Question about radius, dies, and money

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64pan
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Question about radius, dies, and money

Post by 64pan »

Hi everybody.
New guy here, and first, thanks for allowing me the chance to participate in your website. I found it while searching for tube bender info, which was a search-ender for me. No need to look elsewhere - and I am happy to say I am mostly finished building the bendomatic bender. There are tons of other things I am interested in learning about, but I am sure I will never be able to absorb a small fraction of the available information here.

In the midst of what I am jokingly told must be midlife crisis #4, I got the idea to build a kart frame and/ or minibike frame with my teenage son.
FIrst, I resent the idea of midlife crisis #4. Of course it's not that. It's actually only #3.

So I don't want to just buy a kit and bolt it together, though there's nothing wrong with that. I want my son and I to do what we can, from scratch. Even if it means taking a while to learn, because we will hopefully learn a lot, spend more time together and eventually have the reward of what we had done together without much money, but with determination and hard work. A sort of story of America, on a very small scale. In another year and 3 months, he'll be a grownup, and I want to be around him while he still thinks I'm "cool".
OK, I lied. While he still thinks I won't embarrass him too badly.
No less important is the fact that in another year and 3 months, this underachiever I call "me" may not be so inclined to hard work, and the only determination I'll make is how to get a nap in before supper.

So I won't be using my Bendomatic for 1-1/4" tubing. I am thinking for a minibike or kart, 1" tube would work. Is that about right?
I ordered a 1" die with a 3" radius.
I understand that the Bendomatic plans, as drawn, are specifically for 1.25" 4.5" radius, but I didn't know that I would have no idea where to put the hole in the frame plates for the follow bar.
I looked at the original jd2 plans, and the measurements for hole placement are different than the Bendomatic.
I guess I actually have three questions in all, which I hope don't seem too dumb.
1, Why are larger radious dies prefered here?
2, why do they cost more? Is it because they use more material to make?
I ask because in my admittedly feeble mind, it would seem to be more desirable to be able to make tighter bends than larger bends. What am I missing here, please?
3, where do I put those holes for the follow bar, for a 1" die with 3" radius?

Many thanks in advance, and Happy Memorial Day from a fellow vet here.
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[url=http://imgur.com/T3Q4Ev4][img]http://i.imgur.com/T3Q4Ev4l.jpg[/img][/url]









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Re: Question about radius, dies, and money

Post by Customize IT »

1. I wish i had every size die! But for most of chopper frame builds 4.5 is a good looking not sharp flow for tubing on frames.

2. Still want every die size not the cash! 4.5 is the norm does not make bends at such a sharp 90 degree just a little smoother flow on a frame. But we have room to build and mainly strech chopper frames out not compact them.

3. I measured my JD2 and all the follower holes are 1.5 center to center from each other so I would say the smaller radius die would need to be inward toward the piviot 1.5 in from the other hole. The larger size dies cost more just because of the more material and time to tool them.

This print instead of 3 in make it 1.5 in.

http://www.chopperhandbook.com/CBTB-2-1.pdf

My Jd2 has a different arm design thou it is not straight off the piviot?

Thanks for your SERVICE too!
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Customize IT
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SELF INTRODUCTION: I am a young punk kid that needs some help building himself a chopper!!

I am sorry I only have a hotmail account???

Tell me what I need to do I need help with my girder!!!

PLESE HELP????


[url=http://imgur.com/8saXkqN][img]http://i.imgur.com/8saXkqNl.jpg[/img][/url]








[url=http://imgur.com/pXJZqQ0][img]http://i.imgur.com/pXJZqQ0l.jpg[/img][/url]









[url=http://imgur.com/T3Q4Ev4][img]http://i.imgur.com/T3Q4Ev4l.jpg[/img][/url]









[url=http://imgur.com/fsXGYQw][img]http://i.imgur.com/fsXGYQwl.jpg[/img][/url]
Location: Ohio, USA

Re: Question about radius, dies, and money

Post by Customize IT »

It has a 1 in 4.5 in radius die in it now.

Image
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Re: Question about radius, dies, and money

Post by gww25 »

The holes in the JD2 model 3 that the follow bar link pin goes into are as follows, measured from the center of the die pivot pin. 4" rad. for what they call hole#3,
5" rad. for hole #4, 6.5" rad. for hole #5 and 7.75" rad. for hole #6. You small die will use pin hole #4. The location for the drive pin is 1.875" from the center of the drive link pivot hole. The reason the JD3 has the holes offset looking has nothing to do with the geometry of the bender but just allows more steel to encircle the pinholes. You can modify the bend-o-matic easily. The steel should cost about #38 at the home improvement store if you don't have it already.
The picture posted above is not a JD model 3 by the way so don't let it confuse you.
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Re: Question about radius, dies, and money

Post by gww25 »

