Any thoughts amigo...

Most tube benders use similar size dies for similar size tubes. Looking at JDsquare die set the thing to look at is called "CLR" center line radius. That will be the radius at the center of the tube as bent. Imentioned jd square because they are the standard but there are other companies making the dies too, just google your tube size and bend dies. Some times there will be more than one CLR for a tube diameter, that is due to the wall thickness.

 

Well men, you might recall back in my Post #189, 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.

 

Just posting for the record.
I found an article that suggested a rule of thumb method for working out a user friendly CLR for tube.
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.

 

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.

 

I found an article that suggested a rule of thumb method for working out a user friendly CLR for tube.
It seems 3 times the O/D will provide a reliable CLR that should bend without drama and without mandrel.

Go back and read where you found that information, or better yet post a link. Why I say go back and read is, does that also mean they say to use a follower/backer block? Most of the former's you buy come with a follower, and that makes a lot of difference in how tight a radius that can be bent. No follower means a bigger radius is needed.

 

Sorry folks, I've been distracted TCB once more.
I needed to move my recently purchased 2nd hand treadle sheet metal guillotine.
It is one heavy sucker and since I had already found some suitable double castor wheels from FB Market Place for cheap I figured it was about time I finished this job.

 

Looks good, but how do you keep it from moving when in use? I put wheels on my sheet metal bending brake but had to also put some jack screws to keep it from moving around when using it. The jack screws lift it just enough to keep the casters off of the floor.

 

I put a set under my radial arm saw table, the two front ones have foot operated brakes that clamp & lock the wheels to keep it stationary.
It looks like the one in the pic has them?

 

I got locking castors under my bandsaw which work really well.
The guillotine I did a mock up ages ago when I 1st got it, just to get it into my shop and then needed to use it several times and even with no locking castors on a flat floor it showed no sign of wanting to move.
However, Shortbus is correct and I am waiting for the right kind of junk to turn up in my travels, which I could possibly use as some kind of anchor device in the future.
Fingers crossed it will be just a case of a quick weld tack on situation.

I acquired a large chassis fabrication table years ago and wanted to make that mobile.
I saw a sale of wind down car trailer jockey wheels for $15 each, so purchased 4 and attached them to each corner of the table.
I rarely need to move it but when I do , it is just a matter of winding all 4 jockey wheels down and it rolls around real easy.

 

I put a set under my radial arm saw table, the two front ones have foot operated brakes that clamp & lock the wheels to keep it stationary.

But a radial arm saw you use one hand to keep the wood still, and there isn't as much force involved. My brake I used the locking casters and it still wanted to walk across the floor. But the jack screws work, and when I added wheels to the horizontal band cutoff saw they were used on that too.

 

Unfortunately, I've have been struck with a further distraction for now, but I'm almost done with it.
A steel cutting bandsaw I purchased a while back, which I thought would be OK and ready for use turned out not to be.

Outside appearances can be deceiving.
It had sat in an open farm shed for 5 years and got infested inside by rats.
An intital clean out saw 7 dead rat carcasses as well as much chewed up paper, leaves and miscellaneous crap etc.
I assume the farmer had laid poison and they had taken it back into the nest, where they died.
It stank to high heaven and I ended up burning incense inside the wheel house inclosures to help neutralise the stench.

Not having any experience with large bandsaws, I figured that I was now good to go...
Eventually, I got power to it and it ran OK.
However, I quickly discovered that I had no adjustments that would work.
It did not like cutting in a straight line and all threads etc had been corroded by rats pee and time.

So now, I have just completed a rebuild of the top wheel adjuster mechanism, which had to be removed with great difficulty and soaked in diesel for a number of days, yet still required several applications of heat and pressing to free it up.
Fortunately, no damage was done and I have now gotten this unit re-installed and adjusting.

A similar effort was required to free up the lower wheel house which contained the speed adjustments and belt tensioning etc.
That is now behind me, but I find that the saw does not cut straight and the drop down blade guide needed attention, including freeing it up as it was also frozen.
I've come to the conclusion that rat pee is way stronger than Loctite...

In the process of unfreezing the blade guide, I now realise that there are two blade guides and upper unit which is visible and easily accessible, but also a lower guide hidden under the table and hence more seized and frozen bolts and items to remove.

I can say that I have now been well introduced to the inner workings of my bandsaw which I guess is a plus.
Looking at YouTube videos and talking to some guys on a Forum I joined for help, I've decided that the old style fixed metal side blade guides and the rear blade roller bearing is not the industry standard any more, so I've decided to try and modify both the upper and lower guide units incorporating roller bearing side blade guides as well and as re-orientated rear roller bearing guide.

So far I have not achieved all that much progress in this regard as most of my time has been spent contemplating and acquiring suitable sized bearings etc.
Using roller bearing guides seems to be a means to achieve better blade control and reduce friction/heat on the blade which I am told heat is a blade destroyer and blade life reducer, which I guess is obvious.

I dont want to distract too much from my project build but found that I needed to deal with the bandsaw issues and figured others may find some of what I have said as useful.

With regards to my bender project, my next post should included the results of my 1st 1"NB tube bend.
So stay posted...

 

Using roller bearing guides seems to be a means to achieve better blade control and reduce friction/heat on the blade which I am told heat is a blade destroyer and blade life reducer, which I guess is obvious.

