Adventures in Machine Land (IV)

In yesterday’s post I detailed some of the tricky aspects to setting up the Oliver 166 jointer, and mentioned my disappointment at discovering that the middle of the bridge had a twist in it though both ends were dead level. I didn’t feel that was really going to be a problem, however a reader wrote in and advised,

“The most important thing is that the base is not twisted. Any twist in the base will cause the tables to follow the twist as they are adjusted. With the tables zeroed to each other they might be correct, but as soon as you drop the infeed to cutting depth any twist will impact the new position of the table.”

I greatly appreciate readers taking the time to share their thoughts on the blog, and can see why such a situation as detailed in that comment might make a lot of sense – however, I replied that I thought they were incorrect in that assertion. I was definitely open-minded about the possibility mind you. I said I’d make a test to see if the assertion about the twist in the bridge would actually concretely affect the table when it was raised or lowered. I feel the test will confirm or reject the hypothesis, and obviously, it need hardly be said that having a chassis with no twist in it at all would be the most ideal situation. If the chassis/bridge does have a twist, however, is it game over?

As a starting set up, I leveled the table as best I could- the infeed table now, as I had obtained the adjuster screws in the morning from Tim and had set it up on the machine at long last.

The level is set at the end of the table, near the hand wheel:

And then the level is placed up at the cutter head end:

Next, the level is placed lengthwise in the middle of the table:

I take a step back to show the bigger picture, with the level left in the same spot:

You can see that I have the table raised a fair distance above the cutterhead, and that it is pretty darn level at both ends and down the length.

Now I’ll wind the table way down, bringing it much lower than the cutter head, and I’ve set the level up at the table lip end near the cutterhead:

What does the level say?:

Next, with the table in the same lowered position, I’ll place the level on the opposite end of the table near the hand wheel:

I step back to show the bigger picture once again, with the table lowered and the level on the end of the table:

So, as I suspected, a bit of twist in the chassis doesn’t make any actual difference to the level-ness of the table when it is raised or lowered, as the wedge blocks on the sliding carriage below can be screwed in or out to compensate for a high or low spot at that location. Once those wedges are in their places, the tables travel up or down in height takes place entirely upon those blocks. So how could the chassis twist have any effect upon that?

The only way I can see chassis twist affecting anything is if the table were moved back on it’s sliding chassis – then one could imagine the relative amount of twist at a given location could cause the sliding chassis to twist also with the weight of the table directly upon it. However the only time I would draw the chassis back is for purposes of working on the cutterhead, changing knives and so forth. Otherwise the sliding carriage stays in the same place all the time and the wedge blocks are adjusted to suit the situation.

Anyway, glad to have confirmed that hypothesis, at least to my own satisfaction at least. If any readers feel that my test was flawed in some way, or could be improved, please let me know.

Next on the slate was to relocate the power switch for the machine, which, for some reason, had been located right under the brake mechanism for the cutterhead. I located it a bit back from that, and shortened the length of BX cable which fed it from the junction box. The cast iron is quite easy to drill:

Then I used a Greenlee combination drill/tap to thread the hole:

That worked pretty well with the impact gun.

Some 1/4″ cap screws secure the box in place:

Then it was time to connect the three wires:

And then the cover could be reinstalled:

The blanking plug had been knocked out of the wrong end of the box by the previous installer, which explains why the ‘Allen-Bradley’ plate is upside-down.

Once the wiring was done, I plugged the machine back in and it fired up just fine, so that’s another minor ‘mission accomplished’.

Then it was time to fuss the tables a bit more. I unearthed the dial indicator, and zeroed it to the table surface:

I checked few other spots on the same table for comparison’s sake, and they were all ‘dead nuts’, so I then went to check the table in relation to the knife at T.D.C.:

I adjusted the outfeed to be 0.0015″ below the knife, then slid the indicator to the other end of the knife to check that the table was parallel to the knife:

All was good. I set the outfeed table a hair below the knife’s cutting arc to compensate for the slightly scalloped surface one gets from the cutting action.

Then I slid the dial indicator over to check the infeed table’s height relative to the outfeed table, first at one end:

And then the other:

In between the above two photos I had to do a little bit of fine-tuning with the level. At one point I thought it would be interesting to compare the reading off the machinist’s level with a quality carpenter’s level, in this case a 48″ Stabila:

It’s funny to see the difference – the carpenter’s level is looking like a crude tool all of a sudden. And of course it is perfectly fine for general carpentry work, but obviously inadequate for setting up a machine.

Next, the fence went on and I adjusted it to squareness with the table:

Checking at the middle and both ends of the fence, I had squareness in all three spots, a great improvement upon what I had previously. When I was a tender young lad, oh, 5 month’s back, I had to spend several hours grinding about 1/16″ of material off one corner of that fence, using a hand-held 4.5″ angle grinder, just to make it serviceable. Glad those days are a distant memory.

With the table level and at exactly the same height, I could finish off the rebuild with the re-installation of the height indicator arm. For some reason, mine was about 3/4″ short of the indicator gauge on the side of the table, so with some help from the jeweler upstairs, we grafted on some brass to make it longer:

You can see I’ve roughly lined out the trimming I need to do.

A while later, the pointer was re-done, all polished up and looking ready for bear:

It’s almost too nice on the machine, however I do have some oxidation to look forward to of course.

Another view:

Well, all that remained was to actually cut some wood with the jointer – almost a novel concept after the machine has had such a lengthy period out of service. I ran a couple of pine pieces over the cutter, and was delighted with the results right away:

It felt right! I jointed that second piece, placed the two sticks edge to edge, found a slight hollow, and then made a final tweak to the beds, re-jointed, and in the end had the Oliver back where it needed to be.

Maybe I can do some woodworking again in the near future – imagine that! How does that work again?

Thanks for coming by the Carpentry Way Today. Comments always welcome.