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I have plans on building a 2x72 grinder with a variable speed motor so i can both sand and grind. The problem is cost. I have two options, either use step pulleys with an AC motor or use a variable speed motor. The latter is expensive. I already have a variable speed treadmill motor but cant seem to figure out which parts i need and how to wire them to make this motor work. However, it occurred to me that i don't really need one machine to both grind and sand, i can have two different machines for these tasks. Its much easier to build a sander with the materials i have, and much cheaper to buy a belt sander too. I need to know what my needs are. Can i get by with a single speed belt grinder? What about a sander, do i need more than one speed? Please feel free to share your own sanding and grinding machines and how you use them. I have heard that using different grit sanding and grinding belts need different speeds. Is this true? What about disc sanders and grinders, how well do they work? They seem pretty easy and affordable to build or buy. I would like to sharpen tools, sand and grind parts and clean up forgings with these machines. Thanks for your input.
Reply:Others will have their own opinions but from what you describe you could get by fine with a single speed belt grinder for your needs. One machine. One speed. And a good selection of belt grits. Sent from my iPhone using Tapatalk:
Reply:I have a few different belt Sanders or grinders. A 1"x42" sander, a 2" x48" belt grinder and a 2-1/2" x 60" with a 12" disc grinder on the opposite side of the spindle. The 2x48 is homebuilt modeled after a Kalamazoo with a 1 hp 3450 rpm motor. The 2-1/2" x60 is an old Ryman that I modified the base and motor. That currently has a 1 hp 3450 rpm motor that I plan to change to a larger one which may or may not be a 3 phase motor. All are single speed and work fine as I don't use them for fine finishing work.
Reply:
Originally Posted by Lis2323
Others will have their own opinions but from what you describe you could get by fine with a single speed belt grinder for your needs. One machine. One speed. And a good selection of belt grits. Sent from my iPhone using Tapatalk
Reply:
Originally Posted by M J D
I have a few different belt Sanders or grinders. A 1"x42" sander, a 2" x48" belt grinder and a 2-1/2" x 60" with a 12" disc grinder on the opposite side of the spindle. The 2x48 is homebuilt modeled after a Kalamazoo with a 1 hp 3450 rpm motor. The 2-1/2" x60 is an old Ryman that I modified the base and motor. That currently has a 1 hp 3450 rpm motor that I plan to change to a larger one which may or may not be a 3 phase motor. All are single speed and work fine as I don't use them for fine finishing work.
Reply:I'm not gonna tell you what size belt to get, since it's all about how much space you have. The longer the belt, the longer it lasts. Wide belts are good for flat stuff, narrow belts are good for contours. My belt grinders are all fixed speed and sometimes that can be an issue. It'd be nice to be able to slow them down to sand wood.Sent from my SAMSUNG-SM-G891A using Tapatalk
Reply:
Originally Posted by 52 Ford
I'm not gonna tell you what size belt to get, since it's all about how much space you have. The longer the belt, the longer it lasts. Wide belts are good for flat stuff, narrow belts are good for contours. My belt grinders are all fixed speed and sometimes that can be an issue. It'd be nice to be able to slow them down to sand wood. Sent from my SAMSUNG-SM-G891A using Tapatalk
Reply:
Originally Posted by Need Advice
Thanks. How fine of work do you do? What is the finest grit sanding belt you use?
Reply:Also, for metal, FORGET Aluminum oxide. Buy ceramic and Silicon Carbide. The coarse ceramic belts are AWESOME. All my fine belts are SiC, never tried the ceramic belts in fine grits. I recommend buying a grinder based on availability and cost of belts. I swapped from a 1X30 fo a 1X42 recently, because the belts last longer and cost about the same.Another edit: I've been using the same set of ceramic belts on my 4" machine for over a year. On the 'ol 1X30, I'd burn up multiple aluminum oxide belts in a grinding session. SiC and Ceramic last WAY longer.Sent from my SAMSUNG-SM-G891A using TapatalkLast edited by 52 Ford; 3 Days Ago at 11:38 PM.
Reply:
Originally Posted by 52 Ford
I know this question wasn't directed at me, by on my 1X42, I use 220 up to 1000 grit. It has a 1/5HP motor which is horribly underpowered. I like the 1X42 a little slow, since I use it for finish grinding, but it aught to have at least 1/2HP. For a main grinder, I'd pick at least a 1-1/2HP motor, preferably a 2HP or maybe a bit more. I HAVE stalled the 1-1/2HP motor on my 4" belt grinder, belted to about 2,500SFM.Edit: I keep a 36, 80, or 120 grit on the 4" grinder.Sent from my SAMSUNG-SM-G891A using Tapatalk
Reply:
Originally Posted by 52 Ford
Also, for metal, FORGET Aluminum oxide. Buy ceramic and Silicon Carbide. The coarse ceramic belts are AWESOME. All my fine belts are SiC, never tried the ceramic belts in fine grits. I recommend buying a grinder based on availability and cost of belts. I swapped from a 1X30 fo a 1X42 recently, because the belts last longer and cost about the same.Another edit: I've been using the same set of ceramic belts on my 4" machine for over a year. On the 'ol 1X30, I'd burn up multiple aluminum oxide belts in a grinding session. SiC and Ceramic last WAY longer.Sent from my SAMSUNG-SM-G891A using Tapatalk
Reply:
Originally Posted by Need Advice
Thanks. How fine of work do you do? What is the finest grit sanding belt you use?
Reply:Scotchbrite belts are available also-- in three different grits. I like Klingspoor and 3M belts but there are several good manufacturers out there. Sent from my iPhone using TapatalkLast edited by Lis2323; 3 Days Ago at 11:58 PM.:
Reply:Those saw motors i have run at 3500 RPM. Is that too fast for sanding? Is it better for grinding?
Reply:
Originally Posted by Need Advice
That's ok, you can answer that question too, im looking for input. I have a 2hp motor. I also have two radial arm saw motors that i though might make good sanders, i think they are 2 or 2.5 HP but I'm not sure.. I could use those saw motors to power a belt sander, or put a disk on the saw blade side and a drum sander in the chuck on the other side for contour sanding small stuff. What do you use 1000 grit for? Do you make knives?
Reply:
Originally Posted by Need Advice
Those saw motors i have run at 3500 RPM. Is that too fast for sanding? Is it better for grinding?
Reply:5,000 sfpm is about ideal for grinding steel
Reply:
Originally Posted by M J D
5,000 sfpm is about ideal for grinding steel
Reply:
Originally Posted by 52 Ford
Google something like "SFM for belt sander". SFM being short for "Surface Feet per Minute". The RPM really doesnt matter. All has to do with the diameter of the roller that drives the belt. Think truck tires. If you have 54" tires, your first gear will go a lot faster than if you have 32" tires. Sent from my SAMSUNG-SM-G891A using Tapatalk
Reply:Don't necessarily get hung up on HPMy older single speed Burr King 482 is only 3/4 HP and I have never bogged it down. I think the newer versions are 1 HP now and available with variable speed as an option.
Keep a good selection of quality belts handy
Sent from my iPhone using Tapatalk:
Reply:My opinion is for general metal working single speed is fine. IF you can afford it and (or) you are making knives then go variable speed. IF I was a professional that did a lot of grinding I would have a dedicated 12 foot work bench with multiple (3-6?) identical variable speed machines set up with progressively finer grits. Sent from my iPhone using Tapatalk:
Reply:
Originally Posted by Lis2323
Don't necessarily get hung up on HPMy older single speed Burr King 482 is only 3/4 HP and I have never bogged it down. I think the newer versions are 1 HP now and available with variable speed as an option.
Keep a good selection of quality belts handy
Sent from my iPhone using Tapatalk
Reply:got this HF belt grinder/sander severals years ago.installed motor 1 1/2 hp....pulleys are arranged for about 2700 rpm
Reply:
Originally Posted by xmmancharl
got this HF belt grinder/sander severals years ago.installed motor 1 1/2 hp....pulleys are arranged for about 2700 rpm
Reply:
Originally Posted by Need Advice
My neighbor has an old industrial bench grinder he wants to sell for $80. He said once it gets up to speed there is no bogging it down. I thought about buying it and putting a belt grinder attachment on the side.
Originally Posted by Lis2323
Better check out the make, size and HP. The price is irrelevant without specs. 1/3HP is usually 6”. 1/2HP 7” and 3/4HP -8”. If it’s an import machine count on the stated horse power as being exaggerated. If it’s 3450 RPM it might be an okay machine if you intend to do any polishing. Just bolt on a polishing wheel Here’s the 2HP Baldor polisher I sold recently..
