Disk grinder thoughts?

Mudman

Well-Known Member
Hello Dogs,

I wanted some input on purchasing a disk grinder within the next few weeks.

Currently my plan was to buy a setup from Wayne Coe, and add on the table system from Beaumont and the Nielsen hub as well.
I've considered the vari speed version of the TG92, but wanted more working room. The fixed base and table setup for the TG92 seems like it would limit me only to flattening material, without the option of flat grinding blades.

Anyone own the grinder setup offered by Wayne?

Anything to consider with disk grinders in general? This will be an add on tool to the KMG I currently own.


-Mud
 
if you want a basic unit, look at making your own. you can find a 1hp motor with variable speed drive for $200 and up. an 8" flat or concave disc is $60. a mounting plate if you want to go vertical can be made with $20 of aluminum or steel, drill 8 holes and cut a larger hole. now you have a basic unit that will work well. i choose 8" because it is the size our brothers who do lapidary or metallurgical polishing use. there is a much larger selection of PSA discs available for 8" than 9". you can buy a ready to use 8" wet/dry variable speed flat lap machine for about $400.
another approach:
a 3hp 240v rotary phase converter can be found for $300. a 240volt variable frequency drive would be another $100. now you have a solid true 3 phase source you can use with any 3 phase motor.
another approach:
a 90volt DC speed controller for $50 or less. 3/4hp motor for $200 or less.

i dont you know your mechanical/electrical skills. care and feeding of motors, drives, motor controls, wiring, and doing basic machining is a large part of what i do at the office. the office is tongue and cheek, the office is a 1600 ton Schuler Forgemaster forging press that makes 25 4 pound axle pieces a minute.

hope these are some good ideas for you.
 
Thanks for the input Scott, I will consider it.

I'm not too good with anything electrical, but it seems pretty straight forward.
 
I built this horizontal unit a few years back and have found it to be very useful. The 1 12 hp variable motor is mounted to an upright and the workrest is mounted to the motor frame using the four bolts that hold the motor together. I use a Neilsen disc which is a fine setup. The upright, which is removable, is mounted to the workrest surface and allows for material squaring along both axis. It takes a bit of work to make but well worth the effort.
DSC01090.JPG


DSC01088.JPG
 
Thanks for the post Fred,

I saw your setup in my research, liked it a lot. How much would you say it cost you in materials to make that?
 
Thanks for the post Fred,

I saw your setup in my research, liked it a lot. How much would you say it cost you in materials to make that?

I found the motor and controller on e-bay for 150.00, a steal, the aluminum sheet from there as well was 40 dollars. You know about the disc; so most of it was cutting and shaping and aligning the parts to each other so everything was square. I had a vertical set up before the horizontal one and I prefer the latter. Any way you go, a disc is a very useful tool for the knife maker.
 
Fred, that is a nice setup you've got there. I'm seeing the disk grinder really could use a variable speed option. I built a 9" disk grinder with fixed speed with a 1 hp 1725 RPM motor. It's vertical, but maybe this horizontal mount would be better.

Question: Does the typical use of a horizontal grinder require a full 1 hp motor? Seems like most of the grinding is more light grinding, not any "hogging" of material. Would a 1/2 hp be plenty? I saw the 8" lap horizontal grinders tended to be 1/4 hp.

Thanks for any info or suggestions.

Ken H>
 
Well, I have the Rod Neilson disc grinder with a variable speed drive, and think it's super for what I use it for. I also have two belt grinders. One has a flat glass covered platen that I can install small wheels at the top on and the other usually has a 10" wheel on it. I found that to have a disc grinder that will work in a good manner it had to have a speed control and changeable discs for different grits. This machine does . FRank
 
Thanks for the info Frank, but how much power do you think is required from the disk grinder? Do you load your disk grinder very heavy while using? On the belt grinders (2X72) I tend to load pretty heavy while profiling a blade (hogging), but as I doing finish work there is MUCH less load applied.

What is your experience with the disk grinder - mostly light load finish work? OR heavy loaded hogging work also?

Ken H>
 
hi,
lets look at what we trying to do. if I have a 1/2hp disc setup with a 40grit disc at 1750rpm, i am going to quickly remove some steel. do i really need a motor big enough so I can push the blade against the disc with all my weight and not have the motor bog down? If i grind like that, what will happen to the steel? I have done it with plain jane cold rolled and the steel quickly starts to change color till part touching the disc is orange/yellow. doesnt really hurt 1018 cold rolled, but what is that doing to your annealed piece of O1 or 52100 or A2? so i use less pressure, make a few more passes, quench a little more often. you will remove the same amount of material but spend an extra minute or two or five grinding. you will also get more life from your discs.
JMHO
 
Ken,

For most things on the disc, big hp isn't needed. Mostly light touch to even up handle materials; if you use one to grind bevels thats a different call. The set up I built is an all around unit and can handle most any task. I guess you get out of them what you put into them.
Good luck with the build; let us see what you come up with. I will be happy to help where I can if you decide to build the horizontal I put together.

Fred
 
I have a 1 hp disk grinder with a VFD. I don't know what the minimum hp rating should be, but I do know that the price difference between a 1/2 hp and a 1 hp is relatively low. I would keep it under 1hp so you can get away with the KB24 VFD.
 
OK folks - that's the type of info I was looking for..... and just realized I should have started a new thread so as not to hi-jack this thread. I hope I've not taken the thread too far off topic.... Let me just start a new thread.

Ken H>
 
I just picked up the Nielsen disk grinder setup, and ordering a grinder from Wayne in a few weeks.

Looking forward to adding this setup in my backyard shop.
 
OK folks - that's the type of info I was looking for..... and just realized I should have started a new thread so as not to hi-jack this thread. I hope I've not taken the thread too far off topic.... Let me just start a new thread.

Ken H>
Not off topic at all Ken, I found the info very useful as well.

Saves on threads, and more info is never bad. :biggrin:
 
Thanks for understanding - and I do agree with you, but often on other forums I've seen folks get all excited about "hi-jacking" threads and I didn't wish to cause a problem with anyone. I'd not really considered doing anything else with the disk grinder - other than use it, but a lower RPM would be good. Got me to thinking just what I'd really use the disk for - light duty work. OK, just how much hp is really needed for that? I'm thinking 1/2 hp would be good. I'm sure thinking about a 1/2 hp 3 ph motor, set grinder up close to lathe and share the VFD between lathe and disk grinder. Well, maybe I'm just dreaming too much - I've been known to do that :)

Ken H>
 
Got me to thinking just what I'd really use the disk for - light duty work. OK, just how much hp is really needed for that? I'm thinking 1/2 hp would be good. I'm sure thinking about a 1/2 hp 3 ph motor, set grinder up close to lathe and share the VFD between lathe and disk grinder. Well, maybe I'm just dreaming too much - I've been known to do that :)

Ken H>
i have plugs on my inverter/vfd and on the motors i use. once power is turned off, i can plug any of my 3 phase motors into the vfd i want to use. i use left over Harting connectors from the office.
 
All good with me Ken. Your questions got more responses than my original post. I should thank you, I got a lot of info out of it.
 
Ken, The VFD on your lathe is probably not NEMA 4X but is vented with a fan to circulate air through the VFD for cooling. If you are using it while grinding you will probably suck metal grindings inside the VFD and short it out (ruin it). Matter of fact if it is close to the grinding I would probably cover it when not in use if grinding is going on anywhere close.
 
Back
Top