My KMG - M.G. edition pic heavy

Josh Rider

Josh Rider

Stuff maker
Joined
Sep 2, 2014
Messages
2,428
I recently purchased an upgrade for my KMG that was created by Matthew Gregory.
There was a discussion in this thread:
http://www.bladeforums.com/forums/showthread.php/1351035-Converting-a-KMG-to-direct-drive

This direct drive attachment is incredible!
First thing it addressed was my grinder vibrating.
In this first video you can see where a wrench is sliding off my tool arm from the vibration and I have belt wobble which makes plunges tough for me.
Sorry for the vertical video

[video=youtube;KxD4PvPgmbY]https://www.youtube.com/watch?v=KxD4PvPgmbY[/video]

In this next video I have the attachment on. No belt wobble, no vibration, and it's quiet!

[video=youtube;KPc4naQNpqU]https://www.youtube.com/watch?v=KPc4naQNpqU[/video]

It was easy to install and is built like a tank. I forgot to take pics of it straight out of the box because I was so excited to hook it up.
It came with a massive welded plate that has a cutout for the motor face and the screws. Then the other side bolts straight on to the rear support.
It's designed for a 56c motor.
Here are some pictures of the kmg and the parts that no longer get used.




Plus the drive wheel that they made was 5.5". My original was 4" so my belt speed is increased.:thumbup:
Now if I can just come up with a way to flip it horizontal.:confused:

This thing is awesome! Thanks Matthew for coming up with this idea! If you're interested in this upgrade, send him a pm.
Sorry if this sounds like an infomercial lol. I'm just psyched to have the kmg running like it does now!
Order yours today!!
 
Great upgrade, and makes much more sense than a belt/pulley system if using a VFD. I can't believe Rob Frink doesn't offer something like this to begin with, and Matthew dos a really nice job with these.

Congrats!
 
knife to a gunfight said:
Great upgrade, and makes much more sense than a belt/pulley system if using a VFD. I can't believe Rob Frink doesn't offer something like this to begin with, and Matthew dos a really nice job with these.

Congrats!
Click to expand...

Thanks! I agree, I'm glad Matt and his friend let others in on this. I don't know any machinists so this would have come difficult and expensive if I tried to do this on my own.
 
Yep, direct drive is the ticket:

[video=youtube;gPjLrAR8Dr4]https://www.youtube.com/watch?v=gPjLrAR8Dr4&feature=youtu.be[/video]
 
Thanks Josh (and Drew), but I can't take much credit for this. I merely had problems with the pulley design, and in an effort to address it, brainstormed with my friend Joe. He came up with this design, and I just asked if there was anyone else interested in it, as Joe could be described as the clinical definition of 'technophobe'. Doesn't own a computer at all!

If anyone is interested in this, send me an email and I'll pass along your request to Joe.

What we were shooting for with this was the ability to entirely eliminate the pulleys without altering the basic grinder, and also without requiring any modification. The adapter plate uses existing mounting holes, and allows a 56c face mount motor to bolt directly to the machine. The 5.5" drive wheel is offset to compensate for the difference in the original drive wheel offset, but allows for more contact of most C-face motor shafts (they tend to be a bit short).

With a 1700rpm motor, and a VFD that offers frequency doubling, you can manage about 4800 surface feet per minute, and anywhere below, of course. Despite the loss of torque associated with doubling, it's still MUCH harder to bog the grinder because there's no belts to slip, and it's an order of magnitude smoother.

Glad you're digging it, Josh. Please report back after you've had a chance to grind on it. THAT'S where the proof lays!
 
Last edited:
Havent had a chance to install mine yet, as I just got back from a week down in baltimore and Fire and Brimstone.

Here's the kit outa the box =D

kmgcfacemod.jpg
 
Chuck, I know that direct drive is "the thing" you have to have right now and I think a lot of knife makers like the direct drive much better because they had problems with belts, pulleys , and jackshafts. I made most of the improvenments that Matthew Gregory made to his KMG which gave him nothing but problems. I installed a new idler arm extension with a gas piston tensioner and I added a second tool slot and I also made all my tool arms out of aluminum. All of these things made a dramatic improvement to my KMG but I must say that I still use the belt drive and a Kbac VFD and my grinder will run at 4500 SFM with no vibration to speak of. If I had problems I would go to direct drive also but my KMG runs strong smooth and fast. I have another grinder like yours with direct drive that is quieter but not any better at grinding. I use it horizontal with a Travis Wuertz surface grinder. I know it is a wonderful option for KMG owners with problems and thank goodness that Matthew is sharing his knowledge with KMG owners that are having problems but I think some of the guys could get their grinder to perform well with some adjustments usually caused by weak tension on the idler and improper alignment of the drive, idler, and contact wheel or loose belt or bad pulley. The adaptor is a great thing though if you cant get the machine to perform well and I would use one in a minute if my grinder wouldn't play nice. Larry


ofqB79qm.jpg
 
Great little upgrade. I'm surprised Rob still doesn't make one, despite how many complaints there are.

I've been meaning to do this upgrade, but haven't had to yet. Sure my KMG could possibly run better, but so far it's working fine *knock on wood*. This DD kit is definitely on my list though!
 
....I removed this entire post.

Sounded too much like a rant, and it called a knifemaker I have a great deal of respect for out. Not my goal, or my intention.

