New project roll slitter

Jason H · Mar 28, 2011

Team PM,

I have a new project that I would like to start that seems easy enough. I have found photos of a machine that would fit my need, but I don't know who made it and I don't know how I could just go buy one, so I need to build it. These photos came from an auction site that already sold the machine. Tell me what I am seeing here.

What are the components that are being used, what type of HMI is recommended? Any ways to improve on this that you can see. Please point me in the right direction.

The purpose of this machine is to cut rolls of fabric while it is still on the tube. The roll is made perfectly straight on another machine that rewinds it, which I have no problem building.

Jason H · Mar 28, 2011

additional pics

Jason H · Mar 28, 2011

Here is what the current one i have looks like. This is not mine, just a quick image I found. I have tried my best to make it as safe and secure as possible with guards and shields, but work is good, and i am wearing out the one i have. I want to take the time to build something a lot more safe for the operator.

Jason

motion guru · Mar 28, 2011

First off - what are you trying to slit? Fabric? Cores? Paper?

How fast do you want it to go? How wide a web? How many slitters (this machine only appears to have one slitter) . . .

I have done a lot of slitter rewinders from little baby ones all the way up to 30,000 lb rolls of paper running 3000+ fpm making a dozen smaller rolls from one large roll.

adama · Mar 28, 2011

What your showing in the paper industry would be called something more akin to roll saw. it slits - saws the material to width without the unwind - rewind of a typical slitter re winder.

Motion, its a Hss like blade that is darn thin and is fed into the parent roll, its how loo rolls are commonly done (assuming non slit - rewind). Oftern the machine makes multiple cuts moving along the roll of material.

Jason H · Mar 28, 2011

This is commonly refereed to as a Bologna slitter in my industry, but the idea is to take a roll of fabric that has been rewound to a new core, has the edges straight, and then certain widths are then cut while the roll is still intact.

Speed is under 50-75 RPM on the roll of fabric, but the blade can be something stepped down from the motor to have torque but enough speed. On the old school one pictured, the blade runs the oposite direction of the fabric.

The blade has no kerf, and is only edged in one direction. It is sharpened after every cut so there is a stone running on it.

On the custom one shown here I can make out a linear motor that is driving the blade into the material. Mine uses some pretty good strength to get the blade to go through the material. What kind of torque can be developed with those screws ( I assume they are called ball screws, please correct me if I am wrong. )

On the old school machine, there is a chuck with pins to grab the material, I would love something new. The newer machines use an air bladder on the mandrel to hold the paper core. Is this still the case these days?

Thanks

Jason

Jason H · Mar 28, 2011

I would have another machine that would be doing the rewinding as we would use that as an opportunity to inspect the fabric.

We are taking about a width of 130" for the rolls.

Thanks

Jason

motion guru · Mar 28, 2011

adama said:
What your showing in the paper industry would be called something more akin to roll saw. it slits - saws the material to width without the unwind - rewind of a typical slitter re winder.

Motion, its a Hss like blade that is darn thin and is fed into the parent roll, its how loo rolls are commonly done (assuming non slit - rewind). Oftern the machine makes multiple cuts moving along the roll of material.

Adama - the towel / tissue log saws I have seen are far bigger than this. I have had them in my shop and they weigh upwards of 30,000 lbs for the units we service and retrofit with cut rates to 450 rolls a minute. Making toilet paper machinery is my bread and butter business!!

Jason - for the blade - look at Log and facial saw blades - these are the units that I am most familliar with. Perini also makes a good blade - but from what I can tell, these are mostly used in the paper industry.

For mandrels/air shafts - look at External Element Air Shaft | Maxcess International, they make a nice pneumatically actuated shaft that locks the core tight.

We build equipment like this on a regular basis for the paper industry but I have to admit, I have never seen one for use on fabric.

Send me a spec and a big sack of twentie$ and I'll get started! :smoking:

atomarc · Mar 28, 2011

motion guru said:
Send me a spec and a big sack of twentie$ and I'll get started!

Wow........you're a cheap date!

Stuart

Jason H · Mar 29, 2011

I think I have the basics down on how to build this. Thanks for the direction on the mandrel and blades. My lack of experience is leaving some holes in the design:

1. for the slide to shift left to right, how will it handle the perpendicular load when the knife engages the roll? Picture is attached on which I was referring too. Do I need something like this?

Security Violation - 03

2. The other picture is of some kind of joint. The other end of the shaft has a clamp holding it down, but you have to be able to slide the roll onto the shaft. Can anyone tell me what kind of joint this is?

motion guru · Mar 29, 2011

atomarc said:
Wow........you're a cheap date!

Stuart

Note I said big . . .

Jason - your red circle is around a linear actuator - plan on spending at least $5k on a decent setup to carry that SEW Eurodrive motor/reducer + you will need a servo to run it. That looks like a timing belt actuator -
http://www.thomsonlinear.com/websit...nits/belt_units_u_ball_guided_u_/bdbg_wmz.php

You need to consider roll handling in how to get the roll in and out of the machine without damaging it.

You won't likely be able to get the roll onto the mandrel in the machine - more likely the mandrel comes in and out with the roll - the "coupling" is called a chuck - lots of sources for that kind of hardware. The tidland link above should get you to a variety of different kinds of chucks.

