My Rix SA-6 Diesel

[rob.mwpropane]

The forum has been showing error for the last few weeks getting onto the threads. Is it broke? Either that or I've been banned again.

For your described vibration. I would suspect the following
1. You have a counter weight fitted upside down on the crankshaft fan end
2. Or you have it missing on the fan end
3. Or you have a single belt and no counterweight fitted flywheel side of fan side either either or both
4. Or you have the new dual belt flywheel as well as an old 2nd counterweight fitted when you shouldnt
5. Or you or someone else has fitted a dual off the shelf drive pulley with no 19mm (3/4") balancing holes

so thats about it for the counter weight options

Next culprit is the swash plate thrust rider is out of alighnment front end fans side
Turn the power off, Take the shroud off, rotate the pump by hand at the fan and look carefully at the
blue spring on the thrust rider assembly. It should first be under constant tension 19mm (3/4") measure it
and more importlanly not move in or out as you slowly turn the fan by hand. Neither should the thrust rider bar move against the 3/8 silver coloured rod bolt.

Check this out and report back Photos would help.

While you are there grab the swash plate wobble plate bearing that attaches the three pistons to the rod end bearings and yank it about your looking for excessive bearing play. Its a C3 clearence there will be some play but not much its a judgement call.

If you have the correct dual solid pulley with four (4) 3/4" holes (cant remenber the PCD) check that that has the holes drilled right side up.

There is a drawing in the manual that shows both the counterweight fan side and flywheel with holes in corrected position when the1st stage piston is fully down the bore.

If I knew how to post a picture I would. Iain

Thanks Ian. I'll have to look into all that you mentioned. The pulley I believe as per the manual only has 3 holes in it.

I do have some pictures of the shroud off from when I 1st got it (when it was still dirty....has since been cleaned up). The weight is in place... no idea if it's upside down.

 

[iain/hsm]

From the photos your good.
With the 1st stage at TDC fully in, the counter weight should always be at the 6 oclock position. Your are slightly off on the photo but no matter its the correct position.
Always note that the lower trailing edge of the front counter weight (furthest away from the retaining bolt and crankshaft) always follows closest to the swash plate bearing housing as you rotate it.
(if it was ever placed by mistake the other way up the vibration is huge.)

The 2nd 3rd and last photo are also good and show the correct positioning of the flywheel holes,
when the first stage is at TDC the holes on the drive end flywheel are at the base with the front counterweight also in the lower position. So far all id good,

Next check the blue spring during rotation for movement and dont forget to check the equal square bar if it moves against the retaining bolt that holds the spring it dont take much. And an easy fix.
While your in there check the two thrust rider plates turn the pump to get them out the way then feel with your finger
if the plate has worn

If I knew how to post photos on the forum I could explain it better with them. iain

 

[iain/hsm]

I would also change the head bolts for A2 stainless, 1st 2nd and 3rd use plenty of copperslip on the threads
You could do this one at a time and not affect the oring seal, one out one in, they need little torque.
1st is socket head 1/4-28 UNF thread and 2' long
2nd is socket head 5/16-24 UNF thread and 2-1/4" LONG
3rd is socket head 5/16-24 UNF thread and 2" LONG
2 inch would work OK on both

The counterweight bolt is a 1/4-28 UNF thread 1-1/2" long

 

[rob.mwpropane]

From the photos your good.
With the 1st stage at TDC fully in, the counter weight should always be at the 6 oclock position. Your are slightly off on the photo but no matter its the correct position.
Always note that the lower trailing edge of the front counter weight (furthest away from the retaining bolt and crankshaft) always follows closest to the swash plate bearing housing as you rotate it.
(if it was ever placed by mistake the other way up the vibration is huge.)

