Low speed grinders advice please.

[Sturdee]

Currently I have a Seppach 8" wet wheel grinder with the Tormek jigs for sharpening my wood turning tools as well as a homemade grinder for shaping using 8 " white wheel powered by an old washing machine motor.

I'm thinking of upgrading the homemade grinder to a low speed model.

I can find an Axminster 8 " wheel and a Creusen 6 " wheel unit.

Does anyone have either and can give me some advice and is an 6 " wheel suitable for shaping with Tormek jigs and then sharpening on an 8 " wheel.


Peter.

[Groggy]

Peter, Derek Cohen (I am pretty sure) has a 8" slow speed grinder and a Tormek. He also has an attachment to allow use of the Tormek jigs on the grinder, it seems like a sensible setup.

[Big Shed]

Peter, I have an 10" Scheppach wet grinder like yours, using Tormek jigs. I use the same Tormek jigs on a homemade rest similar to the Tormek BGM-100 on my 8" (fast) dry grinder.

This works well for me. I had originally planned to buy the Carbatec 8" slow grinder, but when I went to Carbatec and asked them to switch it on, it had so much vibration that I declined.

Haven't bothered since as my existing combination works fine for both shaping and sharpening.

[mic-d]

Hi Peter, I have a Carbatec slow speed 8" grinder and it has problems with wheel availability. Here is a link (http://www.woodworkforums.com/f65/slow-speed-bench-grinder-127725/#post1242920) to the specific post detailing the problem. I'd be checking any you buy to make sure they are standardised.

[derekcohen]

I have the 8" Carba-tec half-speed grinder and a 10" Tormek. Shoertly after getting the 8" I changed one of the wheels for a Norton 3X (46 grit). This wheel was from the USA as it is not available in Oz. No problems fitting my machine. In fact, the thought that the spindle was an unusual size had not occurred to me until this thread.

Vibration? Nil - minimal. This is a very good machine.

I am wondering if we are talking about the same machine. Carba-tec sell/sold two half-speed 8" grinders, one by Axminster (then $199) and the one I purchased (then $399), which is no longer sold it seems (when I looked on the website). Mine does not have the wide wheel shown in the web catalogue.

Here is mine (with the Tormek BGM-100 tool rest. Note on the left side the blue Norton 3X wheel):

http://www.inthewoodshop.com/WoodworkTechniques/GrindingNirvana_html_85f29ea.jpg

Review of the BGM-100: http://www.inthewoodshop.com/WoodworkTechniques/GrindingNirvana.html

This is the Axminster 8" slow speed machine. It is not the same as mine (it was the cheaper machine offered at the time. I did not consider it as it vibrated so badly!) ...

http://www.carbatec.com.au/images/hires/AW8SRG.jpg

Please let me know whether the machine I have is the one you is referred to as having an atypical sized spindle.

Regards from Perth

Derek

[Jim Carroll]

Peter I use the cruesen 6"grinder

I find it very good to use.

Last weekend at the brisbane show we had one set up to use, everyone was impressed by how quite it was and how quick it slowed down.
They come with a 60 and 100g 40mm wide white alox wheels.

[Sturdee]

This is the Axminster 8" slow speed machine. It is not the same as mine (it was the cheaper machine offered at the time. I did not consider it as it vibrated so badly!) ...

http://www.carbatec.com.au/images/hires/AW8SRG.jpg

Please let me know whether the machine I have is the one you is referred to as having an atypical sized spindle.

Regards from Perth

Derek

Derek, this machine is one of the one I'm considering and the website says that the arbor shaft is M16 x 2 thread so it may be unusual.

Thanks for the info and your setup is something I want to replicate. I will definitely want to see the machine operating and assurances about replacement wheels.


Peter.

[Sturdee]

Good advice for me to look at. Don't want a fast grinder as I'm too inclined to push too hard. and overheat. Too impatient to have a soft touch.

Does the difference between using a 6" wheel first and then an 8 " wheel make a difference.


Peter.

[BobL]

My next grinder will be a small 3 phase unit to which I will fit a variable speed drive. The 3/4 HP VSDs are now as low around $140 ($70 + $70 shipping) on ebay down from many thousands just a decade ago.

With a VSD it is possible to run many different types of 3 phase motors from 240 single phase and to vary the speed of a 3 phase motor from around 10 Hz to as high as you dare to go. In practice this means it will be possible to range the speed of a 3000 rpm grinder from 300 to 3000 rpm. A better range would be to find a 1450 rpm motor and run that from 150 to 3000 rpm.

