I purchased a replacement gib for the Y axis of my G0704. The only information provided by technical support from Grizzly was the factory utilizes the process of hand scraping to custom fit them to mills and then cuts them to the proper length. The replacement gib is approximately 12" long, tapered, smooth finish on both sides, and a notch on one end for the adjustment screw. I have found similar posts on forums, but no answers in-terms of how someone without the benefit of hand scraping expertise could accomplish the task. I assume you can't simply put the full length replacement gib in, adjust to a reasonable fit by moving the saddle back and forth, and then make marks on the gib in the front/back of saddle as a reference to cut to length. Also, what about the smooth finish in-terms of holding oil? No access to another mill. I would really appreciate some help.
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Replacement Gib For Y Axis Of G0704
- Thread starter DJR2015
- Start date
- Joined
- Mar 21, 2013
- Messages
- 4,063
I don't know about the hand scraping part. My gibs are ground on my PM25 (very similar machine). And that is exactly how I was told to trim the length. You may have to regrind (have a bench grinder or dremmel?) the notch for the adjustment screw. As for fitment I would primarily worry about the side that slides against the base, but the other side should be reasonably flat to work well. First, I would take a sheet of 600 grit wet/dry and a flat surface, put a little oil on the sandpaper and gently slide the gib strip back and forth a few times and then inspect for flatness/high spots. Some dykem would be of help here.
If reasonably flat, I then put more dykem on the sliding face and install into the mill, adjust, then slide the Y-axis back and forth a few times. Remove the gib and look at the wear marks. I took an old Craftsman file and put a radius on the end then ground an edge on it. I use this to scrape down the high spots. Reapply the dykem and repeat. DISCLAIMER: I in no way resemble anyone who knows anything about 'scraping'. Nor have I read anything about it. This just seemed like a reasonable, if not tedious, way to get a decent fit on these things.
If reasonably flat, I then put more dykem on the sliding face and install into the mill, adjust, then slide the Y-axis back and forth a few times. Remove the gib and look at the wear marks. I took an old Craftsman file and put a radius on the end then ground an edge on it. I use this to scrape down the high spots. Reapply the dykem and repeat. DISCLAIMER: I in no way resemble anyone who knows anything about 'scraping'. Nor have I read anything about it. This just seemed like a reasonable, if not tedious, way to get a decent fit on these things.
- Joined
- Apr 17, 2015
- Messages
- 323
I have done this process many times. The first thing I would do is make sure all corners are well rounded so the gib does not bind in any of the corners. In the absence of the ability to scrape the gib you can lap it with fine abrasive paper and some thin oil or water but it needs to be done on a known flat surface like a surface plate. The process of scraping is really rather simple the gib is gently rubbed on a plate with a thin coating of bluing on it. The high spots, which show up with bluing on, get scraped off until firs the back of the gib is flat then the front. You must be careful to not remove too much material or the gib will become too thin, and it will not serve its purpose; to take up or adjust the clearance between the mating surfaces on the machine. cutting simply means removing excess material on the thin end that protrudes from the machine. A new notch can be cut for the gib screw if needed. I would suggest getting it machined in so the fit on the screw is good.