The difference a disk makes

[fitzo]

Bought one of the Nielsen Systems and a handful of plates after using three different disc grinders in my shop for 40 years.

Another thumbs-up!

 

[Lorien]

any suggestions on how to get my belts from jumping off the Brodbeck disc attachment while running in reverse?

 

[Crag the Brewer]

any suggestions on how to get my belts from jumping off the Brodbeck disc attachment while running in reverse?

Is that different than running in reverse normally?

I run reverse on my 2x72 for convex/slack belt grinding on the top side.

idk if you do that too?

 

[Lorien]

Is that different than running in reverse normally?

I run reverse on my 2x72 for convex/slack belt grinding on the top side.

idk if you do that too?

I've haven't run my machine in reverse since I installed the switch, I added the switch specifically for the disc sanding attachment

 

[Crag the Brewer]

I've haven't run my machine in reverse since I installed the switch, I added the switch specifically for the disc sanding attachment

I don't understand?
What do you mean adding the switch?

My switch on my vfd is what changes the direction of the motor/belt

 

[Lorien]

I don't understand?
What do you mean adding the switch?

My switch on my vfd is what changes the direction of the motor/belt

that switch

 

[Crag the Brewer]

Ok, I think I got it/understand.

You Chose not to run it in reverse.

But IF you could before, what's different now?
What's causing your belt not to track?


Does your new roller that the belt runs on to drive your disk..... Does the roller/spindle have grooves on the surface from machining? That could cause difficulty tracking.

 

[Lorien]

my vfd didn't come with a reverse switch installed when I bought the machine, so I ordered a reverse switch when I decided to pick up the disc attachment and rigged it up.
Not being able to run a disc in reverse seems like a problem, but I haven't felt the need for reverse on my 2x72.
The machine runs ok in reverse but not with the disc attachment which uses a 2x72 as the drive belt. Belt runs around the drive wheel, over the tensioner wheel and then around an aluminum drum that the disc is attached to. Works great going forward, but in reverse the belt rides into the back side of the disc and off the tensioner wheel, regardless of the angle of the wheel

 

[AbLonewolf]

any suggestions on how to get my belts from jumping off the Brodbeck disc attachment while running in reverse?

Hmmm...
Got my attachment a couple weeks ago and love it. I do not have that issue running it on reverse. Runs as it should.
Send Ben Secrist (Broadbeck) an email in regards to this. He was helpful to me when I dealt with him regarding trimpots adjustments.

 

[Lorien]

Hmmm...
Got my attachment a couple weeks ago and love it. I do not have that issue running it on reverse. Runs as it should.
Send Ben Secrist (Broadbeck) an email in regards to this. He was helpful to me when I dealt with him regarding trimpots adjustments.

that's solid advice
did you end up tuning the vfd?

 

[AbLonewolf]

that's solid advice
did you end up tuning the vfd?

Yes I did, as per the instructions. Ben tells me it will not affect the 2X72 grinder operation.

Quote from him: "Yes the machine will work fine on these adjusted settings and you will not need to constantly change them. It is a more delayed start up to get the mass up to speed with out throwing an error in the VFD."

 

[JV Knives]

that switch

I have the same grinder...and switch. I have to adjust tracking (of course) when I run in reverse on a flat platen....but never had a belt jumping off.

I would eliminate the disc sander attachment and see if the issue continues without it. OR....as suggested, call Ben, Vince, or Ryan and they will hook you up those guys rock

 

[welderboy]

I am thinking of building a 9" disc sander soon. Are people using a flat or bevelled disc? Right now I am making fixed blades with blades from 3 to 7 inches.

 

[Richard338]

Most people favor flat these days. If you think about the beveled configuration, and for illustration, exaggerate the shape into a cone, then you can understand that strictly speaking there is no truly flat region. If I'm flattening scales or something, I'd rather have truly flat than worry about clearance of the other side.

 

[Forrest Taylor]

Here is my home made disc sander. Bought the 3 phase motor off Craigslist, the VFD and DPDT reverse switch off amazon, the beveled disk from KMG. The base is the cast iron body of a craftsman belt/disc sander. I made it mostly to try flattening bevels, but my bevels are pretty flat as ground. So tried it today on the flats. Worked pretty well

 

[Thescrawnylumberjack]

I’m sure it varies by brand but I’ve noticed that the flat disc on disc grinders aren’t always perfectly flat. They get you pretty close. I have the luxury of having a Bridgeport mill so I’ll flatten scales on there and final surface prep for glue up is done on a surface plate with sandpaper. I will rough up the tang of my knives with the disc sander since most of the time I need ceramic to do that properly.

 

[welderboy]

I am thinking a simple build with a single phase motor from Princess Auto and a 9” disc from TR Maker or Nexxus grinders.

The main goal is to use the disc sander to reduce time hand sanding.

Will a single phase 1750 rpm motor work ok or should I get a 3 phase motor and VFD? Sure adds to the price tag.

 

[Forrest Taylor]

I'd go with the variable speed. For me, trying to get the blade evenly onto the sanding surface at 1750rpm would result in lots of $&^%@#

 

[Stacy E. Apelt - Bladesmith]

3-ph and VFD

I am drawing up the plans for making VFD equipment foot controlled. I already have foot switches to turn drill presses, lathes, sanders, etc. on and off, but this would allow changing the speed by foot on a VFD. Think of how nice it would be to rev up a grinder, lathe, or sander from dead slow to high speed while holding the lathe tool or knife blade with both hands. I have quite a few rheostat type foot controls for flex-shaft machines. I need to see what their resistance is.

Seems simple enough to wire one as the remote potentiometer for the VFD. The KBAC remote circuit uses a 10K pot. If I add a pigtail and socket for a remote speed control pot to the VFD, I can simply plug in the foot pedal. I need to measure the resistance of my foot pedals and see if they are in the resistance range needed. If not, it should be simple enough to build a foot control with a 10K pot.

 

[Forrest Taylor]

Good idea.