Has anyone tried using a surface grinder?

[graduate_owner]

Hi everyone,
a friend has a surface grinder for sale and I'm very tempted to buy it. It has the usual screw feeds for in/out, forward/back and up/down travel. I was thinking to use it with an angled jig to clamp chisels and plane irons on for accurate re-grinding. Or to replace the grinding wheel with a hard felt honing wheel for final polishing of bevels. I also thought I could attach a circular saw blade, clamp work to the sliding table, and cut tenons accurately without getting fingers anywhere near the blade - just use the feed screws.

It has a 3-phase motor, so I can alter the rotation speed easily, and it also comes with a removable magnetic table.

Has anyone tried any of these ideas, or have any other uses to suggest, for either wood or metal working?

K

 

[Tinbasher]

It sounds a bit like overkill to me but then all my tools are blunt!

 

[Spindle]

Hi

'You can never have enough machine tools'

If I had the opportunity I'd go for it. Not sure about the alternate uses you propose, my interests are not limited to woodwork so I'd use it as intended.

See here for a chap refining an Eastern import milling vise, (surface grinding begins on pg 29):

http://www.docsmachine.com/projects/4vise/4vise-01.html

Regards Mick

 

[Keith 66]

Surface grinders are intended for removing tiny amounts of metal with a great finish, ideal for planer irons etc but i wouldnt use one as a saw, the motors are usually not that powerful & the saw dust would tend to clog up the sliding carriage bearings.

 

[Gary Morris]

When I was a machine engraver / die sinker, I regulary sharpened family and friends chisels

Gary

 

[Hitch]

We have a couple at work, only use they really get used for regularly is sharpening punches and dies.

 

[Hutzul]

Your chisel sharpening or any tool sharpening will only work if you can keep the workpiece cool, either with liquid or air, as the heat generated will soften the metal.

OR re temper the workpiece when done.

Sorry to bring bad news, but I've sharpened a loadsa tools on a surface grinder and keeping it cool is the trick

 

[graduate_owner]

thanks for all the comments.
I was thinking to use a spray bottle of water with a suitable wheel RPM for re-grinding tools. If I set up an adjustable angle jig and clamp a plane or chisel blade to it, I thought I would be able to get the position and angle spot on quite easily, then use the depth wheel to just touch the steel. I could perhaps rig up a water trough to stop the water from rusting the table. Or perhaps use a spray of oil. I remember watching someone sharpen a chisel for me using a Viceroy Sharpedge, and it was so easy. They crop up on ebay but always seem to be either too expensive or hundreds of miles away.

These surface grinders seem to crop up on ebay (no hydraulic feed etc - just basic hand wheels), but the specs. vary widely. My friend is looking for £120 including magnetic chuck, no VAT and no great distance to have to haul it home, which is fine if it does the job. Otherwise it will be just taking up workshop space, as I can't see myself using it much for it's intended purpose and that is my main issue with it. But then I thought that about my Bridgeport type miller, and that has been really useful.

I suppose what I'm looking for is more ideas for using it so as to have an excuse to buy it!!!

Any further ideas on cutting tenons? My idea was the 'horizontal' feed would act like a sliding table, and the cuts would not be deep so perhaps it's 1HP motor would be OK - don't know about the dust in the works though - good point. The in/out feed would move the work to expose an uncut part of the tenon to the blade. Of course this could be very tedious, but it's the sort of thing people do on a table saw if they don't have a stacked dado head - just nibbling away. I could perhaps fit a wide kerf blade or spindle moulder blade to take a wider cut if the motor can take it. It's all guesswork at the moment, but I'm no cabinet maker and so machinery helps me with accuracy

Still undecided, but leaning towards buying it. Do you guys 'in the know' have any idea if £120 inc magnetic chuck is sensible?

K

 

[Hutzul]

I think at £120 it is quite reasonable, try google to give you a guide of current market prices. Good Luck !

 

[graduate_owner]

Now I've come up with another possible use - what about a finishing sander? I've seen a number of plans for shop made drum sanders and have been thinking of having a go at making one. The surface grinder could do the job instead - I thought a turned wooden drum about 6-8"diameter and perhaps 4-6"wide with abrasive paper wrapped around. The fine feed will allow very accurate sanding, and if the work is wider than 6" then the in/out movement will allow the work to be re-positioned without altering any other settings and so losing accuracy.

I'm definitely going to buy it now. It may be a metalworking machine intended for one specific purpose, but I can see several possible woodworking uses - and maybe more in the pipeline.

K

 

[CHJ]

.....I'm definitely going to buy it now. It may be a metalworking machine intended for one specific purpose, but I can see several possible woodworking uses - and maybe more in the pipeline.

K

I personally would strongly advise that you use a surface grinder for its intended purpose only, that is to:-
1. spin an appropriately rated and specification grinding wheel at high speed.
2. take very light load cuts
3. and used to provide a flat smooth surface on steel and iron components.

And if you have never used one before ensure you get some good instruction on:-
1. how to set up a job. (dial gauges etc.)
2. how to go about truing up the grinding wheel with a single point diamond dresser.
3. and how to go about ensuring that you do not have a serious accident by crashing the grinding wheel into the job.

 

[graduate_owner]

Thanks for the warning, I will certainly get some instruction on it's use. It does look like a reasonably safe machine (I may be wrong here) provided you don't take excessive cuts, but I know any machine can be dangerous if misused. I may just use it for sharpening after all.

