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I Need Help Improving A Home-Made Slab Roller From The Old Wettlaufer Plans

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I just completed building a tabletop slab roller from plans originally published in "Getting Into Pots: A basic pottery manual" by George Wettlaufer, and later in Ceramics Monthly (Feb. 1977). After extensive adjustments and fine-tuning of the cables, the slab roller just doesn't seem to function properly - I haven't even rolled a slab yet because it doesn't seem ready.

 

As others have mentioned, the incoming and outgoing cables tend to get hung up on each other. In addition, as the baseboard gets close to the roller at either edge, the tension from the cables actually pulls the board up toward the roller - this doesn't exactly fill me with confidence about getting even slabs!

 

I've got a video of the slab roller in action

- I hope it's clear enough.

 

Anyone else who's built this model, or is a mechanical whiz, and has some suggestions?

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From watching the other video, I noticed two things. First, just breifly , it looked like there was a different type of flange on the roller that might possibly keep the cable from binding. Second, the other video , Slab roller and workmate, the table didn't get rolled to the end. Maybe you should just use it and not go the full length of the board. Or you could design something to keep the board from pulling up at each end. It also looked like the cable on the second video didn't ride as high. <div> Marcia

 

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Hi Marcia,

 

Thanks for your reply - I was little confused until I found the "other" video you're referring to, and I see what you mean! Unfortunately, this man constructed his roller differently, with no end caps, and that flange actually keeps the cable from sliding right off the pipe. Perhaps I can somehow adapt that concept...

 

It would be nice to be able able to use the most of the board that I can, so I will still want to solve that "riding up" problem as well. I'm sure someone out there will have clever solutions!

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Thanks again Marcia - you're really putting some thought into this! The idea about the guide cable is especially intriguing. Could you please explain the "C" rails? I'm not exactly sure what those are. This also makes me wonder if I could use some type of modified drawer glides - I'll look into these possibilities tomorrow morning.

 

I'm still searching for ideas, so if anyone else has suggestions I welcome them!

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Hi:

 

I just watched the video and while I have no idea as to whether your construction was true to the drawings I noticed a couple of possible conditions that may contribute to your situation. In the first place I notcie that you have no springs on one end of the cables and there is not much in the way of tension adjustments. If the cables are under adequate tension it will eliminagte the problem with the cales winding over each other. Also if the tension is not even side to side it will cause the roller to be skew just slightly. Also there is no way of preventing the platen from rising up as you approach the ends of the roll. If you had spacers on the platen it would keep the height the same with out regard to tension. if you look at professionally made rollers usually there is something that keeps the height constant. The Brent has side rails and the northstar uses a height adjustable with screws that forces the platen to ride at the same height through the rollers for its whole length. I think that if you put side rails on the platen you would eleiminate the problem of the platen riding up and if you put turn buckles (two turnbckles one on each cable) at one end of the roller you can vary the tension as well as some springs to take up any possible mechanically induced slack. I can not tell from your video but are the cables wound in opposite directions on the roller. another way to keep the platen from rising would be to put a guide pulley under the roller keeping the cable below the platen. If the cables are wound in the same direction you may be getting some torsion in the roller frame. To make this a little more clear, is the cable on the right wound clockwise and the cable on the left wound counterclockwise or vice versa? If both cables are wound clock wise or both are wound counterclockwise that may be causing a problem. Since I don't know the original design this is just speculation on my part. Good luck

 

Regards,

Charles

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I made this slab roller late 70’s early 80’s I had the same problems till the cables tor apart. When I replaced the cables I raped it only one round and did not use the screws, just made it real tight and the friction worked. The lifting the wire is not level so you need to raise it till it is. I just live with this part.

 

 

 

 

enjoy slab roller

 

bill

 

 

 

 

 

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Hello,

I built one of George's slab roller long time ago, loved it. Looking at the video, cable's binding on handel side.

if you give cables a bit more room to wind up you'll prob solve the problem > trim your board a bit on the handel side. Enjoy............

