Results 1 to 9 of 9

Thread: New grinder

  1. #1
    Join Date
    Sep 2013
    Location
    Wayland, MA
    Posts
    3,655

    New grinder

    I think my el cheapo Sears grinder that I've used for the last 30+ years has earned its retirement, so I'm in the market for a new one. The Sears is a 6" grinder (much closer to 4.5" at the moment, "1/2 HP" (whatever 1970's Sears horsepower translates to), 3450 rpm, the motor sticks out a long way relative to the wheels, so I keep hitting it when trying to do any sort of angled grind. I long since sawed off the useless stamped steel tool supports and use it with third party supports, mostly a first generation Wolverine.

    This will be used 98% for turning tools, occasionally a mower blade or such. I have different sharpening systems for planes and chisels.

    So, what to get? Conventional wisdom would suggest an 1800 rpm 8" grinder, but lots of folks seem to think with modern steels there is no reason not to go 3450. I'd like a grinder that came equipped with wheels I didn't have to immediately replace. How big a motor? I've never felt like the 1/2 hp Sears was underpowered, but mostly I see people using 1 hp grinders. I'm inclined to go for the lower speed just because I have trouble taking off only the minimum amount of metal requires with the 6" wheels, and 8" at 3450 will be ~twice as fast.

    The Rikon appears to be pretty reasonable with good quality wheels. Many pro turners on YouTube appear to use one from Steel City. Baldor would be a no-brainer, but I hope I don't have to spend $900. in the end, does it matter? Will the 1 hp rikon bring me a lot more joy than the 1/2 HP Rikon, for example.

    Then there is the question of CBN wheels. Are they a lot better than Norton Al Oxide wheels? I've read a number of dire warnings about using them to grind lower grade steels ruining them. That would be bad. What is their primary advantage? I certainly wouldn't want wheels that ground any faster than the aluminum oxide ones I have now.

    Your wisdom on this will be appreciated.
    Last edited by roger wiegand; 12-01-2017 at 4:39 PM. Reason: typos

  2. If you get the Rikon, definitely get the 1hp model. I think it is made to better specs and has better bearings than the 1/2 hp model. I have the Steel City industrial model, and it is smooth indeed, but I hear Steel City is now gone out of business, but if you can find one, I would not hesitate with purchasing the industrial model.....it has premium bearings and industrial rated motor, and has been great with my two CBN wheels. It does come with wheel balancers already installed, and grey stone wheels.
    Remember, in a moments time, everything can change!

    Vision - not just seeing what is, but seeing what can be!




  3. #3
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    12,298
    Quote Originally Posted by roger wiegand View Post
    Then there is the question of CBN wheels. Are they a lot better than Norton Al Oxide wheels? I've read a number of dire warnings about using them to grind lower grade steels ruining them. That would be bad. What is their primary advantage? I certainly wouldn't want wheels that ground any faster than the aluminum oxide ones I have now.
    Roger,

    Some people have reported the Rikon 1/2hp is slow to start up with two heavy steel CBN wheels. I have one with an aluminum CBN and a polishing wheel and it does seem underpowered. I also have a Rikon 1hp and the old Woodcraft NoName grinder and both are far more capable and appear better made. I have two CBN wheels on one. All three grinders are 1/2 speed. The slower speed will probably give you more time to grind and not waste as much steel.

    The grinding wheels that come with the Rikon are either OK or junk, depending on what you happen to get. My opinion, but I'm real picky.

    I was a long time holdout on switching to CBN compared to some, mostly because of the cost. They are a lot cheaper now. I currently use four, one on a Tormek.

    I would hate to have to give up the CBN. They cut better than the oxide wheels, even the good Norton wheels I used for years. They never need truing. They never change diameter. They never need balancing. I had to run the Oneway balancing system on even the best Norton wheels. They are reported to grind with less heat but I didn't put thermocouples on a tool and do a comparison. They definitely create fewer sparks. The CBN wheels do not have the hazard of shattering so most people run them without the guards on the grinder.

    You do have to avoid grinding mild steel but no reasonable lathe tools are made of mild steel. You can grind hardened tool steel just fine. Sharpening HSS and the higher end powder metal tools are great with CBN. I keep two grinders with AlOx wheels, a good one for grinding in my weld shop and a cheaper one in the wood area for occasional grinding of non-hardened steel.

