# Modifying my Home Built Tool & Cutter Grinder



## cfellows

This is my home built tool & cutter grinder...





And here are some more pictures as I'm tearing it down...





















It's made from 4" channel iron and a 5,000 RPM treadmill duty motor with a variac to adjust the speed. I rebuilt the front bearing carrier on the motor from aluminum to increase the accuracy and seal the motor from grinding dust. There is no air flow through the motor but so far it has never overheated. The motor has ball bearings on front and back and runs very quietly with virtually no vibration. I rarely run it more than half speed and have never put any appreciable load on it. I have several spindle attachments for it that allows me to use an assortment of different grind stones.

The grinder has served me well and is reasonably accurate, but is somewhat deficient in user friendlieness. The motor is fixed solidly to the frame and all angle and height adjustments must be made on the work holder attached to the table. I've long been contemplating modifications which would let me adjust the height of the spindle as well as the overhang of the grind stone over the table. So, that's what this thread is about.

Here you can see the 1/4" thick angle iron I added to the side for mounting the vertical column which will carry the motor. The angle iron has two slots that allow it to slide forward and back by about 2 3/8" inches which will give me more or less overhang over the table.



More pictures to come...

Chuck


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## cfellows

This first picture shows how the column which holds the motor attaches to the base. I have 3 holes in the angle iron platform so the column can be mounted in the middle or on either end for moving the motor forward and back.






Here is a view underneath the column platform. It's slotted to allow forward and aft adjustment by about 2 inches. There are also two sets of holes which allow further adjustment forward and back.






Do you get the idea that I want a lot of forward and backward positioning of the motor / grindstone???? 

Here is the motor clamp that I fashioned from 1/8" thick steel sheet.






And here is what the motor holding assembly will look like. 






Chuck


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## bvd1940

Looks real good cfellows,  I am working on an idea for a tool grinder made with a Harbor Freight 3in1 mill/lathe I picked up cheap. I felt that it would cover vertical & horizontal position of the grind wheel  
I see some good ideas with what you are doing so will be watching for further installments :big:


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## cfellows

Thanks, here are some pictures with parts temporarily hung in place.
















Think I'm getting close to being able to put this thing back together. Tomorrow I will remove the metal feet from the motor so it will fit in the ring clamp I made. That will be the point of no return.

Chuck


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## Wrecks

Um, how'd you form the motor clamp?


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## chucketn

Chuck,
Is there a build thread on the origional? I have a treadmill motor like yours looking for a new purpose.

Chuck in E. TN


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## cfellows

RexL  said:
			
		

> Um, how'd you form the motor clamp?



I started with a flat strip of steel, about .110" thick by 3" wide and 10" long. I used my (home made) press brake in my (home made) 20 ton hydraulic press to fold the tabs on each end. Then I laid the strip down across a 3" piece of channel iron with the flat part on the bottom.  I put a 3" diameter billet of aluminum rod on top of the strip, then used my hydraulic press to push the billet down on the strip forcing it into the channel iron and making it curl up around the billet. Then I continued to use the press to finish forming the ring around the billet. I should've made a video or at least took some pictures! :doh:

Chuck


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## cfellows

chucketn  said:
			
		

> Chuck,
> Is there a build thread on the origional? I have a treadmill motor like yours looking for a new purpose.
> 
> Chuck in E. TN



No, sorry, Chuck. I built that cutter grinder a number of years ago before HMEM was even a twinkle in Rick's eyes. I have some drawings which I can probably clean up. The main frame is made from a piece of 4" channel iron about 14" long. I milled the sides down on the front of the channel iron then welded a piece of 1" x 1/4" cold rolled steel on each side to form the y axis ways. I then used a mill to true up the surface and cut the 60 degree sides to form the dovetails. The y-axis block was milled from a piece of 3/4" thick cold rolled steel. The table was milled from a piece of 6" x 11" x 1" cold rolled steel. I milled an integral dovetail into the back of the table and also milled a slot for a 24 pitch rack to fit in so the x-axis would use rack and pinion movement instead of a screw. There was a ton of milling done to form the dovetails and cutting the T-Slots was a very slow, painful process. It was during the building of this cutter grinder that I made a power feed for the x-axis on my mill/drill! If I had it all to do again, I would probably try to adapt an existing x-y table or at least make it out of cast iron instead of steel. 

