So today I worked on the Surface grinder. I did a run & noticed the oil pump wasn’t running. I checked the voltage to verify. Then I pulled the pump & cleaned the strainer. Re-assembled & checked again, still no oil. I pulled the pump all apart and the gears were seized. These gears are almost small enough that @John_Marlow would make them. I cleaned out all the oil from the sump, put fresh oil in. Well it appears to work. There is still work to be done.
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Wow. I’m impressed by the craftsmanship. That must be some mighty micro oil pump. Wish I’d been there to take it apart.
Also kinda wondering if I should be pissed too. Why would anyone spec or design impellers that small? Seems somewhat impractical to manufacture a machine shop tool with parts you can’t get easily somewhere off the shelf.
What’s the brand on that grinder?
Harig Super 612. It has the Teflon ways, unfortunately not the better of them. But I checked the flatness last week from the platen to the spindle, It was good. We need to replace the oil hoses.
Been a long time since i’ve seen any update on the surface grinder. Tim, do we have a plan? And are all the parts with the Harig we have? I dont see a spindle.
Power is our major issue, lack their of. When the big E happens, we will have a spot & power for it.
As a general question about power needs, have we given much thought to retrofitting any machines requiring 3PH with a VFD (Variable Frequency Drive)? Certainly not every machine is a good candidate but in certain situations a VFD can breath new life into a machine even giving it finer motor control than it originally had.
Here are a couple of threads where folks are using VFD’s to power their Harig grinders. From the looks of it, the motor specs on the Harigs (current draw/HP) are quite low. The VFD would provide soft start and stop at a minimum which is quite nice. There are many VFD’s that would fit this range for under $200.
https://www.practicalmachinist.com/vb/general/harig-super-612-power-options-245147/
Just thought I would ask. 
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So I have order some New old stock bearings for the spindle. They should be in later this week.
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I got lost someplace, oil hoses? oil pump?? what does this machine do with the oil ?? This would run quite well on a phase converter, and I would not think it a good candidate for VFD.
There is a small oil line underneath the bed but it has a small valve going to it. If I had to guess it’s 3/16 or 1/8th from memory. It used oil for the ways and gibs for the vertical travel. This is going off memory though. The oil pump is tiny, almost Chris Marlow scale.
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So it has a motor driven pump to lubricate the vertical gibs??
I’ve made some wiki updates in anticipation. All places say “not yet in service”.
- Added to Tools list with a representative photo
- Added to Machine Shop page, Resources category
- Linked from both places to online manual
- Uploaded a copy of the online manual to the committee drive (for when it disappears online)
I have two questions.
(1) What power does it need? (wiki update purposes)
(2) On what metals can this be used? Just steel?
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It uses 208/3 phase.
Currently I think it is best to stick with ferrous metals, others can be ground but takes a little more precautions. I think that maybe a case by case basis.
Yes from what I have read, also the bearings on the height adjustment
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What other metals besides ferrous metals could you possibly grind with this without fouling the rock??
Hard, non-ferrous materials. Nickel alloys like inconel, titanium, carbide. A lot of those will need frequent dressing or a special wheel however.
And a vice or clamps to hold them on the table.
So what’s the latest on the surface grinder?
I’m willing/interested in trying my hand at grinding precision toolroom stones as Robin Renzetti did in his video. https://www.youtube.com/watch?v=DVLXsq7pi9Y
The goal would be to either offer it as a class that could serve as a ‘General use of the surface grinder - Certification’ class. And for anyone interested in a set of precision stones, a MUCH cheaper way to get a set.
The India stones themselves are reasonably priced and are available in several sizes. Norton Combination India Stone — Sharpening Supplies
Would this be of interest to any of you?
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Until we move or 102 it won’t be put into operation. It will have an enclosure built around to control dust.
I received the new oil lines & coupling last week. We don’t have the grease yet for the new bearings.
Tim, after seeing that bottle, i’m trying to avoid thinking you bought the wrong kind of, um, grease.
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Lol it is kinda peculiar that it’s labeled that way.