Hydraulic Tube Bender Engineering Project

[TheBandit]

Thanks guys. I am totally beside myself with excitement and relief. I can't explain the feeling - it's just indescribable having come so far with something like this.

I am currently in the midst of a fun weekend with visiting family, so I am sorry I haven't come back online to update this with pictures or a detailed explanation. Don't worry, more is coming!

I did spend the last half hour or so putting together this video for you guys. It's 18mb, so sorry for the long download. Hope you enjoy seeing the first bending test run!

VIDEO:
http://bender.xtremefabricator.com/BenderTestTube.wmv

[Jpfab]

I love it when a plan comes together.

Looks good,

[TRIGGER]

Very impressive.

[fabcam]

Congrats.

And I am glad to see your brother did not loose a finger.

[liketofab]

Bandit,
Very cool !! And very nice work !
I am very impressed. Great job !!!
And thank you for all the time you put into showing us the prodject from
start to finish, it has been very interesting.
Congradulations !!! And thanks !!
Joe

[Captainfab]

Bandit

That is so cool to see your bender in action. What makes it even better is we have been able to watch the build from the start all the way to bending tube. I'm anxious to see what's next. Thanks for all the time and effort you've put into all of your postings for everyone on OFN to see. This is really one of the highlights of this site. Excellent job...keep it up

[TheBandit]

Originally Posted by Mr.N

Nice to see you this close! It's been fun reading along as you go!

Can't wait for the video of your frist full bend!

Thanks Mr. N! Hope you got to see the video also - it's in my last post above.

Originally Posted by BadDog

Congrats! Looks like it went well!

Thanks man! It was a bumpy start figuring out the relief valve, but now it seems to be working well.

Originally Posted by sapper

Now does the whole world not seem a bit brighter and the weight off your shoulders. I love the feeling you have when you see the results of the major project are complete.

Oh man, you have no idea! The problem is, though, I can't sleep... I keep thinking about all the projects I want to make with it!

Originally Posted by Jpfab

I love it when a plan comes together.

Looks good,

Thanks man! I am stoked.

Originally Posted by JWBURES

Very impressive.

Thank you! It has been a long time coming.

Originally Posted by fabcam

Congrats.

And I am glad to see your brother did not loose a finger.

Thanks Cris! And thanks for all your support. You're going to be hearing from me more and more I'm sure... Pretty soon I'll be dusting off my copy of Bend Tech Pro and running it through more hoops (pun intended).

My brother was just kidding around. He couldn't believe I wanted everyone to wear safety glasses, but with a machine so new and untested, I should have had everyone in blast shelters! You just never know. I am glad he didn't hurt himself even if he was just kidding.

Originally Posted by liketofab

Bandit,
Very cool !! And very nice work !
I am very impressed. Great job !!!
And thank you for all the time you put into showing us the prodject from
start to finish, it has been very interesting.
Congradulations !!! And thanks !!
Joe

Thanks Joe! And you're welcome to! I got a lot from sharing this project - lots of great input and support that I never would have had without posting. Not to mention all the great feedback! Thank YOU.

Originally Posted by Captainfab

That is so cool to see your bender in action. What makes it even better is we have been able to watch the build from the start all the way to bending tube. I'm anxious to see what's next. Thanks for all the time and effort you've put into all of your postings for everyone on OFN to see. This is really one of the highlights of this site. Excellent job...keep it up

Thank you so much Captainfab! It was my pleasure sharing this with everyone. And I am not about to stop here... there's still a lot to be done on and with this machine. This is only the beginning!



Thanks so much to EVERYONE who is watching this project. I will keep bringing updates as I finish things off. There is a project exhibition coming up in June here at Cal Poly. Haas Automation will be there and I am hoping to get an interview. So I gotta get this machine looking and performing great so I can show it off! Look foward to more updates as I get the autostop controller finished up, panel the cart, and get some BRIGHT YELLOW trim on everything.

[sapper]

Originally Posted by TheBandit

Oh man, you have no idea! The problem is, though, I can't sleep... I keep thinking about all the projects I want to make with it!

Oh I know this all too well. You will quickly be looking at all the things you have wanted to do and figure out how to do them with the biggest limitation being time and funding for materials. You will quickly be saying "I could make that..." and you will start to get picky like me......

