Model Boat Mayhem - Forum

Please login or register.

Login with username, password and session length.
Pages: [1]   Go Down

Author Topic: decaperm v ?  (Read 4390 times)

hopeitfloats

  • Guest
decaperm v ?
« on: April 11, 2008, 09:23:40 AM »

i have been trying to decide the best power system for my latest project. i have a choice of  making a dual drive gearbox and  coupling it to a motor i have (from a teleprinter apparently) with low rpm, low current draw, incredible power output and very quiet. a modellers dream really, or trying to get another decaperm and running a prop off each motor. the decaperm option would be simpler but the one i own is pretty noisy and has a  higher current draw. does anyone know if this is normal. at least the noise part.  i got it new years ago and it hasnt had much use. none in a boat.  just looking for any thoughts of pro's and con's of each system.  the hull is 1.5m long and of the 'Atlantic Conveyor'. designed as a twin screw but with a  bit of cutting and glassing could be a single screw. this will be a last option though
Logged

sheerline

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,201
  • Location: Norfolk
Re: decaperm v ?
« Reply #1 on: April 11, 2008, 04:27:24 PM »

I have a decaperm , still in its box, unused as far as I know, it has a 2.75:1 reduction box incorporated in its construction. I found mine to be noisy, a bit vibratory and high current draw also.... thats why it still languishes in its box in my cupboard!
Chris
Logged

hopeitfloats

  • Guest
Re: decaperm v ?
« Reply #2 on: April 12, 2008, 03:42:35 AM »

thanks sheerline. it may be a fault with the design then rather than me buying a dud. 
Logged

banjo

  • Guest
Re: decaperm v ?
« Reply #3 on: April 12, 2008, 07:25:36 AM »

thanks sheerline. it may be a fault with the design then rather than me buying a dud. 

I have decaperms.  With the correct prop they run all day on a spark!   Check that the gear box has a smidgen of grease in it.   The plastic pegs holding the mounting together can be a little brittle so take care when dismantling it.
 :)

Logged

Shipmate60

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,263
  • You bark - I will bite!!!
  • Location: Fareham
Re: decaperm v ?
« Reply #4 on: April 13, 2008, 12:59:50 PM »

What size and type of model are you powering?
Deccaperms run about 2750 rpm have noisy gearboxes,are elecrtically "noisy" and expensive to buy.
There are lots of alternatives.

Bob
Logged
Officially a GOG.

hopeitfloats

  • Guest
Re: decaperm v ?
« Reply #5 on: April 14, 2008, 08:47:32 AM »

have just done a  rev. check and surprisingly the two decaperms have a differential of 500rpm  between them.  thats huge.  i was expecting maybe 100- 150. that combined with a high current draw has finally convinced me to go with a single motor running two props. more work setting it up but i think will produce better running.
Logged

hopeitfloats

  • Guest
Re: decaperm v ?
« Reply #6 on: April 14, 2008, 08:50:56 AM »

just to anyone taking notice in my first post i  had one decaperm and the last thread i had two. i had two all along but couldnt find the second which i now have.
Logged

Martin [Admin]

  • Administrator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 19,055
  • Location: Peterborough, UK
    • Model Boat Mayhem
Re: decaperm v ?
« Reply #7 on: April 14, 2008, 08:54:13 AM »

Is the 2nd Decaperm motor as noisy as the first?
Logged
"This is my firm opinion, but what do I know?!"    -   Mayhem FaceBook Group!

hopeitfloats

  • Guest
Re: decaperm v ?
« Reply #8 on: April 15, 2008, 12:10:48 PM »

yes
Logged

FullLeatherJacket

  • Guest
Re: decaperm v ?
« Reply #9 on: April 15, 2008, 12:24:27 PM »

Having read the original post it would be a shame to waste what sounds like a very good motor. You can easily sell the two Decaperms on E-Bay or on the Sales board on this forum. They are much in demand, especially boxed and unrun.
I know Colin Bishop uses - and favours - 'O' rings and pulleys as opposed to gears. They are cheaper, easier to set up and make less noise. I suppose it really depends on how much reduction you need; you're not going to get much better than about 3:1 with a simple 3-pulley system (but I've been wrong before............... ::)).
If you dig around in the MFA-Como Drills website you'll find that they do a range of toothy-belty-sprockety thingies, as well. Might be worth a shufti?
One promise, please; DON'T even consider turning it into a single-screw model!
Respect the memory of a great seaman and hero.
FLJ
Logged

Shipmate60

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,263
  • You bark - I will bite!!!
  • Location: Fareham
Re: decaperm v ?
« Reply #10 on: April 15, 2008, 12:36:40 PM »

hopeitfloats
What size props will you be using on her?

