Running a DC Motor Sideways - Page 1
Forum section: electronics / projects

author: wmdunn
author_rank: Newbie
timestamp: December 19, 2023, 08:08:57 pm
content: I've read online that it can be bad for a brushed DC motor to run while on its side because it can damage the brushes. Does anyone know if this is true? Ideally my motor will be positioned sideways for economy of space. Thanks!

author: Benta
author_rank: Super Contributor
timestamp: December 19, 2023, 08:42:53 pm
content: Total rubbish.For very large DC motors there may be constraints on the bearings (anchor weight), but we're talking MW sizes here, and they're rare today.

author: moffy
author_rank: Super Contributor
timestamp: December 19, 2023, 10:06:14 pm
content: Traction DC motors on locomotives are all run on their side, and they rate up to hundreds of kW, so I wouldn't put any credibility in the statement.

author: CaptDon
author_rank: Super Contributor
timestamp: December 19, 2023, 10:25:01 pm
content: I wonder what moron posted that a brushed motor shouldn't run on its side on a website of supposed 'knowledge'. What is the option, run the motor vertically?? Unless specially designed like a pump / hydroturbine with thrust plates or thrust bearings then operating vertically ANY motor not so designed would be bad because there is no support mechanism to hold the downward weight of the rotating mass. Probably 90% of all motors run on their side. Possible exceptions (although again designed for the task) would be turntable motors and tape player motors. The brushed D.C. motors used as dynamic brake fans run sideways on G.E. locomotives and vertically on EMD locomotives. The E.M.D. motors have tapered bearings to support the vertical loading. Sounds like a myth perpetuated by CrapGPT?

author: amyk
author_rank: Super Contributor
timestamp: December 19, 2023, 11:52:55 pm
content: Where exactly did you "read online" this?I agree with the others this is nonsensical, since the orientation of a motor has nothing to do with brushes but instead the bearings (and thus whether it's brushed or not is irrelevant.)

author: p.larner
author_rank: Frequent Contributor
timestamp: December 20, 2023, 03:48:23 pm
content: ignoor it,its a load of bollox does it also say santa clause is real and tooth fairys exist too?.

author: Randy222
author_rank: Frequent Contributor
timestamp: December 20, 2023, 05:08:25 pm
content: Perhaps this will not apply to a tiny dc motor, but the concept is valid for mostly bearings.Most bearing supported pulleys in car fail because the belt tension always pulls the axial in one direction. To avoid this the maker should apply some tension 180deg from the drive belt tension (another tension belt, or spring setup), but they don't, so you end up replacing things sooner than they really need to. Cost is the variable they do not wish to increase, etc. Quality bearings can run a long time with perpendicular force on axial, some can't and fail sooner.As for dc brushes, maybe it's the way the brush dust falls down in horizontal vs vertical? I have seen some nasty insides from brush wear down, where that crud goes makes a diff, perhaps even making items wear faster?

author: wmdunn
author_rank: Newbie
timestamp: December 20, 2023, 09:55:08 pm
content: I thought so too, thanks guys! I saw posts on Reddit and Quora saying that.