    Reed Gray wrote a bit about CBN that might be worth reading: http://www.robohippy.net/featured-article/

    I buy from WoodTurner's Wonders since Ken carries aluminum wheels. CBN wheels are available with radiused edges, with square corners, or either with 1" flat down either side. I like the non-radiused with the side grit.

    JKJ

  4. #4
    I have 2 Baldor grinders, and if you have the money, they are pretty much the best you can buy. I think Doug Thompson has a Dayton high speed grinder that is a real work horse. I also have the 1 hp Rikon. It isn't as fine as the Baldor grinders, but for the money, you get comparable performance, though they are a bit louder. The wheels that came with it are junk, about 1/8 inch of run out, and I wouldn't give them to some one I didn't like. I took the rubber feet off and the base was very uneven. I had to grind about 1/8 inch of metal off of one of the feet to get it to sit flat on plywood. I have my grinders on plywood for taking them with me when I demo. The light is junk too, and I took it off.

    The CBN wheels can grind anything from bench chisels and up, with no problems. The softer carbon steel tools, aluminum, brass and copper can load the wheel up. I always use some lapping fluid (I think just about any light oil will work) on the bevels of my tools before I sharpen. If you do get some soft metal build up on the wheels, most of the time, some lapping fluid and a good heavy scraper sharpening will take care of it. It may take a couple of sharpenings. Yes, I have done it on purpose. I would keep one old standard wheel just in case you want to sharpen some thing else. I used to say get an 80 and 180 grit wheel, which was pretty much all that was available. I get comparable burrs on my scrapers with both the 80 and 180 grit wheels. I also have a 600 and 1000 grit wheels, and use the 600 more than the 1000. The really fine wheels give a really nice edge for fine finish cuts, but a lousy edge for any heavy roughing. Don't know about the grits under them (320, and 400 I think). They do cost a bit more, but you get a wheel that is spin and bubble balanced that won't wear out for most people, and there is no risk of them ever blowing up. Kind of like variable speed on your lathe, once you have it, you never want to go back.

    robo hippy

  5. #5
    Join Date
    Jul 2005
    Location
    Cincinnati Ohio
    Posts
    4,731
    I have the WEN brand variable speed grinder. Got it at Walmart dot com last summer for around $80. I don't have much time working with it yet but seems to be a very solid unit.

    "Remember back in the day, when things were made by hand, and people took pride in their work?"
    - Rick Dale

  6. #6
    Join Date
    Nov 2006
    Location
    Erie, PA
    Posts
    564
    I have the big Delta (which isn't made anymore) with two 1 1/2 " CBN wheels. This is my personal grinder which only I use. I have the 1/2 hp Rikon with two 1" CBN wheels which out of the box has run better than any grinder I have set up. Is it a little under powered, probably but you don't need a lot of power for CBN wheels as they cut so well with little pressure. The third grinder is a Woodcraft with stones for roughing in tools. All of these are slow speed grinders

  7. #7
    Join Date
    Sep 2013
    Location
    Wayland, MA
    Posts
    3,655
    Thanks all! Sounds like the 1hp Rikon might be the best current choice for me. Plus looking hard at a CBN wheel. Perhaps this morninh there wil be a Baldor on Craigslist that I can pick up reasonably! (Ever the optimist)

  8. #8
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    12,298
    Quote Originally Posted by roger wiegand View Post
    Thanks all! Sounds like the 1hp Rikon might be the best current choice for me. Plus looking hard at a CBN wheel. Perhaps this morninh there wil be a Baldor on Craigslist that I can pick up reasonably! (Ever the optimist)
    If you can find a 3-phase Baldor, put a VFD on it and have a fantastic variable speed grinder.

  9. #9
    Get a dedicated grinder for turning, and then a cheap angle grinder from HF for the mower blades. Was given a cheap Chicago brand angle grinder 20 yrs ago, and it has sharpened mower blades, ground off hundreds of rusted fast nuts and bolts, and with a cup brush, helped derust several pieces off farm equipment. Best $10 gift I ever got.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •