compressor cant keep up sandblasting

[tom jackson]

well just been to mm and dont have any in stock just typical ,, so going to order one online today can get it for tomorrow, just it doesn't say what bar it is so not sure if will be ok

 

[tom jackson]

ok so i got a new valve and its still the same gets to about 30psi and starts to struggle so im guessing it wasnt the valve at fault , am i looking at worn piston rings now then

 

[The_Yellow_Ardvark]

ok so i got a new valve and its still the same gets to about 30psi and starts to struggle so im guessing it wasnt the valve at fault , am i looking at worn piston rings now then

Pop the piston and clean the rings.
Then give the bore a light hone to remove the glaze.

 

[tom jackson]

hi ive already had that done took to engine shop who honed the bore for me also said rings and bore looked ok so not sure what to do now

 

[Bravheart]

I M O as an amateur.

You need to check the valves and gaskets in the cylinder head.
You say it was running OK before but now only 30psi after taking the piston out so there's either a valve broken, not seated properly or a gasket leaking.
Either way cylinder head off and clean valves and a new gasket set.

 

[carbon]

Is the belt tight enough?

 

[tom jackson]

yh belt looks ok , ive took the belt off and its fine runs well but soon as put belt on it just slows right down so motor seems ok , the only other thing i changed was the switch as old one was falling to pieces held together with tape so just changed it went to local compressor shop and they looked at mine and gave me a replacement so hopefully the right one

 

[carbon]

but soon as put belt on it just slows right down

Is the motor big enough for the pump. The motor should still run at the same speed if there isn’t a problem with the pump

 

[tom jackson]

im not sure was on it when got it motor has this tag pump is twin piston cant see any tags on it

 

[carbon]

From these pictures the belt is not the correct one for the pulley. It should be out towards the edge of the pulley. As it is it could be trying to drive off of the bottom of belt. Is the plug in the third picture the one for the compressor as if it is does it have a fuse in it as the motor is rated at 24amps

 

[tom jackson]

hi yes that's plug for compressor as was when i bought it do i need to change it,, ah so what kind of belt would i need , i did buy new v belt for it as well as old one again was falling apart and had a v belt in it so just bought same type

 

[carbon]

The plug would need to be 32amp with a suitable supply for it. Shouldn’t be connected to a 13amp socket. The belt could be a B section belt but you need to measure the approx width at the top of the groove to confirm

 

[dave h 2]

Tom,
What is the pump output pipe made of?
They are normally metal, but I see a hoseclip on the manifold, which probably means it's rubber so it may have failed inside due to heat and pressure.
It's also odd the motor has a small double belt pulley, but the pump doesn't + the big ali plate. My 3hp comp has a much larger 100mm or 125mm motor pulley, so possibly the pump is being over rev'd. and may explain the squealing belt slip.
You comp seems to have been built from bits m8.

BTW if you fit a smaller air jet to the nozzle in your blast cabinet you wont need so much air.

 

[the snooper]

Tom,
What is the pump output pipe made of?
They are normally metal, but I see a hoseclip on the manifold, which probably means it's rubber so it may have failed inside due to heat and pressure.
It's also odd the motor has a small double belt pulley, but the pump doesn't + the big ali plate. My 3hp comp has a much larger 100mm or 125mm motor pulley, so possibly the pump is being over rev'd. and may explain the squealing belt slip.
You comp seems to have been built from bits m8.

Small pulley on the motor means the pump will run slower

 

[dave h 2]

And it's a 2800rpm motor DUHHH!

 

[carbon]

And it's a 2800rpm motor DUHHH!

What’s wrong with with that. I had a 14cfm single phase compressor with a 2800 rpm motor, it was still running 20 years after it was purchased

 

[brightspark]

What’s wrong with with that. I had a 14cfm single phase compressor with a 2800 rpm motor, it was still running 20 years after it was purchased

i have a twin pump and motor comp 2800rpm gave 75 quid for it and its been hammered sandblasting for hours

 

[dave h 2]

Whats wrong with it is simply the rpm would explain the existence of the smaller motor pulley, that made me think the pulley was too small in my previous post.

I still think the double motor pulley may be wrong as it's not original. What diameter is the pulley on your 2800 motors?