Cadflat Tube Bender Project.

[Oddbod]

While waiting for the mail man, I decided to install a improved back board setup to catch the swarf.
It was a good opportunity to reorganise my attachment stuff.
It appears to be a great improvement to what I had and I am hoping I will be better organised and able to find stuff more easily.

[RiverPatrol]

Swarf - I like that word.

[Oddbod]

I know it has been a while, however, I scored a vice to go with the other vertical adjustable gizmo I got a week or so back.

My mail man also turned up, so I could finally cut my keyway.

I needed a 8mm wide slot so purchased a 7mm cutter and used the adjustment on my new gizmo to cut 0.5mm each side wider.

It has worked out well, but I have discovered my adjustment on the vertical vice holder does have some creep that I must manage.

Some vibration is enough to see it move...

[Oddbod]

I finally was ready and had an opportunity to go see my favourite cousin when it comes to all things metal fabrication.

I took the idle shaft with the square drive pressed onto it and requested his best welder to weld the square to the shaft on both sides.

He said follow me and we walked thru his workshop to a screened off corner at the rear and low and behold is best welder is a middle aged woman from China.
He said she is the best welder in my business so you will be fine.

Ten or less minutes later she turns up in his office with the job done.
I thanked her in Mandarin and took the shaft home and machined off the excess weld, so that the shaft will mate flush with all other flat surfaces and job done.

My cousin also offered me the opportunity to purchase an old milling machine that he is planning to dispose off, I wish I could take it, but reluctantly declined as it must weight 350kgs and I dont have the space for such a machine, mind you I wish I did have the space and I will probably regret my decision...

Time now to move on with setting up my universal connection from my drive plate to accept any other plate I wish to use that will engage with various other forms.
This should be fun..

[Esteban]

It is great following your fabrications!
Thaks for sharing them, including your mistakes and frustrations.

[Oddbod]

No problem Esteban, always a pleasure to share with those who maybe interested.
I know it wont be for everybody...

I'm not going for the Mill machine, my needs are not that great and I figure I've lived this long without a Mill I'm sure I can survive with out it...

Anyway the juggernaut rolls on and I have done a little bush machinist stuff.
I need to put an 8mm internal keyway into the last bender sprocket.
I do own several broaches and guides but nothing that fits the hole size in this sprocket.
I got thinking that one of my broaches pretty much does a 3.2mm or 1/8" width, so I decided to make a broach guide to suit my hole size and the guide slot I made twice as wide to take my broach with a side spacer.

I figure that, I can cut half the keyway out and then switch the spacer and the broach and do the other side which kinders gets me close to the 8mm and I will just finish it off with a hand file.
I drilled and milled out the slot and filed it to a snug fit for the spacer and broach, welded a cap on it and knurled the cap.
The rear shim still fits and fingers crossed it will work as planned.
It looks the business and I guess we will all know how well it works in a couple of days when next I get time to attempt cutting this keyway...

[Oddbod]

Boy, am I glad that last keyway cutting project is behind me now.

I must say if anything it was character building to do this job without all the actual equipment, but its done now and appears that it will work out just fine.

I did strike a problem using side by side broach cuts as they tended to try and centralise or follow the line of least resistance.

Due to the size of the keyway and its depth, I also needed to make up several different thickness shims to aid my progress.

I've since seen a comment after doing this job, from a guy who recommends making shims from steel box strapping.

He is of the opinion that is tensile and lends itself to making up good shims, especially for larger keyways.

Just thought I'd pass that on since it seemed like a good idea for strapping that generally nobody wants once a box/crate is opened.

Finally, I measured an cut the key to fit the new keyway and it fits a treat, I could not have hoped for better.

What I did need to do with my internal keyway once I had achieved the correct depth and almost the correct width except for that centralising issue. I got a piece of 8mm square tool steel (which was my desired width) and set it up with my guide and a small piece, of lets call it square bar stock to my desired dimensions (as a shim) and used my press to force it thru and cut out the small pieces of metal on each edge to square up the keyway.

I did put about a 10 degree sloped face on the cutting end and it did a really good job in one cut of cleaning out the keyway to perfect dimensions.

[Oddbod]

I have some more progress although it is mostly superficial I feel, but progress in the right direction nevertheless.

I've pretty much gotten my turntable and idle shaft mated up and in position and have gone and fabricated a locking gizmo for one of my forms that will hold the end of tube in place at the time of rotation.

It looks to be workable, but we will never know until the power is turned ON.

[Oddbod]

I decided to add a little diagonal bracing to my table before I sat the steel plate top into position.

At the same time, I got to thinking it may be it would be a good idea to add a chain guard to the sprocket on my idle shaft, just to be sure no fingers or clothing gets caught up in it...

So grabbed a piece of left over sheetmetal and fabbed up a guard.

[Oddbod]

Well folks, the chain guard is finished to my satisfaction.

Prior to refitting the table top piece of heavy plate, I got to thinking that there was a bit of space available that was going to be lost, that could serve as a storage place for smaller items that I may need, that will kinder belong to this bender.

As luck would have it I saw on the side of the road somebody had thrown out a broken 2 drawer file cabinet.
I picked it up and took it home and took a few measurements and figured I could cut it down and use the roller runners and create a small drawer underneath the table top.

This was the ideal moment to take this on while the heavy top was out of the way.
Not beautiful but will do the job and I can avoid having to try lifting this top off at a later date if I acted now.

So attached is how it turned out...