Carry on. Nothing to see, here. :)
 
Last edited:
I just switched over to VFD, direct drive. I never had trouble with vibration, I just got tired of moving that stupid v-belt around. Thanks to Matt for helping me get a drive wheel. :thumbup:

My only complaint about the VFD is that it loses torque at low speeds, whereas the pulley system increases torque at low speeds. Not a big deal, though I did stall the motor.
otherwise, I love it.

I also switched to gas piston belt tensioner, and soon I'll be making some aluminum tool arms. My goal is to have a tool arm for every attachment, that way I won't have to be bolting and unbolting platens all the time. I have one platen tool arm, and five different platens...
 
I finished installing the 56c direct drive conversion for my KMG grinder, upgrading to a 3hp motor and VFD at the same time. My 2hp motor and other VFD will be used to build a disc grinder. The next thing to build is a pivoting base for between the KMG and the base-plate, so that I can use the KMG horizontal or vertical. I've also got set up a mist cooling system to use with the grinder too, so I can grind heat treated blades without risking the loss of temper.

I better not be able to stall this out anymore, 50% more hp and got rid of the belts and pulleys!

https://youtu.be/Z9IvRfob_1M

[video]https://youtu.be/Z9IvRfob_1M[/video]
 
Looks like a pretty nice option . I was wondering if the guys who were having problems purchased the aluminum base plate that is a option when you buy your grinder . I have never used a direct drive to compare but my KMG is very smooth and vibration free so I have never considered anything more . Mine sits on the base plate and was wondering if that somehow caused problems.. I don't know but my KMG with a VFD is one of my best purchases . The holes are all predrilled and aligned. Just thinking out loud .. I have owner a Coote two wheel and the mighty Wilton Square wheel before my KMG so I have had a little experience in the past four year.
 
Mark, I had the steel bottom plate (wasn't aware that he offered an aluminum one), and for the initial test of the direct drive kit the chassis was still bolted to it, and there was no difference on or off of it. I didn't bother using it because it just made the grinder footprint almost twice as wide as it is without it, and with no advantage.

I've been getting a LOT of emails from guys with similar experiences. It sounds to me like there's plenty of perfectly operating machines out there, but also machines with issues. Some of the people I've talked to about this just assumed that's how these machines were supposed to work, or didn't know how to go about finding and isolating an issue. I'm willing to bet most knifemakers don't even have the tools needed to test for inconsistencies, for that matter.
 
Marko3 said:
Looks like a pretty nice option . I was wondering if the guys who were having problems purchased the aluminum base plate that is a option when you buy your grinder . I have never used a direct drive to compare but my KMG is very smooth and vibration free so I have never considered anything more . Mine sits on the base plate and was wondering if that somehow caused problems.. I don't know but my KMG with a VFD is one of my best purchases . The holes are all predrilled and aligned. Just thinking out loud .. I have owner a Coote two wheel and the mighty Wilton Square wheel before my KMG so I have had a little experience in the past four year.
Click to expand...

That could be. I was trying to go the most cost effective route originally on a 3 wheel grinder and the kmg did that. I bought the motor and pulleys seperate and didn't buy the subplate. I even drove to Columbus to save on shipping.

The biggest reason I wanted to do this upgrade was because of the belt slipping and it should help to make a horizontal option less complex. And once I bought my vfd there was no reason to use the belts.

Did the gas shock upgrade last night. Another inexpensive upgrade.
Brought to you by big butt doppelbock
 
Last edited:
You may want to flip your piston, to keep grit out of the seal as much as possible.


Josh Rider said:
That could be. I was trying to go the most cost effective route originally on a 3 wheel grinder and the kmg did that. I bought the motor and pulleys seperate and didn't buy the subplate. I even drove to Columbus to save on shipping.

The biggest reason I wanted to do this upgrade was because of the belt slipping and it should help to make a horizontal option less complex. And once I bought my vfd there was no reason to use the belts.

Did the gas shock upgrade last night. Another inexpensive upgrade.
Brought to you by big butt doppelbock
Click to expand...
 
McMaster Carr part numbers

9416K11 Gas Spring with Threaded Ends, 40 Force, 5.90" Extended Length, 2.36" Stroke
9416K29 C-Style Eyelet Bracket for .24" Eyelet Diameter, Gas Spring with Threaded End
9416K84 Zinc Eyelet End Fitting for M6 Thread


Once again, courtesy of M.G.
 
Well that really is a bummer .. And yes my mounting plate is aluminum for sure and I am glad you ruled that out . I guess I got lucky because I would have lost my mind dropping the coin and having vibration issues .. I know you had a square wheel before like me so getting this grinder should have been a pleasurable experience . I do however like the direct drive option but in my case I don't have a good reason to do it . I am getting another grinder next year but I will probably go with another brand just to see what else is out . Talk later Matthew


Matthew Gregory said:
Mark, I had the steel bottom plate (wasn't aware that he offered an aluminum one), and for the initial test of the direct drive kit the chassis was still bolted to it, and there was no difference on or off of it. I didn't bother using it because it just made the grinder footprint almost twice as wide as it is without it, and with no advantage.

I've been getting a LOT of emails from guys with similar experiences. It sounds to me like there's plenty of perfectly operating machines out there, but also machines with issues. Some of the people I've talked to about this just assumed that's how these machines were supposed to work, or didn't know how to go about finding and isolating an issue. I'm willing to bet most knifemakers don't even have the tools needed to test for inconsistencies, for that matter.
Click to expand...
 
You must log in or register to reply here.
Back
Top