Thursday, February 15, 2018

Making of the DG-9 9" Disc Grinder (coming soon!)

It's been a long few wintry month and a half and cabin fever seems to be getting the best of me. While staring out the window at the snow, I started day dreaming about making a 9" disc grinder.

Soon parts started to arrive...Hopefully spring will too.


The KBAC-27D is a Variable Frequency Drive (VFD) that can control the speed and rotation of a three phase motor up to 2 horsepower, rated 208/230 VAC. This VFD has an advantage when used in the gritty environment of a belt grinder because it's sealed up and dust isn't allowed to get inside.






The motor is an Ironhorse 1.5 horsepower 4 pole (1725 RPM) three phase unit from Automation Direct. Similar to the one I used in my Sayber OSG but this one runs at half the speed.







The 9" disc is machined from a solid aluminum billet. I ordered this from USAKnifemaker.com. It is a 9" disc that has a 1° bevel on the face, so really it's a tiny bit like a cone. This bevel is to help prevent the knife that you are grinding from catching the opposite side of the disc and flinging it upwards. 




Along with the basic frame details, I will be putting up some posts on how to wire the KBAC for forward and reverse and installing the main power switch. 

Stay tuned,

Dan

Thursday, January 18, 2018

Got a New Set of Wheels!

New Wheels for Another Belt Grinder Project


In advance of my third grinder project I ordered up some of Oregon Blade Maker's 4 piece aluminum wheel set with a drive wheel having a 5/8" bore.

It should be noted that not all motors can use this drive wheel. Only motors with 5/8" keyed shafts can use this set. Fortunately, Oregon Blade Maker offers a set for 7/8" and 24 mm motor shafts. See the links below for the different bore sizes




The parcel came very well packaged. These made it half way to the North Pole!







Each wheel was individually wrapped in bubble wrap.



The machining on these wheels is very good. All the bearings are sealed and take a 1/2 bolt to mount.


This set has a drive wheel with a 5/8" bore and has a 3/16" keyway. This will work for a NEMA 56 frame motor. NOTE: if your motor is has a different size shaft, say 7/8" then be sure to order the correct set.







The 4" drive wheel and 3" tracking wheel are crowned meaning they have an arch to the part of the wheel where the belt will run.


This is where you get the long 1/8" hex wrench down to lock the setscrew into the keystock



And I got this cool sticker to go on my machine!
If you are looking to buy a wheel set these are the one's I recommend:

NEMA 56 frame motors have a 5/8" shaft then look at the 5/8" bore four piece aluminum grinder wheel set

NEMA 143T and 145T motors have a 7/8" shaft then look at the 7/8" bore four piece aluminum grinder wheel set

If you are using stepped pulleys, pillow blocks and shaft is a 3/4", the 3/4" bore drive wheel comes in a set of four wheels. 3/4" bore four piece aluminum grinder wheel set

If you have an IEC motor with a 24 mm shaft, presently only the glass filled nylon drive wheel is available. 24 mm bore drive wheel only. But you can build a set by adding a three piece wheel set to the drive wheel.

Happy grinding!