Buffer RPM questions

I've been looking through a lot of the buffer threads that I can find and am thinking of getting one. I have one question about them though. Is there a big difference between the 3000ish RPM buffers and the 1800ish ones? The reason I ask is that it seems that it would be much safer to work with a lower RPM, but I don't actually know for sure.
Another reason I ask is that I haven't been able to find a buffer online that's relatively cheap (around 100 dollars or less) that has a lower RPM. The only ones with RPMs below 3000 that I saw were Baldors, and those cost 300 something dollars if I remember correctly.
I know Glen uses the Harbor Freight ones which are very cheap, so maybe he can add any info about working with higher RPM ones. And I saw Brad's restoration videos and he uses a modified grinder which seems to go to lower RPMs. I was thinking of going that route, but didn't know if there were any disadvantages to it. I remember a thread Glen posted about grinders being hard to work on because the distance between the wheel and the motor is small, but Brad's seemed to be pretty good from what I could tell.

Any answers to any of the many questions above would be greatly appreciated.

I use a HF buffer, and I just make sure to constantly check and let the blade cool down. so far I have not had any problems (a lower rpm would probably be easier though), but I use a fairly light touch, and I am always checking the heat. You can get the steel hot enough in your hand to give you a burn with a blister though... especially when buffing small areas like tangs etc. And it can get hot quicker than you think it would, so pace yourself and check often.

IMHO I think you'll appreciate a buffer more than a modified grinder because the clearance issue can really hamper you... sometimes my HF buffer seems like it needs more clearance really :shrug:

Those are my thoughts anyway

Dave

Go with one rated at 1700-1800. Reasoning is simply because of the heat that is generated with polishing & cleaning up a blade. Don't want to ruin that wonderful temper. If you've watched Undream's video's, you will notice that he states he leaves his on the slowest setting...with a Delta, I think it's around 1750 free wheeling speed. Glen has a handful of buffers if I remember the shop pic, don't know the speed of them though.

I've been looking for a 8" 3/4-1 hp in the 1700-1800 speed on the cheap myself. Please post or PM me if you find something under $100, most I have found at the department/home improvement stores are in the $125-150 range.
Scott

This is going to get complicated but here goes,,,

More important than rpm is surface speed,,,

A few people on here have done the math in threads Icedog/Brad did a great one...

What this means is that a smaller wheel going faster actually has a slower surface speed then a larger wheel going slower...

Grinders normally can't use the smaller wheels the walls get in the way, that is what I meant...And keep in mind there are different ones out there with different designs....

The best there is out there, is a variable 1100 -3500 Buffer but yes they are expensive...

A lower speed Buffer is next best at 1100 or 1725
or a variable speed Grinder motor like Brad has using bigger wheels this is another option...

I use the 3450,s but I use 4 inch wheels... Keep in mind I don't use the smaller wheels because of the speed, I use them because I can get into the Hollow grinds better...

The enemy here is heat if you can keep the heat down everything else is a moot point...
With a lower speed you can use more pressure than you can with a higher speed
of the SAME size... BUT is more pressure better??? or just faster??

For polish I use a 1725 I just haven't been able to get the right effect with a higher speed....

Another option is what Floppyshoes uses which is a variable speed Lathe with the buffer wheel attachment...

There are many paths to shine, and that was a ton of stuff I posted so go through it and think about it all..
But keep in mind it is all about heat and heat build up....

Quote:

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Originally Posted by gssixgun

What this means is that a smaller wheel going faster actually has a slower surface speed then a larger wheel going slower...

But keep in mind it is all about heat and heat build up....

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Oh yeah.. forgot to mention that I don't really ever use any wheel sizes over 6" and the 4" is probably my go to. thanks for jogging my memory Glen, it does make a difference.

