Jump to content

Recommended Posts

Hi , I was wondering if it's at all possible to increase the power of my motor set up that I have for my BB diamond demon 48" . The set up I have at present is

Overlander Tornado Thumper v3 28/26 18 1000kv motor 

Overlander  xp2 20a esc

Overlander 2s 7.4v 1300mAh  battery pack.

Propeller 9"x4.5

The reason I ask is I feel it's a bit under powered for where I fly,  it always seems to be a bit too windy for my 1.5lb plane , it struggles on hand lauch take off and doesn't make much advance into wind when it's up there. 

Or should I just leave as is and only fly on very calm evenings. 

Best Regards 

Jonathan 

 

Link to comment
Share on other sites

Advert


Some questions:

Have you measured the current draw with the existing motor/battery? 

Is there room for a 3s battery in place of the 2s?

Is there room to fit a larger motor?

 

The current motor is rated for 140 watts so in a 1.5 lb model that's over 90 watts/lb which should be fine for a model of this type.

Link to comment
Share on other sites

To be honest I fear you may have to accept that in its original guise (vintage free flight?) it was never intended to fly against any wind.

Yes more power will make it fly faster but it may require rather a lot to achieve anything significant and in doing so it may introduce handling difficulties.

I would suggest you just rejoice in flying an attractive slow flyer in calmer conditions.

 

The problems of flying light weight slow flyers is something I also face.

05Jan19a.JPG.6901f407d20cf094ef163003d39f8dd8.JPG

This Antonov AN2 has the same span as your BB Diamond Demon and the same weight but it is a biplane with rigging!.

Fast it is not, neither is the full size, but in calm conditions it really looks the part.

  • Thanks 1
Link to comment
Share on other sites

2 hours ago, Jonathan said:

Thank you Shaun,  the fuselage design is triangular so a bit limited,  if I was to try another battery 3s would you be able to suggest mAh and voltage please. 

All 3S lipos are all the same nominal voltage by definition! It means three celts in series e.g 11.1V nominal ( 3x 3.7V /cell nominal ) to work out the capacity you should choose look at the space available and m ax auw you’d be happy to fly at. Having said all that my first step would be to put the original 2S setup on the wattmeter and check whether a larger portion might also be an option whilst sticking with 2S! 

Link to comment
Share on other sites

Yep I think I'm going to leave as is and be content with flying on calm days ony, next year I will be hopefully flying my junior 60 which might cope with the flying conditions at the field a bit better. 

Thank you for the responses most appreciated. 

 

Link to comment
Share on other sites

I tend to favour "horses for courses".  Don't force a model to be something it isn't.  Yes do bring it out on calm evenings for joyous emulation of its floaty free-flight origins, powered by an engine that fires every other lampost.  But for normal conditions look for something designed for RC in the first place, can still be retro if that's your preference, but with a bit more size, weight and power for penetration, etc.

 

4-Max show recommendations for a range of 60" span vintage models, e.g. Junior 60 or Super 60, typically using standard 3 cell lipos.

Ben Buckle kit converstions can be found in this list:  https://www.4-max.co.uk/recommended-setups.htm

 

Belair kits in this one: https://www.4-max.co.uk/belair-kits.html

 

Link to comment
Share on other sites

8 minutes ago, Jonathan said:

Yep I think I'm going to leave as is and be content with flying on calm days ony, next year I will be hopefully flying my junior 60 which might cope with the flying conditions at the field a bit better. 

Thank you for the responses most appreciated. 

 

Our posts crossed!  Junior 60 a good choice!

Link to comment
Share on other sites

19 hours ago, MattyB said:

check whether a larger portion

 

I guess Matty meant try a 'larger prop'   with the 2S.    But it's only a 20 amp ESC so you need to check with a Wattmeter as Matty said.

 

That 1000kv motor seems rather a low kv for  a 2S - it's only going to give about 7400 rpm on 7.4 volts.    A 3S (  11.1 volt ) would turn a suitable prop at about 11100rpm.

  • Like 1
Link to comment
Share on other sites

6 hours ago, kc said:

I guess Matty meant try a 'larger prop'   with the 2S.    But it's only a 20 amp ESC so you need to check with a Wattmeter as Matty said.

 

That 1000kv motor seems rather a low kv for  a 2S - it's only going to give about 7400 rpm on 7.4 volts.    A 3S (  11.1 volt ) would turn a suitable prop at about 11100rpm.

You're quoting the no load rpm.

The actual rpm would be up to around 80% of the figures quoted if the prop is a good match for the Kv & battery voltage - ie about 5900 rpm for 2s & 8900 for 3s.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...