Sent from my iPad using Tapatalk
Reply:
Originally Posted by Lis2323
Better check out the make, size and HP. The price is irrelevant without specs. 1/3HP is usually 6”. 1/2HP 7” and 3/4HP -8”. If it’s an import machine count on the stated horse power as being exaggerated. If it’s 3450 RPM it might be an okay machine if you intend to do any polishing. Just bolt on a polishing wheel Here’s the 2HP Baldor polisher I sold recently..Sent from my iPad using Tapatalk
Reply:Then again, maybe the saw motor will be ruined by abrasive grinding wheels or buffing compounds. Maybe a saw motor is only good for cutting wood. Maybe it would make an ok wood sander, i don't know. Or maybe i could use those motors for belt driven machines if i protect the motor with a casing of some kind.
Reply:
Originally Posted by Need Advice
Then again, maybe the saw motor will be ruined by abrasive grinding wheels or buffing compounds. Maybe a saw motor is only good for cutting wood. Maybe it would make an ok wood sander, i don't know. Or maybe i could use those motors for belt driven machines if i protect the motor with a casing of some kind.
Reply:
Originally Posted by Lis2323
They will still suck in dust. Sent from my iPhone using Tapatalk
Reply:Maybe those saw motors would be ok for wire wheels. I hate to scrap them.
Reply:The 1-1/2HP motor on my 4" belt grinder is an old ODP motor off one of my bandsaws. Stays coated in abrasive swarf. So far so good. If I ever have any issues with wear, I'll just put new bearings in it.Sent from my SAMSUNG-SM-G891A using Tapatalk
Reply:
Originally Posted by 52 Ford
The 1-1/2HP motor on my 4" belt grinder is an old ODP motor off one of my bandsaws. Stays coated in abrasive swarf. So far so good. If I ever have any issues with wear, I'll just put new bearings in it.Sent from my SAMSUNG-SM-G891A using Tapatalk
Reply:
Originally Posted by Need Advice
Thanks.
Reply:
Originally Posted by 52 Ford
Of course. I just made sure the vents on the motor are facing down. Think about this - you HAVE the saw motors. You DONT HAVE a sealed (TEFC) motor. Use what ya got and swap it out down the road if it's ever a problem. I REALLY doubt it will be - for me, anyway. I didnt even bother bolting my motor down. Welded a hinge to the motor and welded that to the grinder frame. Stick welded it - not little tack welds I can cut off real quick. Sent from my SAMSUNG-SM-G891A using Tapatalk
Reply:
Originally Posted by Need Advice
My neighbor has an old industrial bench grinder he wants to sell for $80. He said once it gets up to speed there is no bogging it down. I thought about buying it and putting a belt grinder attachment on the side.
Reply:
Originally Posted by davec
It is possible it has a weak or bad start capacitor (if it even has such a thing on it given the age) if it is slow getting up to speed. That is how I read your statement above, but perhaps that is not the case...
Reply:Im considering getting one of these belt grinder attachments for a bench grinder. I can get an adjustable speed bench grinder later on down the road to replace the single speed i have now. Has anyone used this attachment? I want something that can hog away metal fast if needed. I wonder if this grinder attachment will do the job.Last edited by Need Advice; 2 Days Ago at 07:03 AM.
Reply:I can also get one of these cheap angle grinder attachments for contour grinding.
Reply:
Originally Posted by Need Advice
Im considering getting one of these belt grinder attachments for a bench grinder. I can get an adjustable speed bench grinder later on down the road to replace the single speed i have now. Has anyone used this attachment? I want something that can hog away metal fast if needed. I wonder if this grinder attachment will do the job.
Reply:
Originally Posted by Lis2323
That would get the job done but certainly not “hog away metal fast” by most definitions. Sent from my iPad using Tapatalk
Reply:I'm a big believer in having multiple grinders on hand. Just picked up an old Jet 2x48 with a 1/2hp motor and it does the job very well. I thought it might bog down like my old 1/3hp bench grinder, but it doesn't flinch a bit at what I ask of it.
While I have a 2x72 on hand, the 2x48 is nice because it's set up with a coarse belt and wire wheel to do a specific job for me. It's just for knocking off burrs and cleaning things up. I'll probably invest in some different grits of belt for it just because it's so handy to have around, but I'm happy with just using it as I do. The belts are far better than stone wheels in terms of life expectancy and how much dust they throw off, and it's really nice to not have to worry about changing from one belt to another.As I recall, Brent Bailey does much the same in his videos, with multiple grinders around the workshop for doing different things. It really is nice being able to flip a switch and get to grinding!
