Cookies used in this website are gluten free, wheat free and dairy free. By using this website you agree to our use of cookies. More Info
Guest
Login Below
Join Us On Social Media!
   
Get The Model Boats App!
Apple App Store
Android app on Google Play


Help Support This Website
£
or enter custom amount

(Non Contributor)

Help support this free
website and donate.



£285 a year is needed to keep the website and apps online. Please consider donating £5 or more to help towards these fees.
All donations are securely managed through PayPal. Amounts donated are not published online.

Many thanks for your kind support.

Model Boats Website Team


Donation History
November 2017: 8 people
October 2017: 9 people
September 2017: 15 people
August 2017: 10 people
July 2017: 16 people
June 2017: 8 people
May 2017: 8 people
April 2017: 23 people
March 2017: 3 people


Unique Visitors This Month

Website Members

Terms and Conditions
Privacy Policy
Advertising
Contact


Model Boats Website
Active Users (7)
Login or Register
To Remove This Ad
Login or Register
To Remove This Ad
>> Home > Forum > Electrical Related > rotating radars off mast
rotating radars off mast
(497 views)
Author Message
seafarer
(Chief Petty Officer)





Forum Posts: 10
7th Nov 2017 18:58  
>> Permalink
mdlbt.com/35457

About to build my mast which has two rotating radars at different levels. Any recommendations for the motors etc and links to purchase would be great!

RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
7th Nov 2017 20:32  
>> Permalink
mdlbt.com/35461

Hi Seafarer, a few basic questions!
Mast for what boat/ship?
Dimensions / pic or sketch of the mast?
Space for drive motors/gears/pulleys etc?
Hint: for the radar on my 1:72 destroyer I used an old servo; disconnected the feedback, and removed the mechanical end stops so it rotated continuously and drove it with a single 1.5V dry cell (alkaline), lasts for years😉 But in my case the scanner aerial sat on the director tower on the bridge, not on a mast, so simple direct drive coupled to the servo (hidden in the ridge) output shaft with shrink sleeve. Does a sweep in a little under one second.
What type of radar are you trying to simulate?
Cheers Doug 😎


Attached Files - Click To View Large


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
seafarer
(Chief Petty Officer)





Forum Posts: 10
7th Nov 2017 22:25  
>> Permalink
mdlbt.com/35470

Thanks Doug,the boat is the Ayton Cross Tug which has the scanner supported from a shelf projected from the main mast.the scale is 1:32. I'm thinking it's an impossible task but just maybe there's a nano motor somewhere waiting for the task!

Dave M
(Fleet Admiral!)





Forum Posts: 1399
8th Nov 2017 00:50  
>> Permalink
mdlbt.com/35473

Hi Seafarer
You can buy very small 4 wire stepper motors that will fit. I bought a ruck from China via E-Bay for a few pounds and they work fine.

The smallest is less than the size of my little finger nail and I need my scope to see the wires which I sourced from Component Shop at Haydock Show.

You do need a stepper motor driver and can control the speed down to single steps with a simple pot. I used an Arduino to test and the program is on the Arduino website.

When I get time I might just do a blog showing how.
Dave


Live long and prosper

Dave
seafarer
(Chief Petty Officer)





Forum Posts: 10
8th Nov 2017 23:00  
>> Permalink
mdlbt.com/35556

Thanks Dave, you've set me off on another adventure into the unknown but I think I'm learning....do I need the Arduino UNO controller and could I control two motors off it (it doesn't matter if the speed is the same ) .
If I don't need the controller ,could you explain a bit more about using the POT (presumably a potentiometer?)

reilly4
(Lieutenant)





Forum Posts: 14
9th Nov 2017 05:33  
>> Permalink
mdlbt.com/35563

Hi Seafarer,
I have a few ships with rotating radars
I have a few of these motors per the link below. They rotate quite well with one cell (1.4 volts)
Gear Motor 3 - 224:1 90 Degree Shaft
https://solarbotics.com/product/gm3/

I also have some of these, but they require a bit more vertical space.
MFA 951 Series Motor and Gearbox 298:1 6volt (from CMB in the UK). I run these on 3 volts.

Both are quite small. I have also used old servos in a couple of places.

Dave M
(Fleet Admiral!)





Forum Posts: 1399
9th Nov 2017 10:47  
>> Permalink
mdlbt.com/35567

Hi seafarer
You do need a four wire stepper motor driver. I used my Arduino as I have one. The pot varies the speed thro the Arduino so it can't be used on its own.
I have some ic chips that can be used as drivers but I have not had time to program and develop so far.
I have used geared dc motors but if in a quiet display area they can be noisy, which is why I intend to use this type of motor.
I will do some more research and get back with possible alternative forms of electronic drives.


Live long and prosper

Dave
jarvo
(Fleet Admiral!)





Forum Posts: 466
9th Nov 2017 13:14  
>> Permalink
mdlbt.com/35581

Hi Seafarer, have you considered a very fine piano wire drive from below deck to the radar scanner, this would lessen the top weight but you do have the wire up the mast.

