Turning a system by 90º part 2 2

[drodrig]

thread404-468702

Hi,

We have already build the turning device. The post where I asked is closed

https://www.eng-tips.com/viewthread.cfm?qid=468702

I just wanted to share some pictures and say thanks to everybody

cheers,

 

[rb1957]

thx, it's nice to see the final result.

another day in paradise, or is paradise one day closer ?

 

[Jboggs]

Nice looking piece of equipment.

 

[IRstuff]

Nice paint and all that; the netting over the handle kind of ruins the vibe ;-)

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[drodrig]

hehe, yes

We could have taken the net out for the picture

I wanted to have more vivid colours, but the options were very limited

 

[moon161]

That looks sharp!

 

[rb1957]

is the CG of the thing on this tool close to the rotation axis ?

another day in paradise, or is paradise one day closer ?

 

[drodrig]

Yes; The idea is that the center of gravity is in the axis line

There are many cables, components, screws... so it is not easy to know. Below the blue plate one can see a black thin one. We have different thinknesses (of the black plates) to play with the distance

cheers,

 

[rb1957]

I think this is a case of "near enough, good enough". The guy on the hand wheel will know where it is !

another day in paradise, or is paradise one day closer ?

 

[robyengIT]

... but probably too late !!

 

[drodrig]

Back to this project

I'm afraid the two shafts might not be well aligned.

How to position the block bearings so their axes are coincident?

We have cut an aluminium L-profile to connect the shafts (the inner ends have a square section); but this doesn't not guaranty anything.

The bearings have a spherical outer surface to compensate for misalignment.

We have a self-leveling cross-line Laser (Bosch GLL 3-80 CG), so we could see from the side and top the laser on the shafts, but the lines are two thick.

What can we do to align the shafts/bearings?

How is this done normally (I mean having two bearings with a shaft is a very standard setup)?

thanks

 

[MintJulep]

Lining the bearings with the laser level should be fine for this.

Spherical bearings and low speed. You don't need very precise alignment.

 

[drodrig]

The speed is not a problem, but the torque

If the shafts are not aligned there will be additional forces

It seems also difficult to place the gearbox in its position: it's heavy. It can easily tilt the shaft

Here some pictures

 

[MintJulep]

The diagonal braces under the gearbox are useless the way they are now.

 

[robyengIT]

As clearly stated bi rb1957 it is important to know where the center of gravity is located : if it is not in line with the shaft (that is the center of rotation) it can be a problem.
I know it is a bit off topic but it can be a suggestion for the future and different applications. The position of C.G. is always plumb (concrete flume) and always inside the footing base (pipe. Furthermore in such a case it is not needed even to anchor the base to the ground)

 

[kjoiner]

@MintJulip

Are you referring to the diagonal braces carrying the load down the stretcher section of the frame? If so, I agree. I think the weight of gearbox could induce some twisting of the stretcher which could lead to difficulty in aligning the gearbox and the shafts even if it is a "3030" type extrusion. It might not be as clean, but a pair of vertical legs going down to the floor with adjustable leveling feet could support the gearbox directly.

I can't quite tell from the photos but is the turning assembly on casters?

Kyle

 

[BrianE22]

I don't think the spherical bearing mounted next to the gearbox is of any use. I'm guessing the output shaft of the gearbox is rigidly mounted. Unless that spherical bearing is concentric to the gearbox shaft you might have large radial loads on the gearbox bearings.

 

[drodrig]

This structure below the gearbox (made out of aluminium profiles) is to relieve the shaft from the gearbox weight.

Since the bearing has this rotating feature if the axis of the gearbox is not well aligned with the axis of the shaft it will tilt it.

We could add some screws under the gearbox to place it in its theoretical position

The question is how to align them properly? How can one measure the position of both axes?

Here another side picture

The assembly turns on the two bearings. And the center of gravity is on the axis of the system. The difficulty is aligning the axes of both bearings and the gearbox

 

[MintJulep]

The diagonal braces under the gearbox are useless the way they are now.

I don't think the spherical bearing mounted next to the gearbox is of any use.

 

[desertfox]

Hi drodrig

Well my first observation is that there appears to be no shims under any of the bearing mounts or gearbox, my company made steel rolling mills which had numerous fabricated frames with rollers mounted between two bearings and driven by geared motors so it was a similar set up. We always had shims to adjust the height of bearing housings and geared motors because you can’t achieve perfect alignment unless the tolerances on the machined components were so tight that it made it uneconomical to produce. In addition to the shims and where possible we built the frames up and had bearing housing pockets machined on both sides of the frame simultaneously to ensure horizontal alignment and used the shims for vertical alignment, also we used laser alignment tools and shimmed accordingly. What tolerances are specified on the component drawings that you are making this thing from?

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein