Grizzly G8750 Compound Slide Table

[iplay1515]

I recently purchased Grizzly G8750 compound slide table to use as a general purpose x-y table and to experiment a little more with CNC.

One set of the dove tail ways on each axis is polished but the opposing set appears to be just ground down with a rough cut rotary grinder or other type of cutter. They are certainly far from being polished. Each axis also has an adjustable gib strip with one polished side that rubs against an unpolished dove tail.

Is this normal for a dove tail type of table or is the machining on this table incomplete?

For the price, the table appears to be a good value with the exception of the damage it sustained to the lead screws during shipping due to very poor packaging. Grizzly customer service has promised a new set of screws, but haven't given me a firm ship date. So far it's been a week since they were notified of the shipping damage.

[Ed from NY]

I think that table is meant for a drill press. You fix it to the drill table and the part to be drilled to it. Then use the 2 axis to align your holes. Not sure if you can successfully use it for something else. Good luck.

[iplay1515]

Originally Posted by Ed from NY I think that table is meant for a drill press. You fix it to the drill table and the part to be drilled to it. Then use the 2 axis to align your holes. Not sure if you can successfully use it for something else. Good luck.

I agree. The table probably was intended mostly for drill press work, but I'm just curious as to why the mating surfaces on the slides were not equally polished.

One of the surfaces is smooth and shiny like you would expect to see while the other looks more like the tool marks from a fly cutter on aluminum plate. The table is made from cast iron.

I'm just trying to determine if Grizzly shipped an unfinished machine tool.

Thanks.

[doorknob]

I have one of those tables - I will try to take a look at it tomorrow to see whether it appears as you have described yours.

[iplay1515]

Originally Posted by doorknob I have one of those tables - I will try to take a look at it tomorrow to see whether it appears as you have described yours.

That would be most appreciated. Thanks.

[iplay1515]

These of some shots of the surface of the ways showing the polished and unpolished mating surfaces. Notice the unpolished surface has swirls similar to a fingerprint that were left by a cutter.

[Ed from NY]

I can not see the pic very well on my phone, but if you are talking about the lower horizontal surface that is fine. Only the top one is supposed to make contact.

[iplay1515]

Originally Posted by Ed from NY I can not see the pic very well on my phone, but if you are talking about the lower horizontal surface that is fine. Only the top one is supposed to make contact.

The arrows point to the surfaces that make contact. Both are horizontal when the table is positioned in it's normal operating configuration. The polished surface is on top and rides on the unpolished slide below. When the table is mounted on my drill press, I have to stoop down and look up to see the polished slide.

The photos are from the front to back axis, but the left to right axis (longer) is machined the same way.

The gibs are ground and possibly polished, and they mate against the slanted part of the dovetails. All of the slanted dovetail surfaces are finished almost as smooth as the polished slide in the photos in my earlier post.

[Ed from NY]

AFAIK the top surface of the dovetail that is on the base is supposed to be polished. The lower surface on that "step" does not matter as the saddle rides on the top. However, given that this is meant for a drill press may be they made it that way.

[iplay1515]

I have a call into customer service at Grizzly, and have asked them to verify that the photos I sent were consistent with the spec. for the product. They also said that the table is suitable for light milling work.

Their catalog doesn't really give any specific designated uses for the table.

[doorknob]

Here is a photo of my Y-axis ways (from the top), along with a close-up.

The ways are not "polished", rather they show the swirl pattern that you mentioned. I did not inspect the mating surface or the gibs.

My (as yet-incomplete) plans for this table are to add X- and Y-axis stepper motors for the purpose of positioning workpieces under the spindle of my drill press so that I can drill repeated hole positions. I may or may not add a third axis of control for the quill. I had not thought of using it for milling.

overview of Y-axis ways:





close-up detail:

[iplay1515]

That's the one!