K

 

[Cheshirechappie]

If you want a 'machine tool' type way of sharpening things, look around for a Tool and Cutter Grinder. These are designed to be very versatile, though they do need a lot of attachments to exploit their full capabilities. Designed to sharpen such things as milling cutters, lathe form tools, taps, dies, drills and so on, they could easily cope with chisels, circular saw blades, planer knives and the like; equipped with suitable interchangeable grinding wheels, they'll cope with hardened carbon steels, HSS and carbides. They won't take up as much space as a surface grinder, either. (T&C grinders can be persuaded to do small surface grinder and even cylindrical grinder jobs at a pinch.) Something like a Clarkson Mk 1 with a reasonable kit of attachments and wheels need not cost a fortune, either; expect to pay more for later models.

For cutting tenons, how about having a go on the Bridgeport as you've got one. A more appropriate machine for the task than a surface grinder, though a tenoner would be even more appropriate.

 

[Andy RV]

As a time served toolroom grinder the surface grinder is a very versatile machine when used with various jigs, fixtures and dressing equipment. For sharpening tools it will be fine, yes you can draw the temper of whatever you are sharpening but only if you get it too hot so take light fast cuts and give it chance to cool down. Get yourself a good wheel as well.

Make sure you do your research before using the machine as they are dangerous, eye protection is a must, if you ever witness a good sized job being ejected from the table at warp speed you'll need to change your underwear!

As I said before put a new wheel on it, ring test it by knocking it with something non-metallic and listen to the resulting ring, a bright ring indicates the wheel should be ok, a dull ring means the wheel could contain hidden defects such as cracks, if so break the wheel so no one else can use it and bin it, it's not worth the risk using equipment you are not confident in.

Wheels should be dressed with a diamond to ensure it is running true, i'd imagine the machine you are looking at has a small wheel within 8" diameter, these can be balanced if you have the equipment but if not you'll be ok with a good quality wheel. Bigger wheels should be balanced.

Soft materials are rubbish to grind, they load the wheel up and don't grind cleanly so if you're working with soft material ensure you dress up regularly, hardened materials are more user friendly up to a point.

Do you research and take care, they might seem like quiet, safe machines compared to a circular saw blade wizzing around at 3000rpm but they will bite if you let them.

 

[graduate_owner]

Hi Andy RV,
there's a lot of useful ( nay essential) information in that reply, and I thank you for it and for your time. The owner isn't time served as yourself, but has been a keen metalworker for a number of years. His workshop contains 3 millers, 2 with DRO, 3 lathes from about 5ft to 7 ft between centres, and another surface grinder with auto reverse hydraulic feed. He's currently making a 1/2 size replica of a Victorian traction engine which is amazing. I know that just collecting kit is no guarantee of ability to use it safely, but he does seem to know his stuff. He has agreed to give me instruction on the safe use of the beast. I also intend to discuss with him my ideas for alternative uses and if he advises against then I shall heed his advice. I know other replies have warned me about using it for the 'wrong' purpose, and I'm not just ignoring those contributors out of hand - I'm sort of looking for alternative opinions, and I have to say I'm a lot more wary about things than I was.

Thanks again

K

 

[SVB]

Also - don't get mixed up. Use of Magnetic clamp for tennon cutting will be a bad mix!

 

[graduate_owner]

Hi,
for use with wood I was going to remove the magnetic table and fix a wooden base in it's place. Perhaps a router mat on that to hold the timber while sanding, with a batten to make sure it doesn't kick back out at speed, not sure of details yet - trial and error with the wood securely clamped to start with. I shall have to build a shroud to attach to my dust extractor.
For tenoning I thought I could use lock-down clamps to secure the timber to the wooden base, with a fence attached to the base at right angles to the blade to align the timber easily. To actually cut the tenon I thought to use the feed handles, and so keep my paws well away from the cutting edge as I'm not sure how well I can guard the blade yet.

That's the plan anyway, so I'm thinking of using it as a multi purpose woodworking machine, as well as for it's intended purpose. I thought that as long as the work is secure on the table, and I take sensible sized cuts at a suitable speed of rotation, then I shouldn't come a cropper. Quite a bit of trial and error - taking things slowly to start with.

K

 

[Wildman]

I am a time served toolmaker and would not use a surface grinder for cutting wood. The wheel spins at 2200 RPM and any problem would be lethal, there is no guard as normally found on a saw. As it is Handraulic with no power feeds I assume it is an Eagle or a superior (I'd be interested to hear what it is). At £120 I'll have if you decide against it. You say it is 3 phase, I assume you have an inverter if not then that is an extra expence unless of course you have a 3 phase supply. You mention reversing the rotation and that is a definate no no, you will kill yourself. I'd love it but then I would only use as intended for tool making.

 

[graduate_owner]

Hi Wildman,
yes it is an Eagle. I have a 3-phase inverter so I can run it OK, plus I can get the speed right down to a safe level. I only mentioned reversing the rotation because it's possible with the inverter, but I wouldn't want to do so on this machine because the wheel would probably come off. I'm going to get it this week and will post some details when I've got up and running. One of the first jobs will be as an actual surface grinder - I need to trim the teeth of some old thick files to use as scrapers on the lathe. I've read good and bad about this. Some books recommend using them, others say they could break like shrapnel bombs because they are not suitably tempered. However I've never actually heard of this happening to anyone.

K

 

[marcros]

One of the first jobs will be as an actual surface grinder - I need to trim the teeth of some old thick files to use as scrapers on the lathe. I've read good and bad about this. Some books recommend using them, others say they could break like shrapnel bombs because they are not suitably tempered. However I've never actually heard of this happening to anyone.

K

is it really worth the risk?