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Breze
12-31-2013, 07:54 PM
I was perusing the new Grizzly 2014 catalog last night and in the section on surface grinders they list a new product, Model G0763. This is a 6 x 18 surface grinder with auto feed on both axis of the table. Of course the other surprising part is it's priced less then $6000 shipped which is an unheard of price for a surface grinder with automatic table movement (magnetic chuck included). Don't know for sure, but from the picture the motors driving the table look like some kind of stepper motor setup, but that's just an assumption. I'll send an email to their tech support to ask about the drive setup.

Anybody else run across this? I haven't been able to find any reviews of the manual 6 x 18 grinder to get any feel of what their surface grinders are like in terms of accuracy, longevity and use.

Ron

KiddZimaHater
12-31-2013, 08:51 PM
It sounds similar to the Surface Grinder that Tormach is now offering.
I know Tormach uses steppers on their machines.
HHMMMMM......
Tormach Surface Grinder (http://www.tormach.com/product_grinder.html)
YouTube video (http://www.youtube.com/watch?feature=player_embedded&v=qNg_fOUc0C0)
FYI: I have the small GRIZZLY 6x12 manual surface grinder, and it's a bit weak. :(
unfortunately, it can only take light cuts, and it takes forever to grind off .003

dalee100
12-31-2013, 09:22 PM
Hi,

I'm not very impressed by that Tormach grinder. The movement appears to be very jerky and not very consistent in speed. And table bounce could be a problem for very close tolerance work. As much as I dislike hydraulics, it would still seem to be a better choice for precision grinders.

dalee

Breze
12-31-2013, 10:15 PM
The Tormach grinder looks to be an automated version of the 6 x 12 that Grizzly and many others sell. Of course that same grinder could be made to many different specs so who knows what version of bearings, etc. are used. I also noticed the awkward table movement. I retrofitted my old Covel 10 with AC drive on the long axis and the movement is smooth and consistent but it is equipped with a speed reducing gear box, 3 phase motor and it's controlled by VFD. Loads of torque so it has no issues moving the table.

Ron

Royldean
01-01-2014, 01:12 PM
Jeez, you'd think tormach would clean up the paint job on a marketing demo unit like that. The finish on the wheel cover is bush league.

tmarks11
01-01-2014, 03:38 PM
I see that Grizzly has formalized the price of the SB 8x18 lathe... it is permanently "on sale" for $1300 off list... And apparently no longer a "close out" item. Sort of like a lot of furniture stores around here.

hmmm...

Doesn't that make the "sale" price its retail price? Oh, yeah SB does not equal Grizzly... yeah...

back OT, looking at the manual 6x18 vs. the automatic 6x18, they look like different machines. Different vertical and cross feed handle locations, different size motors. Looks like completely different castings for the base and column of the machine (not to mention slightly different welded steel stand).

Anybody used the previous 6x18 grinder?

Breze
01-02-2014, 09:53 AM
Having looked at the specs of this grinder thoroughly there is one thing that gives me pause about this machine. It's the single phase motor for the spindle. This machine would be a lot higher on my list of consideration if the motor was 3 phase and controlled by an inverter (VFD). I know this is done in order to make it user friendly for more home shops but I've read a great deal about grinders with single phase motors not being able to achieve the surface finish quality as compared to a 3 phase machine and equipping it with a 3 phase set up couldn't have added more than about $200.00 to the overall price and would have satisfied both needs.

Like tmarks11 I would love to hear of other peoples's experience with the Grizzly surface grinders,

Ron

Tony
01-02-2014, 12:58 PM
I'm new to this SG stuff but just have to ask, is there any advantage / disadvantage to a SG
with a moving head vs. one with a stationary head and moving table?

My gut reaction is that a moving head would be much more rigid. less prone to flex, harmonics, vibration,
etc.. but even more than that.. isn't it just inconvenient to have to reach up to make depth
adjustments?

Arthur.Marks
01-02-2014, 03:29 PM
I see that Grizzly has formalized the price of the SB 8x18 lathe... it is permanently "on sale" for $1300 off list... And apparently no longer a "close out" item. Sort of like a lot of furniture stores around here. hmmm...

"We introduced the 8K and put a lot of effort into producing it (quality control), but people were not willing to pay the price which was over $3K. Those models are being discontinued and have a closeout price of around $1900.00... Once those are gone there will be no new SB 8" lathe. It takes us the same effort for QC on the little lathes as it does the big ones - in fact, the big ones are easier to QC, and we sell a lot more bigger lathes than the smaller ones. By "bigger" I mean the 13", 14" 16" 18" and 21" floor model lathes."