[TheBandit]

UPDATE

This isn't much of an update, but I forgot to mention my initial test results. In the video, the last piece of tubing is cromoly. The others were DOM. Based on the operating pressures I recorded, it took approximately:

3,400 ft-lb of torque to bend 1.75x0.120 DOM tubing.
3,900 ft-lb of torque to bend 1.75x0.120 cromoly tubing

These values were significantly higher than my initial estimates, which is why I had to increase the relief pressure on the control valve. The machine was designed with safety factors that should handle the additional loading. My only concern now is that the motor on the pump will be loaded a little beyond it's rating.

[robs88yj]

Congrats on the successful test. It looked awesome on the video. It looks like all your hardwork and calculating paid off. On the bend pressures, do they drop off significantly once the bend begins or are they consistent throughout the bend cycle? Congrats once again.

[lramberson]

Congradulations on you project, Great job, E-Mail me when you are ready for the shipping address...LOL

[TheBandit]

Originally Posted by robs88yj

Congrats on the successful test. It looked awesome on the video. It looks like all your hardwork and calculating paid off. On the bend pressures, do they drop off significantly once the bend begins or are they consistent throughout the bend cycle? Congrats once again.

Thanks rob!

The hydraulic pressure does drop off as the rams extend because as the arms swing out, less force is required to produce the same amount of torque. The leverage arm increases as the rams extent. The actual bending torque on the tube does not vary significantly after initiation of the bend.

Originally Posted by lramberson

Congradulations on you project, Great job, E-Mail me when you are ready for the shipping address...LOL

Thanks! What exactly am I shipping to you?

[traxman25]

Bandit, congrats on getting this thing to work! I can only imagine how excited you are about it! Looks awesome, only wish I had the will for a project like that.

[jackalope]

WOW!!! Way to go. You really should be proud of yourself. This has really been an amzing thing to see come to life. Well planned and you did an EXCELLENT thing by documenting it's growth. Both the audio/visual/written info was exceptional.
This just shows what can be done by someone who is determined and has the skills.
Again, way to go! --Grant

[TheBandit]

Originally Posted by traxman25

Bandit, congrats on getting this thing to work! I can only imagine how excited you are about it! Looks awesome, only wish I had the will for a project like that.

Thanks! I am so relieved to know that it works, but it's like having a sportscar in the garage without the keys! I am so broke from building it, I can't afford the tube to use it with! I actually had a couple hundred dollars budgeted for the first bending project (the bumper) but I had to spend it on a new encoder for measuring the bend angle. I'll have more on that later as I get the controller up and running.

Originally Posted by jackalope

WOW!!! Way to go. You really should be proud of yourself. This has really been an amzing thing to see come to life. Well planned and you did an EXCELLENT thing by documenting it's growth. Both the audio/visual/written info was exceptional.
This just shows what can be done by someone who is determined and has the skills.
Again, way to go! --Grant

THANKS! It has been my pleasure to share this with everyone! I am a little obsessive about documenting everything I do with pictures and video, but I think it's well worth it when I get such great feedback and people can point out what I am doing wrong.

The entire process has been a huge learning experience for me and I consider myself extremely fortunate to be able to tackle a project of this proportion. When I walk out into the garage and look at that thing, I get weak in the knees thinking that I designed and built every piece of it from scratch. It's truly an incredible feeling!

You guys have been my support all along and I can't thank you enough for sticking with me and encouraging me throughout this project. I really wish I could meet everyone so we could bend tube together!

[Captainfab]

Originally Posted by TheBandit

I really wish I could meet everyone so we could bend tube together!

Hey! ya know what I'm going to be in Mantica CA in August after Hot August Nights in Reno. I don't Know how far you are from there...can't be too far.

[traxman25]

Originally Posted by TheBandit

Thanks! I am so relieved to know that it works, but it's like having a sportscar in the garage without the keys! I am so broke from building it, I can't afford the tube to use it with! I actually had a couple hundred dollars budgeted for the first bending project (the bumper) but I had to spend it on a new encoder for measuring the bend angle. I'll have more on that later as I get the controller up and running.


I really wish I could meet everyone so we could bend tube together!

Yeah I know the feeling, had the same thing after I bought my bender! I bought it but couldn't afford the tube to use it for a couple weeks, it sucks. You'll make it though, just get someone to invest in you and buy a simple set of sliders or something and ask for 50% (materials cost) up front. Well maybe not the way to start, and not the way I started, but you'll get there soon!


Heck bend tube, wheel whatever, it'd be cool to all get togeather one way or another! I'm planning on going to Tinbenders jambo next year, how far are you from that?