Having used the ball(not roller) bearing blade guides on my 18" metal cutting band saw I was lees, very less than thrilled with them. Luckily I had a set of DoAll band saw guide heads that I got in a box of parts at an auction years ago. So I modified the guide posts on my brand new saw to accept the Doall heads and guides. Those are the best saws I have ever used for shape/contour cutting. Almost every where I worked they had DoAll saws. The ball bearing ones had too much slop to hold the blade in position.

This is what the guide inserts themselves look like - https://www.doallsaws.com/4495-saw-guide-insert-1-4

And this is the guide block that the guide inserts go in - https://www.doallsaws.com/119001-saw-guide-block-lower

 

I am not trying to make my bandsaw the best on the block, just to improve it from what I had and at little expense.
Your linked items prices are in US$ so you can pretty much double those numbers (currency conversion and shipping costs) for where I live and I am told USPS is not posting to us right now due to Covid restrictions, so I remain satisfied with the direction I'm going in...
I can purchase ready made roller/ball guides for around $180 that supposedly bolt on, but I have my doubts as my bandsaw would have never been considered at the time of making them as my saw is made in Australia.

 

Not trying to stop you from doing anything. Just giving the benefit of my experiences. I've been there and done things but you seem to think I'm trying to make you do something else.

One thing else though. How are you planing on adjusting the ball/roller bearings to center the blade between the upper and lower guide posts? Or for different blade thicknesses and widths?

 

Side bearings are on a rotating cam with a knurled knob as per the pic's.
Any other adjustment still remains within the original bandsaw setup on the guide post.

The difference between an Australian and an American doing stuff, is that you have the benefit of a huge mail order system and numerous suppliers at realistic prices.

Compared to where I come from, mail order is not the automatic first choice unless you are unskilled and have plenty of money to throw away on rip off prices and long time delays.

The only other option which thru loyalty mostly, that I choose not to send my money to China and again expose myself to poor quality, long delays and the possibility of not even receiving my goods.

It is a whole different senario from the outside looking in.
I wish I had the market benefits of being an American living State side, I'd be like a kid in a Candy Store...

 

As promised I am the bearer of good news.
While my bandsaw stuff continues to consume my time, I took time out to see if I could finally set my partially finished bender up to bend a length of what I know as 1" NB tube which has a 1/8" wall and O/D is about 1 1/4".

Since I had previously set up my 1 1/4" form that I scored way back when which will be able to handle this diameter tube, I mocked up a guide just using 2" x 2" angle iron and only tacked it all together for this test bend.
For my completed machine I plan to use a roller style guide and not a slide style.

I have been wanting to do this test for some time in the hope that all will be well and it will provide me with the motivation I need to keep pushing ahead.

Anyway, the bend was made and it went well and everything held together.
Upon review of the bend, the elongation was not all that noticeable thru the curve, but I appears that I may need to grind the sharp start point of the form as it it is marking the tube slightly.
I had a friend inspect the two bends and he was impressed.

So check out the pic's and merry christmas to you all.

Russ.

 

Next step is to attempt to make a form that will accept 2" OD tube as that is the other size I need to target and hope my machine is capable of bending it.
Since I dont have a form for that size I will need to source some metal stock and head off into uncharted waters.
My main concern is having a piece of stock large enough to fall within the range that is a suitable radius for 2" tube bending, but at the same time fit in my or my buddy's lathe and chuck.

I was aware of a potential source at my local laser cutting and metal suppliers yard.
They carry and cut steel plate in excess of 6" thick.
Boy you want to see slabs of steel that thick, it is scary and no second chances it it dropped.

It seems that they cut out holes in orders, the waste cut out of a hole is called a drop out.
I targeted 3" thick drop outs at approx 8" diameter, still a substantial piece of steel weighing in at about 45 lbs.
I scoured a drop out and then had to carry it about 400 yards back to be weighed and paid for in the Office.
You dont realise how heavy it is during the first few steps but soon discover it is no fun.

Usually the drop outs are left under the laser cutting table until a scheduled clean out is done using a small bobcat style machine.

Anyway I get this darn thing home and determine it ain't gonna fit my chuck and will be tight for bed clearance as well.
I check with my buddy and he too does not have a chuck capable of holding this drop out but his bed clearance is better.
We figure that possibly a hole drilled thru the approx center of the drop out and a shaft thru the hole and locked in a chuck at one end and the other end fixed into the live center could be an option.

We drilled a 15/16" hole and I machine down a short length of round bar that I find, that I machine down to hole size with the intention of pressing it in the hole.
It turns out that this configuration will just fit into my small lathe reluctantly and I still wondering if it is capable of doing the job.
Fingers crossed for now...

And that my friends is where I am upto right now.

 

I got to say, that I must proceed cautiously.
The weight is equal to that of a packed suitcase you would take on a holiday 20kgs.
We are not talking carry-on, this a full luggage.

That chunk of steel, just fits into my lathe, but tool cutter adjustment is serverely limited and it could end up being a major issue as I proceed.
I still have no idea how the hell I am going to make and setup my curved cutting tool to create the form shape for 2" diamter tube.
I have decided to take it 1 step at a time and am quite willing to accept defeat should I hit a brick wall.

 

Your finding out why the ready made bending forms, even though expensive, are cheap. And I had access to a large well equipped shop that had lathes that had up to 24" chucks. You think I'm trying to hold you down or be a naysayer to the project but that isn't my goal at all. Just trying to make you see that sometimes you and all of us need to bite the bullet and spend some money. and believe me when I say I'm tighter with a dollar than most people.

http://www.jdsquared.com.au/

 

It is better to have tried and failed, than never tried at all.
I take no joy out of buying stuff, it is the journey that is way more important...