The 2nd 3rd and last photo are also good and show the correct positioning of the flywheel holes,
when the first stage is at TDC the holes on the drive end flywheel are at the base with the front counterweight also in the lower position. So far all id good,

Next check the blue spring during rotation for movement and dont forget to check the equal square bar if it moves against the retaining bolt that holds the spring it dont take much. And an easy fix.
While your in there check the two thrust rider plates turn the pump to get them out the way then feel with your finger
if the plate has worn

If I knew how to post photos on the forum I could explain it better with them. iain

I think I understand all you said and thankfully one of the 1st times you've posted and I'm more relieved than horrified!

To post pictures you hit "upload a file" at the right hand side of the screen, then hit "choose file" when it pops up. You'll have a window open for your computer files and can select which pictures you'd like to share.

At some point I would like to change the bolts out, so thank you for the sizes!

 

[iain/hsm]

The next thing to do is pulley alignment
Take a ruler 12 inch or more or straight edge and place it edge on onto the front of the main larger driven pulley
Look down from above and ensure no gaps along the contact point line
Slide the ruler over to the smaller drive pulley while still in contact with the driven pulley contact points and check
if the two pulleys are in line and one is not further along its shaft than the other.
Then check alignment from the driven to the driver pulley and again this time from the driver to the driven
Each motor and pump crankshaft and drive shaft need to be 90 degres across from the base plate and be both parralel to each other and aligned in angle to each other. That is much easier to show in a photo than say in words

 

[Geo7]

It's from someone who's never owned a compressor before!

That perspective and the questions/answers that arise from it is what makes this thread so valuable. I almost pulled the trigger on a used RIX but could not get enought details on the condition, and feel that I don't quite have the skills (yet?) to convert it to electric and put it into service. But this thread may be getting me closer...

 

[iain/hsm]

That perspective and the questions(answers that arise from it is what makes this thread so valuable. I almost pulled the trigger on a used RIX but could not get enought details on the conditions, and feel that I don't quite have the skills (yet?) to convert it to electric and put it into service. But this thread may be getting me closer...

To keep the traffic down and this page size we should do a separate post showing the build up from scratch of a block and a compete strip down in the field and service of this compressor.
We did think seriously to do it underwater once in hard hat standard gear and a blacked out visor but it got a tad out of hand.

But a strip down or build up of an SA-6 using the most basic and minimum of hand tools is in keeping to the military field manual. no tourqe wrenches no bore gauges or micrometers using a simple 8 inch adjustable spanner (crecent wrench?) than a set of spanners (wrenches) three allen keys and a collection of sockets is about all you need,
Of course we didnt intend sinking the motor or engine with the block and the crankshaft was already fitted and the fittings with PTFE tape were already connected in the heads but we felt it was possible even blindfolded to build one up and to an operational condition.

 

[rob.mwpropane]

To keep the traffic down and this page size we should do a separate post showing the build up from scratch of a block and a compete strip down in the field and service of this compressor.
We did think seriously to do it underwater once in hard hat standard gear and a blacked out visor but it got a tad out of hand.

But a strip down or build up of an SA-6 using the most basic and minimum of hand tools is in keeping to the military field manual. no tourqe wrenches no bore gauges or micrometers using a simple 8 inch adjustable spanner (crecent wrench?) than a set of spanners (wrenches) three allen keys and a collection of sockets is about all you need,
Of course we didnt intend sinking the motor or engine with the block and the crankshaft was already fitted and the fittings with PTFE tape were already connected in the heads but we felt it was possible even blindfolded to build one up and to an operational condition.

That would be awesome...any chance you could release your manual withal the top secret parts redacted to go with it? Might be asking too much!

 

[grf88]

I am with Rob on this, it would certainly be much appreciated.

 

[rob.mwpropane]

@iain/hsm I think we'd all still love to see that video of a stripdown when you can?

At any rate, I double checked everything, re tightened the pulley's. All is a lot better than it was. Nothing was out of whack on the swash plate or the blue screw.. There's still a little play in the belts, but nothing like it was. Might vibrate ~ 1/4" which I'm 100% is coming from the little diesel engine. Filled another 420cf yesterday morning, she's a champ.