Mark


Etherow Model Boat Club
Trillium
(Commander)





Forum Posts: 66
9th Nov 2017 13:52  
>> Permalink
mdlbt.com/35584

Dave,
Thanks for the tip about using the stepper motors. I found some 6mm x 6mm motors on ebay which will be ideal for mast mounted radars on a future project.
Roy

seafarer
(Chief Petty Officer)





Forum Posts: 10
9th Nov 2017 16:37  
>> Permalink
mdlbt.com/35596

Thanks Mark, the wire would be a solution if the scanner was on the mast centreline but it is off-set half way up and on a shelf so that it can rotate.
The 6mm motors suggested by Trillium appear to be a possible solution fitted underneath the shelf.

kmbcsecretary
(Chief Petty Officer)





Forum Posts: 15
9th Nov 2017 16:51  
>> Permalink
mdlbt.com/35597

I have used the kits from Mr rc World he has option of motors and the controller that comes with it gives you the fine control to set the speed of rotation to what you want and powered by your receiver pack
You can find him on flea bay or on the Web

robbob
(Fleet Admiral!)





Forum Posts: 55
9th Nov 2017 18:21  
>> Permalink
mdlbt.com/35600

Hi kmbsecretary.
Just had a look at the Mr RC World site.
What a great range of useful little modules 👍👍
Not cheap but they look incredibly well made.

https://www.mr-rcworld.co.uk/


"Time flies like an arrow; fruit flies like a banana"
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
9th Nov 2017 19:18  
>> Permalink
mdlbt.com/35607

Yes Robbob, But their radar motors are much too big for mast mounting 🤔


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
Dave M
(Fleet Admiral!)





Forum Posts: 1399
9th Nov 2017 19:24  
>> Permalink
mdlbt.com/35610

I have just posted a video of a model of the Ayton Cross by Alan Read of SRCMBC.
As Doug says the motors need to be small >6mm.


Live long and prosper

Dave
kmbcsecretary
(Chief Petty Officer)





Forum Posts: 15
10th Nov 2017 20:22  
>> Permalink
mdlbt.com/35660

Mr rc World now sells two type of motors the type 2 motors are the smaller foot print have used these on the MMM eldergarth mast works a treat and doesn't stick out that much

marlina2
(Petty Officer)





Forum Posts: 4
12th Nov 2017 15:11  
>> Permalink
mdlbt.com/35706

I have recently constructed a rotating radar mast for my 1:48 scale paddle tug "Forceful" I have used a geared 6 volt 60 RPM motor which gives a realistic scale rotational speed. It is a little noisy but only when close up. it is driven by a direct shaft running up the centre of the mast not prototypical but gives a pleasing effect. I may rebuild this at a latter date to eliminate the noise


Attached Files - Click To View Large

tidtug
(Commander)





Forum Posts: 104
12th Nov 2017 15:32  
>> Permalink
mdlbt.com/35707

When your boat motor is going you won’t hear the radar motor?

marlina2
(Petty Officer)





Forum Posts: 4
12th Nov 2017 15:42  
>> Permalink
mdlbt.com/35708

Your probably right but it just annoys me that I didn't do anything about the noise at the time of contruction

smiggy
(Sub-Lieutenant)





Forum Posts: 20
13th Nov 2017 09:54  
>> Permalink
mdlbt.com/35749

Hi seafarer,
I've scratch built a Type 21 frigate and managed to find motors for the radars. I got them from a company called Precission Microdrives, web site https://www.precisionmicrodrives.com/gearmotors. They don't come cheap, the three on the mast cost £45 - and then there's the replacement for the one I 'lubricated' with super glue. That said the effect is fantastic and they just make a slight whirring noise when running and go all day on the 6 volt battery (I needed to fit resistors to them to get the speed down a bit).
Hope this helps.
Graham
PS The service was very good.
PPS The film of them working doesn't appear to be working so I've posted a still, the motors are 20mm long to give an indication of the size. The air traffic control radar on the bottom platform shows the full length of the motors.
PPPS Web address changed, thanks Dave.


Attached Files - Click To View Large

Dave M
(Fleet Admiral!)





Forum Posts: 1399
13th Nov 2017 11:48  
>> Permalink
mdlbt.com/35754

Hi smiggy
I have a couple of these motors and they are good and mine run off a 1.5v battery (max3v). Planetary gears but relatively quiet at low revs (volts). Mine came from http://www.gizmoszone.com/shopping/agora.cgi
and cost about £6 ea.
Your link should be https://www.precisionmicrodrives.com/gearmotors.
Well worth a look.
The stepper motors I have are 10x14mm (including the shaft) and are direct drive.
I will be posting a thread soon showing more details
Nice scale model
Dave


Live long and prosper

Dave
seafarer
(Chief Petty Officer)





Forum Posts: 10
14th Nov 2017 10:09  
>> Permalink
mdlbt.com/35792

Some great ideas and many options! what I thought was "no hope" to "every hope" of resolving the problem. Need to start to make some decisions and looking forward to Dave's forthcoming thread with more details.👍