# Belt grinder project



## GarageGuy (Feb 11, 2014)

I'm building a belt grinder for general metal work and tool sharpening.  I have the belt pulleys made.  2" x 6" dia for the drive pulley, and 2" x 4" for the idler/adjustment pulley.  The idler pulley has Fafnir German bearings with Teflon spacers.  I'm looking for a specific motor to power it, and that is what has brought the project to a halt.  They are available new, but are very expensive, so I've been watching CL, eBay, and a couple of other auction sites hoping to snag a used one.  It is a 3/4 HP, 3450 RPM, 56C frame, 115v, TEFC housing motor.  The 56C frame has mounting holes on the shaft side flange, and that is the key to this design.  Here are a couple pictures of the design.  I like it because of it's simplicity and small footprint.  My poor garage doesn't have much space left.  This isn't mine, but mine will look very much like this:





The pulleys are done, except for broaching the keyway and drilling/tapping the set screw on the drive pulley.  I found a great deal on a nearly new duMont keyway broach on CL, so I can't wait to find the right motor so I can finish the project.





GG


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## valleyboy101 (Feb 11, 2014)

Hi GG,
I like the design of the idler pulley adjustment.  Mine is the same and I copied it off a Baldor (which I couldn't afford) and it works great.  Yes motors are expensive and sometimes patience or luck is required.  If I see one at a decent price I usually buy it, I recently put into service a 2.5 HP 3450 rpm motor which I bought for $100 in the 1990's.
Michael


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## Plas62 (Feb 12, 2014)

Try here they have pretty good prices and free shipping on some items.

http://stores.ebay.com/PTJ-Industrial?_trksid=p2047675.l2563


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## Bill Gruby (Feb 12, 2014)

Very nice work so far.

 "Billy G"


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## RandyM (Feb 12, 2014)

:thumbsup: Excellent, what a great project.


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## GarageGuy (Feb 12, 2014)

Plas62 said:


> Try here they have pretty good prices and free shipping on some items.
> 
> http://stores.ebay.com/PTJ-Industrial?_trksid=p2047675.l2563



I checked, and they do have exactly the motor I'm looking for.  Free shipping too.  $174 was more than I was hoping to pay, but for a brand new motor it is a good price.  I bookmarked it, and will start saving up.  Thank you!

GG

- - - Updated - - -



valleyboy101 said:


> Hi GG,
> I like the design of the idler pulley adjustment.  Mine is the same and I copied it off a Baldor (which I couldn't afford) and it works great.  Yes motors are expensive and sometimes patience or luck is required.  If I see one at a decent price I usually buy it, I recently put into service a 2.5 HP 3450 rpm motor which I bought for $100 in the 1990's.
> Michael



I thought the whole design was simple and elegant, and liked it from the start.

I finished cutting the pulleys last summer, and have been watching for the right motor.  You're right, patience and luck play a big part.  I had a 1 1/2 HP Baldor motor that I got at an auction for $40, and it would have worked perfectly, but I used it on a different machine and then ended up selling that machine.  1 1/2 HP was more than what I need for this, but the price was right!

Thanks!

GG


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## tommied (Feb 13, 2014)

We have built 3 of these some years back and they work great. Mine is in storage at the moment but will be back in place before long. Need some good weather. tommie


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## ScrapMetal (Feb 13, 2014)

I really like this design.  Is there a set of plans available somewhere?

Thanks,

-Ron


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## GarageGuy (Feb 13, 2014)

ScrapMetal said:


> I really like this design.  Is there a set of plans available somewhere?
> 
> Thanks,
> 
> -Ron



If there are, I haven't found them.  I'm working from these two pictures.

GG


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## ScrapMetal (Feb 14, 2014)

Guess I'll have to save those pictures as well. :thumbzup:

Thanks much,

-Ron


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## bjmh46 (Feb 14, 2014)

Here's an alternative design that uses a standard base mount motor.  I've built more than a dozen of these since the early 70's.  The original is still running in the shop of a friend of a friend.  I've used 56, 143(t), 66, 184 frame motors with slight adjustments to the dimensions.  I did a full set of cad drawings in autocad sometime back in the 90's, but unfortunately, they seem to be misplaced!