Chuck


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## cfellows

I'm in the home stretch now. I've pretty much got everything reassembled. I still have to complete the crank assembly at the top of the z-axis. That crank on top of the z-axis lead screw is just sitting there, not attached. And I have to solder the motor connections back onto the switch, which is reversible, by the way.
















I'm quite pleased with the rigidity of the column and motor assembly. I don't believe there will be any flex or vibration.

Chuck


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## doc1955

Looks good Chuck I keep telling myself I need to build some thing like that but I just keep getting side tracked by other builds. I have been collecting data and examples so I'll have some place to start with.


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## petertha

cfellows  said:
			
		

> ... and a 5,000 RPM treadmill duty motor with a variac to adjust the speed. Chuck



Nice machine! What does 'treadmill duty' mean? Is variable speed important for a T&C grinder? Is the intent to raise rpm over what say a typical bench grinder motor would provide for smaller diameter cup wheels for example. Or reduce it for some reason? 

I was looking at surplus motors, daydreaming about building something similar one day. The motor prices varied all over the map, some quite expensive. This got me wondering if it wasn't more cost effective to just buy a conventional, small duty bench grinder & gut it for its motor. You can get one like this for 50$ new. Is maybe the quality of off-shore bearings not suitable for a T&C application?


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## lathe nut

Chuck, thanks for the tour of the tune up, that really is a nice machine, if it comes up missing call me first, it will be in my shop, thanks again, Lathe Nut


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## cfellows

petertha  said:
			
		

> Nice machine! What does 'treadmill duty' mean? Is variable speed important for a T&C grinder? Is the intent to raise rpm over what say a typical bench grinder motor would provide for smaller diameter cup wheels for example. Or reduce it for some reason?
> 
> I was looking at surplus motors, daydreaming about building something similar one day. The motor prices varied all over the map, some quite expensive. This got me wondering if it wasn't more cost effective to just buy a conventional, small duty bench grinder & gut it for its motor. You can get one like this for 50$ new. Is maybe the quality of off-shore bearings not suitable for a T&C application?



I'm not sure what treadmill duty means other than the motor's were originally manufactured for use in a treadmill. The are rated for up to 90 volts DC although I've run mine up to 115 volts DC. The bearings in mine seem very quiet and smooth although I can't speak for others on the market. Mine has never overheated even though I have the air vents blocked. Of course, I seldom run it for more than 15 minutes at a time. The variable speed is important because different size and type of grindstones are rated for different speeds. Some of my 4 and 5 inch wheels are only rated to 3400 RPM while the smaller cup wheels are rated higher. If you have a slower speed motor, you could probably run all your stones at the slower speed but they might not cut as fast or as smooth.

Chuck


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## steamer

It looks great Chuck! Are you going to make an end mill fixture for it?

Dave


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## kuhncw

Chuck, that is a nice grinder you've built. How is the piece on the bottom of the column attached to the column. I see a slight gap at the joint.

Thanks.

Chuck


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## MachineTom

Great grinder setup Chuck. Look on ebay there were some guys selling Uni-Grind universal grinder holder. I got one, $60 these are new units made in USA maybe went out of business. With those slots an easy and very rigid mount.


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## cfellows

steamer  said:
			
		

> It looks great Chuck! Are you going to make an end mill fixture for it?
> 
> Dave



Thanks, Dave, I already have an air bearing fixture I built for grinding the flutes. I'll post some pictures of it later.



			
				kuhncw  said:
			
		

> Chuck, that is a nice grinder you've built. How is the piece on the bottom of the column attached to the column. I see a slight gap at the joint.
> 
> Thanks.
> 
> Chuck



Thanks, Chuck. There isn't really a gap. I ground a slight bevel around the bottom of the column in anticipation of silver soldering the steel bottom onto the column. However, once I pressed the shouldered down part into the column, it was such a tight fit I decided I didn't need to solder it. The part extending up into the column is 3/8" long and I had to use a 24" long tommy bar on my 20 ton press to get it all the way in. The wall thickness on the column, by the way, is .120".


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## cfellows

I've got the grinder pretty much finished to the point where I've put it back in it's home spot, ready to go to work. 

