I have a couple questions regarding belt length and pulley alignment.
Note: I apologize in advance for my excessive use of similes in this post.;-)
Still working out and dry fitting a motorized version. What you see is a partial mock-up. There is plenty of good information and pictures in the forum files so I've had no trouble finding a design that fits my modest needs.
To be clear, I have a DC motor and a speed control box and a foot switch (stop-start only). I'm using a 14" top wheel and a 2.5" drive pulley with a 1/2" V belt. I've a lot a work to do to the bead roller yet. It needs a decent adjustable fence and I have not added the heavy reinforcement bars to reduce the terrible flex all these HF type CHICOM bead rollers suffer from. That's not my problem. I want to work out the motorized part first.
I'm curious, will the length of the drive belt affect its rpm? (I'm better at fab than geometry & mechanical engineering) In other words, if the electric motor were mounted much lower, would the longer belt required affect the rpm on the big wheel? If so, faster or slower? I want it to turn as slow as possible on its own with as little help as possible from the rheostat. Regardless of belt length, I may still need to add an idler puller for tension, I just have to get it wired up & running today to see.
BTW: The cooling fan is from a late 1960's era AMPEX reel-to-reel tape machine to assist cooling the motor when it's turned down to its lowest running speeds using the rheostat. The frame is a low-cost HF grinder stand. You can't see it but I have welded the bolt together joints on the inside and added solid 7/8" steel plate mounted under the top and bottom shelf, so it's quite heavy & stable as Hell.
I don't like to show such projects before they're finished, but perhaps somebody who knows better will see something else to comment on. Please, if you have a better idea, I'd like to know(it's only a mock-up at this point).
Footnote: I spent over 16 hours alone on; re-turning & polishing the crude HF die set ($109.00 retail), removing and re-cutting the massive burrs from the two drive gear's teeth that prevented them from turning without using great force and most laborious of all, truing the two main shafts (one shaft was warped and rolled like an over-boiled bratwurst on a flat table top.
If you buy one of these HF, Eastwood, Woodward Fab and who knows who else sticks their name on them, think of these CHICOM made tools as an unfinished kit, even more so the dies as they are more, 'nearly finished blanks' not ready-to-use. You will likely want to add zerk grease nipples to the four shaft couplings too. You will have to fab your own adjustable fence (Eastwood offers one as an 'option' that will set you back $79.00 for some hokey thing a high-school kid in shop class can make. Oh! Did I forget to mention the tension knob is just a weird thread count bolt? Yep throw that away, re-tap to a SAE or Metric thread size from this century and make a decent T handle or crank lever. Expect all sorts of other Hokey little tweaks. And lest we forget, as mentioned, for anything thicker than wimpy 22 gauge steel or alloy sheet, you will have to re-enforce the two main backing plates with some serious square stock or the two rollers will go out of alignment under pressure, making your bead look like an aerial view of the Amazon River because those two plates flex like al dente pasta!
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No, a longer drive belt will not affect the speed of your machine. Bob
I bought what is probably the identical bead roller outfit ECCEPT everything was first class condition ( no repairs needed). I think your setup will Not work well. I doubt you will have enough torque and it will probably not be slow enough. I use mine by hand but plan to motorize it. I am planning to use a 30-1 or lower worm drive And similar size pulleys. It is hard to have it too slow unless you have a LOT of experience. I have even made fenders and these machines are very usefull
I have a worm drive reducer if needed, just stuck things together here so I had an illustration to go with the question.
There is a company in China that makes those bead rollers for anybody that buys 50 or more. They range in quality and added features from very rough (Harbor Freight-Northern Tool) to American distributors like Woodward Fab who pay a premium for better fit,finish & quality control. I'm a masochist I guess, I like to take crap and make it work better.
I have a good ole American made manual PEXTO that I use for most work and I hope this one will work for longer piece work when I get the kinks worked out. Jimmy
Probably need the gear box. If you got the motor down to 10% or say 175 RPM (doubt it would have much poop - depends entirely on the DC drive) and those dies are 2" pitch diameter the stock would still shoot thru the rolls at about 180" a minute.
(the 14" pulley turning about 31 RPM)
Faster if the rolls are larger. Slower if smaller.
If belt slips, get a longer belt and use an idler pulley to increase "wrap" on the small pulley
How about a 2 sheave (1 large, 1 small)idler pulley and 2 belts to gear it down and reduce belt flex?
This isn't a very good picture but it shows the drive I put on the older version available from Harbor Freight. There's a DC motor attached to a gear box and this drives a sprocket linked to the drive sprocket by a #40 chain. The small box with a switch mounded to the post houses the PWM supply. The switch turns on the power and I made a foot pedal to control speed from 0 to about 30rpm. The silver box on top (with a switch) controls direction.
You may notice a few other modifications like stiffened frame, grease fittings and a fabricated guide. The older HF rollers where made from 12mm plate and still needs help for anything over 22ga. The newer versions appear to be 10mm plate. You'll find that the arms will walk back and forth and spread on 22ga and above. With mods and power drive, mine will roll 18ga. in a single pass if necessary.
I couldn't live without direction and speed control now. And for sure, it beats trying to hold a line and crank at the same time. Or give direction to an assistant.
I'll see if I can find more pictures if you like.