MTH radar tower: need a motor

https://ogrforum.com/t...dar-tower-how-to-fix

Thanks, stan..   i reviewed your attachment.  i have tried the faller motor,,   its too quirky.  dont want to go that route.  i was hoping someone had used  another mini-motor with success and could possibly provide a source and maybe a part #.  ??

While you wait for someone who has actually done it to step forward...

If I were doing it, I'd look at a DC gearmotor and adjusting the DC voltage to fine-tune the speed.   For example, searching "DC gearmotor" on eBay, I found the following (eBay # 311250697134):

I don't know what you want your tower to spin at but adjusting the DC voltage between, say, 4 - 8V should get something suitable.  To generate adjustable DC voltage, you can use an AC-to-DC voltage regulator module which runs about $3 on eBay (free shipping from Asia).   I just posted the following photo for another thread so it's the one on the right...except rather than 4.5V DC you'd just adjust the voltage for the speed you want.

The electrical side of things is the easy part (IMO) and there are lots of guys on OGR who have used these modules.

The key is your radar requires virtually zero torque since a vibramotor provides very little in the first place.  This makes it a much easier problem for mounting/mating the motor shaft to the radar shaft.  That is, you can use loose/flexible coupling like vinyl tubing, rubber furniture/cabinet bumpers, and so on...there is negligible torque transfer.  This also relaxes the need for precise mechanical alignment.

Re-visiting the Faller motor a bit.  It appears it is a synchronous motor so that the speed is fixed by the 60 Hz line frequency.  From what I can tell it has a couple speed options by using some combination of gears.  Yes, maybe your radar tower speed is a set-it-and-forget-it proposition.  But it seems so much more flexible to simply adjust the DC voltage to fine-tune rotational speed.  Plus, $30 or so seems somewhat steep for the task at hand - in my opinion anyway.

That's a great solution Stan, and cheap as well!

Would this work for the Lionel WW I pylon?  My motor died about a year ago and the Lionel part is "not available" from them.

Thanks much, Stan,  i believe that will work for me.  sorry i couldnt respond earlier as my hard drive quit. just got my  computor back from my it guy today.

og fan posted:

Thanks much, Stan,  i believe that will work for me.  sorry i couldnt respond earlier as my hard drive quit.

I wonder if it was the motor.   

If you get your radar back in business, please post pictures!

POTRZBE posted:

Would this work for the Lionel WW I pylon?  My motor died about a year ago and the Lionel part is "not available" from them.

It looks like others are searching too.

https://ogrforum.com/t...el-pylon-accessories

In looking at the diagram of the no-longer-available Lionel gearbox, I'd say the above gearmotor is too tall.   In searching eBay for "DC worm gear motor" there are several options which might work.  I think the trick is to find a gearbox with a worm gear or bevel gear or where the motor shaft is perpendicular (rather than parallel) to the pylon shaft.  As with the radar tower I don't think there's a huge torque load.  In the following $3 worm gearbox I'm think that odd looking slotted coupler on the Lionel gearbox output shaft could be re-mounted (epoxied) to the output wheel of the eBay gearbox.   Then the AC-to-DC module shown earlier could be used to fine-tune the speed; or use the existing diode and use a cheaper DC-to-DC voltage regulator module.

Alternatively, if it's just the motor that died, can you open the gearbox?  I'd think you might get lucky and find a replacement motor. 

I'm guessing there's a plastic worm gear on the motor shaft that is press fit so you can pull it off and re-attach.  Motor shaft probably 1.5mm or 2mm or something common.  Again, even if you can't find the exact motor with identical voltage/speed characteristics, the AC-to-DC converter module can be adjusted over a wide-range compensate since I think the torque requirements are modest.

The Lionel Pylon motor shows available at Lionel, I also have 1 in my parts as well.