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  • Davek0974
    replied
    Hydrovanes are nice units.

    In its defence, this unit does at least have a cast iron block

    Leave a comment:


  • MrSleepy
    replied
    Originally posted by Davek0974 View Post
    These seem a bit tight for a heavy-duty compressor recommended for "a professional DIY hobbyist" or "enthusiast" although I'm not sure what a compressor enthusiast is??

    The heavy duty workshop continuous use types usually are either heavy cast iron bore or screw compressor.







    Rob

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  • Davek0974
    replied
    Compressor arrived this morning

    I can confirm from the depths of the manual that there is a duty cycle:-
    50% duty cycle,
    15 minutes continuous running,
    12 re-starts in 1 hour,

    These seem a bit tight for a heavy-duty compressor recommended for "a professional DIY hobbyist" or "enthusiast" although I'm not sure what a compressor enthusiast is??

    Anyway, one really good thing is that it's practically silent, compared to the bone-shaking ear-splitting direct drive units it's replacing anyway, might even be able to work in the shop while its running now!

    I'll have the plasma running later so will see how it keeps up.

    Leave a comment:


  • Davek0974
    replied
    Somehow I doubt my cheapy unit will have the option running free

    It probably won't need to start more than 4-5 times an hour, it's not going to be working flat out as I don't do production runs, mostly one-offs so plenty of thinking time between jobs.

    Leave a comment:


  • lakeside53
    replied
    On my 3hp (real) Quincys I have a couple of options for running. If the starts excessed 6-8 per hour they recommend just running them continuously and using the free-run unloader (it just closes the cylinder valves when it needs to pump). Of course, the compressor is good for 50,000 hours... and running unloaded it's very quiet and uses little power.

    The starting duty cycle is is mainly to save power (particularly for those with peak demand metering which I don't have) and to protect the motor.
    Last edited by lakeside53; 09-26-2014, 03:33 PM.

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  • Davek0974
    replied
    Originally posted by larry_g View Post
    I'll have to say I agree with Radkins on the tank size issue. If the compressor cannot deliver the air required for the job then the tank size becomes irrelevant and you will be playing a waiting game. Or as said by one above , scrapping parts.

    One other issue not brought up here is the duty cycle of the compressor your going to use. If you plan on running long cut jobs the compressor may not have the duty cycle to withstand use. A lot of homeowner compressors are rated as low as 4 starts per hour.

    lg
    no neat sig line
    Thats a good point, it's not listed anywhere in any of the adverts so I am just going to run it how i want and see how it stands up. If they do not state clearly a recommended duty cycle then they cannot complain if i kill it.

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  • larry_g
    replied
    I'll have to say I agree with Radkins on the tank size issue. If the compressor cannot deliver the air required for the job then the tank size becomes irrelevant and you will be playing a waiting game. Or as said by one above , scrapping parts.

    One other issue not brought up here is the duty cycle of the compressor your going to use. If you plan on running long cut jobs the compressor may not have the duty cycle to withstand use. A lot of homeowner compressors are rated as low as 4 starts per hour.

    lg
    no neat sig line

    Leave a comment:


  • Seastar
    replied
    Dave
    Sorry about that.
    I need to read more carefully.
    C-Aire does build great compressors though.
    Bill

    Leave a comment:


  • Davek0974
    replied
    Originally posted by Seastar View Post
    The best air compressors built in the USA are C-Aire in Wyoming, MN
    They use top notch components and make great tanks.
    Look them up.
    I don't have any interest in them but do have one of their two stage units in my shop in Minnesota.
    It just works.
    Bill
    Well i would, if I wasn't in the UK

    Leave a comment:


  • radkins
    replied
    For those folks here in the USA it might come as a surprise that, believe it or not, Harbor Freight has a couple of real bargains on compressors! They have two different "brands" with Central Pneumatic being the brand name of the compressor shaped lumps of scrap iron and aluminum they sell and the "US General" brand which happens to be a re-badged American built Belaire at about 2/3 the cost of a Belaire brand! These are NOT Belaire clones, they actually are the genuine article made right here in the USA (South Carolina) with most everything including the tank being manufactured here except the pump itself which is a very good quality pump built in Italy. They come with Square D electrics and either a Century or a Baldor motor depending on the model and are very well built units for a home or small shop type application. I think they only have a couple of different models now having dropped the top-of-the-line model that had a 5 HP Baldor motor and two stage pump mounted on an 80 gallon tank but I have read that there will be another version of that one available sometime next year. This is ONLY the Black painted US General brands they have and they are not to be confused with their Chinese junk compressors, it's somewhat of a mystery why they don't advertise these being American built but for whatever their reasons they don't mention it anywhere that I have seen.

    Maybe they just don't want to spoil their reputation?