So if I'm shooting for something that is as small as possible (don't have a huge space for it), that will be less likely to overheat my blades, and that is most cost effective, the lower speed buffers with smaller wheels seem to be my best bet, right?
Has anyone found any low speed buffers that are close to 100 dollars? The Baldors are unfortunately way out of my range at the moment.

+1 on Glen with surface speeds. Here is a link to Caswell plating and it addresses most of the items you should consider when choosing a buffer/grinder. RPM's plays into it but only as part of an equation.

Introduction To Buffing and Polishing - Caswell Inc.

Horsepower !!!

I forgot that, now two schools of thought here too,

Over 1/2 HP
More power = less strain on the motor = less motor heat up = longer lasting motor...


My theory; and that is all it is
1/2 HP or less, because we are buffing razors, not engine parts, it is light duty work, and I have always had more of an irrational fear of that wheel grabbing my sleeve or my hand somehow, and breaking every bone in it, then I ever have of burning out a motor... or even cutting myself...
Feel free to disagree..

Quote:

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Originally Posted by gssixgun

Horsepower !!!

I forgot that, now two schools of thought here too,

Over 1/2 HP
More power = less strain on the motor = less motor heat up = longer lasting motor...


My theory; and that is all it is
1/2 HP or less, because we are buffing razors, not engine parts, it is light duty work, and I have always had more of an irrational fear of that wheel grabbing my sleeve or my hand somehow, and breaking every bone in it, then I ever have of burning out a motor... or even cutting myself...
Feel free to disagree..

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Are buffers with more horsepower more likely to destroy your hand if it gets caught? I'm really new to any power tool/motor related things, so I apologize if this is a stupid question.

To me, as Glen says, heat is really what you have to watch out for and particularly when using greaseless compounds. I tend to use the 4 inch wheels mainly with the greaseless and will only use it with either an 1800 rpm or 1100 rpm and even here you need to be very careful with the heat as you can burn up a blade pretty easily. I normally use 6 inch wheels with my 3600 rpm buffer and this motor gets used more with my emery or quick cutting buffing compounds. I am very careful of the heat here too. For the medium polishing compounds to the rouges, I use the 1100 or 1800 for the results I like the best.

Buffing like everything else in our sport takes some practice and experimentation. There is also that personal preference thing again that comes into play with your comfort.

Safety is also a very large concern here and should not be taken lightly.

Have fun,

Lynn

Here's a link I posted a year ago explaining the SFM.

I'll copy and paste it here for easy reference

****
I actually just wanted to bring this thread back to life as I always read so many good tips and talks about the polishing and buffing.

It seems I never hear talk of the 'Surface Feet Per Minute' or SFM. If followed properly you can calculate the ideal dia of the wheel to be used for a particular material.

SFM relates to the distance in feet that the workpiece surface or cutting edge travels in one minute.

There's a simple math formula for this.

SFM = 1/4 of the wheels's diameter * arbor speed.

The ideal SFM for Stainless Steel is around 8000 sf/min. Plastics go from 1200 to 4000 sf/min.

When buffing with speeds over 5000 sf/min you get into 'molecule migration' territory. In short, molecules start to move around and this is what cause the heat generation which can become to excessive.

For example If you are using a 3600rpm polisher, by using a 10" wheel = 1/4 of 10 inches = 2.5 inches * 3600 = 9000 SFM.
A little high. It could pass but by chosing an 8" wheel it becomes (2 inches x 3600rpm) 7200 SFM. It's lower but it could work too.

Now you con easily use an 8" wheel on an 1800 RPM polisher = equals 3600 SFM. It's far from the 8000 needed for steel. Difference is it will take you much much longer to get the desired result but at a safer usage.

Off course no one says you need to follow this procedure but it can give you an easy and rough estimate as to what wheel to use.

***

I have an 1100, 1850 and 3600 RPM and use them all.

Thank you to everyone that has been helping me as I try to make a decision on this.

To Max and Lynn, would you guys mind sharing what buffers you're using in the lower (1100/1800) RPM range?

