Home |
Search |
Today's Posts |
#1
Posted to alt.electronics
|
|||
|
|||
Muffin fan installation
Should these be mounted with the faces plumb or level? The RS
273-241 4" fan (new unit) that I'm trying to build an air circulator from seems not to run at constant speed when I test it flat on the bench. |
#2
Posted to alt.electronics
|
|||
|
|||
Muffin fan installation
On 28 Jan 2007 23:01:32 -0800, "Father Haskell"
wrote: Should these be mounted with the faces plumb or level? The RS 273-241 4" fan (new unit) that I'm trying to build an air circulator from seems not to run at constant speed when I test it flat on the bench. Not sure what you are saying but fans can mount in any position; they are usually mounted vertically (Edge down). Bearings on most are probably happiest that way Constant voltage? Constant restriction to air flow? Several fans running parallel from the same supply may try to "sync" and vary the speed as they drop in and out of synchronization. -- ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#3
Posted to alt.electronics
|
|||
|
|||
Muffin fan installation
On Jan 29, 4:38 pm, default wrote: On 28 Jan 2007 23:01:32 -0800, "Father Haskell" wrote: Should these be mounted with the faces plumb or level? The RS 273-241 4" fan (new unit) that I'm trying to build an air circulator from seems not to run at constant speed when I test it flat on the bench.Not sure what you are saying but fans can mount in any position; they are usually mounted vertically (Edge down). Bearings on most are probably happiest that way As I suspected. Constant voltage? Constant restriction to air flow? Several fans running parallel from the same supply may try to "sync" and vary the speed as they drop in and out of synchronization. Fresh out of the box, solid, clean electrical connection. Just sat it on the bench and let it run. |
#4
Posted to alt.electronics
|
|||
|
|||
Muffin fan installation
"Father Haskell" wrote in message
oups.com... On Jan 29, 4:38 pm, default wrote: On 28 Jan 2007 23:01:32 -0800, "Father Haskell" wrote: Should these be mounted with the faces plumb or level? The RS 273-241 4" fan (new unit) that I'm trying to build an air circulator from seems not to run at constant speed when I test it flat on the bench.Not sure what you are saying but fans can mount in any position; they are usually mounted vertically (Edge down). Bearings on most are probably happiest that way As I suspected. Constant voltage? Constant restriction to air flow? Several fans running parallel from the same supply may try to "sync" and vary the speed as they drop in and out of synchronization. Fresh out of the box, solid, clean electrical connection. Just sat it on the bench and let it run. --------------- Sitting a fan flat on the bench is not a good test. You are blocking any air flow and a fan, to do anytthing needs to be able to move air. It may be having a problem in that much of the time the load on the fan is 0 but as air leaks in the load can change. If you set it on edge it would be better as then you have unobstructed air flow. Try it. NB a fan blowing into a heat sink is not equivalent as the heat sink allows air flow. -- Don Kelly remove the X to answer ---------------------------- |
#5
Posted to alt.electronics
|
|||
|
|||
Muffin fan installation
On Jan 29, 9:40 pm, "Don Kelly" wrote: "Father Haskell" wrote in ooglegroups.com... On Jan 29, 4:38 pm, default wrote: On 28 Jan 2007 23:01:32 -0800, "Father Haskell" wrote: Should these be mounted with the faces plumb or level? The RS 273-241 4" fan (new unit) that I'm trying to build an air circulator from seems not to run at constant speed when I test it flat on the bench.Not sure what you are saying but fans can mount in any position; they are usually mounted vertically (Edge down). Bearings on most are probably happiest that way As I suspected. Constant voltage? Constant restriction to air flow? Several fans running parallel from the same supply may try to "sync" and vary the speed as they drop in and out of synchronization. Fresh out of the box, solid, clean electrical connection. Just sat it on the bench and let it run.--------------- Sitting a fan flat on the bench is not a good test. You are blocking any air flow and a fan, to do anytthing needs to be able to move air. 2 x 2 spacers under the frame set far enough apart not to throttle the airstream. Fan RPM was erratic, as if the fan was designed without thrust bearings. It may be having a problem in that much of the time the load on the fan is 0 but as air leaks in the load can change. If you set it on edge it would be better as then you have unobstructed air flow. Try it. NB a fan blowing into a heat sink is not equivalent as the heat sink allows air flow. -- Don Kelly remove the X to answer ----------------------------- Hide quoted text -- Show quoted text - |
