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RF30 Basement Install

YYCHobbyMachinist said:
Brent (@Brent H ), Here is my take on what I was looking at.

View attachment 9855
Click to expand...
I'm just spitballing, but...

There is no way that the gib would be designed to have a taper that changes. Gibs like this should have a consistent taper from end to end. As Brent said, the height would be consistent too.

One possibility is that when the machine was being constructed, there was something wrong with the dovetail ways. (Maybe something slipped during machining the ways?) Maybe they 'salvaged' the machine by butchering the gib? (I'm picturing a ham-handed guy with a belt sander!!) OTOH, you've had some experienced guys examine your machine so maybe I'm out in left field.

If you want to test for certain, you'll need a precision machinist straightedge.

193700d1489641978-18-straight-edge-casting-straight-edge-1200x636.jpg


Use bluing to test the surfaces of the dovetails, etc.

OTOH, using the locking screws seems to be able to take the gross movement out of the table. If you are happy with that, live with it until it becomes an obstacle (if ever).

Craig
 
@trlvn , dabbler and I went and had a look at Craig’s machine. Other than the gib being placed on a surface plate prior to our visit, there were no precision measurements taken or blueing carried out as we felt it was important that the machine be re-assembled (the original problem) and made functional. This was achieved when we were able to install the gib - with some effort, and were able to mount the table and have it move with reasonable force. We deburred, stoned and otherwise improved the mating surfaces with the tools and time we had.

We do agree, there needs to be a thorough inspection, including precision measurements, in order to find out where the problem(s) lie and then repair the mill. The ideal setting for those operations are not a cramped basement. The machine would have to be disassembled, brought up, and then taken to a shop that has the proper equipment. A rough estimate of repair time is 100 hours.

I think the gib is the issue and I would start with that.
 
Well, if you ever worked on an machine that needed work, you will know how labour intensive it is.

Here are “Pros” talking about a Bridgeport Mill (2014 US $s)
359A067A-3C85-4520-9EE8-4459F5A27A22.jpeg


Here is the link to the thread:
https://www.practicalmachinist.com/...spection/bridgeport-way-scraping-cost-296446/

If you don’t have all the machines and need to “farm stuff out” the price / time spent on the project goes up.

@DPittman: How long did it take you to build your nice scope rail? Start to finish counting time to make any missing tool, getting stock, etc.
 
RobinHood said:
The machine would have to be disassembled, brought up, and then taken to a shop that has the proper equipment. A rough estimate of repair time is 100 hours.
Click to expand...

And we all know that's not going to happen. If it migrates out of the basement It ain't coming back.

Craig
 
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RobinHood said:
Well, if you ever worked on an machine that needed work, you will know how labour intensive it is.

Here are “Pros” talking about a Bridgeport Mill (2014 US $s)
View attachment 9856

Here is the link to the thread:
https://www.practicalmachinist.com/...spection/bridgeport-way-scraping-cost-296446/

If you don’t have all the machines and need to “farm stuff out” the price / time spent on the project goes up.

@DPittman: How long did it take you to build your nice scope rail? Start to finish counting time to make any missing tool, getting stock, etc.
Click to expand...
I'm not disputing on how much time it would take to fix the machine I'm just saying that it might not be worth it. If one had all the necessary equipment and knowledge himself it might be justifiable but if you have to "farm" any of that expertise out, a different milling machime might start to look like a better option.
 
That is exactly the type of tough question that needs to be asked. Use the mill as is, or get another machine if the performance is not up to the OP‘s expectations.

Another option could be to work on the machine over time and slowly improve it as experience is gained. Could be a great teaching project.
 
I find it hard to believe that a machine which doesn't appear to have ever been disassembled, has somehow been damaged so severely that it requires a total rebuild/.
I'm going to pull the X-axis gib out of my machine tomorrow and measure it for comparison purposes.
 
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David_R8 said:
I find it hard to believe that a machine that doesn't appear to have ever been disassembled, has somehow been damaged so severely that it requires a total rebuild/.
I'm going to pull the X-axis gib out of my machine tomorrow and measure it for comparison purposes.
Click to expand...

Take photos and post your dimensions please.

Craig
 
@David_R8 I am certain that the anomolies we found are right from the factory. I think it is possible that the gib angle was wrong, so a guy fixed it... badly. I think this is a very capable machine with a serious problem. It is possible to do good work on it, but in ways adapted to this particular machine.

There can be a lot learned on this machine, but to do precision work, an upgrade is necessary, either in the form of a rebuild or a new machine trade up.
 
YYCHobbyMachinist said:
... tried tightening the Gibb lock screws to see what effect they would have. I tightened the saddle first and that had no effect. Locking the left side table lock had no effect. When applying the right hand lock the DI swung 0.004 and now there was less than 0.001 (maybe even nil) movement when I pushed and pulled on the table.
Click to expand...
To be clear, I think the practical course is to use the machine as described above. The gib may be a poor fit but the locking screws seem to be able to compensate pretty well.

I think we all get a bit OCD about machine precision. As long as the machine works to create parts with acceptable tolerances, then all is good! If the parts coming off this machine are too far out AND it is because of the gib, THEN figure out a solution.

Elsewhere on the internet, it seems that Richard King is considered a top notch machine rebuilder. However, I believe he generally starts with the question "How precise does the machine need to be?" IOW, every rebuilt machine still has a level of imprecision no matter how much money is spent.

Craig
 
I agree use it as it is I’m sure @YYCHobbyMachinist just wants to use it for a while.
At some time though it would be worthwhile to take it apart and inspect and thoroughly measure the dovetails on the table and saddle. Especially all the angles. The fact that the gib only fit in one particular spot tells me there is something up with the dovetails. I can’t visualize what it would be though. At that point a decision what sort of rebuild if any should be done.
 
My gib has the following dimensions:
14” long
1.2755 wide/tall at the outboard end
1ee0427a91f86fbbc0d4dcb7f605e213.jpg


.3735 thick at the same end by the adjustment slot
91650c027b2079438e7b90495dc5d030.jpg



1.221 wwide/tall at the inboard end
0a0f7514808d3a37c794c7fe2a8da21c.jpg


.2092 thick at the inboard end.
22dca97aa8c03d027be888c938a0b209.jpg



Sent from my iPhone using Tapatalk
 
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