Noisy Edwards EXT250 Pump

Every fusor and fusion system seems to need a vacuum. This area is for detailed discussion of vacuum systems, materials, gauging, etc. related to fusor or fusion research.
User avatar
Dennis P Brown
Posts: 1344
Joined: Sun May 20, 2012 2:46 pm
Real name: Dennis P Brown
Location: Glen Arm, MD

Re: Noisy Edwards EXT250 Pump

Post by Dennis P Brown » Wed Sep 28, 2016 11:30 am

By the way, some turbo's can have ceramic based bearings available for skate boards. Needless to say, very inexpensive. You measure the size you need and just order it if available. Of course you need turbo oil or grease. There are You-tubes available on this subject.

David Kunkle
Posts: 284
Joined: Thu Apr 17, 2014 4:43 pm
Real name: David Kunkle

Re: Noisy Edwards EXT250 Pump

Post by David Kunkle » Wed Sep 28, 2016 5:26 pm

Just talked to Alpine Bearing. $250 for both bearings. Not bad, right?

Well...also just talked to Turbo Vacuum about a rebuild kit for $700. Includes bearings and the wick- no instructions. But wait... it gets worse. Also need the special tools and this model really needs to be balanced. There's also the risk that the magnetic bearings at the top could sustain just a hairline crack during the process, and then you can kiss it goodbye. He said this model is one of the most difficult to rebuild, and he rated it a 9.8/10, 10 being the biggest pain in the ass. They carry "kits" for it because some companies have the tools, etc. to still do it in house. About $3000 to have them rebuild it.

It's essentially a doorstop as is. I may as well run it till it blows.

I found this EXT255 on ebay. http://www.ebay.com/itm/Edwards-EXT-255 ... SwtnpXoDQr
Might be able to get it for around $400 and take a chance again that it's got more life in it than I need. Should bolt right in. Includes controller, but I don't understand what the other end/multi-pin connector plugs into? The controller for my EXT250 is a separate box that plugs into an outlet, and I don't need anything else. Obviously and unfortunately, I still need some other part to make it work.

Any suggestions for a good model turbo that has an ISO100 inlet. The outlet is no big deal if it isn't NW25- but I'm guessing most are.

User avatar
Dennis P Brown
Posts: 1344
Joined: Sun May 20, 2012 2:46 pm
Real name: Dennis P Brown
Location: Glen Arm, MD

Re: Noisy Edwards EXT250 Pump

Post by Dennis P Brown » Wed Sep 28, 2016 6:01 pm

I have repaired extremely bent blades on intermediate sized turbo's that the company said was not repairable - on two different units (one still had the stray bolt lodged half way down!) The re-balance wasn't a problem - I just spun it by hand, looked along the blades and adjusted the blades by slight bending as needed; when that was good, I'd add power for a second (often placed a flate metal sheet between the blades to judge if the spin was flat or had a wobble) and listened for issues, too. Then by simple judgement, I'd bend some blades slightly to adjust the problem I detected - did it in under an hour for each unit; and the units both spin up to rev's 2K higher than before (that is, before the blades had been bent) and now do better vacuum (faster pump down.) That said, I have no idea on if this is possible with other turbos.

As for your ebay unit, simply ask the seller! They usually respond in a day or so.

Jerry Biehler
Posts: 727
Joined: Tue Nov 24, 2009 8:08 am
Real name:
Location: Beaverton, OR

Re: Noisy Edwards EXT250 Pump

Post by Jerry Biehler » Thu Sep 29, 2016 5:02 am

Well that sucks. No, the drives are not interchangeable. Pfeiffer seems to really like two phase motors where others use three phase.

Looks like a good deal on the other edwards pump. The pic with the multi pin connect is just a pic without the little drive module installed. Nothing special. A lot of new turbos have the drives built in. I have three pfeiffer turbos from the 071 to 1000 and they all use the same drive that fits on the side, the only difference is the voltage you feed to the drive. 24v on the 071, 60v on the 500 and 140v on the 1000.

Oh, a lot of the smaller pumps around 300l/s and less are KF-16.