Bob
Logged
Officially a GOG.

hopeitfloats

  • Guest
Re: decaperm v ?
« Reply #11 on: April 16, 2008, 09:27:56 AM »

the plan shows 2 x 45mm props but i think i will run 2 x 35mm just to ease the load on the motor a bit even though i'm sure it would handle the bigger ones.
Logged

hopeitfloats

  • Guest
Re: decaperm v ?
« Reply #12 on: April 16, 2008, 09:58:58 AM »

Having read the original post it would be a shame to waste what sounds like a very good motor. You can easily sell the two Decaperms on E-Bay or on the Sales board on this forum. They are much in demand, especially boxed and unrun.
I know Colin Bishop uses - and favours - 'O' rings and pulleys as opposed to gears. They are cheaper, easier to set up and make less noise. I suppose it really depends on how much reduction you need; you're not going to get much better than about 3:1 with a simple 3-pulley system (but I've been wrong before............... ::)).
If you dig around in the MFA-Como Drills website you'll find that they do a range of toothy-belty-sprockety thingies, as well. Might be worth a shufti?
One promise, please; DON'T even consider turning it into a single-screw model!
Respect the memory of a great seaman and hero.
FLJ


FLJ - you are a god. i was going to run a toothy-belty-sprockety thingie (i love that description) {-) drive and lost the sites i found them on. como was one.  plan at this stage is to run one prop direct off the motor via the belt system and the other via a 1:1 gear drive off the motor purely to reverse the direction and then on to a  belt drive.  motor only runs at 4000rpm or thereabouts so only need  2:1 reduction. i might just put the decaperms on the mayhem 'for sales' but will have have to do a bit of research first re freight costs x new zealand and payment methods as its all new to me. 
Logged

Shipmate60

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,263
  • You bark - I will bite!!!
  • Location: Fareham
Re: decaperm v ?
« Reply #13 on: April 16, 2008, 10:04:53 AM »

For those size props I would use direct drive with 2 motors.

Bob
Logged
Officially a GOG.

hopeitfloats

  • Guest
Re: decaperm v ?
« Reply #14 on: April 16, 2008, 10:36:48 AM »

that was the original intention with the decaperms. gone off that idea though

Logged

Shipmate60

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,263
  • You bark - I will bite!!!
  • Location: Fareham
Re: decaperm v ?
« Reply #15 on: April 16, 2008, 12:49:49 PM »

Have a look at the Deans Marine motors, they are good.

Bob
Logged
Officially a GOG.

Casper

  • Guest
Re: decaperm v ?
« Reply #16 on: May 16, 2008, 10:27:16 PM »

First post here so please be gentle!

I have a number of old Decaperms that have been taken out of models in favour of other motors, you can get Decaperms to run in very smoothly with little noise, just add PTFE grease to the gearboxes and run them on load for about 5 hours, current draw drops to... But I now take standard 550 motors and rewind them for the performace I need.

I have the same type of motor turning 30mm semi fast props upto 70mm direct in tugs, its just the wire size and turns that change the motor state of tune.

If anyone wants to try this, just stip down an old 540, remove the wire and rewind it wtih .31mm winding wire 80-90 turns per pole... should give you v high torque, and around 4k rpm.

Hope this helps..  O0
Logged

banjo

  • Guest
ReDeca Perm Re wind
« Reply #17 on: May 16, 2008, 10:36:52 PM »

 O0
I'd like to see some pics next time you do one.  I may then try it myself..
Logged

FullLeatherJacket

  • Guest
Re: ReDeca Perm Re wind
« Reply #18 on: May 17, 2008, 04:02:07 PM »

O0
I'd like to see some pics next time you do one.  I may then try it myself..
Banjo
Check your E-mail - I've sent you a prezzie.
FLJ
Logged
Pages: [1]   Go Up