Can you say you save time or money with that kind of drop?
Only by the obvious.
Less pressure=less leaks
Less pressure=less run time
Less pressure = kinder to equipment
If you turn it down and don’t like it, easy enough to turn back up
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Well how can you say it is kinder to you equipment it is designed to run at a higher pressure. I abuse my system anyway making it fill double the capacity it is made for anyway.
The only leaks I have is older hoses I use. Well in theory my system bleeds off very slow.
See if I turned mine down to 125 by the time it goes all the way through my system I may not have that much. More apt to have pressure drops. I build hauler steps at home. I tighten hundreds of Stover nuts at a time the lower pressure the longer I have to hammer the harder it is on my impact and the bolt may not have the torque they need. Time is money.
These are the issues I see with running a compress air system much higher then target operating pressure.
Higher Air Pressure = Higher Pressure drop.
When your air pump tries to build pressure against a higher tank pressure your current draw will increase. More power to produce the same delivered volume per minute at the torch .
Higher Pressure air can hold more moisture then lower pressure air.
Running at slightly above target operating pressure is the most desirable scenario.
If you need more buffer because your storage is too low for demand that is not correctly solved by increasing the system pressure.
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Well true if you’re running high air pressure to over come deficiency’s lower pressure may not work. You know most air tools are only rated for 90psi
But again you can only know if you try.
I am not going to hound you anymore!
You know I have to apologize. When you asked me what psi I am running. I answered off my memory which for the most part isn’t to bad yet. My main pressure gauge is messed up. I had slaved a tank with it at one time it did show 175 I will not guarantee that is accurate. My compressor is set at factory settings any way. It does have 175 psi compressor because I replaced it with a OEM replacement. No intentions to being misleading was just going off memory
Oh come on😁 it’s all good. No honestly if I dropped my air pressure I couldn’t guarantee my parts to be acceptable. That is something I don’t want to do. A impact will lose torque with lower cfm. Lower pressure equals lower cfm. I say that because higher pressure can push more air in a given time. We are not talking about a great deal of pressure difference. So really how much are we gaining. I do know with a impact it doesn’t take much to change the torque.
If your application works for you great. I am all in with you. I don’t see the benefit in my usage.
My impact and sandblasting uses massive amounts of air. My powder coating system doesn’t need much at all. Then my plasma on the middle.
@TinWhisperer so I got home a little early tonight and decided to check the amp draw on my compressor.
I was honestly shocked. Without the after cooler when the compressor started up it was pulling 22 amps by the time the compressor shut off it was pulling 24 amps. Then I reinstalled the after cooler just like I ran it and there was less than amp differences.
The only thing I can come up with is I made a smaller pulley for the motor therefore not as much load on the motor.
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All of us reading this thread are very appreciative of the efforts you are doing.
Thank you Phillip!!! No joking.
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It is a smaller pulley would have made a reduction to 80 % of the original RPM
Pump pulley rpm x pump pulley dia = Motor pulley rpm x Motor pulley dia
That’s the formula to do the math
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My guess is after a while of operation as the heads and tank heated up this number would also go up and the gap would increase.
I wonder what the amperage would go up to you if you had your pressure set to 130 psi for instance.
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nah it isn’t anything. you are very welcome!!
curiosity got the best of me. so as a whole i did this mod without thinking much about it. if i had sat down and thought it through i would have read up on it and probably not done it. i don’t think it was hurting my system. it was for sure working it harder so in the long run it would shorten the life of the compressor…
hopefully this information will help someone. oh and i didn’t mean to high jack a thread it all goes hand and hand i guess.
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i agree the amps was climbing at a steady pace. it is a fairly new motor and in my opinion one the best you can buy… i have always worked around machine shops so Baldor is a industry standard.
my original pulley on the motor was a 5 inch i made a 4 inch to replace the one i broke. i looked at a DeWalt 175 psi compressor today with a Baldor motor the pulley on it was at least a six or maybe a seven.
Definitely the best . I have a Baldor pedestal grinder I’m very fond of.
And thanks again for going to the effort of measuring.
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no problem. like i said before i have changed so much stuff on my compressor i don’t think anyone will see the same results i have. it will definitely be in the same direction though.
Now you know we are all dying to find out the temperature, time to refill and the amperage once you replace the 4 inch pulley with a 5 inch pulley.
…I’ll wait!!!
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dont hold your breath!!! 
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i am tight is why i made my pulley instead of buying one man they plate too much stuff in gold these days.
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What is your pumps optimum RPM? Any idea? I resurrected an old compressor from my dads barn. I had to replace the pump was all. The new pump wanted a lower rpm than the original so I had to downshift it a little. I ended up needing a 4.25” pulley. The equation was in the pump owners manual(same tin posted above). Maybe you aren’t off all that far from spec with the 4” pulley?
And thanks for doing this! I am anxiously awaiting results. I had gathered the stuff for an aftercooler but will probably go a different direction now.
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i honestly dont know i will try to grab the model number and look it up to see. i would have made a 5 inch pulley if i had the stock material. the closest thing i had was a piece of 4.250 4150 steel. it didn’t cost anything for me to make but the value of the material was way higher than what a new pulley would have costed…
if you have the stuff i would install it post tank if you think you need it. when i run run my compressor i do catch some moisture in the post tank cooler… i may run my compressor a little more than a good portion of the guys and gals on here. the coolers really are not necessary in my opinion if someone is just cutting a few signs. the bead cell dryers are more important for sure.
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