Hands up if you think flat bar should be flat

[JohnnieZ]

Ah, a press brake. I first time I saw one of those was when I was in a industrial sign making shop a long time ago. I have a meeting set up with a man that owns a machine shop. Hopefully, he will be able to work with me. I heard that he has a lot of machinery, so he must have one of those.

I'm not sure if the aluminum is 6061 extruded aluminum, I had a friend who makes sissy bars for muscle bikes make the first prototypes. He can no longer work because of health problems, so this is where I'm at on this idea that I had and hope to make come to fruition. I will of course have to make sure I get the same thing when I buy more material. I'm not a big time machinist, I am learning about metals and such, and am glad I found this site in order to have someone to talk to about it.

I was thinking that I may not have to heat up the aluminum bar, but as you can tell, I've been doing a lot of guessing.

I want to achieve about a seventy degree bend, maybe less, as I bend the first one. I'll need to check if I have enough bend by testing it on the bike. If I need more bend then I'll bend it a few more degrees and make sure there is enough bar clearance away from the ground when the bike is in a wheelie position.

Too bad I don't have you for an employee, Denny. Ha!

I paid for the materials to make the first two prototypes, the one you've seen and the other that is narrower is for bikes without shocks. I also paid the builder for making them. He failed on the bending of the bar at the end, but it's nice having two prototypes to go by. I will be looking for the same deal from a new builder. I tried bending the bar more at the end, but I realized it was a no go with what I had to work with. All I need is the bottom bar and the struts to be made, I can do the rest, like drilling the holes, etc. Although getting the holes drilled as well would be nice. All I have are bike tools for working on bikes. Ha! An inventor or developer without a machine shop, like myself, is like a bicycle with no wheels.

Thanks for showing interest in helping me, Denny. If you are any representation of the people here on this site, then I'm in very good shape.

Ziggy

 

[Silverbullet]

I've often used a diameter of choice for the bend. Then clamp and bend wrap to size , if doing several ill weld a small tube thickness clearance and drop a rod and bend to shape. The rod holds the bend , you can make circles easy .

 

[dennys502]

You are welcome Ziggy. I'm 68 and retired. I had a small manufacturing company and I did all the design work and tooling. I made a lot of specialty machines to do things that would make it profitable to make things. Most of my products were point of purchase displays. I made thousands of Paint chip displays for General Paint and Chemical (True Value Hardware) and other paint companies. A lot of dental trays and containers for U of M, U of Oklahoma and others. Too many different items to list but that gives you a rough idea.

Denny

 

[Silverbullet]

I've often used a diameter of choice for the bend. Then clamp and bend wrap to size , if doing several ill weld a small tube thickness clearance and drop a rod and bend to shape. The rod holds the bend , you can make circles easy .

 

[Okapi]

If you want "flat" flat bar, you might start off with cold rolled (CR). CR will also be correct in size unlike hot rolled that varies a bit in dimensions.

The quality you have is clearly the cheapest one, which you use normally to make garden decorations etc…
Normally the seller does ask you what you want to make with the material, here it's cut iron sheet which is the cheapest possible, the cold rolled cost X times for the same weight, but it's perfect geometrically and sized with the tolerance given by the maker.
You can look on this PDF the large number of possibilities you have fot the same size of steel or iron.

 

[JohnnieZ]

You are welcome Ziggy. I'm 68 and retired. I had a small manufacturing company and I did all the design work and tooling. I made a lot of specialty machines to do things that would make it profitable to make things. Most of my products were point of purchase displays. I made thousands of Paint chip displays for General Paint and Chemical (True Value Hardware) and other paint companies. A lot of dental trays and containers for U of M, U of Oklahoma and others. Too many different items to list but that gives you a rough idea.

Denny

Ha! I'm goin' on 63 this year, myself. I find that when people see my Ziggyboy name they think I am a boy. The name is all about keeping a young frame of mind, and my bicycles make doing that easy for me. "Never too old to ride," is my motto. LOL! I ride all kinds of bikes, mountain bikes, etc.

So wow! I see that you have bent enough metal to build a sky scraper, you know your stuff. The creativity is what we have in common, experience, well, that's a different matter. I also see that you are an inventor of sorts. I imagine I have used paint chip displays right off of one you made.

I like to think of myself as an inventor, only none of my inventions have made me any money. I was a backhoe operator and I retired from that as well as I did music. I built chevy cars in my youth and learned that from my dad who was a very good mechanic, welder, etc. So I do the best I can with what knowledge I have while learning more. I enjoy giving to the bike world and want to give something to the bicycle crowd before I leave this Earth. Ever since I was a kid, I loved bikes. I own thirteen bikes. Most of which are vintage Schwinn Stingrays, even the first year, 1963.

Thanks again for giving me some of your knowledge for free. You're a good soul. Hope we can converse about machining more in the future. With all the help I need, I'm sure I'll be back to pester you again. Ha! Ha!

Ziggy

 

[Downunder Bob]

A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.



I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.



Here's what a 6" vise looks like on another PM45 (gt40's)
View attachment 253544

 

[Downunder Bob]

Or if you want precision flat and size get gauge plate, more expensive but you get what you want. should be plenty of steel merchants in Perth, forget bunnings.

 

[2volts]

I know Bunnings is all about price and convenience but I was just surprised that the quality would be that poor.

When I need good quality I go to a steel merchant such as "The Steel Store" in Kewdale which is Bohler Uddeholm, world wide steel vendors.
Like I did today, to get 2m of 32mm x 20mm 1020 carbon steel bar.
No complaints about that purchase.

 

[Rustrp]

I know Bunnings is all about price and convenience but I was just surprised that the quality would be that poor.

When I need good quality I go to a steel merchant such as "The Steel Store" in Kewdale which is Bohler Uddeholm, world wide steel vendors.
Like I did today, to get 2m of 32mm x 20mm 1020 carbon steel bar.
No complaints about that purchase.

Where you buy is only a small part of the equation. With most product being sourced from all over the world, and brokers purchasing from the mills to supply all the smaller distributors, along with the mills being located in China, India, Pacific Rim, etc. HR quality is always in question. What you have is HR strip run through rolls that are worn out or the flattening rolls were not adjusted. If it were sheared from plate or slit from a coil there would be no crown or the process wouldn't produce a crown. Some stainless bar is sheared but there are straightening methods used after shearing. The problem with going to CR is that any bending that's close to 90 deg. with a tight radius will result in cracking unless you heat it up because CR is exactly that, rolled to dimension in a cold state.

After cutting up 500' of 2" x 2" x .188" tube, I discovered one corner radius was larger than the other three. For esthetic purposes, I had cut the tube so the seam was on the back side with alternating (flipping the tube over) 45 deg. cuts. Grinding, sanding and blending the corners produced many expletives.

Just think of this as a low budget steel mill (steel processor) buying used equipment to set up their mill, along with employees who have little training on running the operation. These issues add cost to every product produced along with less than acceptable quality. I get verbose on these topics because just about the time a market gets the kinks worked out and the quality improves, the buyers move to the next cheap, cheaper, cheapest, labor market. -Russ.