Standby I'll pull her out and check.
Nothing on the table side as expected and nothing on the bottom. The culprits appear to be on the table side and top at the same location near the narrow end of the gibb.
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RF30 Basement Install
- Thread starter YYCHM
- Start date
Standby I'll pull her out and check.
Nothing on the table side as expected and nothing on the bottom. The culprits appear to be on the table side and top at the same location near the narrow end of the gibb.
Well you can see there are a few places along the table side dragging but not like the two end spots.
BTB - With the table to right like I posted you can set and jack out the gibb via the bibb adjusting screw once you have it threading in place, so it's not real tight at that point.
Is there any chance the table is bowed? This might explain a few conditions you are seeing. Visualize if the ends were arcing slightly up or slightly down.
- table will appear to enter the center casting dovetail OK (because the effective arc length is short at this point)
- as table gets centered, it appears to slide normally or maybe has slight resistance if I understood correctly? (its just sliding on the horizontal surface, dovetail misalignment is not yet into play)
- now the gib insertion phase. First the non-gib dovetails come together & becomes mated as best it can. Table would now see some sticking resistance. Now even a perfectly straight gib would go into its gap & then hang up once it encounters the pinch point. (Dabbler was saying it was kind of go / no-go sensitive as opposed to linearly taking up slack).
Has table been check in this regard? Ideally lay table on a flat granite surface (ya we all have one of those :/ ) it would show gap underneath if bowed high or would rock if either end up. Maybe there is another way using indicator like how they check granite plates but my brain isn't registering anything. Supposedly if you hold fishing line (wire) taunt across the corners you can see light gap with a flashlight but I've only seen this done in non-machine applications.
The other thing is maybe table twist or some combination of twist & bow?
- table will appear to enter the center casting dovetail OK (because the effective arc length is short at this point)
- as table gets centered, it appears to slide normally or maybe has slight resistance if I understood correctly? (its just sliding on the horizontal surface, dovetail misalignment is not yet into play)
- now the gib insertion phase. First the non-gib dovetails come together & becomes mated as best it can. Table would now see some sticking resistance. Now even a perfectly straight gib would go into its gap & then hang up once it encounters the pinch point. (Dabbler was saying it was kind of go / no-go sensitive as opposed to linearly taking up slack).
Has table been check in this regard? Ideally lay table on a flat granite surface (ya we all have one of those :/ ) it would show gap underneath if bowed high or would rock if either end up. Maybe there is another way using indicator like how they check granite plates but my brain isn't registering anything. Supposedly if you hold fishing line (wire) taunt across the corners you can see light gap with a flashlight but I've only seen this done in non-machine applications.
The other thing is maybe table twist or some combination of twist & bow?
When you first got the mill, did you happen to move the table in the X-axis (before you took it apart to move it into the basement)? If yes, how does the force required to move it in X compare?
Are you using any way oil to assemble the mill (or any lubricant for that matter)?
Are you using any way oil to assemble the mill (or any lubricant for that matter)?
Frack!!!!! Stoning is getting me no where. I really think she's bowed and the table is straightening it out as it moves to engulf it and ultimately the pressure to straighten it causes the binding. Material needs to be removed to relieve the effect of the bow (file) or shorten the gibb (1/2", maybe less).
Which one is it?
Which one is it?
I honestly don't remember, I was so consumed with getting it off the truck and into the shed, but I don't think it behaved this way. Maybe it did?
Right now I'm using WD40. @Dabbler told me to use really thin oil for initial assembly.
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Was just wondering because your ways look dry in picture of post #259.
same picture, looks like the gib is rubbing on its secondary surfaces (blueing is gone)
you can take a file to that area. The gib is not to touch the bottom of the table anywhere along that surface. It appears too tall.
i wonder if the fact that you disassembled the table (probably for the first time since manufacture) caused the gib to bow - as you have observed - because it was not properly stress relieved after machining?
I would in that case heat the gib with a heat gun evenly and wrap it in insulation to let it cool down slowly. Then see if it has straightened out.
another thing: is the lead screw “floating” in its end caps? Are there shims to properly adjust end play? It could be that the lead screw is “bending“ the table if the distance between the end caps is too tight.