Forgot to add that the general rule of thumb for nice clean bends is to keep the centerline radius near 3.5 times the diameter of the tubing. so for 1" tubing a 3.5" radius is typically used, for 1.25" tubing jump to 4.5" clr. You can go to slightly tighter bends if the wall thickness is over .095"
64pan
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SELF INTRODUCTION: 56 year old ex-Navy F4 mech from the corn & soybean fields of Illinois, the Navy got me to socal and spoiled me with the weather so I had to stay. I was riding 2 wheels from age ten starting with a Sears mini-bike, then another, next a '72 Aeromachi X-90, '74 Honda XL-125, '77 Superglide, '68 FLH Dresser (I didn't leave it a dresser for long), currently a '64 Duo-Glide I purchased as a basket in 2003. I am not a "builder" though I once "assembled" my '68 shovel engine/trans/misc. into a Paughco rigid frame with bolt-on stuff to fill the gaps, rode it for over 20 years, including several 4000-something mile rides home & back from California. I have always worked on my own bikes except for the few times when I needed machine work. Now that I am older and dumber than I ever thought I would be, but with my youngest son nearly grown, I now have a little time to try to learn to weld better; would like to learn machine work. I found this site looking for tube bender plans, and looked around to see a ton of great information you have assembled here. Thanks for having me.

Re: Question about radius, dies, and money

Post by 64pan »

Thanks a lot, everybody!
And if I didn't already say, thanks for the Bendomatic plans! I'll try to post a picture of our progress on it soon.
64pan
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Posts: 11
Joined: Sun May 25, 2014 5:25 am
SELF INTRODUCTION: 56 year old ex-Navy F4 mech from the corn & soybean fields of Illinois, the Navy got me to socal and spoiled me with the weather so I had to stay. I was riding 2 wheels from age ten starting with a Sears mini-bike, then another, next a '72 Aeromachi X-90, '74 Honda XL-125, '77 Superglide, '68 FLH Dresser (I didn't leave it a dresser for long), currently a '64 Duo-Glide I purchased as a basket in 2003. I am not a "builder" though I once "assembled" my '68 shovel engine/trans/misc. into a Paughco rigid frame with bolt-on stuff to fill the gaps, rode it for over 20 years, including several 4000-something mile rides home & back from California. I have always worked on my own bikes except for the few times when I needed machine work. Now that I am older and dumber than I ever thought I would be, but with my youngest son nearly grown, I now have a little time to try to learn to weld better; would like to learn machine work. I found this site looking for tube bender plans, and looked around to see a ton of great information you have assembled here. Thanks for having me.

Re: Question about radius, dies, and money

Post by 64pan »

Another question please...
(If this has been covered in another thread already, I apologize for not seeing it.)
I also apologize if my attempt to describe the following confuses anybody else as much as it confuses me. :-?

The width of the assembled frame plates and control arm plates.
I don't have a lot of experience reading drawings, so it's likely I just don't understand it...

Looking at page CBTB-3-1 - frame plates- shows "inside" width as 2.75" to 3.0"
Looking at page CBTB-2-1 - control arm plates- shows "outside" width as 3.5" to 3.5625".
Could one or the other of those be a typo, or do I just not get it? I figured I would make the frame using the maximum dimensions, in case I should need that later on for bigger dies and tubing.
Now I have frame plates assembled, 3" inside, and so my assembled control arms can only be a max. 2.75" outside.
Will this work fine?
Or would it be better to start with what the drawing says is max. outside width of contol arms of 3.5625" and then re-do my frame to be 1/4" wider inside than that?

Thanks a lot again for your help. If I can get this part right, I think I may only need clarification on one other point. Thanks! :D
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Re: Question about radius, dies, and money

Post by gww25 »

That's about how I have mine set up. You only need 2.5" clear in the drive links for the 1.25" die. 3" is only needed if you go up to 1.5" dies. I didn't look at the drawings but I must have reversed those dimensions since the drive links fit inside the frame plates.
64pan
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SELF INTRODUCTION: 56 year old ex-Navy F4 mech from the corn & soybean fields of Illinois, the Navy got me to socal and spoiled me with the weather so I had to stay. I was riding 2 wheels from age ten starting with a Sears mini-bike, then another, next a '72 Aeromachi X-90, '74 Honda XL-125, '77 Superglide, '68 FLH Dresser (I didn't leave it a dresser for long), currently a '64 Duo-Glide I purchased as a basket in 2003. I am not a "builder" though I once "assembled" my '68 shovel engine/trans/misc. into a Paughco rigid frame with bolt-on stuff to fill the gaps, rode it for over 20 years, including several 4000-something mile rides home & back from California. I have always worked on my own bikes except for the few times when I needed machine work. Now that I am older and dumber than I ever thought I would be, but with my youngest son nearly grown, I now have a little time to try to learn to weld better; would like to learn machine work. I found this site looking for tube bender plans, and looked around to see a ton of great information you have assembled here. Thanks for having me.