1100-Caswell 3/4 hp
1800-Baldor 1/3 and 3/4 hp

Have fun,

Lynn

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Originally Posted by heirkb

Thank you to everyone that has been helping me as I try to make a decision on this.

To Max and Lynn, would you guys mind sharing what buffers you're using in the lower (1100/1800) RPM range?

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Quote:

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Originally Posted by heirkb

Thank you to everyone that has been helping me as I try to make a decision on this.

To Max and Lynn, would you guys mind sharing what buffers you're using in the lower (1100/1800) RPM range?

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I'm a sucker for Baldor, mainly because these buffers truly are workhorses for me so they need to perform daily, Baldor really stand behind their motors and other products, it's US made and it's a proven brand. The 1100rpm is a made in China buffer from Caswell that works really well.

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Originally Posted by Lynn

1100-Caswell 3/4 hp
1800-Baldor 1/3 and 3/4 hp

Have fun,

Lynn

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Quote:

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Originally Posted by Maximilian

I'm a sucker for Baldor, mainly because these buffers truly are workhorses for me so they need to perform daily, Baldor really stand behind their motors and other products, it's US made and it's a proven brand. The 1100rpm is a made in China buffer from Caswell that works really well.

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Does the 3/4 HP concern either of you on your buffers? I'm going to wait to hear back from Glen on why he doesn't like high HP, but was wondering what you guys think.

The higher HP will only come to your benefit once you start throwing 10" and higher wheels on those buffers.

On my 1/2HP baldor I can still use an 8" wheel comfortably but feel that if I use a bit to much pressure it slows down. Not by much and it's not really an issue but I have no problems whatsoever with a 6" wheel or smaller. Once I use an 8" wheel on the 3/4HP Baldor I can't get the damn wheel to slow down no matter how much pressure I put on the wheel. lol

4" and 6" wheels is what I use.

Besides the HP, torque would be the second most important thing to look for. A buffer will have more torque then those grinder/buffers they sell. Also many cheat with the HP they list as it's mostly the peak HP they use as a selling gimmick. Ther's always a reason why there will be a difference between a $350 buffer or a $85.00 one.

I too have been looking for a buffer and saw Brads resto vids and he uses a varialbe speed grinder seen here Delta GR450 8" Variable Speed Grinder with Tool-less Quick Change | ToolBarn.com any thoughts if its a good one, it seems to work for him. Not too bad on the price either, do you think this would be a good starting buffer?

Quote:

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Originally Posted by heirkb

Are buffers with more horsepower more likely to destroy your hand if it gets caught? I'm really new to any power tool/motor related things, so I apologize if this is a stupid question.

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:) You missed the key word "Irrational" I won't wear cut proof gloves for the same reason, the thought of the wheel grabbing them, scares me way more than getting cut...

And yes the higher HP and Torque can hurt ya more, I can stop any of my wheels with just a bit to much pressure, and I am good with that...

Myself right now I am thinking of an 1100 rpm one just for plastic/acrylic polishing...

Quote:

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Originally Posted by gssixgun

:) You missed the key word "Irrational" I won't wear cut proof gloves for the same reason, the thought of the wheel grabbing them, scares me way more than getting cut...

And yes the higher HP and Torque can hurt ya more, I can stop any of my wheels with just a bit to much pressure, and I am good with that...

Myself right now I am thinking of an 1100 rpm one just for plastic/acrylic polishing...

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Just as a note, I have been getting good results for plastic and acrylic with the tumbler.

Quote:

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Originally Posted by thewatermark

I too have been looking for a buffer and saw Brads resto vids and he uses a varialbe speed grinder seen here Delta GR450 8" Variable Speed Grinder with Tool-less Quick Change | ToolBarn.com any thoughts if its a good one, it seems to work for him. Not too bad on the price either, do you think this would be a good starting buffer?

