position on the tracking and drive wheels as the big wheel, so it all seems to be working as intended.


There is a replacable platen plate that is bolted to the angle iron backer so that it can be changed out as and when it inevitably developes wear patterns.



There is only the first few belts that have arrrived at the finer end of the spectrum from 120grit to 600 but there is a number of 40 and 60 grit on the way along with another set of idler wheels, one of which will be for the lower part of the small 1 inch wheel for doing the front curve on the knife handles.

I gave the disc grinder a run and it is all that I hoped it would be so along with the leather stropping wheel I think this is all about ready to be put to work.
 
Looks good to me. Mine is made from a modified duel pneumatic drum sander that my father had used to carve decoys with.
 
Von Gruff said:
Must not be up to forum standards so I guess my knives wont be either
Click to expand...

Are you kidding? It definitely IS up to the forum standards... and beyond! Keep in mind this is a knifemakers forum. You may have gotten more feedback in a welders / metalworkers forum such as WeldingWeb.com.

Mi own grinder is almost, piece by piece, exacltly like yours. However I only have a platten and my iddler wheels are made of nylon... since I didn't have time at the moment for a contact wheel! And just a quick advice, If you ever have trouble with the tracking wheel... source a transpalette wheel! They come with their own ball bearings AND are alreado crowned!

I must say that since I put together my grinder I haven't made a single knife... XD. But I use it for general metalworking and it works great. And some handle profiling as well.

Keep up the good work!
 
You must log in or register to reply here.
Back
Top