Slip Rolls

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JetSet
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Slip Rolls

Post by JetSet » Mon Mar 28, 2005 9:21 pm

Hello.

I cant really seem to find any of the major bits im after, so to stop my venture into pulse jets becoming a complete bodge, I will make myself some tools :lol:


Could somebody please check the attached image, it shows my current understanding of what they are, and how they work.

The top roll will be ajustable (via a threaded bar, studding or bolt). The blue mess on the right hand side of the lower part of the image are gears - apparently slip rolls can be hard work, so they are important for me :-p

Should all of the rolls turn, or just the top one? I had planned to have the top one moving, and the bottom 2 moving freely.

What thickness should the bars be? I was hoping to find some 1.5" diameter as a minimum.

What do you think? Am i missing anything?
Thanks!


PS, please excuse the poor drawing!! :oops:
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slip_rolls.jpg
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James D
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re: Slip Rolls

Post by James D » Mon Mar 28, 2005 10:49 pm

Ideally you want two rolls to turn, Its hard for them to grip on stainless steel.

Check this Ebay item.
http://cgi.ebay.com/ebaymotors/ws/eBayI ... ename=WD2V

This design would work better because the metal is gripped firmly between the two vertical rollers, allowing you to roll right to the edge and not leave flats.

Hope this helps

paul skinner
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Re: re: Slip Rolls

Post by paul skinner » Tue Mar 29, 2005 1:57 am

James D wrote:Ideally you want two rolls to turn, Its hard for them to grip on stainless steel.

Check this Ebay item.
http://cgi.ebay.com/ebaymotors/ws/eBayI ... ename=WD2V

This design would work better because the metal is gripped firmly between the two vertical rollers, allowing you to roll right to the edge and not leave flats.

Hope this helps
Or you could GIS for "metal slip roll" and find a link...say like this one

http://www.metalwebnews.com/howto/rolls/rolls.html
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rolls4.jpg
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hinote
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Re: Slip Rolls

Post by hinote » Tue Mar 29, 2005 2:28 am

JetSet wrote:Hello.

I cant really seem to find any of the major bits im after, so to stop my venture into pulse jets becoming a complete bodge, I will make myself some tools :lol:
I've tried several times, to show how easy it is to form conical and circular parts, with a simple, single-roll version of a "slip-roll".

Please look at the following link:

http://www.pulse-jets.com/phpbb2/viewto ... =slip+roll

--my experience with a purchased "slip-roll" wasn't very positive; the tool created wavy edges. My single roll tool only demands a little attention, along with a little personal hand strength.

This will be my last effort to try and boost this device, as a simple and effective tool for forming PJ parts. If anyone would like specifics about the (simple) construction of this tool, please let me know. Think less than $10 US for the whole project.

Bill H.
Acoustic Propulsion Concepts

Dave
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re: Slip Rolls

Post by Dave » Tue Mar 29, 2005 3:05 am

Bill
Using your $10 slip roller method will leave a lot more cash around for engine parts. By all means, please post all the details and recommendations you have. Pictures and step by step instructions on how to build and use the tool would also be nice.
Dave

Mike Everman
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re: Slip Rolls

Post by Mike Everman » Tue Mar 29, 2005 3:59 am

Yeah, Bill, do tell! Though of course, I prefer to skip the whole cone thing, but may need to make a good one soon!
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hinote
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Re: re: Slip Rolls

Post by hinote » Tue Mar 29, 2005 4:32 am

Mike Everman wrote:Yeah, Bill, do tell! Though of course, I prefer to skip the whole cone thing, but may need to make a good one soon!
Here's a photo of the darned thing.

It's just a chunk of 1x2 c-channel, with a couple of u-bolts attached at the ends. The threads are locked to the channel with double nuts on each side, to establish the spacing. I cut the flanges back a little on the ends, to access the nuts on the underside.

A piece of pipe is placed thru the u-bolts; the gap between the pipe and the channel surface is adjusted by the nuts on the u-bolts.

To use this, chuck the channel in a vise (or something to hold it down solid).

Just stick a piece of sheet metal between the pipe and the channel, and gently try to start a "wrap" around the pipe (I use my palms, spread out so my palms/fingers apply the pressure as evenly as possible, and the bend is from the back--pulled up and toward me). Not a whole lot, to start. If you apply a slight bend to one particular length of the sheet metal, then move it slightly further thru the roll, and bend it again. With a little practice you can bend a chunk of sheet metal into a cone in 15 minutes or so. In operation, it's just a series of straight bends along the length of the material--but if you're patient, nobody will notice the individual bends.

A little tip: Form the very edges of the flat stock (that will be joined together--by welding, or?) first--a judicious bend near to the edges will give you a good joint. This is really the only place where a little experimenting will yield improved results. The rest is just patience and a calibrated eyeball.

Again, refer to the above link for a good example of what this thing can do. If you want more, I can provide a number of similar examples. As a test--can you see any lines that represent the individual bends in the roller tool?

I'm tempted to bring a formed (but not-yet joined) part to the upcoming PJ meet at Avenal, CA--to show what this tool can do.

Ya gotta try it, to believe!!

Look at the frustum I formed on the link I attached--I dare you to do better than this with an expensive slip-roll!

Bill H.
Acoustic Propulsion Concepts

".......some day soon we'll be flying airplanes powered by pulsejets."
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hinote
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Re: re: Slip Rolls

Post by hinote » Tue Mar 29, 2005 4:59 am

hinote wrote: If you want more, I can provide a number of similar examples.
OK--here's one more photo of a frustum, formed by my simplistic (but effective) rolling tool.

And, NO--I won't answer any questions about what the part is going to be attached to! Think big.

Bill H.
Acoustic Propulsion Concepts

".......some day soon we'll be flying airplanes powered by pulsejets."
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NanoSoft
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re: Slip Rolls

Post by NanoSoft » Tue Mar 29, 2005 5:08 am

Or you do like me and take a piece of pipe clamp in a vice and then use your hands and a hammer to bend the metal around it. Once I weld it up I use an anvil to "perfect" the roundness of the tube. At first it takes a while but the more you do the easier and faster it gets. I made my entire Chinese engine in about two hours. That includes cutting bending and welding.

Nanosoft

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