I predict that in a few years time nearly all motors on workshop machinery will be 3 phase and will have built in VSDs. I just fitted one of these to a metal work lathe and it works a treat.

[rsser]

I don't get the fuss about slow speed grinders.

Just need a lighter touch and esp. dress the wheel regularly.

And if Peter you blue your HSS turning tools they can take it.

I'm sure you know all this.

If you want a bit of insurance, then look at the Norton 3X wheels that Derek mentioned which are now avail. in Aus:

Jim Davey Planes & Sharpening - eShop - Sales - Abrasives & Grinding (http://www.jimdavey-planes-sharpening.com/EShop/EShop.aspx?EshopID=8607ccbf-fea8-48e0-a1d5-90600a129f1a&CategoryID=39bde3d8-f788-4228-80d8-fc8997ae1c66)

[simonmags]

Having started looking at wet grinders and slow grinders just recently i find this thread very interesting.

So as I understand it the half speed grinders with the norton wheel and a touch of ESP and you can hone a primary bevel?

But with the wet grinders, be it the Tormek or one of the others you can grind the Primary and a secondary bevel if you so choose? Albeit much slower if you have a chipped blade...

The primary reason I think I might need one is so that i can hone a primary bevel much quicker initially saving me some time to work on other projects. The tools, mostly planes and bench chisels, usually second hand and usually chipped, would just need to be honed on a diamond stone or similar and then could be used again...

[Sturdee]

I know that I can use a high speed grinder, been using that for years, but I continually have problems with my impatience and overheat the chisels. Especially when I'm making new tools that require a lot of initial grinding. Also the wheels on the old grinder need replacement, so a complete overhaul would be good.:)

Had a close look at the Axminster 8" slow grinder and the Creusen 6" slow grinder at C/T yesterday.

The Axminster came with a 30mm white wheel and a normal grey wheel. Although mounted on a large board the unit vibrated quite badly and started to move around on the bench. Also was rather noisy.

The Creuson has two 40mm white wheels , one 60 g and the other 100 g. This also will allow me to grind plane blades.

Not mounted on a board, just placed on the bench, it was very quiet and did not vibrate, in all a much better unit although the Axminster came with an overhead light. Not a major problem as I have about 4 flexible light fittings lying around in the workshop waiting for a good use.

With C/T current sale the price difference is not so great, so I ordered a Creusen. As part of a minor reorganisation of my workshop I will end up with a dedicated sharpening bench, having both the Creuson and the Seppach wet wheel grinder.

When I get the grinder and I finish the current renovations I will make a unit like Big Shed and Derek.


Peter.

[derekcohen]

Hi Simon

With a wet grinder you can grind to the edge of the plane or chisel blade without fear of ruining the temper. The hollow so created makes it very quick work to hone a microbevel, especially if you are freehand sharpening. This is a significant advantage over a dry grinder, regardless of speed, since the heat generated means that you have to stay clear of the bevel edge. With more steel to hone, sharping is a slower, more effortful process. Note that this is a relative statement - for me the Tormek makes for much easier (and more accurate) sharpening. This is even more a factor as the steel used gets harder or is more resistant to abrasion (e.g. HSS/M2 over A2 over O1).

The higher the speed, the greater the heat generated. A half-speed grinder will create less heat ... but this also depends on the wheel used (softer is better), ability to shed a worn surface (faster is better), and the coarseness of the grit (more coarse is better). And let's not ignore the user's skill and touch in this equation. The downside of the above is in the speed at which grinding takes place: greater safety = less heat = slower (and vice versa).

Regards from Perth

Derek

[mic-d]

The Axminster came with a 30mm white wheel and a normal grey wheel. Although mounted on a large board the unit vibrated quite badly and started to move around on the bench. Also was rather noisy.

Peter.

FWIW, the vibration is likely only to do with the wheel balance, maybe the cruesin is balanced at the factory. The Axminster runs beautiful and smooth without the wheels on and once balanced it's fine.

[Mr Brush]

A while ago I actually bought the Axminster 8" grinder from Carbatec (Sydney) when they had it on special. On the same trip, I also bought a better (pink alox) wheel from Trend intending to fit this to the grinder.

Well.....I got all my goodies home.....and merrily removed one of the installed wheels from the Axminster grinder in order to fit my new wheel from Trend. Shock, horror :oo:

The outside clamping washer on the arbor was flat (as you'd expect), but the inner one had a huge flange cast into it. This fitted into an oversize hole in the original wheel - I forget the exact dimensions, but I think it was something like 30mm diameter. My new alox wheel from Trend, in common with just about EVERY wheel on the market, doesn't have a big enough centre hole to fit this grinder......even with all the plastic adapters removed.

