Mycom Screw overhaul questions 200SUD

[Howeirdhughs]

Looking for advice on wether I should overhaul our 200 SUD. I am good with precision work. I do all recip overhauls, but have had no training on the screw compressors. I have the book, but I think the translation is spotty since it is from Japan. The overhauls looks very easy, but the thrust bearing endplay setting is critical.
Questions:
1) is this something I can do on my own with the book?
2) is there training available for screw overhaul and where.?
3) If there are a few tips you could offer what would they be?
I thank you in advance for any input. Howeird

[RANGER1]

You obviously have good general mechanical knowledge give it a go .

The only thing which may upset the boat is if you need any reclamation work on rotor journals etc .

Mycom have got to be the easiest and best screw to overhaul .

Once you pull it apart it will look even easier and instruction manual more relevant .

End clearance should be identical on re-assembly , as they use machined spacers which are marked Male /Female .

Attention to detail on re-assembly
ie stone discharge end housing and rotor end faces to ensure no false DEC readings when assembled .

Aslo pay attention to gaskets as oil galleries have to line up ( they can be put on wrong causing oil to go in the wrong places ) .

If in doubt there are plenty of people here to help you out .

[Boaz]

Hi there.
Before you start, make sure you have from Mycom all parts like teflon rings for shaft seal and unloading piston, correct ball barings from SKF (much better then the original NTN). Also make sure to make the time with no compressor on your stand to wait for more parts if you see you need them after opening the compressor.

Basically, just to open, replace the bearings and close is kind of simple, but I do not totally agree with our friend ranger1 regarding the re-positioning of the screws only by putting back the shims as they were. You must close the star ring and check the clearance with a gauge. It is correct that if you are lucky it will be OK, but remember (important to all technical issues in life): What you dont check will go wrong!

One more question you need to ask yourself, as this is a business and not a hobby to you, what is the alternative cost by a proffetional shop, and if it is worth it to take the risk and start the compressor at 3'000 RPM when it is your first time?

Good luck!

[RANGER1]

Boaz ,
Would strongly disagree with you about "shims" as they are not shims but precition ground spacers .
Of course you check clearance but precision bearings are so close in tolerance it does'nt matter .
Also you can use SKF bearings but why would you . The NSK bearings are a matched pair specifically made for Mycom for this application .

You can also buy a overhaul kit with everything in it you need except shaft seal , as there are a few varients .

We all had to start somewhere and mostly without any special screw compressor training .
At least mycom supply manuals not like all its competitors who seem to make them a mystery .

If Howeird dacides to do it we will offer more detailed info at that time if he requires .

[Howeirdhughs]

Ranger, Thanks or the response. It is good to be in the brotherhood.

[Howeirdhughs]

All input is good in this situation IMO. The question of using professional shop is at hand already. We have a shop who does good work. My motivation might just be a bit selfish. I want to learn everything I can. I remember the learning curve on some of the pumps and valves. I also do all the DDC system repairs, but it was hard at first. I feel like I owe it to the owner since he pays me very well to take care of his place. Thanks, and I will take all advice into consideration.

[Boaz]

Dear Friend.
I know that we are kind of far away, but with flight prices today it is not too bad, so I want to invite you to our shop in Israel, where I can give you deeper training with all kind of screws (Mycom, Howden, Trane, York, Bitzer...). I can also assure meeting some of the nicest people arround!

[2400martin]

as a standard in our overhaul procedure we check teh rotors on straightness. the yournals of a yournal bearing machine we restore by choming and grinding to orginal manufactore size. we have fixed prices for contractors

[Magoo]

If you are not confident to handle re-build contact Mycom US and have a factory re-build done. And while you at it ask about shop training.
As per Ranger, the Mycoms are straight forward to re-build, but get one point wrong and all hell breaks loose. Thrust assembly and set up is critical, just to mention one factor.

[CaliforniaRefr]

I don't know where you are in the US but here is the West Coast Service Manager #310 972 8952 his name is Jack. He is in charge of service and overhauls. Mycom over here in Cali is very supportive and will come out to the Job site and assist you