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SteveC
12-26-2002, 08:31 PM
I'm thinking about purchasing a Grizzly model G9249 lathe. It runs about $1900. It has a "Gap Bed". Evidently you can remove a section of the ways to increase the swing. Does anyone have experience with this lathe or the gap bed in general?
I'm also looking at the Grizzly model G3616 vertical mill. It cost about $2300. Any advice on either of these machines would be appreciated.
Both of these machines look like a lot of machine for the money. They probably are not the industryal quality I have been use to using at work, but maybe since they are new and not abused, this might make up for it.
Thanks


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Philt
12-26-2002, 10:15 PM
There is a thread on the subject of removing the gap on a lathe like the Grizzly 12 x 37 on the
Yahoo 12 x 36 group:
http://groups.yahoo.com/group/12x/

I would have some second thoughts about removing
the gap on my 12 x 36 lathe after reading this.

Phil Teague

charlie coghill
12-26-2002, 10:37 PM
Steve
I have a jet 1340 which has a gap bed. I don't remember who told me not to remove the gap, but I was told that. In almost 20 years of owning the lathe I have not removed it.

The gap portion is held in place with four bolts and a couple of dowel pins. I guess with the dowel pin the part would probably go back into the same place but I don't want to chance it. Charlie

1erful
12-26-2002, 11:05 PM
SteveC: DO NOT REMOVE THE GAP!!! It is almost impossible to get it back and in alignment. I learned this the HARD way. From what I observed the gap is not precision machined before it is filled with the part that then is machined to finish the ways. Mine had the pin holes drilled at an angle and they were not taper pins, just dowels, it took me forever to get it back in and properly aligned.
I have posted a question on the 12X board about the idea of correcting the problem and bedding the gap in with epoxy/metal putty but so far no one has done it. The universal chant is "DO NOT REMOVE THE GAP"
WALT

SGW
12-27-2002, 08:46 AM
I've got a South Bend 10K gap bed lathe. (Didn't know they made them? They did!) It was not one of SB's better ideas. They took a regular 10K bed and modified it to have a gap. That leaves the bed casting quite thin at one point...and mine warped at that point.
Now, it IS possible to design a gap-bed lathe correctly, with extra material added to support the gap. Take a look the how the Grizzly bed is made at that point and be sure it does have extra support at the gap to make up for what the gap takes out.
The SB gap was scraped in, with dowel pins, and I could remove and replace it with little difficulty...but it sounds as though the Grizzly does not have such careful fitting.


[This message has been edited by SGW (edited 12-27-2002).]

WJHartson
12-28-2002, 12:43 AM
I had a Grizzly 12 x 36 about 12 years ago and removed the gap. When I tryed to put it back in nothing lined up. After a lot of work I got it back in and lined up. The taper pins were not drilled and reamed with any percision. I also had to grind the bottom of the gap a little in several places to get it to fit correctly. The mating surfaces on the gap were ground by hand at the factory. It was very frustrating.

If you are going to remove the gap from a new lathe I would make all new tapered pins of a larger size and make sure they are parallel to each other and perpendicular to the bed. Do them one at a time. I would also use 4 pins instead of the 2 that it comes with. When all of the pins are fit then take out the holddown bolts.

I have a new 14 x 40 Grizzly lathe and won't remove the gap until I have too and I will put in the 4 tappered pins before I remove it.

Hope this helps.

Joe

Thrud
12-28-2002, 01:48 AM
SteveC:
If you need a gap bed lathe consider a Polish (TUV or Andrychow) 17" and quit screwing around with lost (not a typo) cost wannabes. There is no free lunch - sorry. (the 2 mentioned are in the $20K range with DROs - Canadian). You will get a better lathe too.

SteveC
12-29-2002, 01:55 AM
test

SteveC
12-29-2002, 02:02 AM
Wow... I typed the wrong pass word and the system deleted my intire message. I have no idea why we need a pass world system anyway, but wouldn't it be better to test for the pass word before we type the letter, or at least not delete it and simply require us to retype the password????
Anyway thanks for all the advice. Actuly I'm not looking for a gap bed, it's just that all the Grizzly's in my price range seem to have one.

Take care guys,
Steve