Home Built 2x72 Belt Grinder Finished

[tdriack]

I recently finished building my 2x72 belt grinder and wanted to share some pics. 

First off - this has to be the most rewarding tool I have ever built! The uses are endless - I wish I had made one numerous years ago.

I used mainly scrap pieces of square tubing I had around in 3", 2 1/2", and 2" of  various wall thickness to save on the cost. Due to that fact - The grinder is fairly stout and overbuilt a little - but it works like a dream.

It uses a 1.5 hp motor wired for 110v. Four postions on the pulleys for various speeds. All of the wheels were purchased on Ebay - and although the price of everything did slowly sneak up on me - It was still way cheaper than buying a professionally built machine. The base of the stand is two pieces bolted - so it can be disassembled and transported in a car very easily.

I have been doing some knife work with the grinder mostly since I finished it, and have several other attachments in the works and a few other rests I'm testing out. Any input you could give me on design ideas would be appreciated.

[Crazy Ivan]

Very nice work, that looks store bought even! Well done! 

[Buzzkill]

Looks better than my home built 2x72 by a decent margin.  The only question I have is regarding putting it on wheels.  Even with locking casters you can sometimes get a little movement.  Has that been any problem for you when you lean into it?

I lied.  I have a second question.  Have you used it long enough to determine if 1.5 hp is enough?  I used 1hp on mine and 4 step pulleys like you have but I can stall it pretty easily in the fastest arrangement so I'm thinking of bumping up to 2 hp.

[tdriack]

When I built the grinder, my primary concern was portability (since I'm sure you can see from the pics I'm a tad tight for room - lol). Without the casters locked movement is a problem - once they are locked and the wheels set straight and parallel to the front of the grinding wheels, movement hasn't been an issue. The small foot has two threaded adjustable feet that do a good job of anchoring that end to the concrete floor with friction - probably due to the weight of the grinder with all the attachments in place. It is heavy to move but manageable. My plan was if movement was a big issue, I'd make two wooden block feet - one for each wheel side that were just a little higher than the wheel height, and tip the grinder side to side so I could insert the wood blocks and lift the wheels off the floor - so far this hasn't been an issue.

I did a lot of research and spent a ton of time pondering how I wanted to build this so I wouldn't need to do it twice (start to finish - probably a year of time on and off when I could).

I read a lot of links on motors. In my opinion - the 1.5 hp motor works very well - 1 hp seemed too small from my research. My motor is a 1.5 hp continuous duty agricultural motor from Harbor Freight. I chose this motor over the Harbor Freight 2 hp motor - because the 2 hp wasn't rated for continuous duty and the reviews were poor. I know some guys will probably give me flack for this stores motor - but - I was trying to build the grinder on a budget - and that was the best option I could find at the time for the price. Now that I have swallowed the initial cost of building the grinder - if this motor fails - I'll aim to get a higher quality one as a replacement - but as of now - the motor has worked perfectly with no complaints to speak of. It is possible to bog down my grinder when I lean on a piece of work at the fastest pulley arrangement - but I have never stalled it. One day I had it plugged into a 15a outlet and was leaning on a piece of work hard enough to pop the breaker and had to reset it - it never stalled - if that is any indication of the 1.5 hp motor ability. I use a 20a receptacle for the machine now whenever possible and have had no issues since ( also note - the on/off switch is rated for 20a). Usually I use the second step / speed with very little bog down ever - and can remove enough metal to make me think in my head "slow down - don't wreck this project by removing too much!" In general, My mindset is not to bog down the machine - go a little slower if necessary and baby my new toy. Not to mention the cost of belts ...... I baby those too!

The biggest limitation I placed on my motor choice was my current choice for shop power - it has to run on a 120v 15- 20 amp outlet for versatility in my shop - and if I ever want to take it on the road to a friends place. The 1.5 hp motor wired for 115v does this nicely. I guess if you have the ability to power a 2 hp motor with your shops circuitry go with a 2 hp - the price difference between a 1.5 and 2 isn't that big of a jump. I would have had to probably set my grinder up for 220v if I went with the 2 hp - and that would have put a real limitation on I where I could move it around and use it since my only shop receptacle for 220v is at my welder. 

I hope that helps....

[Buzzkill]

Thanks for the response.  I too was building on a budget and I managed to get the 1hp agricultural motor from HF for under $100 and the only other motors they had at the time were compressor duty so I thought I'd try it.  Now I think I'll get a 2 hp from WayneCoe and move the 1hp to an old table saw whose motor quit on me a while ago. 

I went so far as to make a wooden drive wheel which was a bit of a challenge without a lathe, but it works.  I also used skateboard wheels and bearings for the flat platen and tracking, but I can't really recommend that.  I've only had to replace one set of bearings and I do like the way the steel feels on the wheels when I do direct grinding, but it's just not heavy duty enough for long term use.

I also tripped the breaker on mine once before I realized the lights and another outlet, which was powering halogen work lights at the time, were on the same circuit.  It's an uneasy feeling when everything goes dark and you have to try to remember where everything was between you and the door or breaker box. Now I use a different circuit.  I also only have a single 220v circuit which my buzz box Lincoln is plugged into, but since I'll never be using both appliances at the same time I will probably go the 220v route on the next motor.

I tried babying the belts some, but it didn't seem to pay off for me.  I've read on here to use the belts as if they are free and replace them as needed.  From my limited experience I have to agree.  I wasted more time and effort trying to get a little more life out of a belt than if I had just switched to a new belt, and if I was trying to grind too lightly to "save" the belt life again I would end up wasting too much time to justify it.  YMMV.  I do keep partially worn belts to start grinds that would strip a lot of abrasive off a new belt and I hang on to some broken belts that have life left to use like emery cloth for handle shaping and such, but in general for me it works best to use 'em hard and toss them when they stop cutting well.

[Forging Carver]

Nice work! How much did the entire grinder cost you? I wanna make my own grinder but I have to figure out a general amount that it will cost me. I am thinking that the steel can be free, and I would just need the motor and wheels. I know the wheels cost about $150 on eBay and the motor is $100, at least from harbor freight that is. Thanks

[tdriack]

If you go with your own metal and welding you can save a lot. That being said, I would still have to say it will cost you at least 350-400$ being realistic. Wheels, motor, pulley sheaves, shaft, bearings, belt..... etc. If you decide to get rubber contact wheels, small diameter wheels and holder... etc --> easily double that. I see that ebay has new nylon wheels for way less than aluminum - But I'm skeptical on their long term use and on the belt tracking properly.

All I can say is -- the 2x72 grinder is one of the most rewarding tools I have built - If I had known how useful it was --- for stuff beyond blacksmith and knife making -- like woodworking - I would have built mine much faster than I did. It's a very impressive tool! 

[rhitee93]

Nice looking grinder!  I run mine on a 1HP with a VFD, and it is certainly under powered.  However, I have some power limitations in my shop and have blow the breaker a couple of times as it is.  I also have some grinding skill limitations so it may be just as well I don't have extra HP capacity at this time

Regarding babying the belts:  Some belts, especially the high performance ceramic ones will go dull faster if you don't use enough pressure.  The belts will last a long time when used correctly, but that requires enough pressure to keep the ceramic particles fracturing as they wear.  Otherwise they get rounded over and become useless.   If you start using the Blaze type of belts, and I recommend you do, you have to lean into them pretty good to keep them cutting.