David Kunkle
Posts: 284
Joined: Thu Apr 17, 2014 4:43 pm
Real name: David Kunkle

Re: Noisy Edwards EXT250 Pump

Post by David Kunkle » Thu Sep 29, 2016 4:59 pm

Started the turbo again this am to do some research. High pitched whine is noticeably worse and probably getting worse the longer it runs. Unfortunately, NOT my imagination for certain. About as loud as the first one before it blew, but the vacuum is still good. In fact, it just hit E-7 Torr according to my gauge. Seems to be working better with bad bearings. ;) (Or my chamber is better outgassed since it was open not too long ago, come to think of it)

I made an offer of $350 for the used Edwards 255H yesterday, and they countered with $400. New bearings. oil, wick, etc. just to attempt repair of this EXT250 (no guarantees there) would probably put me over that amount.

Dennis was right about asking the seller about what the controller plugs into. I'm too used to sellers having no clue because they're pickers that get the stuff at auction or buy out a whole lot of ancient university equipment. These guys specialize in used scientific equipment at least. Kind of what I thought- the EXDC80 controller is further controlled electrically elsewhere- which doesn't help me.

Then discovered on ebay another EXT255H with the exact model of controller I have running my EXT250! Sold as a running setup- except for a lot more $$$ than $400. Now I know I should just be able to slap this 255H in there without any mods to anything. Same vacuum fittings on both models, too.

So, dragging my feet on what to do, until I heard my pump run again this am. Accepted his offer of $400. Guaranteed not DOA. Comes with the EXDC80 controller; which seem to be going for at least $150 and up on ebay separately. If I sell the controller, the pump only cost me $250!

Then they sent me an email asking if I'd be interested in another of the exact same pump. Told them: No thanks- amateur budget, and I'm counting on this one lasting forever ;) .

David Kunkle
Posts: 284
Joined: Thu Apr 17, 2014 4:43 pm
Real name: David Kunkle

Re: Noisy Edwards EXT250 Pump

Post by David Kunkle » Tue Oct 04, 2016 3:06 am

Ran the turbo several times lately. Went to start it yesterday and nothing- just sat there. Figured it seized a bearing after it spun down last time. Removed it tonight, and surprisingly, it spins freely. No wobble, grinding. etc. Seems fine. Tried to turn it on and nothing again. Turned the rotor a little to a different position, and it started. Little intermittent like that- starts most times. Put it all back together, and so far it spins up like usual, but still singing. Almost seems like a bad spot now where it won't engage electrically. Anyone know what this means?

David Kunkle
Posts: 284
Joined: Thu Apr 17, 2014 4:43 pm
Real name: David Kunkle

Re: Noisy Edwards EXT250 Pump

Post by David Kunkle » Tue Nov 01, 2016 6:56 pm

When I got the "new" 255H, I attempted to hook it up to my old controller. Surprise! It doesn't connect. Certainly looks like it should, but the differences in the connectors are very subtle. Finally find out Edwards made 24V and 80V Models- with the same designation. Brilliant. My old turbo and controller are 80V; the new 255H is 24V. The seller was kind enough to outline how to make my own controller, plus the wiring diagram from the Edwards manual. Power cord from an old microwave, 24V 10A PS from ebay for $18, D-SUB VGA 15pin Female Adapter Jack Terminal Breakout PCB Board from ebay for $11 (didn't know there was any such thing- makes it sooo easy to connect all the wires on a 15 pin connector), some old wire, and the darn thing actually works for $29! Rotor starts to spin up like normal, though I haven't bolted it to my chamber yet.

In a previous post, I mentioned how there seems to be a dead spot on the rotor where the pump will not start. Happened again recently. Didn't feel like unbolting it, so I got the idea where I pump the chamber down with the roughing pump, switch on the turbo, then quickly open the up to air valve for a short time to force the rotor to turn from the air rushing thru it. Jump starts it just fine- except the bearing whine is still there of course. Temporary fix for a chronic problem, but it'll do until this 250 turbo finally blows up, and I replace it with the 255H above. Hope to sell the old controller for about $150. Not too bad- $429 for another working turbo setup minus $150 for old controller= $279 out of pocket.
Attachments
dzfjkl 001.JPG
dzfjkl 002.JPG

Silviu Tamasdan
Posts: 136
Joined: Wed Jun 28, 2006 11:17 pm
Real name: Silviu Tamasdan