This should be a fairly easy machine to build - don't ignore the controls . . . a couple of zero frame UniDrives with EZ motion modules should work to manage the slitter positioning and plunge.

Just think about the control you would have if you put this out for RFQ . . . you could be the tightwad customer demanding short turn around, cheap cheap cheap costs with every feature imaginable and 5 year warrantee, free training, NET120 payment terms, 10% retention on last payment until you are perfectly happy and have achieved 120% ROI . . . :Yawn:

Jason H · Mar 31, 2011

You think the left to right is done on a timing belt drive and just driven at one end? Would this be a better option than using a linear motor to position? Do they make linear motors in the 130" range?

No problem on the mandrel chuck. The old school slitter has old school version of this, but something off the shelf would be fine.

on that note about the unidrives, I can't say enough good things about Emerson. One of their App Engineers was here at the plant until 8 PM last night trying to perfect something I did. All the people at Emerson I ahve worked with are fantastic. Great company.

Thanks again,

Jason

motion guru · Apr 4, 2011

A suitable linear motor for 130" of travel - figure $100 / foot for magnets + 2k for the motor and now you have to have a bearing that can keep the motor within about 0.030 inches of the magnet with about 250 - 400 lbs of attractive force between the motor and the magnet + linear encoder and hall sensor package . . . if you can do that for $5k - go for it!

Jason H · Apr 4, 2011

motion guru said:
A suitable linear motor for 130" of travel - figure $100 / foot for magnets + 2k for the motor and now you have to have a bearing that can keep the motor within about 0.030 inches of the magnet with about 250 - 400 lbs of attractive force between the motor and the magnet + linear encoder and hall sensor package . . . if you can do that for $5k - go for it!

Thanks MG you are worth two large sacks of $20's in my book.

Instead of a linear motor, what do you think of a driven chain and linear slide? Using the chain and the servo driving it to index for 1/2 inch increments would be fine for my application. A slide like this looks like it would fit the bill:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130452200650&ssPageName=STRK:MEWAX:IT

I got the idea after looking at my 25 year old traveling head die cutter.

Thanks

Jason

surplusjohn · Apr 5, 2011

the old fashioned one was made either by Utica Mill Specialty, or Frisching, also in Utica and related. Utica Mill Specialty still makes these, and they are not expensive. http://www.uticamill.com/umsm_slitting_machines.html
BTW, that is a pretty cool Schwabe double head D behind it.

Jason H · Apr 5, 2011

Also was a company called Judhelson, who was bought by dusenby, now part of parkinsons Technology.

Item # Model 3100, Dusenbery 3100 Single Knife Cutter on Parkinson Technologies

This is the grandchild of the old school one I posted above. Price is 6 figures! I would rather spend that on a machine shop to make the machine!

motion guru · Apr 5, 2011

Jason - those linear rails should be fine. I don't know what kind of moment load you will produce when cutting - if in doubt, buy 2 rails and 3 cars.

The chain approach to positioning will always leave you guessing - better to use a long piece of timing belt - mitsumi has a good catalog of pulleys / anchor plates for various timing belts on the small side - or you could make your own parts using Gates or any other power train distributor's parts.

A timing belt on a SEW motor reducer with encoder will give you +/- 0.020 or better positioning accuracy just off the motor encoder.

3t3d · Apr 5, 2011

I might be Under thinking this, but do the rails have to take the push loading from the cutting saw? If the carriage was moved along a structural rail (tubing) it could be clamped in place once it was positioned, and rails would not need to take any side/thrust load. All the rails have to do is position the saw assembly.
Light rails and a structural tube that the carriage can push against for the cut.

Good call on using three trucks on two rails. If a single rail carries two trucks the spacing of the trucks will subtract from the length of the rail you find.

Also, be sure you find suitable trucks for the rails, or a cheap set of rails that you cannot find cheap trucks for will not be the best bargain, compared to finding a matched set of rails and trucks.

Thanks again, for an interesting project!

motion guru · Apr 5, 2011

3t3d - the rails will serve two functions -

one will be to resist the cutting force as the blade plunges into the product (not insignificant)

second will be accurately positioning the blade - it needs to cut all the way down to the mandrel without hitting the mandrel. If the product is really dense - it would require a back-up roll as well to keep the roll / mandrel from deflecting. You have the same concern for the rails that hold the saw - they shouldn't deflect under load either.

Jason H · Apr 5, 2011

motion guru said:
3t3d - the rails will serve two functions -

one will be to resist the cutting force as the blade plunges into the product (not insignificant)

second will be accurately positioning the blade - it needs to cut all the way down to the mandrel without hitting the mandrel. If the product is really dense - it would require a back-up roll as well to keep the roll / mandrel from deflecting. You have the same concern for the rails that hold the saw - they shouldn't deflect under load either.

Some of the thinner fabrics get extremely dense as they get closer to the core. Since there is no kerf on the blade it has to push the material out of the way to continue cutting. I am anticipating going overboard on the blade setup to be able overcome this.

Some other types of slitters unwind the material, slit on a single ply level and then rewind. I thought about this design but controlling the rewinding efficiently and accurately exceeded my abilities. Once the fabric is slit it goes to other machines and +/- .125 variation is a big deal.

Thanks for the direction on the timing belt setup. Sounds perfect for this. I will follow up with my success / failure on this project.

Thanks

Jason

New project roll slitter

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