Choosing the most appropriate grinder for this job

[justinpeer]

Hi all,

I've been an occasional hobby woodworker for years but for the past decade or so, I've mostly just been fixing things and making stuff around the farm rather than doing more interesting or fine woodwork. I have a modest workshop and my sharpening gear has been a diamond plate and stones, a King 1000 grit and Norton 4K and 8K, with a Nagura stone and leather strop, shown below, which has worked for my occasional use and modest collection of chisels and plane irons.

A little while ago, a friend's father passed away and I was gifted his old Coronet Major Lathe with accessories and a box of turning tools and an old combination bench grinder. I've built a stand for the lathe now but it needs some proper clean up and rust removal. I have new belts for it as the old ones are well past they're best. I should add that I've no experience turning anything yet.

The grinder had no rest and the water wheel wasn't really much use. I picked up the veritas tool rest and bought a new white wheel for the high speed side but, despite hours of YouTube research and experimentation, it still doesn't balance that well. I decided that I'll probably use it as a rough grinder in the garage and, if I can get an adapter made to fit, convert the slow speed side to high speed as well and that can be used for cleaning up old vehicle parts etc as I'm rebuilding an old MX5.

Given the amount of cleanup and sharpening ahead, I decided I need a proper grinder and, after more research I think I've decided to get a grinder with CBN wheels (probably one to start with and another as funds allow) which should do both woodworking and turning tools, much inspired by @Derek Cohen (Perth Oz)

So, grinders then. Slow speed seems the most suitable option and the options seem to be the Axminster grinder at £210 plus the cost of wheels at £140-£170 each so about £370 if I go with a single 180wheel and add a second later. Then there's the Dictum with a 180grit wheel included at €400 or Hope Woodturning with their grinder and a CBN wheel at £385.

The Dictum and Hope grinders are 400w (½HP) whereas the Axminster is 900w (1HP) and I'm wondering if that's really going to make a big difference and if anyone has suggestions either on an alternative grinder in the same price range or whether any of these are significantly better than the other in quality. I've had an eBay search open for Creusen grinders for months with nothing coming up, not helped by being down in Devon when anything that does come up always seems to be collection only from the north.

I should add that I did look at the linisher options from Sorby and Axminster but they're even more expensive and I like that with the CBN wheels I basically don't have to replace them ever given the level of use I'm likely to have.

Be grateful for your thoughts.

 

[Phil Pascoe]

Fix that grinder down and fix a block of wood in front of it, devising a way of clamping a devil stone to block so it just touches the wheel. Switch it on and if you just a hear the devil stone touch the wheel once every revolution, leave it run until there's no noise. Adjust the devil stone again so it just touches the high spot, and keep doing it until the wheel is round. You must fix the devil stone down, you will not get the stone round/balanced trying to do it freehand - the dresser just rides the highs and lows.

 

[Duncan A]

https://www.shentonwoodcraft.co.uk were selling a slow speed 8" grinder with CBN wheels at Daventry Woodworks recently. Price seemed quite good but there's nothing on his website at present - about £500 for the grinder and two CBN's I think.
He sells his own sharpening jigs; somewhat cheaper than the big names.
The grinder spun up with two CBN's quickly without fuss whereas high speed grinders of similar power (400/500W) tend to struggle with two CBN's.
The Axi 900W jobbies will be fine as well of course!

Bear in mind that CBN wheels are good for HSS sharpening, but some people say they may clog up on carbon steel tools - which many of those tools in your picture may well be. No idea whether this is actually a problem or not, I'd recommend asking potential suppliers or asking the gestalt mind on here.
Duncan

 

[Inspector]

I would pull the white wheel off and run the grinder without anything on the shafts to see if it is still unbalanced and takes a while to slow to a stop when switched off. If it takes a while to slow to a stop the bearings are good. If it runs smooth then the wheel needs to be dressed. Unless the shaft is badly bent it should run smoothly.

I also agree with Duncan A's assessment of the lathe tools being carbon steel in which case the white wheel will be better than the CBNs until you upgrade the tools to HSS.

Pete

 

[justinpeer]

Fix that grinder down and fix a block of wood in front of it, devising a way of clamping a devil stone to block so it just touches the wheel. Switch it on and if you just a hear the devil stone touch the wheel once every revolution, leave it run until there's no noise. Adjust the devil stone again so it just touches the high spot, and keep doing it until the wheel is round. You must fix the devil stone down, you will not get the stone round/balanced trying to do it freehand - the dresser just rides the highs and lows.

Thanks, I'll give that a try when I have some time to make something suitable.

 

[justinpeer]

https://www.shentonwoodcraft.co.uk were selling a slow speed 8" grinder with CBN wheels at Daventry Woodworks recently. Price seemed quite good but there's nothing on his website at present - about £500 for the grinder and two CBN's I think.
He sells his own sharpening jigs; somewhat cheaper than the big names.
The grinder spun up with two CBN's quickly without fuss whereas high speed grinders of similar power (400/500W) tend to struggle with two CBN's.
The Axi 900W jobbies will be fine as well of course!

I'll take a look at them, thanks.

Bear in mind that CBN wheels are good for HSS sharpening, but some people say they may clog up on carbon steel tools - which many of those tools in your picture may well be. No idea whether this is actually a problem or not, I'd recommend asking potential suppliers or asking the gestalt mind on here.
Duncan

Been doing some reading on this and most of what I've read say that tool steel seems to be fine but not regular mild steel etc. I was assuming, perhaps incorrectly, that any turning tools would have been made using tool steel similar to chisels and plane blades which seem to be fine to sharpen on CBN wheels. I'll ask a couple of retailers and see what they say. Thanks for raising the issue.

 

[Duncan A]

I'll take a look at them, thanks.

Been doing some reading on this and most of what I've read say that tool steel seems to be fine but not regular mild steel etc. I was assuming, perhaps incorrectly, that any turning tools would have been made using tool steel similar to chisels and plane blades which seem to be fine to sharpen on CBN wheels. I'll ask a couple of retailers and see what they say. Thanks for raising the issue.

That makes sense.
I did read somewhere that anything above Rockwell hardness 45 should be OK but that was a very old post. Also came across a comment that a dirty or clogged wheel would clean itself through normal use over time - and there are cleaning stones of course.

 

[justinpeer]

doing more research and have found mention that using a hard steel on a loaded can wheel is a good way to clean it. Also, found this reference from early last year to issues with Axminster slow speed grinder and their can wheels where they apparently say they've got problems with all their stock not being able to be balanced properly.

https://www.model-engineer.co.uk/forums/topic/slow-speed-grinder/page/2/#post-631822

No idea if they've got that solved yet but doesn't bode well for their quality control. Be interested to hear if anyone on here has had similar issues.