home built belt grinder 2x72

[M.G.]

I feel bad that I've been such a ghost around here lately, the last half a year has been way super busy, and full of projects. I will get you guys caught up a little bit here, with a focus on a 6 month journey that has been a thought egg for years. 

Back in June of last year I had come to a realization that, the time had come in my creative process to fulfill a tooling need. Always an exciting prospect that I'm sure everyone here understands. As well as you are likely familiar with, the struggle and time old question that comes hand in hand with that excitement. "Do I build or buy?" 

 Well...the fact that I myself am quite a frugal maker, and I have a strange attraction to the world of digital marketplace type things. The answer came to me while scrolling the place of market and having a cup of coffee. Just listed, near me, like literally around the corner from my workshop. A used Baldor 1.5hp TEFC electric motor. It has been on an older belt driven lathe that was being sent to scrap. And the price was too good to pass it up. So I ran out after I finished my cup and snatched it up. 

Now I was faced with the fact that I would need to build a grinder from and by scratch and by scrap. With minimal machines at my disposal I would be free handing most of the build. But I knew the precision in the build would need to come into play with hole alignment and squareness. So I guess I would be adding another new tool to the workshop as well. Oh bummer, it was time to buy a standing drill press. (Found one quite readily on the faceplacemarketbook).  But as far as cutting was concerned, I would have to use my 4 1/2 in. grinder and cut off disks. As well as grinding disks and a wire wheel. 

I knew I would need to build some telescoping tube sections, as well as a frame and some plates for motor mounts, tooling and wheel attachments, as well as a platten and D plate. It's a small list as far as raw material goes really, so I was on my way to the local scrap yard to see what the had on offer this week.  

I was able to come up with a bit of 1/2" plate, some 1/4" plate, and a bit of 1/4 wall square tube in 1 1/2" and 2".

I would also need to track down some wheels, these I decided to go the rout of bought not built. (Maybe I'll end up with a lathe some day, but it wasn't in the budget for this build.) I picked up a CNC machined aluminum set. With a 5" drive wheel, and domed tracking wheel. As well as wheels for the D plate. It was a really exciting day when that package arrived! 

I mean dang! I now had a 2"x72" belt grinder. This is great! I thought as I set the box on the pile of raw materials on the shop floor...... Where they,      would. SIT................ For nearly 3 months without more than a fever dreams nightmare throughout the weeks as life took over....

As the summer hotted up, and house projects and responsibilities took over my immediate attention I took some time to sketch up and revise some plans, as well took some time to really dive in to see and analyze how other grinders were being built in all ends and corners of the internet. Then returning to my sketches and making revisions and changes, which continued up to and throughout the build process, and there will likely continue to be modifications and upgrades to the grinder as it is used and as I need more tooling. 

As my wife and I finally wrapped up the biggest and most pressing project at the house and the summer was quickly drawing to a close, I got some downtime that I was able to translate to some up time in the workshop. I needed to fulfill an order for a custom hammer, so I would fire up the forge and spend a couple days breaking down squaring up some bar stock from truck axles to make a few heads from. While I was waiting on heats I prepared most of the stock material for the grinder and started mocking up the frame and tower. 

At this time I needed to remove the interior weld beed of all of the 2" square tubing that would need to accept some 1.5" tube as tooling arm or work wrest components. I did this with hand files and patience. I worked on it any time I had 10 minutes to kill. It took days. And days. And days. 

The progress was but fleeting, and life takes over yet again for another couple months, while I study and prepare for, and test and obtain a few structural welding certifications, to add to my arsenal of skills in my workshop.

After I wrapped up with my certification training and testing, I finally had a small block of a couple weeks before the holidays, to really put in the time and effort in the workshop to finish fabricating all the components for the 2x72. 

At this stage everything that would need to be welded or telescopic got a nice long bath in white vinegar to strip all the Mill scale and rust from the scrapyard. Just over 24 hours and most of it brushes right off.  

WIth everything clean and prepped it was now time for the dance of squares and clamps, as I fought with the table and clamping positions trying to get each piece fixtured and fit up. It was time for welding. Time for the fun. I got the frame the receiver and the tracking tower all welded up. After some grinding and rewelding, I decided to take a break from all the fab and welding. I needed, I wanted to do some hot work from the forge. So I took a day to hammer out a handle to release tension from the tracking wheel during belt changes. Then forged a piece of leaf spring into a flat platten face plate that could be heat treated to resist wear.

Now I was ready to mock up fitment and alignment of all the components and wheels. After a bit of fiddling around with alignment, I could mock up the motor placement and mounting alignment. When I was happy with how all of this important nonsense looked, I drilled and tapped the motor mounting plate. Then got the baseplate and motor mount welded to the frame of the machine. 

At this point we are almost caught up to the present, the new year celebrations were about to get started all across town, there were drinks to be had and hats to be worn. But not before I wrapped my creation in the warm embrace. I mean what was I to do, just let her sit there in the nude to shiver and rust?  

It is time to do the final take down and prep for paint. Meticulously stripping hardware from components and tossing it in a number of hardware store baggies with secret codes and costs scribbled on their faces scattered across my "workbench", amongst dirty tools, bottles and jars of who knows what and the reminanc of projects past. Then got to work giving everything to be painted a solid wire wheeling, and acetone wipe down.  

I was able to get a few coats of automotive primer on everything that was to be painted, just as night set in.

The next day I was able to get everything painted up and ready to assemble.

This morning was final assembly and tracking system, drive wheel and motor alignment tuning. In running the belt by hand the alignment seems pretty spot on, and the tracking controls the belt from side to side across the platten easily. 

I still need to decide on if I am going to invest in a VFD for total control. Or if I will take the frugal route and opt for just a power switch. Once I decide, and get it installed. I will report back with final results and a running machine. 

I hope everybody is doing well, and I hope you all I enjoyed the build thread. Once I wrap up this project I will try and be more active in sharing more blacksmith related work again, and more productivity.

[Frosty]

That's quite the story M.G. I can see why it took so long to build. Just a couple questions, why didn't you use a hacksaw to cut the sq. tubing and the disk grinder to true it up? You ARE going to turn the grinding belt the right direction before using it aren't you? Running it backwards like that can cause a seam failure and slap the crap out of the operator.

Frosty The Lucky.

[M.G.]

Good eye Frosty! I will be sure to run belts in the correct direction for operation purposes. I was running the belt by hand back and forth to get everything tracking properly. I am still a couple weeks from having it running on its own power. I still need to order some controls and a power cable before I can call it done.

I probably could have used a hacksaw to cut the tubing, and it would have been more cost efficient and less messy, but in all honesty, the Hacksaw is probably my least favorite tool in any shop. And I treat it as more of a last resort/ life saver only when it is the only tool for the job. Otherwise I would be more likely to use a sawzall. But the cut off wheels did me okish enough to get the job done.

 Thanks for checking out the build, hope you are doing well Frosty!

[Irondragon Forge ClayWorks]

I would say ya done good on your build. It looks like it would be comparable to the KMG we bought and I bet it cost less (not counting your time of course).

I have never been able to cut a straight line with a hand held hack saw. One of the first machines I got for my birthday 40 years ago is the horizontal/vertical metal cutting band saw. A floor drill press was next. I did manage with my wife's help to build 3 of the 4 forges in the blacksmith shop.

 

I can't control the wind, all I can do is adjust my sail’s.~ Semper Paratus

[Frosty]

I can't not see things like that, I mean how many arrows were pointing the wrong direction in plain sight?

No comment on people who can't cut a straight line with a hack saw. 

Frosty The Lucky.

 

[M.G.]

Thanks Irondragon, it's been pretty satisfying to get to this point. And if I'm honest, it's was cheap for the most part. 

75. Motor

100. steel

200 ish on hardware and disposables for the project. 

90. Maybe for the wheels. 

I won't count the drill press, it will pay for its self. But it was only 100 bucks.

So my guess is right around 550 all said n done. 

Considering I still need a control switch and some wiring. 

And I will not be counting the time invested towards cost, it was not tracked effectively.

 

And a horizontal band saw is definitely on my list of tools to keep an eye out for good deals on.

[Frosty]

I don't see a tracking adjustment, where is it? Hand turning the belt tracks very differently than running it. You have to fine adjust tracking with it running and it's common to need fine adjustment depending on humidity. 

Frosty The Lucky.

[Buzzkill]

There is a hinge on the tension arm idler pulley mount.

 

If you are using a 5 inch drive wheel you may find you can stall the motor, but probably only if you're being aggressive with it.  You can always drop down to a 4 inch if that happens.  Otherwise it looks like a good build to me, and I think you'll wonder how you got on without one for so long.