#6
Posted to alt.electronics
|
|||
|
|||
Muffin fan installation
On 29 Jan 2007 20:35:18 -0800, "Father Haskell"
wrote: 2 x 2 spacers under the frame set far enough apart not to throttle the airstream. Fan RPM was erratic, as if the fan was designed without thrust bearings. How about flipping it 180? If you set it on edge the speed remains constant? Interesting idea with the thrust bearings. Ball bearings shouldn't matter they can support some axial loading without a problem - and the impeller is usually very light. Sleeve bearings might be another matter. Most of the fans I've disassembled had ball bearings - but the ones with sleeves make little or no provision for thrust loading - a bronze washer or two or the really cheap ones a few plastic washers. One bearing is sometimes visible under a paper or plastic label on the stationary part of the housing. You can look to see what you have, if that's the case. Sleeve bearings are nice when you want a quite fan - and they frequently outlast ball bearings - but they should be mounted on edge. They are rare in fans And you are talking about Radio Shack . . . their parts aren't always the highest quality. You'd be better off with a mail order surplus parts outlet. -- ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#7
Posted to alt.electronics
|
|||
|
|||
Muffin fan installation
"Father Haskell" wrote in message ps.com... On Jan 29, 9:40 pm, "Don Kelly" wrote: "Father Haskell" wrote in ooglegroups.com... On Jan 29, 4:38 pm, default wrote: On 28 Jan 2007 23:01:32 -0800, "Father Haskell" wrote: Should these be mounted with the faces plumb or level? The RS 273-241 4" fan (new unit) that I'm trying to build an air circulator from seems not to run at constant speed when I test it flat on the bench.Not sure what you are saying but fans can mount in any position; they are usually mounted vertically (Edge down). Bearings on most are probably happiest that way As I suspected. Constant voltage? Constant restriction to air flow? Several fans running parallel from the same supply may try to "sync" and vary the speed as they drop in and out of synchronization. Fresh out of the box, solid, clean electrical connection. Just sat it on the bench and let it run.--------------- Sitting a fan flat on the bench is not a good test. You are blocking any air flow and a fan, to do anytthing needs to be able to move air. 2 x 2 spacers under the frame set far enough apart not to throttle the airstream. Fan RPM was erratic, as if the fan was designed without thrust bearings. ------------------ That blows my idea. How is it in a vertical position? -- Don Kelly remove the X to answer ---------------------------- |
#8
Posted to alt.electronics
|
|||
|
|||
Muffin fan installation
On Jan 30, 11:01 pm, "Don Kelly" wrote:
"Father Haskell" wrote in message ps.com... On Jan 29, 9:40 pm, "Don Kelly" wrote: "Father Haskell" wrote in ooglegroups.com... On Jan 29, 4:38 pm, default wrote: On 28 Jan 2007 23:01:32 -0800, "Father Haskell" wrote: Should these be mounted with the faces plumb or level? The RS 273-241 4" fan (new unit) that I'm trying to build an air circulator from seems not to run at constant speed when I test it flat on the bench.Not sure what you are saying but fans can mount in any position; they are usually mounted vertically (Edge down). Bearings on most are probably happiest that way As I suspected. Constant voltage? Constant restriction to air flow? Several fans running parallel from the same supply may try to "sync" and vary the speed as they drop in and out of synchronization. Fresh out of the box, solid, clean electrical connection. Just sat it on the bench and let it run.--------------- Sitting a fan flat on the bench is not a good test. You are blocking any air flow and a fan, to do anytthing needs to be able to move air. 2 x 2 spacers under the frame set far enough apart not to throttle the airstream. Fan RPM was erratic, as if the fan was designed without thrust bearings. ------------------ That blows my idea. How is it in a vertical position? Fine. Complicates the circulator's design (tower, corner of room, simple preferred because it looks better by its relative absence), but workable. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Old Hunter Fan Installation | Home Repair | |||
Extractor fan installation? | UK diy | |||
two (2) gable fan installation | Home Repair | |||
Cieling Fan installation? | Home Repair | |||
Fan Installation | Home Repair |