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I think that if I were to get this, I'd just pay the extra forty bucks and get the Caswell 1100 (or was it 1800? I forget now). It seems that having a buffer so that I don't have to worry about hitting the motor and whatnot would be a safer bet for me.

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Originally Posted by Muirtach

Just as a note, I have been getting good results for plastic and acrylic with the tumbler.

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Wow I would have never thought of that, gonna give it a try Thanks....Corncob I assume???

I am new to buffers, I got the 1/4 hp 1800 rpm Baldor and can say its just perfect for a newby. You do not want to go into the 3650 rpm ones until you have good deal of experience with something slower, the wheels will grab the blade and spin it down so fast that you would have next to zero time to react at those speeds.
I quickly learned to hold the blade at the right wheel position so it does not get caught (for me its slightly above the horizontal level of the diameter of the wheel). Heat generation is not only dependent on the SFM but the pressure you apply on the wheel with the blade, the more pressure the more heat. For me I do not get a lot of heat on greaseless, and I am sure because I apply a little bit less pressure than what would be optimal judging by my current results. On polishing compounds on the contrary I get a lot of heat because of more pressure. As many already stated above its all about experimentation what works and how to do it.
The Baldor I use is not big by the way ~15" from wheel to wheel so it does not take too much space, if you have to use shaft extenders then it becomes more space consuming but they can be mounted/dismounted fast and easy. I find the extenders very useful especially with 4" wheels.

Quote:

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Originally Posted by gssixgun

Wow I would have never thought of that, gonna give it a try Thanks....Corncob I assume???

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I've been using it just like a blade progression, but with less time. I've been getting pretty good results from just an overnight run. Also working quite well on CA finished woods (corn seems a bit too soft for initial runs, need to hit the walnut first for sure) and the horn I tumbled last night came out great as well.

On the Safety related note, while I have not yet gotten into the razor resto process, I have worked plenty on grinders.

basic rules apply!

1) TAKE OFF ALL JEWELRY! no rings, no bracelets, no necklaces.

2) SNUG FITTING clothing only! no loose sleeves, no wide collar gloves, and great googly moogely, TAKE OFF THAT TIE!

3) SAFETY GLASSES! and no, your eye glasses dont cut it! unless they are made of saftey glass. Otherwise the lenses will become embeded with fine grit, and you will be replacing them before you know it.

4) Long Haired hippy freak? (like myself) TIE YOUR HAIR BACK! preferably use a hair net to keep it well contained. Ever see a guy get his hair caught in moving parts? it aint pretty!

I wont get into the actually usage of the grinder/buffer. This is just the obvious stuff, which often gets overlooked.

Good luck kids!

I actually like the 3/4 hp with the 1100 and 1800 rpm. The reason is that this is where I do most of my polish work and I can put a fair amount of pressure on the wheel if I want to and it definitely will not be slowing down, but its really not going that fast where I worry about overheating as quickly. I can feel the metal get warm and do occasionally have to dunk in water when using the 1800 rpm. I use a lighter touch on the higher speed 3600 on the 1/2 hp motor when I am using the more cutting compounds. This gets hottest the quickest and I am dunking all the time after just a few seconds. The 1100 rpm works very nicely on acrylics for me.

Lot of personal preference here.

Lynn

I think it's all about knowing how to use what you have or can lay your hands on...or that's how I understand what the "go to" guys have said.

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Originally Posted by shooter74743

I think it's all about knowing how to use what you have or can lay your hands on...or that's how I understand what the "go to" guys have said.

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Now that I've reread Max's post, it does seem to me that I could get away with a 3450 RPM buffer if I use smaller wheels like 4 inch and 6 inch ones.
I did the rough calculations for the SMF and it comes out to be, respectively, 3450 smf/min and 5175 smf/min.

On the other hand, if most of you are using lower RPM buffers with smaller wheels, the SMF you're working at is much lower than 3450 even. It'd be in the 1800 to low two thousands.

One other question I have is if lower RPMs are better for the final polish as opposed to the earlier stages. Glen already said that he finds that they are, and I inferred it from Lynn's post that he uses lower RPMs for his final polish, but I just wanted to make sure that I'm not just inferring randomly.

For you guys up north around the NJ area, please check this buffer out...he won't ship by the way, I tried before bidding. Grizzly 1750 rpm 1 1/2 hp buffer, less than 24 hrs left, last check it's at $15.00: Grizzly Heavy Duty / Buffer / Grinder / Unused Mint ! - eBay (item 170462740128 end time Mar-24-10 20:02:14 PDT)

If someone wins it, I deserve at least a thank you...Talk about a score...

Quote:

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Originally Posted by shooter74743

For you guys up north around the NJ area, please check this buffer out...he won't ship by the way, I tried before bidding. Grizzly 1750 rpm 1 1/2 hp buffer, less than 24 hrs left, last check it's at $15.00: Grizzly Heavy Duty / Buffer / Grinder / Unused Mint ! - eBay (item 170462740128 end time Mar-24-10 20:02:14 PDT)

If someone wins it, I deserve at least a thank you...Talk about a score...

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Woah! Thank you big time on this. I will definitely try to get this one if it doesn't skyrocket in price.

Quote:

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Originally Posted by heirkb

Now that I've reread Max's post, it does seem to me that I could get away with a 3450 RPM buffer if I use smaller wheels like 4 inch and 6 inch ones.
I did the rough calculations for the SMF and it comes out to be, respectively, 3450 smf/min and 5175 smf/min.

On the other hand, if most of you are using lower RPM buffers with smaller wheels, the SMF you're working at is much lower than 3450 even. It'd be in the 1800 to low two thousands.

One other question I have is if lower RPMs are better for the final polish as opposed to the earlier stages. Glen already said that he finds that they are, and I inferred it from Lynn's post that he uses lower RPMs for his final polish, but I just wanted to make sure that I'm not just inferring randomly.

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I also fine that the lower SFM gives a better polish. I'm sure that there are other techniques that can give the same results at a higher surface speed. Be sure to check the Caswell link I posted to this thread earlier for the best 'Cut' and 'polish' methods.

Here is another option for a variable speed buffer. Takes more work but.....

http://straightrazorpalace.com/forge...fer-setup.html

The first pic is what I am referring to.

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Originally Posted by Joed

I also fine that the lower SFM gives a better polish. I'm sure that there are other techniques that can give the same results at a higher surface speed. Be sure to check the Caswell link I posted to this thread earlier for the best 'Cut' and 'polish' methods.

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Thanks Joe. I read through that once, but I will make sure to refer back to it a few times so as to retain the info.

The reason I use a variable Delta is completely about price. It is the cheapest ~1750rpm motor you can buy, basically (I think I paid $115 for it), and, I do occaisionally dial it up to 3400 for certain things, which is nice.

I just wanted to clear it up that if money were no object, i wouldn't recommend it. Obviously baldor or caswell would be preferred.

Also, as Glen has mentioned, the motor gets in the way when using 4" wheels, I have to move my wheel to the other side in order to do the other side of the blade. Pretty big annoyance, costs me a few minutes overall. 3" or 2" wheels are impossible to use on it.

For 6" & 8" wheels though, it works great, no clearance issues with the motor. 8" wheel @ 1750 is too fast though, IMO. you really need an 1100rpm buffer if you want to use 8" or 10" wheels for greaseless.

I really like about 2500sf/m for greaseless. I dial up my 4" wheels to about 2400rpm to acheive that speed, and run my 6" wheels at 1750rpm...which yields ~2650sf/m.

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Originally Posted by Undream

The reason I use a variable Delta is completely about price. It is the cheapest ~1750rpm motor you can buy, basically (I think I paid $115 for it), and, I do occaisionally dial it up to 3400 for certain things, which is nice.