Reply:
Originally Posted by VaughnT
I'm a big believer in having multiple grinders on hand. Just picked up an old Jet 2x48 with a 1/2hp motor and it does the job very well. I thought it might bog down like my old 1/3hp bench grinder, but it doesn't flinch a bit at what I ask of it.While I have a 2x72 on hand, the 2x48 is nice because it's set up with a coarse belt and wire wheel to do a specific job for me. It's just for knocking off burrs and cleaning things up. I'll probably invest in some different grits of belt for it just because it's so handy to have around, but I'm happy with just using it as I do. The belts are far better than stone wheels in terms of life expectancy and how much dust they throw off, and it's really nice to not have to worry about changing from one belt to another.As I recall, Brent Bailey does much the same in his videos, with multiple grinders around the workshop for doing different things. It really is nice being able to flip a switch and get to grinding!
Reply:
Originally Posted by Need Advice
... a 2x48 belt grinder attachment for a bench grinder...
Reply:
Originally Posted by VaughnT
Scott Turner, Forme Industrious on Youtube, swears by his 2x36" Multitool grinder attachment, and you can certainly see him putting through its paces in his videos.I was thinking about getting their 2x48" version when the ol' Jet showed up on the local scene. The only caveat I'd offer about the Multitool is that it will bog down if you stick it on your average 1/3hp 6" bench grinder. Certainly better than nothing, and I highly recommend them for folks that are just starting out. They are orders of magnitude better than using stone wheels or woodworking sanders. If Scott can use his to do all that building, there's no doubt in my mind they are a good tool.
Reply:
Originally Posted by Need Advice
The only thing i don't like...
Reply:
Originally Posted by VaughnT
Everything's a trade off. Brent Bailey has one of his grinders mounted to a wall stud so it's vertical all the time. Takes up no space, yet is right there when he needs it.No tool rest? Make one. You're getting into this so you can learn some stuff, so make designing a tool rest the first thing you try to cobble together. Or, if you're like me, don't worry about it and get to making other stuff. They are handy for when you're making a knife, but they certainly aren't absolutely necessary and I still don't have one after all these years. The Multitool attachment will get you well down the road, lots of projects under your belt. There are a ton of videos on youtube that show you how to fabricate your own grinder from nothing. You can make them out of lumber if that's all you have. There are good and bad in every design, so don't let perfection be the enemy of good enough. I'm the world's worst at that, so take a lesson from me and just get something going so you have something going. As you learn about using one of them, you'll learn things that you just can't learn any other way than by using the grinder for awhile. Heck, when I built my 2x72 with my dad, I thought it was perfect and I'd never need anything else. Two weeks after that, when I had some grinding time to judge things by, I found a dozen things I'd change if I could do it all over again. Never would have guessed at any of that before I had the 2x72, and that's one of the reasons why I started hunting for a second grinder.
Reply:
Originally Posted by Need Advice
old radial arm saw motor i have but the belt would spin the wrong
Reply:
Originally Posted by 52 Ford
LOL! I forgot about this till you said that. The motor on my 4" grinder spins backwards. I just unhooked the starter winding and start it by hand. Never been an issue. I put my hand on the belt and drag it about a foot down the platen and it spools up. If I cut it on and don't start it, it'll trip the breaker on the power strip it's on. It REALLY isn't a problem. Takes about a second (maybe two) to start it. I thought about adding a pull start from a small engine, just because it'd be kinda funny.Sent from my SAMSUNG-SM-G891A using Tapatalk
Reply:I'm not sure about this statement "There are good and bad in every design, so don't let perfection be the enemy of good enough."If you are building a tool for yourself to have for sometime to come, do it right. There is not shame in making changes to make it better.Now to the grinder I built a 2" X 60" belt grinder (maybe 1985) and used the heck out of it. It was simple 2-- 6" wheels and a vertical platen 2 HP motor loved it did great. About 2 years ago I moved to a 2" X 72" belt grinder, these things are so flexible, they have many grinding possibilities. Being able to adjust the angle of the grind and different optional attachments allows then to fit into many projects start to finish. I understand not everybody can afford or have the time to build one but if you do you will be happy you did. This is the Jeremy Schmidt design, I did make a few changes, I did CNC Plasma cut the custom shaped parts.
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DIY CNC Plasma table USB BOB Price THCHypertherm 65Everlast PowerTig 255 EXTMiler 180 Mig13" metal latheMill/ DrillECT, ECT, |
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发表于 2021-9-23 23:26:57