New grinder build

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Insanty

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I have been working on grinder designs on and off over the last year. I think this will be the final design. The 1/4" steel side plates add a huge amount of rigidity. The rest of the frame parts are 1/2" cold rolled steel and the arm is the standard 1 1/2" steel. The platen side plate is 3/8" steel.

With KMG selling such a nice machine I decided to make something a little beefier. I am making one to keep for myself with stainless steel side plates.

I usually make gun parts but started a little side shop with a buddy to make other stuff. We have started making a few knives but they are not nice enough to show anyone yet, but getting better. We bought a new Haas CNC mill and equipped it with the Renishaw probing system to make our toys on. We sell just enough stuff to cover our costs to play but demand for the grinders is high. They are just no fun to pack and ship at over 100 lbs including the box we build.

We had a couple of them coated in black nitride and they looked really good, but at $150 each we had to stop doing this.

The improvements we plan to make are making handwheels for the sliding arm lock and tracking arm wheel instead of a thumbscrews. Any other suggestions are welcome.

ry%3D480


ry%3D480
 
I've been looking into building one of these... The hinged models that go horizontal seem to be an awesome modification worth having... That is if your into a thread genre of "pimp my grinder"... I dig motorcycle grips on the tracking arm!!!
 
seems like this grinder is a kmg copy but a little less refined.. could be tough to sell unless the price is significantly lower but with all the cnc capabilities you have, I would think that it would be. are you making the wheels also?
 
I have never bulit a grinder but I have made my own tool arms and 3 tool rests and a couple of grinding jigs and it is fun to do. I have modified my KMG grinder a couple of times changing the tracking arm arm and the spring to a gas piston. The machine you guys are building is very nice looking and looks strong and solid. Is the tracking wheel crowned as well as the drive wheel? Is the jackshaft a 5/8th diameter shaft and do you turn your own wheels of aircraft 6061 aluminum? Your grinder would look serious with a bright powder coat job in red or blue-green or even competition yellow. Do the pillowblocks have sealed bearings that do not need lubrication? Your grinder looks like it is a bit more compact than the stock KMG grinder. An all stainless steel one would be really handsome and fun to use. I would love to know more if the forum rules allow....like where to price one. You are aware I'm sure that KMG will sell just the frame with the drive and tracking wheel and toolbar and rest for $605. Good luck with your very nice machine. Larry
 
In my opinion it NEEDS another tool rest socket, and a crowned tracking wheel. You will also find that a large tracking knob and tool rest knobs will make adjustments must easier. It looks like a clone of the of the KMG grinder to me. While nicely made, I think if you made some improvements on the design and made it your own, you would have a much larger market for it.
I would take a look around at some of the high end grinders that are being made recently like the Fellholter Uber grinder, the TW-90, the wilmont tag grinder...... all of these are unique designs that have lots of features that most makers are wanting.

Just my .02
 
BenR.T. said:
In my opinion it NEEDS another tool rest socket, and a crowned tracking wheel. You will also find that a large tracking knob and tool rest knobs will make adjustments must easier. It looks like a clone of the of the KMG grinder to me. While nicely made, I think if you made some improvements on the design and made it your own, you would have a much larger market for it.
I would take a look around at some of the high end grinders that are being made recently like the Fellholter Uber grinder, the TW-90, the wilmont tag grinder...... all of these are unique designs that have lots of features that most makers are wanting.

Just my .02
Click to expand...

Thank you very much, this is the type of response I am looking for, I am new to grinder making, not CNC machining so improving the design is everything. The tracking and drive wheels are crowned (I think I used a substantial 9 1/2" radius). I used solid side plates to make it much more rigid than the KMG, not that theirs needed improvement in rigidity, but I wanted to offer something different. My bearing mounts are also one solid piece with the frames instead of bolting on separately, again, not that there is anything wrong with other designs, I just wanted to offer my own design and still use the sliding tool arm like KMG and Bader.

Please offer any other suggestions, I will see if any and all can be added to the design.

I will look up the grinders you mentioned, I have never looked at them before.
 
Very nice machine and I like the side plates. The only two items I would add were to consider using a gas spring instead of the coil spring and consider beefing up the tool rest (maybe using 1/2" or 3/8" stock instead of 1/4").
 
You beat me to it bjansen, I was going to suggest a gas spring too.

You may want to look at making an option for direct drive with a 56C frame motor, like the GIB. With the side plates you are using I would think that would be pretty easy to offer as an option.

Also a another tooling socket as already mentioned and the ability to make it filppable to horizontal
 
I am going to make some tool rests out of 3/8 instead of 1/4" as many have suggested. I have made a few blades lately and agree that it would benefit from being thicker.

I am going to do a direct drive with the frame motor that can go horizontal but it will take me a few tries to get it right. For now I will be making these as a way for knife makers to get a super heavy duty set up for a fairly low cost, throw whatever motor they have laying around on it, and start grinding. I mostly just sell the wheels for home builders on Ebay but want to take my grinder design to a high level. I have Grisly 2 x 72" knife grinder and felt I could greatly improve on its performance. The grinder in the above photos works so much better than the Grisly it is hard to even compare them.

I will have to extend the side plates to make multiple tooling sockets, and use a frame motor so it can tilt. I worked out the plate frame model (Pictured above) so it would not just be a rip of KMG. I still wanted to use a tool arm like KMG and Bader and this is what I cam up with without just copying either of them.

Thanks for all of the help so far, I will do my best to ad all of the improvements everyone has suggested and make a really desirable machine.

Does anyone have suggestions of where I can have rubber applied to large contact wheels? I can make the wheel but don't want to use cast polyurethane since it is not as good as real rubber. I have not been able to find a source for applying rubber that charges less than I can buy an entire wheel for at retail.
 
The next thing you need to do is upgrade your membership to Knifemaker/ Craftsman/ Service Provider.
As a registered user, you are not allowed to display or discuss items you are or will be selling. I left this going because it was mostly discussing features on grinders, but now you are discussing selling directly.

I am closing the thread for now. Once you get your membership upgraded, send me an email/PM and I will gladly re-open it.
 
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