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Pulley ratios vs. the Real World
- Thread starter jschmidling
- Start date
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- Jan 20, 2018
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- 5,653
Because both diameters are multiplied by Pi, the Pi's cancel out. The ratio of the diameters equals the ratio of the circumferences. (D1*Pi)/(D2*Pi)=D1/D2 (Alt key codes only seem to work with a 10-key pad, at least for me).
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See how simple that is? See why I have a calculator within easy reach at all times? See why my wife balances the checkbook?
Thank You, Mr. Whoopee
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- Jun 4, 2019
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- 91
First of all,I am glad I found this forum and I want to thank all who responded. Too many to name but you know who you are.
1. I am so old that I thought VFD's still cost in the thou$ands. Seems like I could have bought one for less than the cost of the new motor and solved all the problems at once.
2. I think I was working with ID and OD on the ratio problem but even with the corrections, it still runs too fast. The manual posted was a real help. I was able to take the vertical slop out of the spindle by following the directions I never would have guessed at.
The lowest speed is supposed to be around 700 but the best I could do was about 850.
By changing to a 3/8" belt I do get about 700.
3. That is still too fast for what I have in mind for this thing which is to make a crude milling/boring machine out of it.
The first step was to buy a cross slide vise which is a story in itself but it does what it does and is useful in a limited way.
I then attacked the speed problem like my old mill/drill did it, i.e. another speed control pulley in the loop. Don't what this is called but the pic included here is what I came up with. I am now down to about 300 RPM.
The next problem was an up-stop, not to be confused with the down stop.
I added the gray plastic knob that runs up and down on a 1/4-20 threaded rod. The bottom of the knob pushes on an extension the drives the spindle down at 1/20 inch per turn. That and the locking knob gives the vertical finesse needed.
I should point out that I have more fun building or redesigning things than just throwing money at problems.
As a point of interest, my shop and barn were totally destroyed in a fire last year and I was hard pressed to find a screwdriver the next day. We rebuilt the shop and barn but replacing all the toys and treasures is a hopeless task but I'm slowly getting things together again in a much smaller way.
Thanks for the help,
Jack Schmidling
Marengo, Il
1. I am so old that I thought VFD's still cost in the thou$ands. Seems like I could have bought one for less than the cost of the new motor and solved all the problems at once.
2. I think I was working with ID and OD on the ratio problem but even with the corrections, it still runs too fast. The manual posted was a real help. I was able to take the vertical slop out of the spindle by following the directions I never would have guessed at.
The lowest speed is supposed to be around 700 but the best I could do was about 850.
By changing to a 3/8" belt I do get about 700.
3. That is still too fast for what I have in mind for this thing which is to make a crude milling/boring machine out of it.
The first step was to buy a cross slide vise which is a story in itself but it does what it does and is useful in a limited way.
I then attacked the speed problem like my old mill/drill did it, i.e. another speed control pulley in the loop. Don't what this is called but the pic included here is what I came up with. I am now down to about 300 RPM.
The next problem was an up-stop, not to be confused with the down stop.
I added the gray plastic knob that runs up and down on a 1/4-20 threaded rod. The bottom of the knob pushes on an extension the drives the spindle down at 1/20 inch per turn. That and the locking knob gives the vertical finesse needed.
I should point out that I have more fun building or redesigning things than just throwing money at problems.
As a point of interest, my shop and barn were totally destroyed in a fire last year and I was hard pressed to find a screwdriver the next day. We rebuilt the shop and barn but replacing all the toys and treasures is a hopeless task but I'm slowly getting things together again in a much smaller way.
Thanks for the help,
Jack Schmidling
Marengo, Il
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Jack, are you the same Jack Schmidling of "Maltmill" fame?
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- May 22, 2019
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Thanks guys for all the input on this. Cleared up a couple things for me as well.
Jack, I feel your pain on trying to get set up again, some things can just not be replaced...course some things do get replaced and the "way I always wished they had been" in the first go around,
Good luck with the rebuilding and remember Churchill "Never Give Up"
Jack, I feel your pain on trying to get set up again, some things can just not be replaced...course some things do get replaced and the "way I always wished they had been" in the first go around,
Good luck with the rebuilding and remember Churchill "Never Give Up"
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- Jun 4, 2019
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Yes indeed. The MALTMILL (R) was forced into retirement. All that is left is a few souvenirs.
On top of all else, our roller vendor had a very large lot of knurled rollers ready to ship. We had to pay for these and tell him to give them to his scrap dealer.
Then there was the insurance policy that I never bothered to read. Structures not covered if any business was carried on within. Couldn't get a penny for the shop and had to rebuild it at my own expense.
God works in mysterious ways.
Jack Schmidling
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- Mar 3, 2013
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- 1,448
Jack, The MALTMILL ® served me well back when I was still brewing. Unfortunately having beer always available on tap did nothing good for my waistline. 