Any input on this surface grinder.

T

techna

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Dec 10, 2005
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I was offered this surface grinder by a local seller. My problem is that I know nothing about it, and the seller knows very little as well. He seems to be typical of the reseller that buys things at auction or at estate sales and tries to move them for a quick buck. I'm ok with that, but the rub here is that it does not look like I will be able to test the grinder since it is still on his trailer. Plus, he wants to deliver and I am almost certain my only 220v receptacle will not mate with the plug on the machine (if there even is one). Also, I have only seen this one picture.

So, my question is....If you had to make an offer based on this very limited info, what would it be? 300.00 or so?
 

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I would not have a problem paying up to $1000 for that. As long as it's not China made.
Ask name brand and why can't you go look at it before he delivers? It might also be 3 phase, in which case I would want to pay less, because a phase converter would be needed.
 
First off if it's 220v you didn't mention if it's single, 2 or 3 phase? Does it have automatic feed?
I think $300 would be a steal, especially if he's willing to deliver it.
I would look on ebay just to get some ideas on prices for a similar machine.
 
Thanks guys. Single or three phase (220v was an assumption on my part) was the first thing I asked after he sent the picture and manuf. info was the second. Have not heard back yet. I hate to have him drive it over if I am at all sketchy about taking it at my offer. He originally asked for 500.00.
 
Don, I talked to the seller over the phone and got a few answers. Though he knows very little about the machine, he did confirm that it is three phase. The urgency to deliver quickly was because it was on a rented trailer and he hoped to get it sold before the trailer needed to go back. Since I can't make it happen tonight, he will unload it at his house for my inspection in the next day or so. I won't be able to run it, but he is a super nice guy and I can't help but feel good about things. The best part is that he offered it to me at 250 if I pick it up. Don't know how that's gonna happen, but at the price I think I will figure something out.

Now, if anyone could give me pointers on the single to three phase conversion I will need to get it running......
Thanks!
 
Techna, the magnetic chuck on that grinder is probably worth more than $250.

All you will need is a phase converter, one rated for the HP of the grinder motor. Shop around, check Ebay, they're not too expensive.
 
Phase converters arent that hard to get, if i had a shot at one like that for 250 you'd better not be standing between me and the nearest ATM =) Congrats (i hope) on your new surface grinder =)
 
I hope it does work! If not, for $250, it's worth a shot. If the motor is bad, replace it for another $150.
 
Run the table all the way to one side so you can see the ways under the table. Put a straight edge on it. It should be flat (I've seen them with a 1/16" gap)

Run the motor and put your hand on the casting near the spindle, it should feel dead - no vibration.

If it fails these tests, it is still worth what he is asking for it, but it wont grind flat with a good finish. A good grinder that size is worth several grand.

A surface grinder motor should run perfectly smooth, that is why it is difficult to replace a motor on one - even the pulley is balanced on the motor shaft as a single unit. Everything has to be perfect for it to grind smooth. However, most knifemakers settle for less than smooth - they're not grinding mold shutoffs etc.

Remember to use thick oil for the ways and thin oil for the spindle. Never use thick oil for a spindle. Hydraulic fluid works.
 
Thank you for the info and suggestions Nathan. Running it wont be possible until I have it home and have my power supply worked out, but the other things I can check easily. As you said, none are deal breakers at the price, and it is good to be informed.

Since a variable frequency drive does not seem appropriate here, will a static phase converter work out? Something like this? http://www.phase-a-matic.com/StaticModels&Prices.htm

Or, due to the horsepower drop, should I go with a rotary phase converter? It looks like those can be built from plans offered on ebay without killing the budget.
 
Hello Techna

I would suggest spending an extra $100 or so and getting a VFD. It sounds like you will be saving a lot of $ over what you would normally pay for a surface grinder. You can use one VFD to run your surface grinder as well as other equipment in your shop (belt or disc grinders, drill press, lathe) by using some in-line plugs and receptacles. Home Depot and Lowes sell them. There are quite a few threads around discussing what VFD to get and how to protect them from the conductive dust thrown off by your grinders.

If you do get one, let me know if you need help setting it up. I am in Houston too.

Take care.

Phil
 
Well I got it home and so far I am very pleased. I have not checked it out in the manner that Nathan suggested yet, but everything turns and moves like butter and the thing is rock solid. The 1500lb weight almost killed not only my truck, but myself and a buddy that helped move it. Four to load it laying down into a pick-up from a nearly height matched trailer, and only two, with no mechanical assistance, to get it to the ground upright......I am still shocked that we managed without dropping it.
It will be a little while before I can run it as I have decided to build a rotary phase converter. The needed single phase motor for it is on hand already, and this type of phase converter seems to be not only easy to build, but also the most robust. Even with the phase converter build cost, I will have less than 325 in the the whole rig, and that is such a good deal its just stupid. :D

Oh yea, and the magnetic chuck is a USA made Suburban 6" X 18"!
 

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Bill Burke said:
you need a three phase motor to build a rotary phase converter.
Click to expand...

You are of course correct Bill. Now that I have taken the time to actually READ the info I have on rotary phase converters, I see my mistake. Hmm, so a rotary phase converter is just a static unit used to get a three phase motor spinning, where upon the three phase motor becomes just a generator for the three phase output power needed. Maybe that is not so cost effective since I have no freebie three phase motors laying around to use as the idler motor. I could probably buy a VFD for less than building the rotary, though I am not crazy about dropping an inexpensive NEMA 1 device into a home brew enclosure. NEMA 4 enclosed VFDs like my KB are a little more spendy so.....
I dont know just yet how I will go, but for some reason I am driven to keep the "killer deal" theme going all the way through the phase converter purchase.
 
Look around, In industrial areas three phase motors are very easy to find cheeeeeeap. The last two that I got were free and there was nothing wrong with them. I prefer the rotory route because it can be wired into you shop with a three phase circiut and you can run more than one machine off from it or you can run an entire shop full of machine off of it at the same time as long as you do not exceed the horse power rating of the converteryou are fine. I actuall bought the converter that I use off eb*y. It is a ten horse converter it cost five hundred dollars with free shipping and was brand new. I typically run a hydraulic press a milling machine and a surface grinder off of it. most of the time the surface grinder and the press are running at the same time.
 
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