# Custom jetter build



## skitian (Apr 5, 2011)

My boss threw an idea at me this week. We have a KJ-1750, yeah a bit small. It works ok for doing preventive maintenance and opening small clogs. We can't justify dropping big bucks into something significantly larger, but we hate turning away work too. It's also a pain to get a hold of a trailer jetter on the few occasions we need one. 

So here is the idea. We want to try to use our 40 HP diesel air compressor to run an air powered motor connected to a larger jetter body. We can buy all the components for jetters individually. So, we're thinking jetter body, unloader valve, relief valve, few other small components. We already have about 150' of 1/4" hose with our current jetter. We are working on the calculations to match up the HP and RPM's to see what size jetter body we can get up to. There is an Edco facility here we have done work at, we're going to see if we can get an air powered motor there. Like the one we have on our air powered slab saw. 

The whole project is still in theory for us, if we start getting some stuff built, I'll post pics. I'd like to see what you'll think of our lil idea.


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## drs (Jun 17, 2011)

How will you hook this up? There has to be a loss and you have to size the pump to the HP that can be used. 

I like the idea but what do you do if you need a water tank?


Why are you having a problem getting somebody to jet a line?


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## Redwood (Sep 8, 2008)

I wouldn't bother as the losses you are going to see are quite high. It's just the nature of compressed air. All that heat of compression is lost energy and you know how hot compressors run... :whistling2:

Figure with a 40 HP rotary screw compressor you will see about 175 CFM, and an air driven motor flowing about 150 SCFM yields about 5 HP.... :laughing:

So you only loose 35 HP in the conversion... 
Might as well buy a gas driven pressure washer at a fraction of the price....

Now the Di Pietro Rotary Air Engine will offer higher efficiency but you still have the compression losses. and a much higher cost engine....


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## drs (Jun 17, 2011)

Is there something in the compressor that you can run some belts off of it and spin the pump?


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## Redwood (Sep 8, 2008)

The only thing I can think of that could possibly be viable is a PTO where the engine either drives the compressor or, the pump and the pump is mounted on the compressor.


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## skitian (Apr 5, 2011)

Ok, here's where we are at now. According to our calculations we can run an air powered motor between 9 and 12 HP, but we are going to have those numbers double checked. 

We are also considering modifying one of the pulleys on the engine to run a second belt to a pulley and shaft above the air compressor. And setting up a mount on top of the air compressor with a shaft coupler to attach the jetter body when we need it.

Our 3rd option, which I'm hoping is the one we go with, is picking up an old beater air compressor, removing the rotary screw setup, and adapting the jetter body to connect there. Putting a water tank where the jack hammers would usually go, and probably another tank up top. Changing the throttle from air actuated to hand control. We know another company that has more than a few extra old compressors with flat tires taking up space in their yard, hoping to work out something with them. 

Who knows, we're playing with all those details for a bit.


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