I just wanted to clear it up that if money were no object, i wouldn't recommend it. Obviously baldor or caswell would be preferred.

Also, as Glen has mentioned, the motor gets in the way when using 4" wheels, I have to move my wheel to the other side in order to do the other side of the blade. Pretty big annoyance, costs me a few minutes overall. 3" or 2" wheels are impossible to use on it.

For 6" & 8" wheels though, it works great, no clearance issues with the motor. 8" wheel @ 1750 is too fast though, IMO. you really need an 1100rpm buffer if you want to use 8" or 10" wheels for greaseless.

I really like about 2500sf/m for greaseless. I dial up my 4" wheels to about 2400rpm to acheive that speed, and run my 6" wheels at 1750rpm...which yields ~2650sf/m.

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Thanks for your input Brad. I'm probably going to go with the Caswell 1100 buffer since it's not that much more than what I've been able to find the Delta at. It's much slower than other wheels, which means I'll have to spend more time on it, I think, but I prefer that to something that's quicker but more likely to cause damage.

Quote:

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Originally Posted by heirkb

Thanks for your input Brad. I'm probably going to go with the Caswell 1100 buffer since it's not that much more than what I've been able to find the Delta at. It's much slower than other wheels, which means I'll have to spend more time on it, I think, but I prefer that to something that's quicker but more likely to cause damage.

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or use bigger wheels if you can fit and feel comfortable with for higher SFM speeds.

I have read through this old post and have a question.

According to what i read 8000 SF/m is optimal for steel buffing but other than faster work(getting more done faster) does it hurt anything to go REAL slow like 200 RPM using 4 inch buffing wheels? I am not going to do the math but that would be real low SF/m if i were to use greasless compound and go 200 RPM using my mini lathe for safety reasons would it produce bad results or just take forever? Which i dont mind...

I played around tonight and chucked up a 2" x 1.5" rubber sanding drum in the mini lathe. And had good results tonight cleaning up a razor. I made my own sanding drums, by wrapping them in tape(sticky side out) then wrapping in wet dry paper i went from 120grit to 600grit and due to the very slow speed my paper never tore off. It was in my opinion easier and faster than hand sanding. And almost as safe...for clearence i just reversed the direction and worked on the other side of the drum. As i said it was slow enough i felt safe doing this.

I had the idea to try out some 2" or 3" or 4" buffing wheels and using greasless compounds chucked up in the mini lathe at 200rpm. I can't think any reason it won't work other than taking forever...
Pleaee offer up any opinions you have...

Ken rupkalvis told me about a thing you can put on it to lower or raise your rpm's

Sidmind,
Using the low speeds like 200rpm is where the sandpaper will shine. Use it up to at least 2k. You will be amazed how shiny your restored blade looks. Then you can take some rouge to a fresh wheel and finish it off to a nice and mirrored polish.

Quote:

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Originally Posted by shooter74743

Sidmind,
Using the low speeds like 200rpm is where the sandpaper will shine. Use it up to at least 2k. You will be amazed how shiny your restored blade looks. Then you can take some rouge to a fresh wheel and finish it off to a nice and mirrored polish.

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I did that for years. there is a thread about it in the workshop somewhere.
I had a very cheap low rpm grinder with a 4" wheel. I just mounted strips of sandpaper on the wheel using double sided tape.
Work your way up to 2000 grit and the surface will be unbelievably smooth and shiny. From there you can finish with a bit of polishing compound.

It sounds like I should just skip my idea of spending all the money on greasless compounds and 4 inch buffing wheels, and stick to what I have around already.

I like it only I need to design some drums that are softer and slightly larger, the 2 inch diameter was just slightly smaller than the hollow grind radius, I think I can build some new drums out of wood and rubber tubing or something, then chuck them up in the mini lathe between the live center, and have plenty room on each side.

hmmmm... now I have to start designing something.