2x72" grinder help?

[postleg]

I'm collecting for a sander build also. I happen to notice at work the maintance dept was throwing out some brand new stand up fork lift wheels. I got 3 3 x 6 in. And 3 3x3 in wheels. They are very heavy steel with a hard rubber tire fused to them. Buying them fo 15 cents a lb so if they don't work I won't be out much. Do you see any problem with using a 2 in wide belt on a 3 in wheel? My thought is as long As it tracks straight I' don't see where the extra wheel width would cause a problem.

[Steve Sells]

to avoid the rubber rubbing off on the work, you CAN buy 3 inch belts...

[knots]

I'm collecting for a sander build also. I happen to notice at work the maintance dept was throwing out some brand new stand up fork lift wheels. I got 3 3 x 6 in. And 3 3x3 in wheels. They are very heavy steel with a hard rubber tire fused to them. Buying them fo 15 cents a lb so if they don't work I won't be out much. Do you see any problem with using a 2 in wide belt on a 3 in wheel? My thought is as long As it tracks straight I' don't see where the extra wheel width would cause a problem.

 

If you have access to a metal lathe they could be turned to 2" width.  I don't know about company policy but  where you work, but it sounds like there would be a machine shop .

 

Alternatively careful application of a metal cutting saw and a file could result in an accurate trim to size.  

[Steve Sells]

good point there Knots.... too obvious for me to see .. DOH...

[postleg]

Great point. That never even occurred to me. I have a 9 in Southbend lathe in my shop. Duh

[knots]

The amazing thing about building such tools as your grinder is that, considering the $3600 price tag for a new commercial grinder, you could buy a nice South Bend lathe and all of the parts and pieces and build your own and still have money left over.    Not to mention having the lathe and grinder.  

[Everything Mac]

Mac, a friend is using roller skate wheels.  Thanks for the idea on the skateboard wheels.  For a contact wheel I've heard of using a lawnmower wheel, haven't tried it myself.  Still in the planning stage.

You need to use "old school" long board wheels apparently.

Currently waiting on a new pcb for my welder which has broken down. It's put a real spanner in the works with regards to a few projects I had going! Luckily it's under warrantee still.

[gerald brostek]

 

The amazing thing about building such tools as your grinder is that, considering the $3600 price tag for a new commercial grinder, you could buy a nice South Bend lathe and all of the parts and pieces and build your own and still have money left over.    Not to mention having the lathe and grinder.

 Your right. I could have,and saved some money, but I could afford it, and now I have a top of the line machine with 5 different size wheels, 4 additional attachments, and I am using it instead of building it. my dicision to buy was based on the fact that I could afford it and needed it Now.

[knots]

 
 Your right. I could have,and saved some money, but I could afford it, and now I have a top of the line machine with 5 different size wheels, 4 additional attachments, and I am using it instead of building it. my dicision to buy was based on the fact that I could afford it and needed it Now.

 

I can't argue that point.  If it is more cost efficient to purchase a new fine machine, then by all means buy it.  For most of us serious part timers, making a tool is as rewarding as making anything else.  But that is a different case.

 

I bought my Wilton back in 1992.  My shop, at that time was not adequate for a fabrication project ( I was in a rental house) but I needed the grinder so I bought mine.  If I were acquireing another today I would build it  simply for the pleasure of building it.  But then I am not in a position  where I need to be productive .    Also a metal lathe is a basic part of kit for anyone who makes their own tools.  So I would suggest that getting one anyway that you can is a good idea if you are really serious about tooling.  

[Dan C]

I'm planning on building this one next week, finally have enough pennies saved up.

 

Shank Knives How to Build a Belt Grinder, How to Make Your Own Custom Homemade 2x72 Belt grinder Plans - Shank*Knives

 

I wanted to build the mobi-dick 2x72 seen in this thread,

plans for building your own belt sander - Pirate4x4.Com : 4x4 and Off-Road Forum

but without at least some basic dimensions, ie. tooling arm and no spare time for experimenting I'm going with the shank knife plan whose frame I might be able to make from cut-offs.

[petere76]

DC,

In regard design, consider the (2) pivoting points of contact design. By buying the two Beaumont machine wheels and arranging the two to pivot, you get a lot of versatility. The fixed one position arrangements are stout but they limit your options. Look at the no weld design and work off that concept. You ate still working inside of the 72 in limits so there are only so many ways you can go.

You can easily beef up the components and weld them together. The only draw back on tubing is that you have to hand file the interior seam to make everything work. If you are faced with this procedure, weld a handle on each end of the file so you can get some decent leverage. This technique will save you some time and minimize the aggravation. I have a 72 in (welded) in the shop and it works great, very versatile. The belts do the work but the surfaces ( 2 rounds and the flat platen) are central to the processing different shapes. You will use the flats all the time to square different pieces.

Good luck.

Peter

[Dan C]

Thanks for the suggestion Peter, saw this a little late as I've cut and welded most of the frame.  I don't know what you mean with the 2 pivoting points of contact.  Here's where I'm currently at on the grinder.  Unfortunately finishing it is going to have to wait as my wife needs foot surgery, the money for the motor, wheels & pulley's is going to pay for the deductible.  At least I've had some recent requests for things, so once those are completed I should be back on track. 

 

[petere76]

Dcraven,

Sorry to hear about your wife's difficulty. Spare cash always an issue when you have med bills rolling in. Certainly hope all goes well for you guys.

