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RF30 Basement Install

YYCHobbyMachinist said:
This is worth giving a try. Heat at what temperature for how long? I would have to use our oven to heat it or a propane torch. What would suffice as insulation?
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i would go to ~200C, for about 20-30 min or so to make sure it is soaked. I would not use your kitchen oven - unless you plan on getting a new one and use this one in your shop going forward. Oil will burn off, any paint on it will blister, any solvent will off gas, smoking out your house.

Propane torch outside with some fire brick as a heat shield (or an old BBQ) and then a welding blanket for insulation (KO wool or RockWool should work as well).

All this procedure is assuming the gib got bent because of internal stresses. It happened to me when I made a new gib for my SM1340. After milling it to size and removing it from my jig, there was a bow in it. My gib is out of 1018 mild steel, so I just carefully straightened it in the vice. I would not attempt that with CI as it would probably break.

I am not an expert, nor have I ever done this stress relieving procedure myself. I’ve only watched a very experienced blacksmith stress relieving CI and that is the procedure he used. He had repaired a CI part (welded it), put it into his forge at low flame for about half an hour, took it out, covered it in a heavy blanket and walked away. The next day he completed the project with some grinding of the weld and repainting the part because all the paint had burned off.

Perhaps someone with more knowledge / experience can chime in?
 
We blued it in on my surface plate, and it is not bad at all. there is a 3/4 of a thou bow in the gibb. That is less than my first mill, and it reassembled just fine. So that;s not the problem. I found by using Prussian blue on my surface plate that there are some very minor bumps on the gibb, but nothing serious to do this. I cut some oil ways (well scratches, really) onto both sides and re-stoned the gibb.

The next thing to check is up/down gibb positioning. since it bound tight in open air, it is certainly not the hold down bolts in any event.

There is a 3 tenths taper where there it should be flat, but that's not enough to bind the thing 3/4 inches out of place in the gibb adjustment. The mystery is getting deeper, that's for sure...
 
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@RobinHood - keith fenner is back making videos and in part 2 (his most recent viedo) he tempers a spline shaft using a lime bucket. Worth watching, for sure.
 
I don't think this gibb is CI.

I took the gibb over to @Dabbler today and he blued it on a surface plate and stoned all the high spots off. We confirmed that it is indeed bowed to around 0.008". However it is flexible to the point where you can negate the bow with nothing more than your thumb. John spent a good 2 hours with me and is convinced that the gibb isn't the issue here but rather how it's seating.

John gave me some way oil, proper assembling oil, and a better stone to use (Thanks John!!!)

When I got home, I pulled the table and cleaned all the mating surfaces with Varsol, re-inspected (didn't find anything of interest), lubed the mating surfaces and tried again. It's closer but not close enough.

Craig
 
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Sounds like you are in good hands with John C., Craig.

sure is a mystery why this thing will not assemble properly. You have been through all the obvious things multiple times...

interesting that the gib is not CI from factory...
 
Within limits cast iron is actually quite flexible. When I took welding the instructor asked us what we thought. Then he held out a cast iron welding rod and a steel rod. The cast iron drooped like a wet noodle.
 
I think the gibb is CI. When I stoned it it made the little sandy swarf you get from stoning CI or malleable iron.
 
Hey Craig,

When I was making the new gib for my lathe I had that sucker true as anything and there was pretty much nothing high that would or should cause a jam up - but it did.....took me forever to find out why -

there were a couple high spots at the end of the dovetail on the cross slide base - just a couple very small dimples...like 1 to 2 thou - in my case I had machined the dovetails but the cutter failed to remove the high spots as they were the hard nickle repair metal I had used. Once I found the spots, I had to carefully grind them

There could be a few tiny dimples or dents that are messing things up for you. To locate the possible issues, what I did was take the blueing and apply it to the dovetail ways using a foam brush. you want a very thin coating but you want it uniform. take your gib and run it through the dovetail in the correct orientation with a steady pressure. Once you make the pass, check the way for any high spots (bluing will scrape off to a shine or leave a streak on the gib)

This could be as simple as a wee dent that happened when you pulled the table apart, believe me- it does not take much and can drive you mental

In your picture below I circled the cleaned off blue on the gib- where is this happening when you crank in the table? that may be the area you need to look at for any issue.

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Brent H said:
In your picture below I circled the cleaned off blue on the gib- where is this happening when you crank in the table? that may be the area you need to look at for any issue.
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Brent, I eliminated that issue area by stoning but it didn't have any effect in the end. @Dabbler thinks I may have stoned a little too much off the gib now.

In any event, @Dabbler and @RobinHood are coming over to inspect the machine together. If they can't solve this mystery no one can.

Craig
 
It may not be a gib issue Craig,

My previous post was to call your attention to seeing where on the ways you may have an issue. just a wee dent may be the whole problem - but yes - you have assembled the dream team :)
 
YYCHobbyMachinist said:
What would that do? I don't think you could thread it in from the wrong side or could you?
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It’s possible for them to be a bit off center. The leadscrew will bind if assembled incorrectly. It only matters if is can accidentally be rotated though. I had that issue on the cross slide nut on my Southbend lathe.


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Johnwa said:
It’s possible for them to be a bit off center. The leadscrew will bind if assembled incorrectly. It only matters if is can accidentally be rotated though. I had that issue on the cross slide nut on my Southbend lathe.
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I never removed the nut from the saddle so it's not reversed if that's what you mean. The leads screw threads in fine from the right and the table moves freely for the first 1/4 of travel or so, after that it gets stiff.
 
Johnwa said:
It’s possible for them to be a bit off center. The leadscrew will bind if assembled incorrectly. It only matters if is can accidentally be rotated though. I had that issue on the cross slide nut on my Southbend lathe.


Sent from my iPad using Tapatalk
Click to expand...
I was just thinking the same thing maybe try loosening the shaft caps. I was thinking about this too that colouring on the nut Paint or is that from rubbing?

CDAE4942-573A-4A08-9B83-B56EC35F6DEE.jpeg
 
Tom O said:
I was just thinking the same thing maybe try loosening the shaft caps. I was thinking about this too that colouring on the nut Paint or is that from rubbing?
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That's yellow paint. It must mean something to the assembly line.

Keep the idea's coming guys. I'm grasping for straws here.
 
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