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I'm always intrigued when I find a thread that is exactly what I've been reading lately.

 

I wrote to the (sorry, name escapes me) man who did the initial video about his PVC roller figure 8 drive slab roller. (this is the video we're all talking about here, I just forgot his name). He mentioned a PDF with directions, but no luck yet. I have checked the book out from the library so I'll be taking the plans and everyone's experiences to him soon and we'll give it another try.

 

In the meantime, I went "shopping" at Bailey. They have a new mini-slab roller (priced under $250.00 with free shipping) and it is almost exactly like the one we're all referring to in our recent posts here. You might want to take a peek at the picture in their online catalog and see if it offers something you haven't thought of, or understood clearly, yet.

 

Personally, my husband and I have two sets of tires, two crowns, two airline tickets and two property tax bills to pay right now but even with all that debt, the thought of Bailey delivering a ready-made roller to my door has a lot of appeal.

 

Let's keep this thread going until we fix the problems. Certainly seems like there is a lot of technical know-how in this group!

 

Take care

 

Sue

bandonARTS

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I'm always intrigued when I find a thread that is exactly what I've been reading lately.

 

I wrote to the (sorry, name escapes me) man who did the initial video about his PVC roller figure 8 drive slab roller. (this is the video we're all talking about here, I just forgot his name). He mentioned a PDF with directions, but no luck yet. I have checked the book out from the library so I'll be taking the plans and everyone's experiences to him soon and we'll give it another try.

 

In the meantime, I went "shopping" at Bailey. They have a new mini-slab roller (priced under $250.00 with free shipping) and it is almost exactly like the one we're all referring to in our recent posts here. You might want to take a peek at the picture in their online catalog and see if it offers something you haven't thought of, or understood clearly, yet.

 

Personally, my husband and I have two sets of tires, two crowns, two airline tickets and two property tax bills to pay right now but even with all that debt, the thought of Bailey delivering a ready-made roller to my door has a lot of appeal.

 

Let's keep this thread going until we fix the problems. Certainly seems like there is a lot of technical know-how in this group!

 

Take care

 

Sue

bandonARTS

 

 

A couple of main idfferences between the commercial slab rollers and the video the OP posted is that all of the commercial rollers have the rollers restrained so that there is a physical guide to kep the platen and the roller at a consistenet height. There recently was a slab roler posted in the DIY section of Ceramic Arts Daily and again, that roller, while being PVC tubing (I'd replace the PVC with steel myself) was adequately restrained by the rail of the box and there was adequate tension through the use of the turnbuckles. As a mechanical engineer of many years experience I see so much misinformaiton being bandied about that flies in the face of logic regarding things like tension and loading. I'd actually like to see the original drawings because I suspect that there is something missing in the translation from the drawing to the final assempbly.

 

Regards,

Charles

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Having read Charles advice on various posts, and looking at this background, I would put the most credence in his advice. it's too bad that the original plans can't be posted.

Watching the video, I wonder why all the wrapping of the cables around the pipe. It seems to me that that is where there is much binding and torque, resulting in the uneven rolling and lifting of the platen. Couldn't the cables be wrapped just "once around" each side, and that would hold the pipe in place? Charles?

 

In my opinion the best small roller and the easiest to duplicate is the Brent Mini-SRC. The more wraps you have around the roller the less chance there is of slippage. The Best DIY roller I've seen is the one featured in the Sept 10 Ceramic Arts Daily that was built by Dale Savoi. Both use two rollers and have good ension and even rolling and a means to keept the rollers at a constant height through the roll. If you look a them carefully you will se that both have at least two wraps and the opposite sides are wound in two directions. Both have a means of adjusting the tension. if you've ever wrapped string on a spool such as in making a fishing rod, or a sail boat winch, or even a come-along you knwo that as you increase the tension the cable winds evenly because it rides up against the previous wrap and just winds next to it, if it can wrap over the previous wrap you get a mess.

 

Dale Savoi's video is particularly good because he shows the roller from several perspecives and you can see how it works.

