Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: Brian60 on December 07, 2014, 04:39:44 pm

Title: Motor to drive radar---
Post by: Brian60 on December 07, 2014, 04:39:44 pm
Anyone in the market for these? too early for me but someone might like them, 8rpm motors , very cheap as well.


http://www.ebay.co.uk/itm/6V-8RPM-2-Wire-Connecting-Cylinder-Shape-Reduction-DC-Gearbox-Motor-/191237638113?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item2c86a6c7e1
Title: Re: Motor to drive radar---
Post by: Netleyned on December 07, 2014, 04:46:21 pm
Thanks for the heads up Brian.
Just ordered a couple.

Ned
Title: Re: Motor to drive radar---
Post by: Brian60 on December 08, 2014, 10:55:03 am
No problem Ned. I had a look at his ebay 'shop' its obviously a trading arm of some large company in Hong Kong, they sell loads of stuff. I've ordered 30 microswitches, only a fiver! %% who cares it may take 10 days for delivery at that price, I wait that long for stuff to arrive in Spain from the UK! I've bookmarked the shop because there will be other stuff I want later in the new year, but for now I can pick up the switches from my UK home when we return end of next week.
Title: Re: Motor to drive radar---
Post by: Netleyned on December 08, 2014, 04:17:10 pm
Lots of interesting stuff on that site Brian.
No problem with the postage times when the
build is crawling along %)

Ned
Title: Re: Motor to drive radar---
Post by: Tug Fanatic on December 08, 2014, 05:13:17 pm
They also do a 12v 14rpm one which might be a better speed for smaller radar units. AND cheaper !!!! At 6v the speeds would be very similar.

http://www.ebay.co.uk/itm/DC-12V-14RPM-2-Wires-Electric-Geared-Box-Reduction-Motor-/190879714836?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item2c71514e14
Title: Re: Motor to drive radar---
Post by: Ralfred on December 13, 2014, 09:42:23 am
Just ordered a couple of these, starting to build up a supply of various bits and bobs while im still working, will post when they arrive.
Title: Re: Motor to drive radar---
Post by: inertia on December 13, 2014, 09:49:02 am
Isn't that a bit slow for a radar sweep arm? I thought they were more like 30RPM, but I stand to be corrected.
DM
Title: Re: Motor to drive radar---
Post by: Netleyned on December 13, 2014, 11:06:48 am
Type 978 radar , standard navigational radarfitted to
Warships in the 60's  rotated at 20 rpm
The Bedstead AKE antenna rotated at 10rpm

There will probably be other uses for a slow rotating
unit.

Ned
Title: Re: Motor to drive radar---
Post by: Brian60 on December 13, 2014, 05:01:07 pm
S band or X band type radar systems in maritime useage generally rotate between 2 and 6 rotations per minute. I would imagine the slower ones being weather radar. This is from wikipedia.
Title: Re: Motor to drive radar---
Post by: Netleyned on December 13, 2014, 05:28:19 pm
Raytheon X band Marine radars
come with three lengths of antenna
8 , 12 , and 18 ft
The rotation speeds are
In the range 18 , 22, 26 and 40 rpm
depending on antenna length and
usage.

Ned
Title: Re: Motor to drive radar---
Post by: Netleyned on December 15, 2014, 01:25:14 pm
Motors arrived today.
7days not bad for free postage
There is a UK address for returns
and aŁ3 off coupon for uxcell.com.
Tried one on six volts with a fishing
boat radar 1/16 and it looks spot on.
Well satisfied :-))


Ned
Title: Re: Motor to drive radar---
Post by: Brian60 on December 15, 2014, 02:29:08 pm
Motors arrived today.
7days not bad for free postage
There is a UK address for returns
and aŁ3 off coupon for uxcell.com.
Tried one on six volts with a fishing
boat radar 1/16 and it looks spot on.
Well satisfied :-))


Ned

 :-)) :-)) :-)) :-)) :-))
Title: Re: Motor to drive radar---
Post by: Butts on December 18, 2014, 03:25:29 pm
Postman has just dropped off a 12v 14rpm version. Seems to work well.

I'm planning to add a rope drum to it to make a winch to take up slack in my tugs tow rope.

Don't know how they can sell them at that price, it even came recorded delivery!
Title: Re: Motor to drive radar---
Post by: Tug Fanatic on December 18, 2014, 04:12:05 pm


.........................I'm planning to add a rope drum to it to make a winch to take up slack in my tugs tow rope...............


I think that you might be asking a lot! Don't forget that the tug will try to pull the rope off the winch - the load on the winch is the full pull load that you are putting into the tow including any snatch load. That is why towing winches are heavy duty bits of kit.

As you have one of these is it up to that job on your tug?
Title: Re: Motor to drive radar---
Post by: Butts on December 18, 2014, 06:15:44 pm
I take your point. 

I've seen similar jobs done with small motors, but I guess I'd need to look at one to see how they avoid the problem to which you refer.

If nothing else, it will make radar motor!
Title: Re: Motor to drive radar---
Post by: Netleyned on December 18, 2014, 06:21:33 pm
Looking at the ones I've got, I don't think the gearbox
would be up to the torque required for tug towing.
Good for radars but not much else.

Ned
Title: Re: Motor to drive radar---
Post by: Butts on December 18, 2014, 06:28:25 pm
On reflection Ned I think you are both right, I was possibly being a little over ambitious :embarrassed:, radar motor it is.
Title: Re: Motor to drive radar---
Post by: Skimmer Fan on December 18, 2014, 06:34:44 pm
For you winch have you thought about a continuios servo.
Title: Re: Motor to drive radar---
Post by: Tug Fanatic on December 18, 2014, 06:57:46 pm
Converted electric screwdrivers - the small ones rather than a drill/driver - work well.
Title: Re: Motor to drive radar---
Post by: Butts on December 18, 2014, 07:03:33 pm
Yes, I think that is what our some of our Club Members tend to use now you remind me. 
Title: Re: Motor to drive radar---
Post by: Islander51 on December 19, 2014, 08:08:05 am
With a worm and gear setup there should be no problems with the line coming off the drum.


Edward
Title: Re: Motor to drive radar---
Post by: Tug Fanatic on December 19, 2014, 09:14:07 am
With a worm and gear setup there should be no problems with the line coming off the drum.


Edward

That is true but by the time that you have purchased one of these plus acquired the worm gear set and made the gearbox housing it would have been easier & cheaper to go the screwdriver route and you would have a much more capable winch.
Title: Re: Motor to drive radar---
Post by: Butts on December 19, 2014, 06:34:42 pm
Thanks for the ideas Guys, I know where I'm going :-))