Potential Surface Grinder Purchase

There’s a lot to this that I don’t think we’re considering… Tooling, metrology, training. I would love to learn it and maybe make a few parts (1-2-3 blocks for example) but right now I just see a lot of people like me who want to learn but don’t have any applications.

Several belt grinder manufacturers make ‘surface grinding’ attachments for knife makers, that might handle most of what DMS needs. I can’t imagine there are a lot of parts that get made at DMS and need to be flat/square to tenths.

If y’all decide to buy it I will be excited to learn how to grind, but like Bob and Nick I’m not sure this is really the best use of the floor space.

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From the look of the picture, and I could be wrong here, but it looks like the arm has enough height that it could in theory be used to resurface engine blocks and cylinder heads.

Of course, you would have to buy or make a fixture for it to sit correctly on the bed, but it’s still an application that it could be used for (potentially).

Frankly, I’m surprised some of the Automotive guys hadn’t said something about that yet.

Yes there are. Regular wheels are $35 the fancy stuff goes for up to $700 for cubic boron nitride. They also make wheels for non ferrous metals.

I’m in favor as I have a number of project ideas in mind such as grinding sets of precision ground toolroom stones which I believe would be of value to many who use the machine shop and who appreciate the value they provide to machined surfaces. 1-2-3 blocks would also be a great project/class. I’ve said in the past that I would be willing to start developing some training material for the Harig Surface grinder as soon as it is running so the same holds for this one.

I agree it should be under RFID control and should have a similar level of sign-off that the HAAS has although I’m sure the training could likely be handled in a single night followed by a sign-off appointment by an approved instructor.

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One other general safety Pro over the Harig is that it has a manual top surface dresser for the wheel. It’s enclosed inside the wheel housing and should be less prone to mistakes or catastrophic failures with dresser fixtures being pulled into the wheel due to accidental placement on the wrong side of the wheel. A top dresser like this makes for a much more controlled/repeatable behavior.

So one question is how much larger is the CNC machine than the surface grinder we have ? I doubt we need both, so there’s some of the space we’d need. How much more ?

I hope the more run of the mill wheels for non-ferrous materials are not the ones in the $700 range.

@procterc and I were talking about what it would take to repair or refurbish the mills. I believe the table will have to come off to do that. ( table, not deck. Didn’t have the right term and knew it… )

Maybe @procterc can explain what he had in mind. I’m not super familiar with the positioner myself.

we don’t have a cnc in the machine shop other than the HAAS. The XXL (which is 48x54") and is housed in the dedicated space allocated to the PigSIG. Space is already allocated in the Machine Shop area for the current surface grinder. If we swap new for old, there is a net gain/loss of zero.

You’re right. I doubt we’ll get as much use out of a SG than the XXL, so the choice is easy if it comes to that.

Surely this surface grinder requires more floor space than was allocated to the current surface grinder?

Wrong thread?

I mean the proposed CNC surface grinder purchase vs the existing surface grinder. The existing one is not a small machine as I recall.

My recollection is that you want a minimum surface texture on an engine deck for the gasket to adhere to. A ground surface might allow the gasket to blow out too easily.

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“Who is going to teach the tool; already there is inadequate teaching for what we have?”

Amen to this statement!

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Several years ago I used a surface grinder at work to sharpen a bunch of small beat up dies that came with a small sheet metal punch I have. (puck like part in this photo). It was nice to have access to a surface grinder.

I don’t think our typical safety based training would be adequate. I think we would need something where the first 4-5 times someone used it we had an experienced person working with them. Maybe have a once a month timeslot where we have some skilled volunteers involved to keep a watchful eye on it. Personally I would like to have a surface grinder at the makerspace. You don’t need one often but when you do, there is no better way other than a surface grinder.

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There is a possibility of getting a load positioner in the deal. This is a pneumatic device that takes the load and holds it in position. One can then raise or lower the load by hand, and the load stays where you want it.

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For me, it would be great, I have several applications in which a surface grinder would be of benefit. Especially a large one. Several parts I am making do need to be flat to tenths, in fact having this might completely change how I approach my parts. More importantly, the sheer value of being able to learn to do such operations, is a simply magical to me, just as learning the HAAS was and still is.

As far as space goes, in my personal opinion a surface grinder would benefit the shop more than a third manual mill. Plus, swapping it for the existing surface grinder also seems to be an OK option.

To me, the only con is how niche it is. I would ask this: what else could we do with the money? As some of us have informally mentioned, having a CNC Sherline or equivalent mill could be a good avenue to get a wider audience into the HAAS. It seems that several people have engaged with the CNC Sherline despite it being so new. And, it would probably cost somewhere slightly less than this scale of money. Hell, we could convert a larger manual mill to CNC (like a larger precision matthews or grizzly) for that amount of money.

I am still in favor of this surface grinder, but we should at least consider what else we might do. What are y’all’s thoughts?

I would agree this purchase comes down to a decision of space and prioritization of money. I am personally 50/50 on this one. Either way this goes, I don’t think I will be too upset. Let me throw my .02 Canadian (worth less than 2 cents) into the conversation.

I joined because DMS has super awesome tools that an armchair hobbyist simply can’t afford. Where else can I get amateur access to the multicam, festools, auto lift, electronic scopes, etc.

Let’s face it, the SG is a niche tool much like the rotary table for the end mill. How many people signed off on the Bridgeport would be comfortable mounting and using the rotary table? We still have one. I realize the cost difference, but if forced to choose between another endmill or the SG, I’ll take the SG.

Will it be used every day? Probably not. Does it round out a well tooled machine shop? Yes.

Long story short, I would vote yes to purchase, however I wouldn’t be heartbroken if we passed on it.

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Agreed. I’d rather see one of these for the money. It would at least pay for itself in what we save on bandsaw blades on the current vertical bandsaw.
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Could not agree more about the roll-in bandsaw being used 10-20 times as much. Or more.
The grinder is a beast and can really blow a wheel up fast, hydraulic power feed DOES NOT stop. On the other hand it can also do alot of work quickly.
Typically you would only grind ferrous material with these.
I would go for the mucho-mucho training plan, as in lots of it, including a couple of runs on the small one first and dont get rid of it as they are super handy and you can put small spin fixtures on them also. I dont know anything about the new shop layout, but the old one requires a small footprint.
I am guessing most of the projects at DMS dont really reqiure it, how much problem has it been to not have the small one working ?

I’m glad to see the discussion. I’m not sure how long the guy is going to hold on to it. I am thinking about holding a special meeting Tuesday night, but I have to make that decision before 7 tonight.

A quick poll

  • Yes I’m for it
  • No
  • I’m indifferent

0 voters