Re: Question about radius, dies, and money

Post by 64pan »

Thanks,
I think you did a great job - and it must have taken a lot of time to do all the writing and explaining and taking pictures, and I am amazed you haven't been selling those plans instead of giving them away.
It is really appreciated!
Mike
64pan
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SELF INTRODUCTION: 56 year old ex-Navy F4 mech from the corn & soybean fields of Illinois, the Navy got me to socal and spoiled me with the weather so I had to stay. I was riding 2 wheels from age ten starting with a Sears mini-bike, then another, next a '72 Aeromachi X-90, '74 Honda XL-125, '77 Superglide, '68 FLH Dresser (I didn't leave it a dresser for long), currently a '64 Duo-Glide I purchased as a basket in 2003. I am not a "builder" though I once "assembled" my '68 shovel engine/trans/misc. into a Paughco rigid frame with bolt-on stuff to fill the gaps, rode it for over 20 years, including several 4000-something mile rides home & back from California. I have always worked on my own bikes except for the few times when I needed machine work. Now that I am older and dumber than I ever thought I would be, but with my youngest son nearly grown, I now have a little time to try to learn to weld better; would like to learn machine work. I found this site looking for tube bender plans, and looked around to see a ton of great information you have assembled here. Thanks for having me.

Re: Question about radius, dies, and money

Post by 64pan »

I have not yet received my JD2 brand 1", 3" radius die, so I am finishing up the rest of the bendo-matic.
I still am not 100% sure I got it right, but so I can be clear, the picture shows the 1/4" pilot hole in the frame plates, which I drilled before I realized the instructions said, "do not drill until you verify dimensions of your die". So basically I just need to relocate that hole 1.5" to the left, is that correct?
20140529_164036.jpg
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Re: Question about radius, dies, and money

Post by gww25 »

That's correct and also if you didn't drill all 4-holes in the drive links you need to drill the hole for the small die 1.875" down from the link pivot pin hole center. You may have to slightly modify your drive pin by cutting off the 'bail' so that the drive link can go further 'into' the frame links or just make a new pin special for the small die as I showed in the bender how-to article.
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Re: Question about radius, dies, and money

Post by bosshasr »

So if I wanted to use a die for 1-1/8" tubing with a 3-1/2" CLR, I would probably be using the hole labeled #2 for the pin?
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Re: Question about radius, dies, and money

Post by gww25 »

It's not as easy as that since the die makers have various drive pin location and different follow bar pin locations but in general the follow bar radius will be either 4-inches of 5-inches from the primary one-inch link pivot holes. That's holes #3 and #4 on a JD bender. Hole #2 isn't used on any dies that I'm aware of and I typically don't drill it. The follow bar for your 1.125/3.5 die will be marked for the hole to use. If it's the same as my one-inch die that will be hole #4
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SELF INTRODUCTION: 56 year old ex-Navy F4 mech from the corn & soybean fields of Illinois, the Navy got me to socal and spoiled me with the weather so I had to stay. I was riding 2 wheels from age ten starting with a Sears mini-bike, then another, next a '72 Aeromachi X-90, '74 Honda XL-125, '77 Superglide, '68 FLH Dresser (I didn't leave it a dresser for long), currently a '64 Duo-Glide I purchased as a basket in 2003. I am not a "builder" though I once "assembled" my '68 shovel engine/trans/misc. into a Paughco rigid frame with bolt-on stuff to fill the gaps, rode it for over 20 years, including several 4000-something mile rides home & back from California. I have always worked on my own bikes except for the few times when I needed machine work. Now that I am older and dumber than I ever thought I would be, but with my youngest son nearly grown, I now have a little time to try to learn to weld better; would like to learn machine work. I found this site looking for tube bender plans, and looked around to see a ton of great information you have assembled here. Thanks for having me.

Re: Question about radius, dies, and money

Post by 64pan »

Gary, I want to thank you again for the great, free bender plans.
Even now, I can go look at what I made from your plans and cannot believe it.
It is totally functional and it's the coolest tool I own, now.
I had been thinking about buying a hardtail to weld onto my '64 duo-glide frame, but then I see what people are willing to pay for these first-generation swing arm frames. I don't want to lessen the value of an original piece.
Now, I think I will tackle making a complete frame, based on your plans here. I hope I ain't just blowing smoke. Times are tough and money is short, but with the help of http://www.choppercompendium.com I don't think it could be done for any less money.
I'm gonna try and attach a pic of the mini bike I built, just in case there's any "If there's no pics, it didn't happen" folks around...
Here's to ya.
:obscene-drinkingcheers:

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bosshasr
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Re: Question about radius, dies, and money

Post by bosshasr »

Thanks for the help!

Has anyone else noticed that the location of hole #5 is over-defined on drawing TB1-1? The sum of .9062+1.3438+1.25+1+1.5=6 not 6.5. I'm assuming the dimension is supposed to be 6 since 6.5 would over-define the location of the top edge as well. i.e. 12.9375-6.9375=6 not 6.5.
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