LandyManLuke

If i didn't already have an air ratchet and air chisel, i would have been down to the end of the road for one of these sets Luke (of Sheffield, in the poor deprived north )

Definitely looks interesting! Well done Si, for breaking the mold yet again and coming up with something refreshing and new. Luke

Yes, ok, thats a nice vice. However! That's not an air tank THAT's an air tank!

I believe Hardy Spicer and GKN are now the same people, or at least both are owned by the same people.

Halfords 'automatic' charger. I've got one, has resurrected a few dead batteries, and i use it to keep the battery in the garage topped up. it has charging and trickle-charging modes and generally just gets on with it. My ol'man uses one to keep the cranking and deep-cycle batteries on the boat charged over winter and that doesn't go anywhere for about 4 months....

They came from RS, because i'm lazy. No doubt they could be sourced locally for a lot less than the £9 (each) i paid for them, though at that price they're still significantly cheaper than a 12v or even 240v air solenoid valve. 240V version would be in plentiful supply at your local scrappy! The valve is the same unit, the coils are removable and swappable. they're ok for simple use, but they are only truely one-way, and they don't like operating with a small pressure difference across them.

this is the current set up i have, a washing machine valve tee-d off before the NRV. it works pretty well . just need to sort control now.

I pour the fuel down the outside of the filter element, so it gets filtered before going to the engine.

I think Roger tried taking a standard pressure switch apart to look at it, at which point it distributed itself around his workshop, with the aid of the big spring (that was) inside it.

I've got a working solenoid dump valve - 12v water/heating solenoid! cheap as chips, though not good for much else. A shaft position/speed encoder is easy to implement. alternatively, you could deduce start up procedure by measuring the change of pressure in the line to the NRV. try to start a pump close the solenoid see if the pressure is increasing open the solenoid try to start the next pump close the solenoid see if the pressure is increasing, quicker than before (ideal factor of 2) iterate for more pumps Would be easy to do in software, saves extra hardware and complication that includes.

Yup, the trouble with them, as Roger found, is the fridge/freezer compressors don't output enough volume to close the dump valve on startup. running a few pumps into one valve would generate enough volume, i'd think, but then you lose individual control.

It may have been 'on cam' ie held at it maximum throw by the cam, so the hand lever cannot move it up and down. In such a case, turning the engine over a bit moves the cam, and the hand lever will work. when i suffered complete lift pump failure, the engine wouldn't run above about 1500 rpm due to fuel starvation. Incidently, when i bleed my 200tdi i just fill the fuel filter up before i screw it on, then fire her up, and off we go. Edit: Sorry Dunk, we posted at the same time!

I love when people say they tried leaving the freezer open during the summer to cool the room down!!! :D :D

Rog, It's all constructive , I was just trying to justify what, as you said, appears to be a bit pointless , It's certainly not for everyone, but this post may sow a few seeds for someone. Any extra heat i can get into the garage, the better! it's getting cold down there! Mad professor brain? I think i may well just be mad . Chuck me a PM or email any time. Cheers Luke

Waste of time? for me, no. I agree that the application is marginal, but it holds merit for my use. My garage is the ground floor of the (3 floor) house, the end of a row of three, slap bang in the middle of Sheffield. I often work with the garage door closed, and the noise of the compressor is deafening. Using anything like an air ratchet has the compressor on and off every 5 minutes or so, which is annoying. The freezer pump runs almost silently and with the 300L tank, there's plenty of air as and when i need it. As an aside, the development of the system is very much a learning process, valuable to me for both my degree and, i hope, my career. The electronics are a product of research and investigation, trial and error, and help from others (including a few from here - Roger, Fridge, Si). Luke

No guessing needed as to which one then?

You think you can tell the difference?

Rick, thanks, I've got a gallon or so of ATF, i'll try some of that as a comparison. Luke

It was your email that spawned this thread!

Agreed, i just didn't have a 230v fan, but did have a 12v, and i have a 12v supply in the garage. again, in theory, agreed. However plonking one on the top has done pretty well so far. I've had a thermocouple on different areas of the pump body and it runs at about 30-35 degC with the fan on, >65 degC without.

Pretty low, but not insignificant. There are two approaches, either run a few pumps in parallel as Roger intends, or have a large enough reservoir that you don't really care, like me I run the pump for a few hours before i need air, to fill the 300L tank. if i'm in a hurry, i cycle the Machine Mart (noisy) compressor to fill the big tank about half, and the 50L fully. the valve work i have allows me to do this easily. I leave the freezer compressor going all the time, sporadic use of air tools is about equal to the constant drip feed from a single freezer compressor, i suspect two or more would easily match (my) demand. One of Roger's intended uses is grit/bead blasting, so his air consumption is significantly higher. Luke

Evening, My (slightly out of date) page on this project is here this is my freezer compressor, with 12v PC fan mounted on the top for cooling

Les, you're right. It's pants! big one is on the shopping list. Sadly dad wanted to keep his nice old vice that's at home. Luke

The scopes.. and the home made bit - an extension lead/ connection box thing

Currently, its for streaming music off the network locally, or radio 1 off the interweb, looking at datasheets, looking at PDF format of WSM, etc etc. In the fullness of time (when i'm not so busy), I'll finish the interfacing for the compressor setup, so the PC can monitor and manage the compressor and tanks. Just got two oscilloscopes, they predate me by a good 15 years (1970) but they're still going strong, and they were free, that's my favourite price! alas, i didn't build them.