As far as a VFD goes, I do recommend them.  Being frugal as well, I went with a cheap chinese one I got online.  However, those are not designed to operate in the environment that exists around a grinder.  If you buy one of those make sure it is rated for at least 50% more hp than you plan to use, and build an enclosure to keep all the dust and abrasives out of it.   It has to be large enough for the heat to dissipate or you have to have heat sinks exposed to the outside air if you will be using it for long.

FWIW, mine is still functioning more than 5 years later.  However, when/if I need to replace the VFD I'll probably go with the NEMA rated version that was designed for that type of environment.

 

[M.G.]

That's correct Buzzkill. The I made the tracking hinge from half inch plate that I drilled and cut corresponding notches from the drilled end and used a long stainless bolt and locking nut and a few washers n a shim to tighten up my sloppy hinge. There is also a tiny bit of adjustment in the mounting of the hinge that allows for wheel alignment adjustments to be made as needed.

Also I appreciate the input from experience. And I already assume that I will end up running this at its limits pretty quickly and will be wanting to upgrade the motor and add the VFD at that point. 

I hardly got by with out having a belt grinder in the shop. But I'll be honest, besides not wanting to spend the money, I kind of hate grinding for the most part. It's a super messy part of the job so I avoid it where I can, and spend a lot of time getting to know the limits of my patience with hand files. But really I mostly do forgings that require very limited grinding, lots of hammers. A bit of ornamental work and hardware. But I've always wanted to have one. And have used them in the past, so I knew what I was missing out on, but just kept working as I could. 

The remainder of my electrical components should be here next week then I'll get to test it out and see how it really runs.

[Mike BR]

We'll have to teach you to make a hinge 

Of course, my simple 2-wheel grinder uses a door hinge I won at a raffle . . .

[JHCC]

17 hours ago, M.G. said:

I already assume that I will end up running this at its limits pretty quickly and will be wanting to upgrade the motor and add the VFD at that point. 

I hardly got by with out having a belt grinder in the shop.

Regarding the first, I've been running my 2x90 grinder on a 1 HP TEFC motor for six years, and so long as the belt is sharp, I have yet to exceed the motor's capacity. Given that, the big advantage of the VFD is control over the belt speed, especially in finer grits.

Regarding the second, you will be astonished at how useful they are to have around. It's like a welder or a drill press: one of those machines that expands the capacity of your shop disproportionately to its size.

[Buzzkill]

Without knowing the surface feet per minute of belt travel it's hard to do an apples to apples comparison though.  For instance, if your drive wheel is 3 inches in diameter, that would produce a much lower number than his 5 inch drive wheel.  It may be significantly harder to stall your 1 hp motor than his 1.5 hp motor in that scenario.  If your motor is rated around 1800 rpm, and his is a 3600 rpm motor that would also change things significantly.

 

[M.G.]

The motor for this build is

1.5 hp, 1750 RPM, and I have a 5 in drive wheel.

This puts the belt at 2289 sf/m

 

 

And MikeBR

I know how to forge several styles of hinges, I've even done up some quite large strap hinges for my 200+ lbs shop doors. I just didn't feel like a forged hinge was the way I wanted to go here, so I went fabricated instead. 

That being said, I'm always interested in learning a new way to do things, so I'm all ears.

[Buzzkill]

Is your motor single phase or 3 phase?   The reason I ask is I don't think a VFD will work on a single phase motor, but I'm not 100% sure.

It looks like there is a box for a capacitor, which would mean single phase, but I've learned not to assume too much.  I've been wrong too many times.   1.5 hp is the typical cutoff point for 110v circuits as well, which also points to a single phase motor.

[Mike BR]

I was just reacting because that sounds like an inefficient way to build a hinge — to get the full benefit of 1/2” leaves, you’d probably want a 3/4” pin. But come to think of it, there’s no harm in building the vibration damper into the hinge . . . 

[M.G.]

Single phase, Buzzkill. 

I think you are correct, I would need a 3 phase motor to run a VFD.

Also, I took this opportunity as motivation to equip my workshop with a 220v 40a power source. In doing so, allowed me to set up the grinder to run on 220v and to ots full in this configuration. 

So I guess that brings us to the completion of the 2x72 grinder build. And an update for Frosty, the tracking runs true and allows for manipulation of the belt across the width of the flat platten.

I couldn't be more pleased with how this project has come together. And I am looking forward to running this as part of my daily kit in the workshop.

I may pop back in here in a few days with some clips of the machine in action if I can.