Minor pitting in bench tubes

[peterag]

Dear All,

Intro, if only for amusement:
Someone in my local wood turning club gave me a Mark V, from 1954, as per the serial number. [Motor runs! Honestly, just amazing.] Years ago, I had inherited a 1980s vintage Mark V from my late father-in-law, which I have since 520'd, but I am inclined to ( = will ) use the tubes of the older machine (and possibly the entire frame/chassis). For instance, quite apart from the greater thickness of the tubes, the way tubes at least are straighter (I believe/hope). I am believe/hoping that <some of> my alignment issues will disappear. I also found that the BENCH tubes 'appear' straighter on the old unit, although it mignt simply be a case of skewing of my 1980's version bench tubes: my test was running a piece of 12'' X 18'' (particle board) along the bench tubes of each machine, resting the board simultaneously on both the 'infeed' and 'outfeed' tube. On my 80s machine, I can rock the board a little when I place the board against the legs, but not in the center [I can rock it 'forward' at one end, and 'backward' at the other, which makes me think it is skewed; I have not tested this seriously, by first removing the legs, say, and leveling the support chassis, etc]. On the other hand, on the 1954 machine, the board does not rock at all, regardless where I put the board. In any case, I don't know to what degree a twist in the bench tubes matter - although Dusty and JPG will know better, and have posted much on this. Furthermore, without more measurement, I don't know whether the fault lies in the 1980's chassis mold, the tubes themselves, or the assembly - probably the latter; if so, one could perhaps shim the tubes before tightening, but.... Comments?

Real question: the 1954 (the headstock is a Greenie; the chassis is silver) was somewhat rusty, especially the bench tubes, as chassis and attached bench tubes had been kept in the shed outside - the way tubes, tables, and motor, had been kept inside, and were 'mostly' immaculate. I cleaned off the rust from the bench tubes with 330 sandpaper, but there still remains minor pitting, if that is the word: see the picture for a typical sample. Clearly, this is just esthetics, but can I, and is it worth the effort, even assuming that esthetics matter, correct the spotting? In the forum posts, words such as Evapo-Rust, Flood-Penetrol, and MickyD, figure. If I wanted to paint the tubes - I probably won't - what paint would one use? (I must say, what a pain are the forum broken links. There is an otherwise wonderful took, called the WayBack Machine, for retrieving old, now disappeared, internet posts; it never works for Shopsmith forum posts, at least for me). And - I shouldn't bother about cleaning the interior of the pipes? I am inclined not to - the tube exterior did not take me two hours to clean, and I was watching a wood turning presentation (Cindy Drozda) at the same time.

BTW, the 520 tables that I have come from ebay, and the main table at least is not flat. Serves me right for being cheap.

Thanks, Everyone.

Peter

[GreyOwl]

Are you sure your floor is level? Then put a level across and then lengthwise on the tubes. That will tell you more.

[peterag]

The floor is far from level. But again, there is no skewing/deviation with the 1954 unit, at least according to the board test above.

[chapmanruss]

peterag,

You can combine parts of the 1954 Greenie with parts of the 1980's Mark V but there are differences. First off, the Bench Tubes are a different diameter. The Mark 5's from the 1950's had 1-7/8" Diameter Bench Tubes while later, starting in the 1960's continuing to the present, the Bench Tubes are 1-3/4" diameter. The Way Tubes have always been 1-3/4" diameter. Because of the different diameter Bench Tubes the Bench Ends (Base/Arm and Headrest) are different to accommodate those different Bench Tube diameters.

The pitting you show on the Tube is not a big concern even if it were on the Way Tube. With the rust removed protect it from further rust damage and it will work fine. As for painting the Bench Tubes the Goldie Mark 5 came with Bench Tubes painted silver as did the Mark 2.

[JPG]

Re twisting tubes:

Way tube twist would be a concern and possibly correctable with a large alle - whoops hex wrench.

Bench tube twist - who cares - how does one correct - flat earth?

[peterag]

I would have thought, JPG, given your viewtopic.php?p=41470&hilit=Level+Way+tubes+A#p41470, that we might want to care about the flat earth...

"Level the bench tubes (both ends). This establishes a reference for adjusting the way tube stop. Shim the tubes if necessary."

[JPG]

I would have thought, JPG, given your viewtopic.php?p=41470&hilit=Level+Way+tubes+A#p41470, that we might want to care about the flat earth...

"Level the bench tubes (both ends). This establishes a reference for adjusting the way tube stop. Shim the tubes if necessary."

If you look closer at the first pix, It shows leveling the bench tubes by placing shims between the horse and the tube.

That becomes a reference for the following assembly of the way tubes with no twist as the goal.


Gee someone actually looked at that thread!



Way tube twist and bench tube/base tilt are different thingies. The goal of eliminating way tube twist is to ensure the headstock/table carriage do not rotate about an axis parallel way tubes as they are relocated along the way tubes. It is the lack of elimination of twist that historically made the aux table to not match main table front to rear tilt at both ends(spt mounts).

One of my frustrations with well intended tweeks is the adjustment of the leveling screw to achieve matching tilts at the expense of possibly creating twist.

The dual tilt design has minimized the possibility of way tube tilt(assuming all else is as intended).


A multitube of possible causes lurk here.

[peterag]

Aah... I hadn't noticed the shim in your picture. I had stupidly interpreted/extrapolated your instruction as to mean placing a shim between the bench tube and frame to assure alignment before tightening it into place; obviously, had you wanted that, a relatively complicated procedure, you would have shown the process in a picture.

Be that as it may, here is a picture of one of my 1980s bench tube. Pretty bent! 'It seems to me' that being crooked like that makes it impossible to align, say, the tailstock with the headstock for turning. The 1954 tubes are straight as can be. So I am going to use them - they are thicker; so much so that to my surprise they do not fit into the holes of the 1980s chassis. I will have to use the older chassis, which, as per your thread, does not have a way tube leveling screw, alas. And more alas, because my father-in-law had installed on the 1980s unit a nice big heavy shelf attached to the leg supports, strengthened with heavy metal below, on which one can put sandbags, to stabilize the Mark while turning, as need be, which I will need to move - unless I can stand the difference in colors with the 'legs' silver gray, and the tube support chassis dark gray. (I am posting pictures of the shelf, not only for entertainment purposes, but because it might be useful to someone - always assuming that the weight of the sandbags was not what bent the bench tubes!!!!! There is a second shelf that ran above, that I have removed for the time being, but protected the one below from shavings.)

[JPG]

I think if you use the bent bench tubes both with the convex side up it should align ok. To me tail stock alignment is accomplished with the off set thingie anyway.