Quote by Papagrizzly (http://www.practicalmachinist.com/vb/south-bend-lathes/new-south-bend-lathes-251259/index5.html#post2146360) 10/30/2013

boslab
01-02-2014, 07:45 PM
Ive seen a tormech working and to be honest it wasn bad, the motors appeared to be servo, they didnt make the stepper noise but i may and usually am caught out by that one!, if i had nothing it would be better than an eagle or somthing
Mark

Mark Rand
01-02-2014, 07:59 PM
The only bad thing I saw from the YouTube video of the Tormach posted above was that the silly sods hadn't dressed the wheel before filming it. Hence the nasty buzzing noise instead of a clean hiss.

For a single phase machine a clone of a belt drive like a B&S or Jones&Shipman would give a better result than a clone of a direct drive machine like the Harig. They're more compact as well. Ok, it adds another $25 in the manufacturing cost, so there's no chance of that...

Breze
01-03-2014, 11:11 PM
I heard from Grizzly tech support today and they confirmed that the drive motors were stepper motors. They also indicated that was all they could tell me because the grinders are still en route.

Ron

adatesman
01-03-2014, 11:42 PM
They also indicated that was all they could tell me because the grinders are still en route.

They come in a giant box of Cracker Jack? How do they not know the specs after ordering them? Or do they expect them not to match the PO????

tmarks11
01-04-2014, 11:49 AM
They come in a giant box of Cracker Jack? How do they not know the specs after ordering them? Or do they expect them not to match the PO????
You expect the low paid phone "technical support staff" would have access to that type of information?

It probably exists only in the file cabinet of their engineering staff. Who will not be taking phone calls from the public.

Once the prototype lands on these shores, the technical writers and mechanics will disassemble, reassemble, and write the instruction manual, which they will then provide to the "technical support staff" so they can answer your questions.

Which, based on past history of new Grizzly releases, is probably months in the future. Notice that this item doesn't show up as "In Stock" on its webpage.

They seem to still live in the days of giant print catalogs being the primary way to sell equipment, so they tend to try to rush all new equipment into the new years day catalog, even when it won't actually be available for delivery until the summer.

adatesman
01-04-2014, 01:45 PM
You expect the low paid phone "technical support staff" would have access to that type of information?

If it's in the catalog, then yes, I expect the support folks to at least have a preliminary spec sheet based on what what they ordered from the factory.

Breze
01-04-2014, 06:47 PM
Given the use of stepper motors in CNC applications, it was probably only a matter of time before this technology would show up in positioning and movement applications on surface grinders. If it proves to be a good fit for this application then it would only mean reasonably priced auto feed grinders which will put this type of machine in reach of many more small business and home shop type users. Maybe Grizzly should be applauded for leading the way in this effort. With Tormach pursuing something similar it would tend to make one believe it's a viable application. Of course, as with all things, time will tell.

Ron

tmarks11
01-04-2014, 07:21 PM
With Tormach pursuing something similar...
I gotta believe that this new product in Grizzly's catalog just ruined New Year's day for a lot of folks over at Tormach.

Tormach has modified the much smaller 6x12 grinder, the manual version selling for $1800 at Grizzly.

Grizzly has modified the much larger (three times the weight) 6x18 grinder, charging $5600 for an automated version of the $4400 6x18 grinder.

I think we have just seen a price cap placed on Tormach's offering. If they can't bring it to market for $3000-3200 or so, I think it will be DIW.

http://www.tormach.com/blog/wp-content/gallery/psg612-intro/straight-on.jpghttp://cdn0.grizzly.com/pics/jpeg500/g/g0763.jpg

Rosco-P
01-05-2014, 04:53 PM
I gotta believe that this new product in Grizzly's catalog just ruined New Year's day for a lot of folks over at Tormach.

Tormach has modified the much smaller 6x12 grinder, the manual version selling for $1800 at Grizzly.

Grizzly has modified the much larger (three times the weight) 6x18 grinder, charging $5600 for an automated version of the $4400 6x18 grinder.

I think we have just seen a price cap placed on Tormach's offering. If they can't bring it to market for $3000-3200 or so, I think it will be DIW.



$5600? I think I'll pass. I can buy an old DoAll 6x18, hydraulically automated on 2 axis and have it professionally rebuilt for less money total including shipping.

Breze
01-05-2014, 08:38 PM
$5600? I think I'll pass. I can buy an old DoAll 6x18, hydraulically automated on 2 axis and have it professionally rebuilt for less money total including shipping.

Seriously? Warranty on the rebuild? Sounds interesting.

Ron

Rosco-P
01-05-2014, 10:03 PM
Yes, seriously. Just because a machine is used, doesn't mean it's all used up. Lots of shop with a surface grinder sitting idle. Not much mold and die work going on in the USA these days.