    Leave a comment:


  • Seastar
    replied
    The best air compressors built in the USA are C-Aire in Wyoming, MN
    They use top notch components and make great tanks.
    Look them up.
    I don't have any interest in them but do have one of their two stage units in my shop in Minnesota.
    It just works.
    Bill

    Leave a comment:


  • Davek0974
    replied
    Thanks Rich,

    I will check on the temperature, I did read that hot air is not good. I'm not sure the neighbours would agree with my putting the air intake outside though . It's fairly cool in my shop all year though as the roof is well insulated and walls are concrete slab.

    I have read that 10-20' of iron pipe can be used as a cooler to good effect if needed.

    Leave a comment:


  • Rich Carlstedt
    replied
    Dave, As Paul mentioned somewhat in the second post on this thread, air temperature is important.
    Giving the compressor cylinders the coolest air possible will improve compressor efficiency dramatically.
    In an Industrial application,I increased compressor (2x 90 HP) performance 25 % when I mounted the air intakes
    outside, including the intake Filter units .
    This also takes the compressor noise out side .

    If the receiver tank is cool to the touch, you are doing good.
    If it is warm, watch your drier !

    Rich

    Leave a comment:


  • Davek0974
    replied
    The tank volume means practically bugger all in my case

    It's running a plasma cutter mostly so if the pump can't handle it, the plasma will cut out and the part is wasted (usually).

    I've purchased the cheapo one on the strengths of the customer reviews and that they have a good warranty, if it falls to bits then its their problem.

    I need (at present) a modest 4cfm @ 80 psi constant, in the future i might get the next plasma cutter up which needs 7cfm @ 90psi , the compressor listed shows the useless displacement figure of 14cfm and general advice seems to be to take 2/3 of that as usable delivery which gives me a possible 9.3cfm of usable flow rate.

    Having a reasonable tank at 90ltr will at least allow the plasma to get running before the compressor kicks in, what I don't want is for both to start together as that would certainly blow a breaker or two

    Leave a comment:


  • radkins
    replied
    Originally posted by J Tiers View Post
    It can be the case for home users..... so long as the tank doesn't leak down (like mine does). Trying to quantify it as "removing one wheel" or whatever, is not helpful to understanding, because of course you and I have NO IDEA what a particular user will do, and can't possibly make a statement as to what particular job is going to be typical, how much air it takes, and/or whether "X" CFM is enough..

    If someone wants a particular job done, and has info on CFM requirements, peak, average, or duty cycle, then the thing can be calculated. A yea or nay statement can be made.

    You can list a slew of jobs where it would have no chance. I can list an equal number of jobs which would be fine. There's no point in even starting up with that noise.

    It's the exact same duty cycle deal as a cheap little Lincoln welder, with the exception that if the tank isn't full when you get there, it has to fill first..... at least the welder works best when you first turn it on.

    Fact of the matter is that the tank will hold up above some pressure for a certain time at a given airflow, and after that, it has to be pumped back up. A big pump does that fast. A little pump does it slower. If that's good enough, then it works, if not, it won't.


    I gave the "one wheel" as a "just for instance" and of course there are many situations where the same would apply, such as needing to use an air blow gun for a short period, maybe to run a pneumatic jack, or any number of other situations and I never disputed that. In these instances you are correct and I never disagreed but I think you may be missing my point, it's the all too common mis-understanding that leads some folks to think a bigger tank is going to help their compressor keep up with an air hungry tool. The situations where one tankful of air may do the job or intermittent use will allow for the tank to recharge while it would not be used anyway is not usually the problem, it's where people are having to wait for the compressor to catch up while trying to run high demand tools such as pneumatic grinders, cut-off tools, bead blasters etc where the problem really lies. It's not at all uncommon for folks to waste time and money trying to install extra tank capacity which does not help in THESE situations or go out and buy another compressor and make the wrong selection by passing up the factors that really matter because they are looking at a big tank when what they really need is CFM! Over on the auto paint and body forums I visit it's common to have newbies (the old timers already know better!) ask about what compressor do they need and the usual question is "do I need a 60 gallon compressor or will I need an 80 gallon model?" as if that's what matters most when in reality it hardly matters at all! I know that's paint and body work but the principle remains the same and it is still a fact that a (for instance) 15 CFM compressor with a 60 gallon tank, or even a 40 for that matter, will easily outperform an 80 gallon version with only 14 CFM! The bottom line is if the CFM is not there when selecting that new compressor then a bigger tank is simply not going to make up for it in spite of what some folks want to think except in situations maybe like you mention where one tankful of air might get the job done, honestly how many of us buy a compressor thinking they are only going to need one tankful of air at a time? At other times where most people are running out of air that bigger tank only trades one wait for another!
    Last edited by radkins; 09-24-2014, 12:11 PM.

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