Shopsmith Forums

I don't know what I have been thinking. Maybe I have not been thinking. I have tackled this problem, unsuccessfully, so many times that I may have quite thinking.

A ball joint (which I already use) positioned on the pivot line and 1 3/4" below the work surface of the OFT will produce minimal sag of the outfeed table as it is tilted left or right as far as it will tilt.

The solution for the fixture on the underside of the OFT is right here.

No machine shop required. It can all be done with the equipment we use every day. Brain storm this was not. All I had to do was think. The awakening occurred when I dropped that plumb bob off the edge of the table and watched what it did as I moved the table through the tilt range.

rpd wrote:They stock the aluminum angle at Rona also.

Thanks rpd.
I will look into it .... Rona l'entrepot & Reno-Depot are some of my favorite but I also look into Home Depot sometimes.
Next time I am in the city.

If anyone is contermplating the build of an outfeed table, especially one than uses a diagonal brace to the bottom of the main table leg, make yourself very aware of the pivot line. It is important.

In fact, it is crucial.

I am closing in on this OFT now with a much brighter outlook. What I hope to be my last mechanical change to this version of my OFT is shown in post #25 of this thread.

I just posted a couple new images of what I refer to as the upper ball joint (at the upper end of the diagonal support bar).

The fixture is just clamped in place right now while I debate as to whether or not I want to make it adjustable.

The brackets shown in post #31 don't work so very well. These may well become aluminum scraps. I did learn from these though. Scotchbrite pads are terrific on aluminum.

I am done for now. I once again have the OFT put back together and it can be used.

I was not able to achieve the level of stability that I would like to have but it certainly is better than it was. There is some deviation from the plane of the main table but it is minimal - I think all of you will agree.

Coming to understand the pivot point of the main table and determining where that pivot was with respect to the OFT was the key to success. In the video that follows, the blue thumb tack is "close" to the pivot point.

The point is approximately 1 1/4" down from the plane of the main table.

Ed Reible mentioned "pivot point" in some of his comments so I believe he understood all along and maybe did all the rest of you but I did not. I do now.

This video may be one more bit of trivia but it was proof of concept to me.

As they say : one picture equals a thousand words.
But still .. :
- the support needs to be able to move at the point where it meets the OFT ?
- and it has to have a certain leeway in order to perform well ?
I just want to make sure that I understand.

camerio wrote:As they say : one picture equals a thousand words.
But still .. :
- the support needs to be able to move at the point where it meets the OFT ?
- and it has to have a certain leeway in order to perform well ?
I just want to make sure that I understand.

Is there something you are trying to understand about my posts? If so, just ask.

the support needs to be able to move at the point where it meets the OFT ?
and it has to have a certain leeway in order to perform well ?

This is why I ended up using the "ball joint" at that point.

The contact surface between the upper ball and the underside of the OFT is as close to 1 5/16" below the work surface of the OFT as I could make it.

Why 1 5/16"? Because the center of the trunnion pivot is approximately 1 5/16
" below the work surface of the main table.

PS: 12/28/2013 - After working with this a lot more, I would now say that the true pivot point for the main table trunnions of a 505/510/520 is located 1 11/32" below the work surface of the main table.

I just wanted to confirm that I understood what you came up with ....
That ball joint on you pipe, where did you get that and what size of pipe ?
I re-read the whole thread and I could not see this information.

I am not sure what the ball joint is buying you. My 'perception' is that if the OFT pivot and the table pivot and the support arm are coplaner, that the OFT needs only pivot about an axis that is in alignment with the table pivot(s).

It has been the lower end of the support tube that has not been coplaner that has caused the 'sag'(maybe the OFT support attachment location as well?).

Now that I have said all that, It caused some thinking(rational I hope).

I now am not sure the location of the lower end of the support tube needs to be 'coplaner' in a vertical pane. That pesky tube/pivot offset is not a problem.

All that is required is what I stated above(the table pivots and the OFT support pivot must be along a common axis). If that be true, the location of the lower end of the support tube does not matter. The OFT pivot will not move relative to the bottom end of the support tube no matter where it is located. The distance to the OFT pivot is constant regardless of the tilt angle.

JPG40504 wrote:I am not sure what the ball joint is buying you. My 'perception' is that if the OFT pivot and the table pivot and the support arm are coplaner, that the OFT needs only pivot about an axis that is in alignment with the table pivot(s).

It has been the lower end of the support tube that has not been coplaner that has caused the 'sag'(maybe the OFT support attachment location as well?).

Now that I have said all that, It caused some thinking(rational I hope).

I now am not sure the location of the lower end of the support tube needs to be 'coplaner' in a vertical pane. That pesky tube/pivot offset is not a problem.

All that is required is what I stated above(the table pivots and the OFT support pivot must be along a common axis). If that be true, the location of the lower end of the support tube does not matter. The OFT pivot will not move relative to the bottom end of the support tube no matter where it is located. The distance to the OFT pivot is constant regardless of the tilt angle.

You are very, very close in your thinking.

The lower end of the support tube does not need to be coplanar with the pivot point of the trunnions.

The upper end of the support bar must be in the same planes (horizontal and vertical) as the pivot point of the trunnions if you expect the OFT to remain coplanar with the main table through a table tilt.

This has been the wrinkle all along. Any deviation in that contact point causes the OFT to waiver during a tilt operation.

The upper ball joint does make a difference. Not to the OFTs' coplanar relationship with the main table but to the smoothness of a transition from tilted to level or vice versa. Any joint will work that does not bind OR introduce a change in length. My support tube evolved and at one point I thought that the ball joints were needed because the support bar moves at the ends. Now all they do is allow the tube to be used either way.

Text is red changed to comply with the critique of an ME. See next post below.

dusty wrote: . . .

The upper end of the support bar must be coplanar with the pivot point of the trunnions if you expect the OFT to remain coplanar with the main table through a table tilt.
. . .

If the OFT support arm pivot is on a common axis with the table pivots, there is no 'plane', but merely a straight line.