Breze
01-07-2014, 11:30 AM
$5600? I think I'll pass. I can buy an old DoAll 6x18, hydraulically automated on 2 axis and have it professionally rebuilt for less money total including shipping.

Bear in mind I'm not trying to be argumentative here, however the reason I ask is because everything I've read about reputable machine rebuilders typically states that the cost is usually about 2/3 the price of a new machine and that doesn't usually include shipping. Throw in the price of the machine itself and I just don't see how the math works out to those kind of numbers. Most of the 2 axis auto machines are in the $12,000 to $14,000 range new and 2/3s of those prices are much more than $6000.

When you take into account that one can easily spend $3500 getting a spindle rebuilt.....like I said, I just don't know if the numbers you state are a reasonable expectation. I'm not pretending that the Grizzly grinder is in any kind of league with the older quality machine tools, especially a professionally rebuilt unit, but if you're gonna throw out numbers like that you need to be able to cite a certain circumstance in which this turns out to be the case, otherwise it's just speculation.

Ron

tmarks11
02-09-2014, 11:14 AM
If Tormach can't bring it to market for $3000-3200 or so, I think it will be DIW.

well Tormach's pricing is out... $3989 for the PSG612. Since this is essentially the same 6x12 grinder that Grizzly sells for $1800, they are charging a premium of $2189 for automating two axis with stepper motors.

And it really looks like their design rules out use of coolant, which is a mistake IMHO.

I like Ron's solution better. If you haven't seen it, check out his blog post. Very awesome, and not a stepper in sight...

http://breseplane.blogspot.com/2013/03/automation-and-dodgy-left-shoulder.html

I am really not sure why Tormach thinks a stepper solution is needed for the y-axis, since it does not need precise positioning. It just needs to make it past your work piece by several inches before it returns. I assume that Tormach's choice of stepper motors is because they already have all the pieces and parts in their warehouse, and their engineers could cobble the prototype together in an afternoon.

Breze
02-09-2014, 01:24 PM
Actually if you attempt to grind a slot the precise positioning would be critical and I'm assuming they are designing for all applications. Of course if just the top surface is your focus then it's not a big deal.

Ron

tmarks11
02-09-2014, 06:50 PM
Actually if you attempt to grind a slot the precise positioning would be critical and I'm assuming they are designing for all applications. Of course if just the top surface is your focus then it's not a big deal.

Ron

That might be true... except the Tormach doesn't provide that type of control. No feedback of position vs. workpiece, no ability to define precise slot widths, etc.

It is somewhat ironic that they call it a "cnc grinder", yet it seems to offer only a little more functionality than old-school automatic grinders. It has four control modes, which define the pattern across the part.

The automatic (hydraulic) surface grinders essentially allow one pattern for y-axis movement... the end of each x-axis stroke causes the y-axis to increment by a pre-set amount until it hits the limit, and than the y-axis increments the other direction. The tormach gives you three options (incrementing at the end of each stroke, incrementing at the end of the right-hand stroke only, and a zig-zag pattern), plus straight line. ok. I am not sure that really improves the functionality.

John Stevenson
02-09-2014, 07:07 PM
I automated one many years ago by fitting a rodless air cylinder on the back of the table. On the front of the table was a 5/2 valve that reversed the air flow when hit.
Worked fine, speed was controlled by air pressure and because the table was so free, like most grinders it wasn't jerky at all.

If you want to manual grind anything you just pulled the pin between the table and the cylinder.

http://www.airtec.de/tl_files/products/Pneumatikprogramm/Kolbenstangenlose%20Zylinder/images/ZR40L.jpg

Breze
02-09-2014, 08:39 PM
You make some good points, and you're right looks like the same grinder just automated. I had a used grinder of this type for a while, I think it was MSC brand. I never could get a decent surface from that grinder. I have no idea what they're like new. Mine had not been new for a long, long, time.

Ron


That might be true... except the Tormach doesn't provide that type of control. No feedback of position vs. workpiece, no ability to define precise slot widths, etc.

It is somewhat ironic that they call it a "cnc grinder", yet it seems to offer only a little more functionality than old-school automatic grinders. It has four control modes, which define the pattern across the part.

The automatic (hydraulic) surface grinders essentially allow one pattern for y-axis movement... the end of each x-axis stroke causes the y-axis to increment by a pre-set amount until it hits the limit, and than the y-axis increments the other direction. The tormach gives you three options (incrementing at the end of each stroke, incrementing at the end of the right-hand stroke only, and a zig-zag pattern), plus straight line. ok. I am not sure that really improves the functionality.