Re: Noisy Edwards EXT250 Pump

Post by Silviu Tamasdan » Sun Aug 20, 2017 11:51 pm

David Kunkle wrote:When I got the "new" 255H, I attempted to hook it up to my old controller. Surprise! It doesn't connect. Certainly looks like it should, but the differences in the connectors are very subtle. Finally find out Edwards made 24V and 80V Models- with the same designation. Brilliant. My old turbo and controller are 80V; the new 255H is 24V. The seller was kind enough to outline how to make my own controller, plus the wiring diagram from the Edwards manual. Power cord from an old microwave, 24V 10A PS from ebay for $18, D-SUB VGA 15pin Female Adapter Jack Terminal Breakout PCB Board from ebay for $11 (didn't know there was any such thing- makes it sooo easy to connect all the wires on a 15 pin connector), some old wire, and the darn thing actually works for $29! Rotor starts to spin up like normal, though I haven't bolted it to my chamber yet.

In a previous post, I mentioned how there seems to be a dead spot on the rotor where the pump will not start. Happened again recently. Didn't feel like unbolting it, so I got the idea where I pump the chamber down with the roughing pump, switch on the turbo, then quickly open the up to air valve for a short time to force the rotor to turn from the air rushing thru it. Jump starts it just fine- except the bearing whine is still there of course. Temporary fix for a chronic problem, but it'll do until this 250 turbo finally blows up, and I replace it with the 255H above. Hope to sell the old controller for about $150. Not too bad- $429 for another working turbo setup minus $150 for old controller= $279 out of pocket.
Would you mind sharing the wiring schematic for the 24V EDXC160? The reason I'm asking is, I'm looking at purchasing an Edwards EXT255H and a controller; the pump is 24V so I need the 24V controller. I have looked at the schematic in the manual for the older model of the controller, the 80V one, and it's not hard to figure out. However the older controllers used a 9-pin connector, and the newer 24V ones use a 15-pin connector. But for the life of me, I can't find the manual for the 24V controller anywhere. Without the manual I don't know which pin is what on the newer connector.
There _is_ madness to my method.

John Futter
Posts: 1214
Joined: Thu Apr 22, 2004 2:29 am
Real name:
Contact:

Re: Noisy Edwards EXT250 Pump

Post by John Futter » Mon Aug 21, 2017 3:32 am

Edwards turbos used to be relabeled Micro Seiki or Seiko Seiki pumps from Japan
We had a mass spec that used these pumps and they screamed right from new
In fact Health and safety came in and made everybody in the lab wear earmuffs.
We did a minor CAPEX and replace all of them with Phiffer turbos and sold the Seiko Seiki's on ebay to help defray expenses

David Kunkle
Posts: 284
Joined: Thu Apr 17, 2014 4:43 pm
Real name: David Kunkle

Re: Noisy Edwards EXT250 Pump

Post by David Kunkle » Tue Aug 22, 2017 2:37 pm

I managed to dig up the schematic for the controller. Only had a hard copy to scan in. Don't remember where I got it. You should be able to see the original wiring diagram thru my scribbling. My writing is how my non-electrical engineering degreed brain wired mine. Bottom of pg. 8 is what # wires I bundled together, and what the bundles got attached to. FWIW, not necessarily pretty, but it works perfectly, and it's dirt cheap.
EdwardsControllerB.pdf
(501.05 KiB) Downloaded 34 times
EdwardsControllerA.pdf
(305.83 KiB) Downloaded 28 times
Although, after I read John's last post, I wish I could have read that a long time ago- explains a lot. Thinking my first Edwards was heading for bearing failure, I proactively bought the 2nd- not realizing of course that it took a different controller- and shelved the first one. Well, now this second one is making the same irritating high pitched noise and getting worse. Annoying, but I don't think I need earmuffs- yet. ;) "screamed right from new"? WOW! What did Edwards have to say about their singing turbos? I take it they were sold because you couldn't stand the noise after a while?

Anyways, I bought those Edwards partly because they seemed plentiful on ebay, so I thought they must have been good/popular and Edwards sold a lot of them originally. Now I'm thinking they're plentiful on ebay because nobody wants them!

You might want to rethink this whole Edwards EXT255 thing and go with something else.

Post Reply