Its hard to imagine the table or base could be distorted to the degree that would cause this kind of binding so Rudy makes a good point, maybe stress relief of gib strip once disassembled caused gib to bow. But that should be evident on the straightness test laying on mill table for example. I'm pretty sure my RF-45's were cast iron but its still capable of bending. It seems its the introduction of the gib where things go south. Without the leadscrew engaged & gib installed loosely the table should slide back & forth by hand when oiled. Actually the way the tightening (table lock) action works on these Asian machines is the screws push against the gib strip which squeezes the table dovetail which holds it in stationary position, so there has to be just a smidge of float in there to begin with.
If the table is sliding smoothly with gib and then you get different results engaging the leadscrew then Rudy is exactly right. Some misalignment could be drawing the table in one direction or another. Could be leadscrew, end castings, leadscrew nut (+/- shims). But I get the impression you are resorting to the leadscrew to physically jack the table into position? If so this is just a big red flag something is amiss with the gib/dovetail geometry. Establish table action first, leadscrew assembly second unless there is no other way.
So dumb question time, did you traverse the x-axis before disassembly & it was smooth through the range?
Does it look like the gib strip belongs to the machine, like usually tell-tale overspray of same paint? There's nothing wrong with replacing a gib with good intentions if worn or broke, but a lot of this stuff is kind of hand fitted on the factory floor and a 'new' one meaning same part number may not fit up the same. I saw a lot of this cut'n'grind to fit action on my lathe.
Probably fine but I'll ask anyways - are the X & Y adjustment screws interchangeable or maybe one belongs to a specific hole. The gib stickout on X&Y looks roughly the same on both axis but just wondering if the (wrong) screw is artificially lifting the gib & causing friction?
If the table is sliding smoothly with gib and then you get different results engaging the leadscrew then Rudy is exactly right. Some misalignment could be drawing the table in one direction or another. Could be leadscrew, end castings, leadscrew nut (+/- shims). But I get the impression you are resorting to the leadscrew to physically jack the table into position? If so this is just a big red flag something is amiss with the gib/dovetail geometry. Establish table action first, leadscrew assembly second unless there is no other way.
So dumb question time, did you traverse the x-axis before disassembly & it was smooth through the range?
Does it look like the gib strip belongs to the machine, like usually tell-tale overspray of same paint? There's nothing wrong with replacing a gib with good intentions if worn or broke, but a lot of this stuff is kind of hand fitted on the factory floor and a 'new' one meaning same part number may not fit up the same. I saw a lot of this cut'n'grind to fit action on my lathe.
Probably fine but I'll ask anyways - are the X & Y adjustment screws interchangeable or maybe one belongs to a specific hole. The gib stickout on X&Y looks roughly the same on both axis but just wondering if the (wrong) screw is artificially lifting the gib & causing friction?
Attachments
Stoning eliminated the top binding. It's all in the last inch of the table consuming the gibb on the table side now.
With the table all the way to right I can slip a piece of paper between the gibb and the saddle dove tail. Once the table approaches the end of the gibb (as in consume it), the paper is pinched tight. It's as if the gibb is being flattened (or rolled) into the saddle dove tail.
This machine is minty. I don't think it's been used much or ever disassembled. I put the first cracks in any enamel, and what looks like rust in the images is original grease/preservative.
Craig
Yes numerous times.
