DC motor for alluminum fan blade - Page 1
Forum section: electronics / general

author: T_guttata
author_rank: Regular Contributor
timestamp: January 15, 2025, 09:39:48 pm
content: HiI'm looking for a small fan, which sustains very high temperatures of roughly 300°C. Since I could not find anything, I thought to use an alluminum fan blade and search for a suitable motor. The motor would stay outside of the hot area.The fan blade should be roughly 60-80mm in diameter, the speed should be roughly 1000-2000 rpm. Since I'm not familiar with all the different motor types, I have a hard time to find something suitable.Could anybode advice me how to find a suitable motor? I had a look at gear motors, but this is overkill.Thanks for your help.

author: SteveThackery
author_rank: Super Contributor
timestamp: January 15, 2025, 10:18:15 pm
content: Any chance you could find one designed for a domestic oven?

author: andy3055
author_rank: Super Contributor
timestamp: January 15, 2025, 10:48:52 pm
content: eBay has plenty of them.

author: johansen
author_rank: Super Contributor
timestamp: January 16, 2025, 03:32:06 am
content: pull the motor and fan blade out of a toaster convection oven.

author: BrianHG
author_rank: Super Contributor
timestamp: January 16, 2025, 04:13:16 am
content: Quote from: johansen on January 16, 2025, 03:32:06 amCareful, not all those motor designs have the motor itself exposed to the full heat, just the fan blades.If you do not need really high speed, you may also try a chain drive and locate the motor away from the heat source.Or, a long axle and once again keep the core of the motor as far away from the heat as possible with a sheet of steel or aluminum between the fan blade and the bulk of the motor.

author: T_guttata
author_rank: Regular Contributor
timestamp: January 16, 2025, 05:07:42 am
content: The motor of a PC fan is very small. If I search for DC motor, it is usually much larger (longer).What motor type would you search for? How do you determine the required torque?

author: IanB
author_rank: Super Contributor
timestamp: January 16, 2025, 05:57:03 am
content: Assuming the motor itself will stay outside the hot area, you do not need a special heat resistant motor.If you are buying the fan/impeller and motor separately you start with the impeller. Ideally you will get a data sheet for the impeller, that will give you speed/torque/power characteristics, ideally as a chart. You find a suitable size impeller that gives the desired air flow given the installed flow resistance at a reasonable speed, and then you find a motor of a suitable physical size that has the necessary power output at the required operating speed.

author: johansen
author_rank: Super Contributor
timestamp: January 16, 2025, 06:18:28 pm
content: Quote from: BrianHG on January 16, 2025, 04:13:16 amthat is quite literally the point of pulling the motor and fan blade out of a toasterconvectionoven. its already designed to survive 600F.

author: T_guttata
author_rank: Regular Contributor
timestamp: January 16, 2025, 06:46:24 pm
content: Yes, but it is not easy to find an impeller with data sheet. And if you don‘t know the motor types, it is quite a hassle to find something suitable. Often times the price is ridiculous.What motor type would you prefer for such an application?

author: IanB
author_rank: Super Contributor
timestamp: January 16, 2025, 07:32:19 pm
content: You are not really describing the application.Does the motor need to run continuously, or for short periods?Does it need to run from mains voltage or low voltage?Should it run at constant speed or adjustable speed?How far does the motor need to be from the fan blades?Is there a physical size constraint on the motor?Can you use an existing motor/fan combination, but put the fan on the inside of the oven (?) and the motor on the outside?There are fan convection ovens available. Can you repurpose an existing fan from one of those?

author: amyk
author_rank: Super Contributor
timestamp: January 17, 2025, 05:52:42 am
content: Quote from: T_guttata on January 16, 2025, 06:46:24 pmShaded pole.

author: thm_w
author_rank: Super Contributor
timestamp: January 17, 2025, 10:21:40 pm
content: Quote from: johansen on January 16, 2025, 06:18:28 pmThe fan blades are, the motor itself is not. Its in an insulated section outside of the oven that has venting if not active cooling of the windings.