I've got to change out the crank handle on the y-axis since it interferes with the x-axis handle. I'm waiting delivery of a small timing belt which I will use to connect the lead screw to the handle after moving it a couple of inches to the right... the way it was before!

I finished the z-axis crank assembly on top of the column and re-purposed the tool post tightening lever from my mini lathe to now serve as the clamp screw for the motor assembly to the column.






huck
	

	
	
		
		

		
		
	


	









Next I'll be looking at some different tool holding fixtures to see if I can improve on what I've got...

Chuck


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## cfellows

I'm beginning work on updating my existing grinding fixture and perhaps adding some new ones. The first thing I did was spiffy up the piece of angle iron that attaches the fixture to the base. I radiused the side and the base and rounded over the outside edges. After 40 years or more of working around metal I'm finally learning to remove as many of the sharp corners and edges as feasible because sooner or later I'm going to bang my hand against one of them.

Here's the base attachment and a steel disk with newly scribed graduations. This will be part of the horizontal angle adjustment and has 5 degree and 10 degree graduations.






Here is the setup in my mill drill for cutting the graduations. The disk is mounted on my smaller rotary table. Each full revolution of the crank handle rotates the disk 5 degrees. The scribing tool is just a boring bar that takes 3/16" square high speed tool bits. The tool cuts on the upstroke which makes the inside end neater and the bit of metal that is removed comes out on the edge which is easier and cleaner to remove.






This is a closeup of the boring bar and the 3/16" tool bit. You can see that it is ground to a sharp point with the cutting edge on top.






Hopefully this will all make more sense as I get it put together.

Chuck


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## coopertje

Hi Chuck, Very nice grinder you have made there! Love the base you have made, could have been made in a factory :bow: . 
I am in the phase too to make some jigs, I just posted (Tacchella tread) an idea of a universal jig for cutters, drills and radius tools. Your opinion on this would be very much appreciated.
Keep on the good work and I am eager to see your progress!

Regards Jeroen


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## ShopShoe

Petertha,

I don't mean to hijack Chuck's excellent thread (Way to Go chuck!!!).

I tried to use the motor (3600RPM) from a cheap grinder for a project: These are designed to start with no load or low load and build up to speed. I couldn't use it because it wouldn't start and spin up to speed with anything but it's original wheels.

I also second the comment that variable speed might be desirable in a grinder like this.

Thanks for the chance to interrupt.

--ShopShoe


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## Swede

She's a beaut, Chuck! And very handy, too. I'm surprised by the number of guys who are very active home machinists but rarely sharpen tools. Something like this is hugely useful, and a fun project to boot.


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## cfellows

Thanks for the comments guys... always appreciated!

I've got this thing pretty well finished, except perhaps for some additional attachments. Today, I made brass ball knobs for the x-axis spin handle.







I also added 5 & 10 degree graduations on the work holder...
















And I reinstalled the belt drive on the y axis crank. I had to move it to the right so it wouldn't interfere with the x-axis spin handle.






Tomorrow I plan to make video tour of the grinder, time permitting.

Chuck


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## cfellows

Here's the video of my Tool & Cutter Grinder. 

[ame=http://www.youtube.com/watch?v=U6L8ZYrQm3U]http://www.youtube.com/watch?v=U6L8ZYrQm3U[/ame]

Chuck


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## SBWHART

Thats a real andy bit of kit Chuck thanks for showing.

Plenty of inspiration their.

 :bow: :bow:

Stew


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## ShopShoe

Chuck,

That really turned out well. thanks for showing it to us.

--ShopShoe


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## cfellows

Thanks, all, for the kind words. Here is a picture of my home made fixture for sharpening the flutes on end mills.






The spindle has just enough clearance so it floats on a cushion of air when hooked up to a low pressure air supply.  This makes it very easy to spin while moving in and out. In it's current configuration it will handle cutters with a 1/2" shank on one end and 3/4" shanks on the other end. I can also do other shank sizes by using bushings. I'm going to try to adapt an er20 collet chuck to it so I don't need to use bushings.

Chuck


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## bronson

That is a really nice little sharping rig that you have there. Nice work Chuck.


