Any recommendations for shed air compressor

My Bambi came from a dentists where it was running pretty well continuously, when I got it the tank was about half full of water, don’t know how often it was drained down but certainly not often enough. Quick oil change and a hydraulic test on the tank just to make sure and job done. Got it on a time switch so it only runs during working hours so it starts about 9:00am and goes off about 6:00 pm if I don’t use it during the day it will cut in a couple of times due to leaks, with normal workshop use it will operate perhaps four times a day, I would imagine that if they are used by dentists they must be capable of fairly hard work.

There ws a 'project' years ago in I think MEW for the construction of a compressed air 'puffer' shaped rather like a large penwith a little button at the end if I remember. It was specifically designed with an orifice which gave gentle puffs to clear things like blind holes of swarf after tapping and such like. Maybe someone will post a reference. It's the high pressure air that does the damage quite capable of blowing particles through the skin. Just enough is all you need and it's safe.

regards Martin

Using compressed air to clean machines of swarf and chips can force them into places they’d never normally go. Not much point in having wipers and seals etc on your machines if you’re going to do your best to circumvent them using compressed air. Cleaning up the workshop is another issue.

I have a couple of 1” paint brushes next to my lathe and mill for sweeping swarf away until the shop vac gets turned on.

The HSE say this in their safety booklet.

104 Blow guns

Blow guns consisting simply of a reduced orifice in direct line with the supply hose can be extremely dangerous, unless preceeded by a pre-set tamper- proof pressure regulator set at a reduced pressure from the normal 80 psi airline supply. Models are available commercially which incorporate an air curtain designed to provide a protective shroud around the nozzle. Although not completely safe, these designs significantly reduce the risk of eye injury and the dangers from close skin contact. If designed correctly such nozzles can often help to prevent the operator from being subjected to excessive noise. Because air is vented directly into the atmosphere, clean dry air is essential and lubricators should not be used. Blow guns can exhaust significant quantities of air and place extra loading on the compressor system. In view of this and the attendant risk arising from use of blow guns, their use should be considered carefully with a view to using alternative means for cleaning down machinery or components.

Blow guns can exhaust significant quantities of air and place extra loading on the compressor system.

Doesn't really describe what I was talking about. The device I remember delivered short puffs and as I said it was not intended to clean down machines more clear chippings from tapped holes or odd bits of swrf from dies etc. A lot safer than blowing down the hole as your mouth is  rather close to your eyes.

Incidentally in a cardbeard plant of my acquaintance the standard proceedure for maintainance on the infeeds of machines was blow down with an air lance. Just about the only way you could clear all the carboard dust. Compressed air can be dangerous but there are times when a flow of air is what you require. planning ahead and providing yourself with controlled low pressure air dusters etc avoids accidents. As usual think before you act.

regards Martin

Edited By Martin Kyte on 15/09/2020 20:48:12

The most effective way of cleaning welding jigs in a car body shop was to blast them with dry ice pellets and a 12bar air blast, the noise is unbelievable and full PPE was needed, ear plugs and ear defenders. Modern weld control has minimised expulsion from spot welding and the equipment stays very much cleaner now.

Mike

I have a similar compressor, branded as Orazio, from Amazon. It cost about £120. It is quiet enough to run at night in a domestic garage and hold a conversation at normal level. It takes longer to fill than my more conventional compressor, but it has never been a problem. I can run die grinders from it without any problems.

James.

There are a load of "silent" compressors on ebay. Cheap as chips from abroad, (pre-Brexit without import duty.)

You can get "safety" blow guns that have nozzles that entrap air to amplify flow and reduce the chance of injection injury and I would think blowing swarf into slideways too. Much recommended.

Standard Bambi duty cycle has always been specified as 50% maximum with run time under 10 minutes. My experience is that they last a very long time at 30% or less duty cycle with run times of 5 minutes or less in normal ambient conditions. Run longer, harder and in hotter environments life rapidly falls off. One reason a Bambi is so quiet is that there is effectively no cooling. Just conduction onto the case. No ring-ding-dingy fins to add noise but they can get way too hot inside if not given a decent cooldown period between runs.

If you want serious air, to run air tools or a blaster, a hydrovane is about the only realistic option. Not as quiet as legend says but certainly not noisy. Cooling fan mostly. My 502 will run the gun in a small Guyson blast cabinet using the smallest nozzle pretty much continously and keep ahead of ordinary air tools. Uses 10 cfm nominal at 100 psiI think. Have a504 in stock that was supposed to replace it but motor is 440 volt delta and I've not figured a sensible way to run that without full fat three phase.

Unfortunately the import silent compressors are anything but. Just as noisy as local brands with the same configuration. Unsurprising as the engineering differences are basically badge and colour.

Cylinder spacing on my old Atlas Vee twin was just right to take a Saab 9000 air filter. A long cylindrical thing. Mad a big difference to the noise. Sold it to a mate who prompty ripped the filter off, refitted the standard wee cans with a bit of mesh inside to each head. Then complained about the noise.

Bottom line is that with small "consumer affordable" piston compressors you are getting around 3 cfm at 100 psi per hp. Which isn't going to come quietly without careful engineering. Quiet usually means low pressure or low delivery. But 30-40 psi is more than enough for most home shop things so daiphragm units can be avery good match in practice.

Ex lorry air brake compressors driven by a standard induction motor can work well if you must have higher pressures. The ones I've seen are fairly hefty iron castings which don't ring like the lightweight alloy heads. But sorting out what you actually have can be a nightmare.

Clive

Edited By Clive Foster on 15/09/2020 23:11:22