Cadflat Tube Bender Project.

[Oddbod]

Another step in the right direction.

[Oddbod]

Just by way of explanation, with regards to that roller I made.
I purchased to small sized roller bearing and one thrust roller bearing.
I machined out each end to accommodate and press in the roller bearings, plus at the lower end I allowed additional space to also install the thrust bearing in the hope that this roller will not be impeded by much drag or friction.

It appears to me that there will be a critical moment in time when bending any tube, which is right at that initial tangent point where full load will be required to convince the tube to let go and comply to the shape of the form.
I'm sure there are more scientific and eliquent words to desribe what I am getting at, but they are not really in my vocabulary.

I figured that I would be better off making that instant point as smooth as possible and hence the use of bearings and not bushes and washers etc...

[Oddbod]

I just scored this tool, which I figure will help if doing multiple bends at various angles.

Not new but should still do the job.

[Oddbod]

As I continue to do the house keeping on this project, I have reached the satge where I need to make and attach a bend angle indicator, probably called a protactor.

I cut out a piece of light sheet metal into a half circle and can see how it could be mounted etc.
However, I am hoping somebody may have a suggestion on marking it up.

This is something that I have not had to do before and would like to do it once and do it right if possible.
Any ideas out there???

[Oddbod]

Well, no luck with Christmas offers of engraving a protractor for me, so in the meantime I found this old school chalk board item which is close to the right radius and could be covered with a thin piece of perspex and do the job and requires little effort from my end...

Just remove the handle and cut a recess out similar to my metal template.

[Esteban]

On your previous post I didn’t get exactly what you needed, but looking at the pictures now it’s very clear.

What about printing it on self adhesive paper? That way you can replace it as often as needed due to the normal wear & tear.


Esteban

[Oddbod]

Esteban, that is a good idea.
I must have lived a sheltered life as I am unaware of such a product and that it could be printed on...
I have the wooden item now and anticipate using it.
I had hoped to find sombody capable of preducing a metal arc with engravings that I could say poprivet onto my piece of metal and it was done.

Somebody else suggested acquire a Summit Racing Cam Degree Wheel, which also is a good idea, but cost prohibitive in my location, both currency, shipping and middle man ridiculous mark ups where I live.

I am no fan of woodwork but it seems on this ocassion my choices are limited.

[Oddbod]

Well folks, you might recall back in my Nov 17th Post, I mentioned trying to incorporate into my machine all variations of bending.
With respect to the wipe arm, there were two options, one of which involved holding a fixed center form, while the arm rotated around it.

As luck would have it I saw quite by accident a promo done on YouTube by one of the Myth Busters Team discussing the use of lazy susan style bearing races.
It got me thinking that this could be the solution to keeping the form fixed while the arm was free to rotate under the form.

I ordered what I thought may work and have now received it in the mail and set it up to ride ont top of the wipe arm.
No test runs yet and I'm not that ready yet but here are a couple of pic's of what it looks like.

So, now I have a base ready to accept a fixed form, once I get around to finishing this setup.

[Oddbod]

Just posting for the record, I've been trying to work out what radius to choose when making a form for bending tube that will be guaranteed to work,

I found an article that suggested a rule of thumb method for working out a user friendly CLR for tube. CLR means center line radius.

It seems 3 times the O/D will provide a reliable CLR that should bend without drama and without mandrel.

I could not find a with mandrel rule of thumb, but I guess at some point it will depend on the power of the machine, quality of mandrel and method of bending, plus trial and error.

[Oddbod]

I got my protractor figured out now.
I cut it to fit and then cut a thin piece of perspex to shape with a small oversize lip all round.
I clamp the perspex over the wooden protractor and proceeded to run a bead of clear silicone sealer around the edge to kinder seal it in and prevent any staining from water or oil etc into the future.
That was the best I could come up with for very little $'s.