Thread: Elliot 8-18 Surface Grinder

Hydraulic pump unit



Base



Table

Originally Posted by simonl

I bet Michael is reading this now and laughing at me. He had been hinting about the benefits of a small manual type machine and now I'm learning why!

Once you get it running and start doing a piece that has a bit of size to it and you can go do something else for ten minutes while the grinder does it's thing automatically, you will have the last laugh..

Originally Posted by simonl

I bet Michael is reading this now and laughing at me. He had been hinting about the benefits of a small manual type machine and now I'm learning why!

There is noticeable wear on all the ways which has me a little concerned. I guess if it's even wear then it' just taken up by dressing the mag chuck.

I must admit to smiling when I read that but no laughing at you - we all start somewhere and as Richard points out once it is going it will be far better than the SG I have. A machine with power feed would be very nice but in reality I don't have room and all I am likely to use the SG for is small pieces. (The first part ground in anger was all of 2" long and a bit over 1/2" x 1/2" in cross section)

Remember though that you don't have to go the full cow chaser on it. If it has wear, it has wear. You have learnt the skills and Connelly will give you guidance so you can fix it if you want to, but you don't need to before you can use it. Richard, Ray, Ewan and Phil all use their grinders to make money. You (and me) do this for fun, so imperfections we can live with until we are feeling brave enough to do something about it.

For the moment I'd suggest just taking it apart enough to check that things are working (repair bits that are not), clean it and then use it. Once you have the feel of the machine and have used it for a few things you will then have an idea whether it is worth putting in lots of effort to reclaim those last few tenths.

Michael

Originally Posted by Michael G

I must admit to smiling when I read that but no laughing at you - we all start somewhere and as Richard points out once it is going it will be far better than the SG I have. A machine with power feed would be very nice but in reality I don't have room and all I am likely to use the SG for is small pieces. (The first part ground in anger was all of 2" long and a bit over 1/2" x 1/2" in cross section)

Remember though that you don't have to go the full cow chaser on it. If it has wear, it has wear. You have learnt the skills and Connelly will give you guidance so you can fix it if you want to, but you don't need to before you can use it. Richard, Ray, Ewan and Phil all use their grinders to make money. You (and me) do this for fun, so imperfections we can live with until we are feeling brave enough to do something about it.

For the moment I'd suggest just taking it apart enough to check that things are working (repair bits that are not), clean it and then use it. Once you have the feel of the machine and have used it for a few things you will then have an idea whether it is worth putting in lots of effort to reclaim those last few tenths.

Michael

Thanks Michael. I think I did mention this before, the machine is about 3 times the size of what I really need. I wasn't expecting it to be that big. I nearly fell over when I first saw it in Sydney! So It's taking me some time to get used to the physical size of everything! Having said that, I felt a similar way when I bought my band saw. I have since used it to its full capacity and it has been a great acquisition so I'm hoping with time I will feel the same way with this. I am fighting the urge to totally disassemble everything and replace every bearing and seal. Like you said, I really can't see the value in that just yet. I don't think I will re-paint it either however, the table does not have much paint left on it so I'm not sure about that. Who knows, once it's all cleaned up it may look quite acceptable even without some paint. One of my concerns is to have it all cleaned up and back together and running, only to find out the hydraulic rams leak like a sieve, when all that would have been needed was maybe a handful of O rings or other seals. There are no signs of massive (land rover type) oil leaks anywhere in the moving hydraulic parts so I may be thinking too much.

Anyway, Summing up I think that is a good plan of attack. Clean it all up, put it back together and see how it goes. Oh, while I got your attention, I notice the manual says that the spindle bearings should be repacked with grease every 18 months. Should I take a chance and perform this function? Bit nervous about that thought. I have repacked wheel bearings and my mill spindle bearing I don't have any experience with a precision spindle bearing of a quality machine.

Simon

Originally Posted by simonl

I notice the manual says that the spindle bearings should be repacked with grease every 18 months. Should I take a chance and perform this function? Bit nervous about that thought. I have repacked wheel bearings and my mill spindle bearing I don't have any experience with a precision spindle bearing of a quality machine.

On receipt of any machine with an unknown maintenance history I usually clean, change belts, apply/change oil and grease (and check the electrics are safe and work). Sometimes bearings if they are not difficult to get to or horribly expensive. Probably the most critical part on a SG is the spindle - if the bearings are shagged or not looked after it will reflect in the finish obtained.
If the manual does not give precise instructions on how to repack then there is probably another member here who can guide you through.

Michael

Hi Simon,
I think its just a nice size, and you'll soon be thankful your not cranking that table back and forwards by hand.....On the other hand it doesn't weigh 2.7T and take up 6 or 8 square meters......

As for leaks, is the oil tank an open design? You will probably find that any leaks will simply end up back in the oil tank if it is. The exception is the ram seals leaving oil on the ram and it dripping off at the end of the stroke. I had this, but i was able to pull the end caps of the ram off and replace the seals with the table in place. Actually replacing the seals did little to stop the odd drip, but with a bit of use the drips seem to have dried up.

Ew

Oh i forgot, your paint. If the machine has been running flood coolant thats why the paint is bad. The speed of the wheel turns some of the coolant to mist, which showers over the grinder, more on the LHS, and slowly strips the paint. Coolant is slightly alkaline so there is not much you can do to stop it happening.

I find the effect of the wheel on the coolant fascinating, as you bring the wheel down to touch off the coolant start to hiss, then almost crackle, you can tell just how far you are from the job by the sound it makes.

I'd also recommend you dress your wheels with the coolant on to try to keep the dust down.

Ew

Originally Posted by Ueee

... the ram seals leaving oil on the ram and it dripping off at the end of the stroke. I had this, but i was able to pull the end caps of the ram off and replace the seals with the table in place. Actually replacing the seals did little to stop the odd drip, but with a bit of use the drips seem to have dried up.

You might find that some of that leaking is due to scratches or scoring on the rod. We overhaul gear containing hydraulic cylinders at work and the rods are probably the most critical part. Diameters have a small tolerance band, surface finish is fine and no pitting or marking is allowed. The difference between dry and wet grinding is that you go from a metal dust to a metal paste. Either way, get some near the rod/ seal interface and it will abrade the rod and damage the seals.

Michael

Thanks Ueee, that make sense. Given it's a pretty cheap and simple job while I got it apart, I may replace the seals in the rams, particularly the one under the saddle since it would be a PITA to have to do it later. The hydraulic system is not the open system you describe. The resevior is totally enclosed and it has about 4 return lines from both the hydraulic exhaust and from the ways. The hydraulic lines feed into small reseviors in the table where the lubricating rollers are, the overflow from these then run down small holes that feed directly onto the saddle ways where there are once again rollers in a resevior. The saddle ways then drain through small holes into hose lines back to the hydraulic tank. Any leaks will just end up as a pool of oil!

You didn't mention the spindle bearings! I have been thinking about that, I suggest I don't touch them until I have it back together and see how it performs. If it gives "good" results then I won't touch them, I'm not likely to wear out anything further on this machine with my use.

Cheers,

Simon

Originally Posted by .RC.

Once you get it running and start doing a piece that has a bit of size to it and you can go do something else for ten minutes while the grinder does it's thing automatically, you will have the last laugh..

Originally Posted by Ueee

... and you'll soon be thankful your not cranking that table back and forwards by hand...

You guys are just jealous that one day I'll have a left arm that Schwarzenegger would be proud of. (Have to think of something to do to build up the right...)

Michael

The hydraulic system is not the open system you describe. The resevior is totally enclosed and it has about 4 return lines from both the hydraulic exhaust and from the ways. The hydraulic lines feed into small reseviors in the table where the lubricating rollers are, the overflow from these then run down small holes that feed directly onto the saddle ways where there are once again rollers in a resevior. The saddle ways then drain through small holes into hose lines back to the hydraulic tank. Any leaks will just end up as a pool of oil!

Hi Simon,

Just double check you aren't confusing the automatic lubrication system, with the hydraulics.... The ways will be fed by an automatic pressurized lubrication system, it should be small diameter copper pipes, if you follow those back you should find an oil reservoir and a lubrication pump... the overflow from the lubrication system sometimes goes into a waste oil tank.

Ray

Originally Posted by Michael G

On receipt of any machine with an unknown maintenance history I usually clean, change belts, apply/change oil and grease (and check the electrics are safe and work). Sometimes bearings if they are not difficult to get to or horribly expensive. Probably the most critical part on a SG is the spindle - if the bearings are shagged or not looked after it will reflect in the finish obtained.
If the manual does not give precise instructions on how to repack then there is probably another member here who can guide you through.

Michael

Yes I agree, but even the spindle on a SG isn't quite as critical as one might imagine. I hadn't noticed any real finish issues in mine, but had been meaning to pull the spindle anyway and service it. When I did so I discovered the spindle was actually bent! A bit of forensic work suggests some idiot has driven it down in to the table by the looks of things, and bent it around the front bearing. I was horrified, but the reality is this all gets dressed out at the wheel. Definitely not ideal, but not the show stopped I previously would have assumed. There's a slight vibration that I'd always put down to unbalanced wheels, but now think comes from this bent spindle, not a lot, but now I notice it. Eventually I'll probably have a go at heat straightening the spindle, and if I screw that up just turn up a new one. The beauty of running Hercus gear is it's rather agricultural to begin with, so any repairs are equally low-tech

Originally Posted by RayG

Hi Simon,

Just double check you aren't confusing the automatic lubrication system, with the hydraulics.... The ways will be fed by an automatic pressurized lubrication system, it should be small diameter copper pipes, if you follow those back you should find an oil reservoir and a lubrication pump... the overflow from the lubrication system sometimes goes into a waste oil tank.

Ray

HI RAY,

Yes, the ways are lubricated with a pressure fed system. There are small copper lines that are tapped from the traverse piston and they feed up into small reservoirs. So, the system is lubricated with hydraulic oil. Looking underneath the main body, you can see hose attachments under the saddle ways and these return back to the main hydraulic tank. There are about 4 separate return attachments to the tank, all next to each other. What happens inside the tank I am yet to find out. Perhaps it has internal baffles so that the return oil from the ways is kept separate from the bulk hydraulic oil or perhaps it's just a triple intercepter type system. I did mention that the hydraulic oil in the lines seemed pretty clean so whatever the system, it seems to work well.

Michael, I was thinking you may end up looking like one of those crabs with the one really big arm!

Hi Pete, Sorry to hear about your spindle. But like you said, runout is compensated with wheel dressing. Besides, a new spindle would be a morning job for you I dare say!

Simon

Originally Posted by simonl

Hi Pete, Sorry to hear about your spindle. But like you said, runout is compensated with wheel dressing. Besides, a new spindle would be a morning job for you I dare say!

Simon

All kidding around aside, yes it would be a straight forward turning job between centres. Looking at it I think the most difficult part would be in accurately setting the taper, but even that is easier as I have an old taper to work off.

The reason I don't just do it is because I'll probably take the opportunity to change the LH thread to metric and machine up a bunch of wheel arbours at the same taper so I can swap them on and off more easily. That's something I'd dearly love for the Clarkson, and he may get a new tapered spindle too, just so I can do the same thing. I swap wheels on the T&C grinder more frequently than the surface grinder, and it would be nice to be able to swap wheels without as much dressing as they need now. All in all it's a bigger job that it could be, and "one day" it will get done.