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## crab

I like really your grinder Chuck.I have a X-Y table and base from a mini mill I bought at a yard sale that might work good for one.Add your column and a treadmill motor and control I have and it might work.I am going to build it when I get in better shape.Thank you for showing this.
Bill


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## jct842

golly jeeze I now have to start looking for a xy table. that grinder is a must for any shop worth working in. I really like it. I got to have one soon! john


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## steamer

Sweeeet rig Chuck! ....Is that air spindle to Glen Wilson's design, Phil Duclos design, or CFellow's Design... ;D


Those are not easy to make as the tolerence is quite tight for a simple groove compensated air spindle :bow:

Dave


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## cfellows

Thanks to all for the kind words.



			
				steamer  said:
			
		

> Sweeeet rig Chuck! ....Is that air spindle to Glen Wilson's design, Phil Duclos design, or CFellow's Design... ;D
> 
> 
> Those are not easy to make as the tolerence is quite tight for a simple groove compensated air spindle :bow:
> 
> Dave



Dave, I was using Phil Duclos's design as the basis for my fixture. I think I scaled it down some from Phil's design. I ultimately made mine out of aluminum because I was unable to get the smoothness and tolerances I needed out of steel. I went through 3 or 4 iterations before I finally got the result I wanted. Cast iron would have been the best, but I didn't have any in the right size at the time.

Chuck


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## cfellows

I got my end mill flute grinding fixture hooked up to the air supply and have been practicing sharpening on a 3/4", 2 flute end mill. The fixture will "float" the spindle at about 5 PSI and essentially becomes frictionless, except for the flute of the end mill riding on the small post which keeps it oriented withe grind stone.

I began thinking about a fixture that would easily let me grind the bottom cutting edges of the end mill and had visions of a fancy collet holder with indexing, etc., that would let me sharpen a tool at any angle, any rake, any number of flutes, etc. But when I got to looking for suitable material, my practical side kicked in (some might say it was my lazy side :-X) and I remembered this old, cheap Enco end mill sharpening jig I had bought years ago. After some searching I managed to locate it and after some head scratching, here's what I came up with.
















Here's a couple of pictures of the lash-up I used to drill the holes for attaching the new base to the old one.











And, here's a picture of it sitting on my T&C grinder, ready to go to work as soon as I bolt it to the T-slot in the table.






Not real fancy, but it will do the job until I get the urge and the time to make something better.

Chuck


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## Don1966

Chuck I love your tool grinder this will be a must in my shop.  :bow: There was something in the video that caught my attention. I noticed a two conductor cord going through a hole where you mounted your switch. Having your setup made of all steel I see a Danger of Electrical shock or execution. Not meaning to demean any of your work. I am an Electrician and it is easy for me to notice this. When I was younger I ended up in the hospital by 120 volts AC latching on to me and not being able to let go. I hope all that read this heeds my caution. I would not want to know of anyone being electrocuted. Keep all of your equipment well grounded and all circuits going to any outlet properly grounded and polarize. Also when going through any hole use connectors to prevent chafing of the cord.

Kinds regards Don


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## cfellows

Thanks Don. I had already fixed that with a rubber grommet, but a gentle reminder never hurts. One of the things I like about this group... The members tend to keep folks from hurting themselves!

Chuck


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## lee9966

Nice job Chuck. I happen to have a treadmill motor and controller sitting in my pile of cool things to use someday. Now I know what to do with it! 

Lee


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## Don1966

If your treadmill motor is not a DC motor and is what we call a universal motor. This is like a drill or saw motor they can run on AC or DC . Only if It has field coils and not magnets. You can use this http://www.grizzly.com/products/Router-Speed-Control-20-Amp/G3555 from grizzly for $34 to control your grinder.

Regards Don


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## Swede

The beauty of Chuck's machine also is the ease with which it can sharpen HSS lathe bits. Going from hand-held sharpening in a cheap bench grinder to something like this, it is amazing how superior the results are when you use a true T & C grinder. You can also use one to add neat chip breakers and the like.

One other attractive thing is the ease with which you can create specialized jigs/gadgets and simply bolt them right on to the table... even things like cylindrical grinding rigs or motorized cam grinders. This sort of tool forms the basis for a large number of specialized applications.

Way to go, Chuck!


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## colin james

Where have all the images gone that are referred to in the text?


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