The two points of contact I mentioned. The no weld design has 1 large and 1small contact wheel. They stretch the belt across the platen. The tubing with the wheels on either end rotates on a central pivot. Thus you have 3 position options, the flat platen with the wheels above and below. Or, either the small or large wheel protruding.

We built ten of these units at the NESM with Dereck Glazer in the summer of 2012. They utilized 1.5 HP 120/220 V 60 Hz mtrs to keep the cost reasonable.

I will try and take some pics in the shop today so you can see the pivoting wheel arrangement.

Peter

[petere76]

D Craven,

Pics are in IFI under the title 2x72 belt sander build. Not sure how to copy the internal link but its a quick search.

Peter

[Dan C]

Thanks Peter your description makes sense now.  I was planning on using different size wheels for the platen like what's shown in the mobi-dick youtube video though initially I want to get setup w/ a 10" contact wheel to do a hollow grind with.  I'm told treadmill motors work well so I'm keeping my eyes open for one, and any wheel alternatives.  I did buy all the nuts & bolts needed prior to learning about the needed surgery, so I can make some progress there.

[yahoo2]

Instructables DC treadmill motor drive

[Steve Sells]

love this guy Cacho509.  after the article clearly states dangers and says having a basic understanding of electricity is needed to build electrical things has the audiacity to ask what to do with the black red white and green wire... hmm, I hear the sound of IQ POINTS FALLING, I fear for the continuation of the human race as a sepcies

[Dan C]

LMAO, yes after reading that disclaimer and Cacho509's comment, it sounds like he is going to eliminate himself from the gene pool.

[L Smith]

I loved the one about the guy worrying about his pig burning in thirty seconds! The other guy is toast by now and it didn't take thirty seconds!

[Dodge]

If you have access to a metal lathe they could be turned to 2" width.  I don't know about company policy but  where you work, but it sounds like there would be a machine shop .

 

Alternatively careful application of a metal cutting saw and a file could result in an accurate trim to size.  

 

I turned my idler rollers on my harbor freight 7 x 10 mini lathe.

 

[Dodge]

love this guy Cacho509.  after the article clearly states dangers and says having a basic understanding of electricity is needed to build electrical things has the audiacity to ask what to do with the black red white and green wire... hmm, I hear the sound of IQ POINTS FALLING, I fear for the continuation of the human race as a sepcies

 

 

LMAO, yes after reading that disclaimer and Cacho509's comment, it sounds like he is going to eliminate himself from the gene pool.

 

Well, at least he asked the question ("only dumb question is one that is not asked") and didn't try the trial and error method. ZZZZZAP!! ;)

[David Gaddis]

ELECTRICITY
It makes great excitement for the Trial and Error community.

And it reduces things that can be reduced....like ego....finger prints....hair

[Dan C]

Yesterday I picked up a treadmill on CL for $20.  The seller said the walking belt slips but did show me that it ran and you could adjust the speed.  Looked almost too nice to scavenge, almost...  Got it home and took out the motor a PM DC P/N M-215392, 1.75 HP cont. duty.  I'm planning on using the controller that came with the treadmill and a 5k ohm potentiometer.  I assume I need to put the control board in a vented metal box to protect it from dust. 

 

 

I'm wondering about the motor not being enclosed, though as many treadmills showup in garage sales and CL maybe shouldn't be concerned, just replace as needed.  What about leaving the fan and flywheel on?  Keeping the flywheel would mean I could cut a groove in the pulley to drive the belt vs. buying a pulley, anyone see a problem doing so?  For at least a few weeks my budget for this project is at zero now due to my wife's surgery.  Does the motor need the fan for cooling or is that just going to increase the amount of dust that goes into the motor?  Not sure which is going to shorten it's life sooner.  On the Shank Knives website the pictures show the flywheel and fan removed with a shield over the motor, maybe that's my answer.

 

I assume when hooking up the potentiometer that the blue wire, which the schematics show as 0-4k ohm speed pwm is the wiper on the pot.  Then the outer connectors are ground & power, depending on which way you plan on turning it to increase speed.

[yahoo2]

It looks like I should have read the link I posted right to the end before I posted it. I apologize,

There is a difference between between analog controllers and ones with a digital console and I assumed he had posted solutions for both types.

 

What you have is a MC2100 controller and the blue wire does regulate the the motor speed BUT it needs a specific signal type to do it (a variable duty cycle square wave pulsing at 50 milliseconds). It is not that difficult to build but it certainly isn't for beginners in electronics. I had a quick look on the web, I couldn't find an obvious commercial prebuilt kit conversion in the USA. The only ones I see throw the digital controller board away and replace it with a controller from KB Electronics or Baldor.

 

For a first try the best controller to start with is the MC-60. it is on the most basic old treadmills and I would be surprised If they are not obtainable for free but as always there is a chance that it has been cooked.

it is a straight conversion with a single turn linear pot.

old slider control panel on an analog treadmill console.

[Dan C]

Thanks, that confirms what an electrical engineering friend at work was trying to tell me,  I'll either do what you're suggesting by finding an MC-60 or see if he'll build it for me, he likes doing that sort of thing.  I found this link late yesterday and it looks easy enough if you had experience and the right tools. 

 

http://sonsofinvention.wordpress.com/2013/05/22/an-update-and-simplification-of-the-original-mc-2100-pwm-circuit/

 

No rush anyway as I still have to come up with wheels.