Building a 1x30 grinder

[JTknives]

After seeing travis's little 1x30 belt bevel grinder I have wanted to build one. What started me down this path was the weird motor I found in the recycle bin. At first glance it looks like a standard 1HP 3hp but further looking reviled that it's different. It says 60hz rpm 1750 then says max rpm 6000. I have not seen this on a motor befor. It also has a 6:1 gear box on the shaft and a 110v fan on the other end. It also has a built in encoder on the fan side. The 6000rpm is what got me thinking about using it for the tiny 1x30 grinder. I would strip off the gear box and keep the fan maybe and see if I could use the encoder with a vfd. So if any of you know anything about this motor that would be helpful.

My next issue is where to acquire contact and drive wheels that are 1" wide. Preferably not super pricy wheels so I can get a few for different hallow radius. I'm thinking about running it up to around 6000sfm max.

Any one build one of these or have any ideas on how to pull it off in a simple, clean and vibration free manner.
Thanks guys

 

[SpyderPhreak]

That looks like a LOT of motor for a 1x30! Overkill? I like it!

In all seriousness, why not go 1x72 with that motor? Just get a cheapy HF 1x30 bench top model for something smaller. Just a thought.

BTW, 6,000 rpm seems a bit fast. Would think the SFPM would be a bit high. The HF 1x30 is bad enough. Never seen a motor like that.

 

[mike-E]

Are there high quality 1x42 belts available? I wouldn't build a grinder around an odd ball motor. That's just my opinion though. I would build it so a belt will get around a 6" drive wheel and at least an 8" contact wheel.

 

[SpyderPhreak]

Are there high quality 1x42 belts available? I wouldn't build a grinder around an odd ball motor. That's just my opinion though. I would build it so a belt will get around a 6" drive wheel and at least an 8" contact wheel.

Absolutely there are. 1x30, 1x42, 1x72 are available in most of the popular brands/types.

 

[JTknives]

Is the harbor fright 1x30 comment a joke? I'm not looking for an entry level grinder for a few bucks. I'm looking for a high end small belt grinder to just do hallow grinds. The narrow belt makes it easyer to fallow scribe lines when running the belt backwards and using a rest under the contact wheel to set your grind height. I don't know if the 1x42 is a common size or not but I know there is quite a good selection of belts for the 1x30. I don't think 1HP is overkill considering I have 2hp on my big 2x72 and I need/want more. I would like to have around 5HP on my 2x72.

The trick will be the tracking becaus the 30" belt length is not long enough for a 3rd wheel when using larger contact wheels. I don't think the motor is an odd ball I think it's just built specifically for being ran on a VFD so thy put the max rpm its rated to go up to on the days plate. It mounts the same as any other motor. My thought is the grinder frame will bolt to the face of the motor and the motor will have around a 3-4" drive wheel. The frame will hold the tracking contraption (not sure yet how to do it) and there will be a single tool arm to hold wheels. I'm thinking The entire grinder will pivot on the base of the motor. Build a hinge type mount and then there will be a jack screw off the end of the frame close to the wheel that holds the wheel up off the table rest. You adjust this to raise or lower the contact wheel off the hard surface rest. Then you run the belt backwards and lay the knife on the rest and slide it along the belt and adjusting how deep your hallow is by lowering the contact wheel down.

 

[Randy3000]

I have taken some stuff off of motors by just cutting and prying when it looks thin enough. Be careful cutting into the pack of bearings! I dont know what grease they pack around bearings but it burns with the light of a thousand suns when a cut off wheel gets into it. All the ones i cut into anyway.

 

[JTknives]

The gear box just bolts onto the face of the motor and the shafts Are connected with a lovejoy coupling.

I have taken some stuff off of motors by just cutting and prying when it looks thin enough. Be careful cutting into the pack of bearings! I dont know what grease they pack around bearings but it burns with the light of a thousand suns when a cut off wheel gets into it. All the ones i cut into anyway.

 

[Randy3000]

I think i misinterpreted "pull it off in a simple clean vibration free..." i thought you meant pull the end off the shaft but now i think you meant pull the whole grinder project off.

 

[JTknives]

Yeah the entire build is what I meant.

 

[Tin.Man]

If I recall the mini one wuertz is using is a 1x42 or 48. Contact rubber and sunray poly and bader will make you 1” wide wheels. I don’t think an 8” will work for a 1x30 but definitely a 1x48.

His uses a high end rd motor. I think an 1/8 size.

I’ve been tinkering with making a mini grinder for a while. Industrial sewing machine motors are something I’ve played with as well. Smaller and brushless and more power for their size then the leeson and Balfour motors we are used to.

Can’t wait to see what you make.