[TheBandit]

CaptainFab - I was actually thinking about going to Hot August Nights again this year. It depends if I am in school during that time or not; I will have to check my calendar. That is a fun event. Last year I witnessed some bozo in a mint condition Cobra (kitcar) rearend a Chevelle because he was peeling out and reving his engine to show off as he approached the stoplight.

traxman, I have vowed to go to next years TB Jamboree if it kills me. I went the first two years (2004 and 2005) and had a blast. I was thinking fabcam should pay me (haha!) to tow my tube bender to the lakebed with Bend Tech on a laptop to make parts and sell his software. How much fun would that be?

[TheBandit]

UPDATE 5/15/06

After some headache with the encoder I bought off eBay, I finally broke down and bought a new one. When it arrived I hooked it up and got things to work perfectly, so I am on track to having the prototype NC controller working very soon. This encoder is significantly different in proportion, so I will be making an adaptor later this week to mount it where the other one was.

When that's finished, it will be a simple job of dialing in the angle you want, pushing the control valve, and waiting for the machine to automatically stop. All the while there will be a big green digital readout to tell you what angle you're at.

I also order 12 sticks (240 feet) of 1-3/4x0.120 HREW which arrived last week. Once the controller is working, I will be tackling my first project, this bumper for my 4Runner.



UPDATE

As mentioned earlier, had to get a different encoder to get proper operation with my controller. Originally I bought a used BEI encoder off eBay. This is a very high end encoder that would sell for as much as $800 new. It has an insane resolution of 12,700 pulses per revolution. With the proper decoding, this equates to up to 0.007 degree accuracy! Unfortunately decoding this sucker requires faster processing than my PLC controller is capable of, so I needed something less accurate. To replace it, I bought a smaller Koyo encoder with 360 pulses per revolution. With the proper decoding, this can provide 0.25 degree accuracy, which is still more than enough for me. Most importantly, it will work with my PLC!

Here are the two sensors side-by-side. As you can see, the BEI is a lot bigger than the Koyo! It also has an integrated coupling, which allows a slight misalignment between the encoder and the shaft it's measuring.



I spent hours trying to figure out a new mounting system for this encoder. I already made a mounting bracket for the BEI encoder, so my choice was to either make a new mounting bracket for the Koyo or adapt the Koyo to the BEI bracket. After going around and around trying to come up with a good bracket design for the Koyo, I finally settled on making an adaptor that would replicate the mounting of the BEI. Here's what I came up with.





As you can see above, I practically converted the smaller encoder into the bigger one. This took a big hunk of aluminum round bar, which was significantly more expensive than the flat bar I used to make the BEI bracket. But I felt this solution looked much better than a large drop bracket to appropriately position the new encoder and allow room for a coupling.

Sorry I didn't get any pictures making this stuff! It wasn't terribly difficult though. I started with a round piece of aluminum, chucked it up in a lathe, and turned the outter features. Then I drilled the large center hole using the lathe. Next I transfered the part into the mill, faced off the end, and drilled the seven holes required for mounting. Finally, I ran the mill back and fourth to make the deep slot for accessing the coupling.

Here is what the mounting bracket looks like that this bolts to. This is one of the parts I made during my frenzy to get the controller working. At that time I had a lab partner working with me on the controller, so I had him do the welding and I did the machining on this bracket.



Below: Another part that came out of that frenzy was the shaft that the coupling hooks to. I started with a piece of flatbar steel, milled the edges to allow clearance for button head screws, and drilled a hole in the center. Then I MIG welded in some of the hydrauilc tubing I had to act as a shaft.



Below: Here are all the parts mounted to the bender. It's tough to see the stackup, but the shaft piece above is turned over and screwed onto the lowest part of the main die arm. The large aluminum bracket is bolted to the lowest part of the follwer die arm. Then the encoder (and adaptor) are bolted to the aluminum bracket. An aluminum coupling connects the encoder to the shaft. This allows the encoder to measure the angle between the main die arm and the follower die arm, which happens to be the bend angle of the tubing!



I have some rewiring and minor reprogramming to do first, but I should have a working controller by the end of the night. Hopefully I can post up a video to show how the autostop controller works!

[TheBandit]

UPDATE

The numerical controller is working!

I now have a real time digital display of the bend angle and an automatic stop when the tube is at the desired angle. When dialing in the desired angle, the dispaly switches over to show you what you are putting in. Then after a few seconds (or as soon as you start moving the machine), the display switches over to show you the current angle.

Here's a video if it in action with my girlfriend at the helm.

NC VIDEO
http://bender.xtremefabricator.com/BenderTestNC.wmv