 

Regards,

Charles

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I have posted the plans for the Wettlaufer slab roller, in case those who want to see the original plans might be able to help the OP out. The photographic quality is only okay, but I think it will suffice.

 

They are in my Gallery here at the forum, under my Profile:

http://ceramicartsda...album&album=187

 

I'd like to see those but it seems that I do not have the necessary permissions to actually see them. I'm logged in and I tried using my log in to sign in as requested by the gallery and nothing.

 

Regards,

Charles

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Sorry, I don't know why that would be, I thought the gallery was for users to post other pictures (Like pottery) that they wanted others to see.

From the "Help" file :

"The gallery can be used to upload images you wish to share with the community."

I can see it if I am NOT signed in.

What a PITA.

I have posted them on Flickr :

http://www.flickr.co...s/55220890@N06/

 

 

thanks, I got it!. It appears that the design does not rely on friction of the windings but rather having the cable attached to the roller so one can pull the board through without much tension. The thing that strikes me is that without a means of restraining the board there is no way to keep it from raising at the ends cince the cable becomes more vertical and therfore increases the rising forces on the board. I'll post a diagram showing what I mean. If you haven't started your roller seldomseenkid I would strongly recommend using the design shown in the videos see; http://tinyurl.com/24wklxv Dale Savoie' s roller is a much better design. I don't se how one can roll a slab of consistent thickness except in the very middle fo the roller. The only thinkg preventing the boad from rising is the resitance of the clay and you know that is not very much.

 

You could restrain the board by adding side rails on it.

 

 

Best regards,

Charles

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I know what you mean, Charles, I thought of that, that when the roller gets to the end of the cable, , the cable has to go somewhere, so it is going to wind UP, and since it is attached to the board, the end of the board goes up at both ends.

Perhaps something like a drawer slide with a roller in a channel could be used to hold the board down at the ends.

What was also a little daunting was the caution in the text that you can't just drill a hole in the center of the pipe caps, they need to be exactly centered, and this requires the services of a machinist with a lathe. That's too much trouble for me.

Actually, I wasn't thinking of building this roller, but wanted to help somehow. If I were going to build a "roller" it would be very low tech, as in : I would fill four/five inch dia. PVC pipe with concrete, put a thick piece of Masonite on my garage floor, and use slats and canvas for different thicknesses. I would roll by hand of course. I could store it all away against the wall, as I don't have the room for a table with a roller.

 

 

I love it! That may be low tech but very effective. I used to have a prof in college who always required us to simplify work we turned in. Wasn't it the Greeks who philosophized that there is beauty in simplicity? I think you have a great idea. The only thing simpler would be to do away with the masonite, put canvas directly on the concrete floor of the garage, set up a couple of rails on either side and roll.

 

Best regards,

Charles

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Thanks for your help, Warrior!

 

I built the slab roller as true to the plans as possible - the cable tension is adjusted by screwing eye bolts in or out. Also, the cables are wrapped clockwise for one end of the roller, counterclockwise for the other end. I still have to play with the cable tension adjustment, but I don't know if I'll be able todo anything to prevent the base board riding up. See below for my replies to everyone.

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Hello again, Warrior,

 

I can email you a copy of the plans photographed from the original 1977 Ceramics Monthly article, but they're too large to upload here and I can't reduce the file size. They are a tad, um, short on thorough illustrations and instructions - I suspected that there may have been a few corrections to these instructions in a subsequent issue, but I no longer have these issues.

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Hello again, Warrior,

 

I can email you a copy of the plans photographed from the original 1977 Ceramics Monthly article, but they're too large to upload here and I can't reduce the file size. They are a tad, um, short on thorough illustrations and instructions - I suspected that there may have been a few corrections to these instructions in a subsequent issue, but I no longer have these issues.

 

 

At the risk of being redundant you can keep the board from raising at the end of the roll buy adding rails the thickness of the slab you want to either side of the board. If you do not provide a mechanical stop (the rails) the boards wil raise at the end giving you a slab that is tapered.

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