 

[SpyderPhreak]

Is the harbor fright 1x30 comment a joke? I'm not looking for an entry level grinder for a few bucks. I'm looking for a high end small belt grinder to just do hallow grinds. The narrow belt makes it easyer to fallow scribe lines when running the belt backwards and using a rest under the contact wheel to set your grind height. I don't know if the 1x42 is a common size or not but I know there is quite a good selection of belts for the 1x30. I don't think 1HP is overkill considering I have 2hp on my big 2x72 and I need/want more. I would like to have around 5HP on my 2x72.

The trick will be the tracking becaus the 30" belt length is not long enough for a 3rd wheel when using larger contact wheels. I don't think the motor is an odd ball I think it's just built specifically for being ran on a VFD so thy put the max rpm its rated to go up to on the days plate. It mounts the same as any other motor. My thought is the grinder frame will bolt to the face of the motor and the motor will have around a 3-4" drive wheel. The frame will hold the tracking contraption (not sure yet how to do it) and there will be a single tool arm to hold wheels. I'm thinking The entire grinder will pivot on the base of the motor. Build a hinge type mount and then there will be a jack screw off the end of the frame close to the wheel that holds the wheel up off the table rest. You adjust this to raise or lower the contact wheel off the hard surface rest. Then you run the belt backwards and lay the knife on the rest and slide it along the belt and adjusting how deep your hallow is by lowering the contact wheel down.

No, I wasn't joking, but I think there's misunderstanding on both sides here. When you said 1x30 and bevels in the same post, I certainly wasn't thinking you were talking about using such a small belt for doing primary grinds. I thought you meant for smaller stuff, like clips or swedges or the like. And the admittedly cheap HF 1x30 does that job just fine in my experience.

A 30" belt definitely doesn't give you much to work with. I still think you'd be better going 1x42 or even 1x72. Good luck.

 

[JTknives]

Those 1/8 motors are spendy little suckers.

 

[mike-E]

I was just saying that it would suck to build a grinder where the Max drive wheel you could get on it with 30`` belts would be too small to get the 6000 fpm you want from a normal 1800 rpm at 2x speed. Especially if 42''belts aren't available, which it appears they are. If you build it, make it with tool pockets just like a big boy grinder. I think a miniature version of a 2x72with two 1''square pockets would be neat as hell.

 

[Lieblad]

Awesome freebie motor.
Hope nothing serious wrong with it. Encoder feedback to VFD would be great, but maybe more work than its worth.
Fwiw, 1x42 is common size belt.

 

[Geoff Flato]

Might I ask why the desire for short and expensive to run belts? Lots of people run a 1" wide contact wheel and split belts on half on their 2x72. That's the route I'm planning to take.

 

[JTknives]

I'm not really fond of the edges on split belts. I have to split belts for my little miketa hand held belt grinder and the edges are allways sketchy. I think and I am most likely wrong but my thoughts are that shorter belts will be smoother at higher SFP then longer belts. It seams like long belts can build up an osalation vibration along the long runs between the wheels. Like I said I have no proof of this it was just something I had though about. I am not the originator of this idea, travis is. But I would think with his grinder experience there is a good reasion for it.

 

[Peppie]

I admire your need to DIY. I too make many things in my shop to help a project or system work better or improve quality. But sometimes it is just better to pay the Money to get the results you are expecting to get. You save time, headache and sometimes $. Travis has invested lots and lots of R&D in his mini.

 

[JTknives]

I admire your need to DIY. I too make many things in my shop to help a project or system work better or improve quality. But sometimes it is just better to pay the Money to get the results you are expecting to get. You save time, headache and sometimes $. Travis has invested lots and lots of R&D in his mini.

It is my understanding that, that grinder is not for sale yet and was just a prototype. I would love to own one of his machines as thy are top notch. But sadly in my shop I normally don't have the thousands of dollars needed to spend on things I can make. I enjoy making every tool I own. Yes in the end I end up spending sometimes close to what it would have cost me to buy X tool but other times I come out ahead. So with that said all the tools and machines I have made have never disappointed me in there performance. Plus as my wife says building stuff keeps me out of her hair.

 

[DanF]

A 1x30 with the ability to control the belt speed would have many uses in anyone's shop.

 

[Natlek]

You adjust this to raise or lower the contact wheel off the hard surface rest. Then you run the belt backwards and lay the knife on the rest and slide it along the belt and adjusting how deep your hallow is by lowering the contact wheel down.

Why you need to complicate things ? Because Travis already do that ? Why not raise or lower grinding surface rest ? Something like this will do that perfectly or I m missing something ??

I m almost finished with second one two wheel 2X 40 belt grinder ....I like them, quiet , and scary fast