Some of you have maybe read my past saga with the Diablo HPA compressors which were being sold inexpensively on eBay earlier this year. Long story short: I ended up buying 5 of them. All were in really bad shape when received, or broke down very quickly. The seller quickly refunded ALL my money for them, so I ended up with 5 free compressors to play with. To date, with much time and little money spent in parts, I have brought 4 of 5 back to life, and my original has now functioned great for the past few months, filling guns and/or bottles almost every day.
NOTE: These compressors are completely manual in their operation and do not have any type of electronic shut-off once desired pressure is reached.
One of the units I received had lost the plug in its gauge, and therefore all of its glycerine needle damping fill. It was rusting and corroded inside, and couldn't be considered functional:
Panel mount analog gauges of the seemingly correct diameter were available for +/- $25 on eBay from a U.S. seller, and were available in a more reasonable full scale of 0-5,000 or 0-7,500 psi. I bought one and it worked, although it didn't fit into the (metric?) hole in the compressor lid, so it stood about 3/16" above the metal instead of fitting nice and flush.
I then thought about maybe looking at digital 3" direct replacement gauges. None I could find were flush panel mounts with back inlets, so I just got one with a bottom inlet (1/4" NPT) for proof-of-concept. It cost me just under $100, and was soft mounted on the compressor for function testing:
I really liked how this worked as it really showed the progress of the pumping operation, and whether it had stalled (like if the bleeder valve was not completely closed). Clear to read, and accurate from what I could tell. (I assume that the electronic gauges on my Daystate rifles are likely the most accurate gauges I have, so I check any pressure gauge against at least 2 Daystates). Digital gauge appeared to be within 1-2 bar of the Daystate readings. Without sending it out to a test/certification lab, this was the best I had.
I had seen that the China sourced 3" digital pressure gauges were available off AliExpress for about half the cost of the Amazon sourced gauge, I wasn't in any hurry, and I had a couple more compressors I might use them on. So I ordered a couple of these:
AliExpress 3" Digital Gauge
They are full scale 0-400 bar, and I received them today, exactly 21 days after I placed the order. One reason I went with these was that they had the needed 1/4" NPT thread on the gauge (others seemed like they shipped with thread adapters), they were of the best full scale range for my use, and they were available at a reasonable price.
They arrived well packaged, both functioning, in good shape and wearing thin rubber covers (which won't provide much protection, but since the covers are so thin they are easy to remove for battery replacement):
It is nice that these gauges are very easily readable, and if you have a gun which fills to psi, you can set them for that unit with the quick press of a button.
I just bent a little piece of sheet metal and mounted it using one of the existing holes for the analog gauge on top of my compressor. The gauge is soft mounted to the back plate with a couple of zip ties, since it will need to be removed periodically for battery replacement.
I tested it with a Pulsar, and if anything it reads up to 1 bar under what the gun reads, which if it has to be off, that is what I would want.
Durability, longevity, accuracy over time are all unknown at this time, but as far as initial performance goes I am very happy with these gauges at half the cost of the ones you can buy on Amazon. Purchases through AliExpress can be hit-or-miss, but this was a good one. And overall I really like the use of the digital gauge on my compressor as compared to an analog one. I do wish they had a re-settable time out or sleep time, but I have gotten used to just shutting it off when I finish the fill. And if I forget, all I am potentially losing is 2 AAA batteries.
NOTE: These compressors are completely manual in their operation and do not have any type of electronic shut-off once desired pressure is reached.
One of the units I received had lost the plug in its gauge, and therefore all of its glycerine needle damping fill. It was rusting and corroded inside, and couldn't be considered functional:
Panel mount analog gauges of the seemingly correct diameter were available for +/- $25 on eBay from a U.S. seller, and were available in a more reasonable full scale of 0-5,000 or 0-7,500 psi. I bought one and it worked, although it didn't fit into the (metric?) hole in the compressor lid, so it stood about 3/16" above the metal instead of fitting nice and flush.
I then thought about maybe looking at digital 3" direct replacement gauges. None I could find were flush panel mounts with back inlets, so I just got one with a bottom inlet (1/4" NPT) for proof-of-concept. It cost me just under $100, and was soft mounted on the compressor for function testing:
I really liked how this worked as it really showed the progress of the pumping operation, and whether it had stalled (like if the bleeder valve was not completely closed). Clear to read, and accurate from what I could tell. (I assume that the electronic gauges on my Daystate rifles are likely the most accurate gauges I have, so I check any pressure gauge against at least 2 Daystates). Digital gauge appeared to be within 1-2 bar of the Daystate readings. Without sending it out to a test/certification lab, this was the best I had.
I had seen that the China sourced 3" digital pressure gauges were available off AliExpress for about half the cost of the Amazon sourced gauge, I wasn't in any hurry, and I had a couple more compressors I might use them on. So I ordered a couple of these:
AliExpress 3" Digital Gauge
They are full scale 0-400 bar, and I received them today, exactly 21 days after I placed the order. One reason I went with these was that they had the needed 1/4" NPT thread on the gauge (others seemed like they shipped with thread adapters), they were of the best full scale range for my use, and they were available at a reasonable price.
They arrived well packaged, both functioning, in good shape and wearing thin rubber covers (which won't provide much protection, but since the covers are so thin they are easy to remove for battery replacement):
It is nice that these gauges are very easily readable, and if you have a gun which fills to psi, you can set them for that unit with the quick press of a button.
I just bent a little piece of sheet metal and mounted it using one of the existing holes for the analog gauge on top of my compressor. The gauge is soft mounted to the back plate with a couple of zip ties, since it will need to be removed periodically for battery replacement.
I tested it with a Pulsar, and if anything it reads up to 1 bar under what the gun reads, which if it has to be off, that is what I would want.
Durability, longevity, accuracy over time are all unknown at this time, but as far as initial performance goes I am very happy with these gauges at half the cost of the ones you can buy on Amazon. Purchases through AliExpress can be hit-or-miss, but this was a good one. And overall I really like the use of the digital gauge on my compressor as compared to an analog one. I do wish they had a re-settable time out or sleep time, but I have gotten used to just shutting it off when I finish the fill. And if I forget, all I am potentially losing is 2 AAA batteries.