Took the grinder back to Carbatec and showed them the problem. Unless you buy the (very limited) range of replacement wheels from Carbatec, there are virtually NO wheels on the market that will fit the Axminster grinder. The outside section of the arbor may well be the standard 5/8" shaft, but standard wheels won't fit due to the stupid internal flange. You can't see this until you need to change a wheel - I suspect several forumites have this grinder, and are in for a shock when they need a new wheel.

Carbatec were very good about this - they could see the issue, and swapped the grinder out for the more expensive slow speed 8" one (same as Derek has). Not only this, they gave me a VERY good price on the replacement for my trouble, so no complaints at all on the service front. I pointed out that they could possibly buy more of the EXTERNAL washers from the factory and use them to replace the stupid internal washers with monster flanges, thereby ensuring the Axminster grinder would be able to use standard wheels made for 5/8" arbor - not sure if they have done this.

So......in summary......do NOT buy the Axminster version unless you want to be limited to completely non-standard wheels !

[Sturdee]

So......in summary......do NOT buy the Axminster version unless you want to be limited to completely non-standard wheels !

Did ask about getting different wheels for the Axminster, and was told that only replacement wheels sold by C/T fitted the machine.


Peter.

[mic-d]

Did ask about getting different wheels for the Axminster, and was told that only replacement wheels sold by C/T fitted the machine.


Peter.

Hi Peter, It's good to know this problem has filtered through to the staff, I wonder if they are offering that advice without prompting though. For the sake of completeness, in case an owner of the Axminster grinder stumbles on this thread with stated problem, it is easy enough to buy a 31.75mm bore x 25mm wide x 8" (mixed metaphor?) stone, available in a suitable variety of grits and fit that to the machine with a 5/8" washer either side.

[Glen Bridger]

Wow, its been a long time since I logged on.

I have just been reading this post about slow speed grinders. I have just been involved in the setting up/modifying one of these Axminster grinders. The solution (other than not buying one) is to machine off the built in bushing incorporated in the inner flange. Then purchase whatever wheels you want, then machine up a bushing to suit from Delrin plastic.

The problem is the shaft on the grinder is metric and most wheels have imperial bores. The bushings I made had a 0.706" bore and 1.000" outer diameter. If you don't have access to a metal lathe, this may be a costly exercise.

Glen.

[rsser]

As best I understand it the wheel is held by the pressure on the washers and some slop in the bushes on the shaft shouldn't be an issue. I understand that this is not the prob. referred to here but the suggestion to source a similar external washer and use it on the inside would solve it if I'm correct.

[Mr Brush]

Ern - you are correct, again..... :D

[rsser]

Credit where it's due: the 'hold' on the wheel was mentioned by DJs Timber a while ago when I was publicly cussing the business of trying to get some shim strip between sloppy nylon bushes.

[Mr Brush]

Once everything is tightened up, its always a good idea to dress the wheel to true it up (especially on a new grinder just out of the box.......)

[rsser]

Yeah, almost always necessary.

Don't forget the tap test before mounting either. (Not referring to the missus here either :D )

And dressing regularly (oh dear, no, I won't venture further).

I'm going to have a play with a star wheel dresser to try to preserve the coarseness of my wheel. Appreciate that there are conflicting opinions about this but it's clear that a diamond T-bar dresser smooths a coarse grit wheel; the old carborundum stick when used aggressively does better but tends to put the face out of true.

[Glen Bridger]

Hi Ern,

Your concerns about getting the bushing right are warranted. It is true that the flanges do clamp the wheel in place and keep the set up "true". However the bushing ensures the wheel is located correctly prior to clamping it in position.

If the bushing is the wrong size or poorly manufactured, you cannot get the wheel located correctly and it will not run concentric or square to the shaft. Yes you may be able to dress the wheel and make the circumference run "true" but it will not run concentric and may result in vibrations during operation.

The machine I repaired, had bushings which had been re-sized to suit the shaft of the grinder, however they were a 'bit' out. The wheels could not set up correctly and all the dressing in the world could not get them to run 'True'.
The machine had a vibration that could be heard and felt through the work shop.

As I said originally, two new accurately machined bushings allowed the wheels to spin concentric and square to the shaft. After dressing the wheels, the machine run smoothly and quietly.

