Thinking of a new grinder..... but oh, the hurdles

[KenH]

I have about $1500 invested in my Wilmont LB1000, that total includes 3 motors, a VFD, a second drive wheel, 3 spare tooling arms, and the electrical wiring. the LB1000 design is such that I can change out the motor in 10 minutes

Scott, I've been thinking about this post since you posted it earlier this afternoon. You mention you have a VFD, yet have 3 motors which you can change out in 1- minutes. Please enlighten me why you feel the need to change out motors when you have a VFD which will run either of your 1720 or 3450 rpm motors anywhere from 300 SFPM to over 4,000 SFPM without changing motors..... Assuming at least one of them is 3 ph.

The TW-90 is probably the best all around do-everything machine, and has a price tag to match.

John, even with my fussing about 1-1/4" tooling arm, I tend to agree with you. While I've never did any grinding on a TW90, I did have the pleasure of meeting Travis at Blade, and looking over the TW90 there. I was VERY impressed with the grinder - it ran just as smooth (maybe smoother - I've got a photo with a quarter balanced on edge with my grinder running 4,000 sfpm so how much smoother is needed?) as the homebrew KMG clone I built.... once I changed to VFD with direct drive.

John, I was with you on "what is the need of a horizontal grinder".... until I added that ability to my KMG clone. Now, I don't use it often, but when I do it sure does make things nicer. The need for horizontal position is like my idea of VFD when I was running a 3 stage pulley setup - what is needed with VFD? Well, there is no comparison. $300 well spent!

Ken H>

 

[scott.livesey]

Scott, I've been thinking about this post since you posted it earlier this afternoon. You mention you have a VFD, yet have 3 motors which you can change out in 1- minutes. Please enlighten me why you feel the need to change out motors when you have a VFD which will run either of your 1720 or 3450 rpm motors anywhere from 300 SFPM to over 4,000 SFPM without changing motors..... Assuming at least one of them is 3 ph.Ken H>

all the motors are 3 phase. to go slow 300-500 SFPM the VFD is putting out less than 20Hz and performance is not what i wanted and the motor heated quickly. so an 800 rpm motor for finishing. if you shop, motors are not that expensive, all were new old stock and cost less than $75. didn't plan it that way, just sorta happened. some folks can't stop buying wood, for a while i bought a bunch of motors. the direct drive mount on the LB1000 is easy to access and changing a motor is pretty quick and easy.

 

[John Wilson]

John, I was with you on "what is the need of a horizontal grinder".... until I added that ability to my KMG clone. Now, I don't use it often, but when I do it sure does make things nicer. The need for horizontal position is like my idea of VFD when I was running a 3 stage pulley setup - what is needed with VFD? Well, there is no comparison. $300 well spent!

Ken H>

That's good to hear. There are those times when I'm bent over trying to look sideways when I'm doing inside rounding such as contouring a finger notch when looking straight down would be way better. Or squaring things up- times like that are when I dream of a horizontal ability, but those times are rare and I guess I got used to doing without. You make a good point. If I had that ability at my fingertips I'd probably smack myself for not not doing it long ago.

 

[seber]

I don't really have a say in here as far as machines scince I'm new at all of this. That said there is a young kid selling plans on You Tube named Jeremy Schmidt he built his own grinder. The thing is a Tank and I believe it addresss most of your issues. I believe he sells the plans on Estay? Granted you would have to build it though.

I checked out this grinder and all the youtube videos for it. Unfortunately he used an off the wall program to design it. Instead of drawings you will need to scale the parts from his assembly. It will be tedious and you will need to keep your computer in the work area. You will also need to buy the program to run it and it does not work with other CAD systems. It does look like a great design though.

 

[Smallshop]

I don't know of any CAD system that won't output industry standard files. Maybe just contact him and ask for .stp, or igs., or dxf.

 

[seber]

I did contact the designer. The program is Sketchup. It will export 2D CAD drawings but Jeremy did not make any. All you get is a 3D model that does not export as a standard format. A person could make his own drawings of course, but I've already had to learn CAD in three different programs over the years. I'm really not anxious to add yet another.

 

[bodam]

I use sketchup for simple floor plans at work. It's free and very easy. Just download it for the design files.

 

[khopesh]

After researching some more, and calling to ask Travis Wurtz, it appears that almost all grinders adjust the tracking from the tensioner wheel, and either use springs or gas cylinders for tension.

The TW9o uses the same size tooling arms that the Baders used, and it was made to be compatible with those as they were more prevalent when the Tw90 was made. Now most of the grinders are KMG clones to one degree or another, and that is why the larger sized tool arms are more common in the market now .

The TW90 adjusts the tracking from the drive motor and uses a ratchet style tensioner. Apparently the drive wheel tracking system changes how the belt loading is distributed to the wheels under working tension. The belt is said to move less when working compared to the other systems. The TW90 uses sockets instead of tubing to attach the tooling arms.

Basically it boils down to KMG clones with belt tracking on the tensioner, and spring or gas tension, with 1.5 tooling arms, and various methods to attach them, with the direct and non direct drive versions.

And then there is the TW90 which is a different system.

I could see a direct drive non pivoting KMG style grinder with 1.5 steel tooling arms as useful if it was a fixed station that didn't need reconfigured much. I don't like the concept of their tensioner, and tracking adjustment system though.

I think a much sturdier grinder than a KMG could be built out of a massive solid block of billet steel, with thicker 2" or larger solid arms if it was that important.

 

[John Wilson]

The downside to the KMG tracking wheel setup is that the belt won't track well in reverse, if running in reverse is important to you.

 

[KenH]

The downside to the KMG tracking wheel setup is that the belt won't track well in reverse, if running in reverse is important to you.

If everything is lined up correctly the KMG clone WILL track in reverse just fine. I'd not ran my grinder in reverse until a few weeks ago when somebody mentioned that was good for sharpening. I'd been using a Tormek for sharpening. I decided to try my KMG clone in reverse, and had to do some alignment, but now it tracks nicely in reverse with both 8", 10", 12" contact wheels, as well as with platen. The belt might move 1/8" when switching from forward to reverse, but that's not bad. Sharpening works so well in reverse I changed the ON-OFF switch to a ON-OFF-ON switch for ease of reversing. For testing I'd been using buttons on VFD.

I saw the TW90 at Blade and was intrigued with using the motor for tracking adjustment - I think that method would work good. Were I building another grinder I might try that rather than tracking wheel.

Ken H>

 

[sybo]

I have a KMG and a Northridge, NORTHRIDGE HANDS DOWN!!!!!!!!!!