Bob


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## 110octane (Feb 14, 2014)

Nice work!  Where did you find the cast aluminum alloy lamp shade?  I know that these used to be fitted to Rockwell/Delta products.  In "the day" they were available as spare parts, albeit rather pricey.  If there is a contemporary source, that would be great.  They are small enough to stay out of the field of view of the operator.  They do get really hot....

I really like your stage on the last post.  I need to work up something like that for my "imitation" Baldor tool grinder; just being lazy for the moment.  What is the machine adjacent to the belt grinder?
Thanks, Geoff Morgan


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## GarageGuy (Feb 14, 2014)

bjmh46, did you use a 1725 or 3450 RPM motor?  How much difference do you think it would make on a belt grinder?  I've been holding out for 3450 because most bench grinders are that speed, and with a 6" drive wheel my cutting speeds should be similar... but that is an uneducated guess on my part.  Thanks for your thoughts.

GG


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## bjmh46 (Feb 14, 2014)

The lamp is a Delta "retirement" lamp as they are called on the old woodworking machines forum.  I bought it new sometime in the late 70's or early 80's at a local Delta/Rockwell dealer.

The machine to the left of the belt grinder is a hand operated shear.  16ga. x 10 inch capacity. I think it's a DiAcro.

The machine to the right is my swivel head bandsaw, also ho-made.  You just barely see the lower frame.

I've used both 1725, and 3450 rpm motors.  The two belt grinders I have in the shop right now both use 1725's.  My lower drive wheels are fabricated from 6 inch schedule 40 pipe, and the finish diameter is about 6.5".  This gives a belt speed of about 3000 SFPM.  Conventional wisdom says you should use 6000 for metal and 3000 for wood.  I've worked both mediums at both speeds, and for me, the 1725 motor giving 3000 SFPM works the best for the type of work I do.  I do use open coat belts for wood, and closed coat for metal and I do probably 10 times as much metal as I do wood on these machines.  You can see just the top of my drill grinding fixture sticking up behind the motor (in it's storage location). If there's any interest, I can install it and snap a pic.

Regards
Bob


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## 110octane (Feb 14, 2014)

bjmh46 said:


> The lamp is a Delta "retirement" lamp as they are called on the old woodworking machines forum.  I bought it new sometime in the late 70's or early 80's at a local Delta/Rockwell dealer.
> 
> The machine to the left of the belt grinder is a hand operated shear.  16ga. x 10 inch capacity. I think it's a DiAcro.
> 
> ...


Thanks!  Of course, I thought immediately that I had found a new source for an item that was made with quality.  As the tired old cliche' says:  They just don't make them like they used to.
Geoff


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## furpo (Feb 14, 2014)

We’ve always use motors of Jet water pumps.  Usually find on garage sales that have been left out side and the pump is frozen and busted.
There all 3450 RPM


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## GarageGuy (Feb 19, 2014)

3450 RPM with my 6" drive pulley will give me 5416.5 FPM belt speed.  I plan to use it primarily for metal.  If 6000 FPM is considered a good speed for metal, I'm in the ballpark.

I ran across a 1725 RPM motor, but think I might be better off waiting for a 3450 to come along.  Spring is almost here (so they say), and maybe I can find a jet pump motor once the garage sales come into season.

I like the idea of a new motor, but I don't want this to be a large $$ project.

Thank you!

GG


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## furpo (Mar 16, 2014)

*Will it blow up in my face?*

Anyone have any thoughts on why these could not be used for the wheels?
Just peal the Polyurethane off, machine a crown and adapted to your shaft!
http://www.ebay.com/itm/400180341423?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


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## uncle harry (Mar 16, 2014)

GarageGuy said:


> I'm building a belt grinder for general metal work and tool sharpening.  I have the belt pulleys made.  2" x 6" dia for the drive pulley, and 2" x 4" for the idler/adjustment pulley.  The idler pulley has Fafnir German bearings with Teflon spacers.  I'm looking for a specific motor to power it, and that is what has brought the project to a halt.  They are available new, but are very expensive, so I've been watching CL, eBay, and a couple of other auction sites hoping to snag a used one.  It is a 3/4 HP, 3450 RPM, 56C frame, 115v, TEFC housing motor.  The 56C frame has mounting holes on the shaft side flange, and that is the key to this design.  Here are a couple pictures of the design.  I like it because of it's simplicity and small footprint.  My poor garage doesn't have much space left.  This isn't mine, but mine will look very much like this:
> 
> View attachment 69798
> View attachment 69799
> ...



As a motor source possibility try "Googling" _Surplus Center_.  They have had some reasonable prices. They're in Lincoln, Nebraska.. Bunches of other stuff too.


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## Terrywerm (Mar 16, 2014)

*Re: Will it blow up in my face?*



furpo said:


> Anyone have any thoughts on why these could not be used for the wheels?
> Just peal the Polyurethane off, machine a crown and adapted to your shaft!
> http://www.ebay.com/itm/400180341423?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649




Might not be a need to remove the poly at all, and if left on, those wheels would not even need a crown machined on them, as they come with a rounded tread face when new. They may even have too much crown!

I believe they would work just fine without blowing up, but there is only one way to find out: mount one on a motor, mount the whole thing in a safe place outdoors, stretch out a long cord and plug it in from a safe distance.  I am pretty sure that the worst thing to happen would be for the poly tire to start to separate from the aluminum hub. I am pretty sure that the aluminum wheels would hold up just fine.

When I was in high school some of the guys built belt sanders using a three wheel design. All three wheels were cast in our own small foundry then turned on the lathe. They worked just fine.


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## rgray (Mar 16, 2014)

*Re: Will it blow up in my face?*



furpo said:


> Anyone have any thoughts on why these could not be used for the wheels?
> Just peal the Polyurethane off, machine a crown and adapted to your shaft!
> http://www.ebay.com/itm/400180341423?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649




I use a 6" drive wheel that I crowned the poly on. Mine has a cast iron center. I removed the bearing built an aluminum spacer to fit my shaft. A wheel already aluminum would be nicer to work with.

The 8" in the pic is also cast. I use it with it's bearing on the work end.


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## furpo (Mar 16, 2014)

I was scared the cast wheel would be to heavy!
Or:
Maybe a fly wheel would be a good thing?
Furpo


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## ScrapMetal (Mar 16, 2014)

FWIW - I did find a set of plans online for a grinder that is very similar to the one from the OP.

http://www.offroadfabnet.com/forums/showthread.php?t=4062&p=45826

Just scroll down to the plans.

-Ron


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## rgray (Mar 17, 2014)

furpo said:


> I was scared the cast wheel would be to heavy!
> Or:
> Maybe a fly wheel would be a good thing?
> Furpo



I bought from the same ebayer. I bought 3" wide is why it is cast iron I guess.
Can't tell any difference in driving wheel weight wise (I'm using 1 1/2 hp 1750rpm) I have an 8"x2" spoked with rubber (solid) that I also crowned. then the 6" in previous post and a 4" that I built out of nylon.
The big 8" idler is where you notice a difference, when you shut the machine off it turns inside the sanding belt for a couple of seconds.


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## Dino Devine (Mar 18, 2014)

Very interesting thread. I've made a copy of the KMG but am really looking into my next project which is the TW90 grinder, the tilt table does it for me. I've got several photos to work off but no measurements. Has anyone got some plans or even sketches with dimensions they can send me.

Thanks
Dino


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## GarageGuy (Apr 7, 2014)

ScrapMetal said:


> FWIW - I did find a set of plans online for a grinder that is very similar to the one from the OP.
> 
> http://www.offroadfabnet.com/forums/showthread.php?t=4062&p=45826
> 
> ...



Great find!  Thank you!  I got a new Marathon 3/4 HP, 3450 RPM electric motor, and should be moving forward soon now that the weather is warming up.  I'll post photos as I get them.  Thanks!

GG


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## Bill Gruby (Apr 8, 2014)

I looked at the plans and ask this. Is there a reason that the two pulleys are not aligned up and down? The top pulley center line is forward of the bottom pulley center line. I understand that they cannot be in a direct line but at the same time the belt should be streaght up and down. In the picture the belt is canted forward at the top pulley.

 "Billy G"


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## Bill Gruby (Apr 8, 2014)

OK -- I just finished drawing the assembly full size. In order to get the belt straight vertically using a 4" upper pulley and a 6" lower pulley, you need to change the 3" dimension center and front hole to 2 9/16" on the "Upper Wheel Mounting Rocker. Everything else can stay the same.

 "Billy G"


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