Cheers,

Glen.

[Jim Carroll]

Another problem with current grinders is the washers they use today are basically pressed metal into a shape and dont have a lot of strengh.

So if someone gets a bit over excited and tries to clamp the wheel too much this can distort the flanges and the wheel gets that waving motion .

As greg indicates no amount of dressing the circumfrence will get rid of the vibration that it now causes.

I have an old GMF grinder that has cast flanges and this grinder never vibrates and the wheels do not have any wobble no matter what we put on there.

[mic-d]

Here are some photos to explain the problem with the Axminster grinder flanges since the story seems to be getting confused.

Photo1
This is the flange arrangement as it arrives on the grinder. One side has a standard flange the other has an integral bush. The shaft of the grinder is a bee's peepee over 5/8"(maybe metric) , the OD of the "bush" is 32mm.
172518

Photo2
This shows the bush flange mounted on a replacement wheel that is 25mm wide. You can see that the bush is short enough that it will accept a wheel down to 25mm wide WITHOUT MODIFICATION. The closest standard and common arbour size to the 32mm OD 'bush' is 31.75mm. It is a very simple matter of wiping the bore of the replacement wheel with wet and dry until it is a snug fit on the bush. You do not need to modify the bush or turn a new bush.
172519

Photo3
A photo of the 25mm wheel mounted on the shaft. This is where the real problem lies. As you can see, the thread on the shaft is not tapped in far enough to allow the nut to reach the flange when using a 25mm wide wheel. The narrowest wheel that can be accepted without some work-around is 30mm (not standard). The grinder comes with 32mm wide wheels originally (also not standard).
172520

Photo4
By simply obtaining a good quality 5/8" washer and reaming it very slightly, you have a low cost spacer which sits on the grinder-side of the wheel and packs the wheel out to where the nut is able to tighten down on it.
172522

Photo 5
Happy days, it fits. For the price of a 5/8" washer you have now opened up a greater range of wheels to your Axminster slow speed grinder.
172521
The problem does not require machining off the bush, the problem lies with the shaft thread being insufficiently tapped to accommodate 25mm wheels. If you machine off the bush, you will not have solved this problem and will then have to fabricate another bush. A 5 cent washer is all you need. There is also no problem with wheel slop if you leave the integral bush on there. You can wipe the 31.75mm bore out to a perfect fit. As I stated, the integral bush will accept wheels down to 25mm wide without modification.

[Glen Bridger]

Hi Mic,

Thanks for the photos, yes thats exactly what we had. Your repair is very clever and as long as you got the wheel to run true, then you have achieved the end result.

I did forget the issue with the thread not being long enough. I had to machine up a 1/4" thick spacers.

The biggest problem I see is POOR DESIGN. Unless you buy true top quality industrial machinery, then the tools/machines we purchase for home workshops and hobbies will be made to a price, and quality control may be questionable even when we think we are buying "good quality".

This slow speed grinder is poorly designed, when you consider the limited number of accessories that can purchased for it, and the fact that it requires so much thought, discussion and attention to make it suitable for most applications.

I would suggest that people steer completely away from it, and maybe the importers might get a company to machine an "adapter" to allow a greater range of wheels to be fitted.

Glen.

[mic-d]

I would suggest that people steer completely away from it, and maybe the importers might get a company to machine an "adapter" to allow a greater range of wheels to be fitted.

Glen.

I agree. If you don't have one, don't buy it.

[The Bleeder]

So Mic how much is some manufacturer going to charge for a reamed out 5 cent 5/8' washer :o .......I like your way of thinking ... :2tsup:

[Mr Brush]

The difference between Chinese-made and Taiwanese-made woodworking gear increasingly seems to be that the former often requires modification/fixing/replacing parts by the purchaser to work properly, while the latter generally at least fulfill their intended purpose out of the box.

Certainly true for the grinder(s) and disc sander I've purchased from Carbatec.

Yer pays yer money and yer takes yer pick.....

[Sturdee]

Today i picked up my low speed grinder. I got a Creusen 6 " which has two 40mm white wheels, one 60 and the other 110 grit.

I haven't given it a good workout yet, as I am still doing renovations ( tail end :2tsup: ) and reorganising my workshop and wood storage area. However I switched it on straight out of the box and there was no vibrations and it was super quiet.

When it is put in the new (to be made) sharpening station with the wet grinder and tormek jigs I'll be very happy.

Thank you for all the advice in helping me make this purchase.


Peter.