Robin Renzetti in a recent video mentioned again that “everything is rubber” referring to how easy it is for materials to bend and deform. That fact can not be over stressed. Even seemingly very stout pieces of CI, or steel will deform under surprisingly small forces. Case in point: on my SM 1340 I had spent a lot of time fitting the compound onto the cross slide and get a super smooth operation over the full range of travel. But every time I had the BXA size tool post in a certain spot, the compound would be smooth for about 2/3rd of its range and then bind up (still move, but not as freely). I lived with that for years. Then one day I decided: I have a surface grinder, why don’t I grind the TOP of the compound (mostly to make it look nice and practise my grinding on CI). The grind finish was/is not the best, but it reduced the length of the “bind-up” to about 1/5th of travel. So I was happy. Another few years passed and then I got fed up again and revisited the problem. Noticed that depending how tight the tool post nut was I could get the compound to move freely through the full range. The difference between binding and free was maybe 3*-5* of angle on the spanner (ie, very little). So off came the tool post. It was factory ground on the bottom, so I had left it for good thinking that they knew what they were doing. Ah, what the heck, I’ll “dust it off on the surface grinder”. Took about 20 min. to grind the bottom. Seemed pretty flat as the wheel traversed I had contact all the way across. But, from the sparks, I could tell that in the center there was a very shallow ”dish” about 1.5” diameter. So I ground that out with a light second pass and a cleanup pass. Put the TP back on the lathe and tightened down. Now i can put the TP in any orientation on the compound, tighten as much (or little) and it no longer binds up anywhere.
my point: things will distort; easily!
back to your mill: those hold down bolts - make sure that they are barely snug; do not crank on them. You will bend your base on top of the wooden table. Lead screw: make sure the caps are spaced properly, that the nut is in the same plane and does not bend it in any way. As @PeterT suggested, set your table and gib without the lead screw installed. It has to be a sliding fit and you have to be able to move the table by hand to set the gib tension. Then install the lead screw. On my BP, the table “floats” on the saddle when pushed by hand. Very little force required (it is sliding on way oil, not just WD40 though). I set the gib that way, with just a bit of ”drag”, as per the manual. As @Tom O suggests, make sure the opposite surfaces are free from dings (I see that you have already checked numerous times, great). All surfaces must be clean (you mention preservative is still on parts of the machine). Clean all of it off. That stuff gets hard when dry and will give you grief if in the wrong area, even the thinnest film.
main thing: you are close to getting there. Be patient, don’t assume anything. I know you want to have it up and running and make chips - we are all rooting for you as well.
my point: things will distort; easily!
back to your mill: those hold down bolts - make sure that they are barely snug; do not crank on them. You will bend your base on top of the wooden table. Lead screw: make sure the caps are spaced properly, that the nut is in the same plane and does not bend it in any way. As @PeterT suggested, set your table and gib without the lead screw installed. It has to be a sliding fit and you have to be able to move the table by hand to set the gib tension. Then install the lead screw. On my BP, the table “floats” on the saddle when pushed by hand. Very little force required (it is sliding on way oil, not just WD40 though). I set the gib that way, with just a bit of ”drag”, as per the manual. As @Tom O suggests, make sure the opposite surfaces are free from dings (I see that you have already checked numerous times, great). All surfaces must be clean (you mention preservative is still on parts of the machine). Clean all of it off. That stuff gets hard when dry and will give you grief if in the wrong area, even the thinnest film.
main thing: you are close to getting there. Be patient, don’t assume anything. I know you want to have it up and running and make chips - we are all rooting for you as well.
The gibb is bowed, no if ands or buts. You can see it and feel it. Lay the gibb saddle side down on the top of the table and she rocks. Lay it table side down and it doesn't rock and you can see light between the gibb and the table. I can slip a 0.005" feeler gauge under it.
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historicalarms
Ultra Member
Just an observation from previous post when you had the thing apart in your shed & were trying the gibs for fitting & and you mentioned "tapping" with a beater of some kind. I appears to me that the gibs maybe got a bit "peaned" on the ends...soft metal will pean real easy. with your calipers, check "thickness" of the gib at both ends and at a few spots in the middle where you say it isn't binding....might reveal a slight bit of "thickening" at the ends.
historicalarms
Ultra Member
If the bend is your problem , there should be a corresponding rub mark in the center of the bend as well, just on the oppositee sides of the gib from the end rubs
I cranked the table off the saddle while it was in the back of the truck and I didn't have any problems taking it off.
While in the shed I had issues getting the saddle off of table and had to resort to using a hammer cushioned by a 4X4 on the back of the saddle. The saddle remounted on the table no problem.
At no point did I beat on a gibb.
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?
Craig
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