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[gregk9]

I have just aquired a second hand 1:24th scale perkasa [think its a precedent kit]. it is fully built and in previous owners hands, it ran with an ic engine. however, I intend to use with electric motors.

What motor/s would any of you suggest.
would you use a single motor or twin motors?

The boat has a single prop installed, but am prepared to remove and fit twin props if necessary.
next question is, what prop/s and suggested battery voltage?
I can install 8.4 volt sticks, 11.1 sticks [both as twins] or even go 12volt, purely for capacity, as think this hull would cope with some weight, even if just to keep it down in the water !

Oh and i want it to "plane" across the water, not just simply "cruise" along

[Perkasaman2]

Hi gregk9, I don't know which material your hull is made from (timber or grp) but this thread is worth reading, especially if you intend to use twin 'brushed' motors in your 1:24 Perkasa. I used twin heavy lead 12v 7amp/hr batteries but modern lighter nimh high capacity batteries will give even quicker performance. Other Mahemmers will advise on a twin 'brushless' motor installation if you prefer this route:

http://www.modelboatmayhem.co.uk/forum/index.php?topic=18030.0                 

[gregk9]

Thanks fro your reply, its a pity the initial pictures on that link have been removed, so Im unable to see them, but your pictures give me a lot of data to use on mine.

Yes, my hull is fibreglass based. it does have a couple of runners originally installed for the ic engine to bolt to.

So would you recommend twin 700 or 800's as a preference, in not too fussed to go for brushless units, id far sooner fit something to last, rather than a flash in the pan that needs replacing the moment the brushless esc overheats and melts, causing a short on the motor windings.

I think I need to do some super detailling to the forward 40mm gun, it seems to lack a lot of details, can you get a better detailled gun anywhere? or is it simpler to source some pics over the internet?
id post some pics of my boat, but my image files are too large for this site to cope with. may have tio use a cheaper camera with lower pixel quality image capability.

[tobyker]

There is a thread about resizing pictures. It is not difficult amd that nice Mr Gates has a way of doing it.

[Perkasaman2]

Hi gregk9, this link is the one referred to. It explains issues and gives directions on re-sizing your pics. (Your present camera is fine and not the real problem. )

This Mayhem thread may be more helpful:

http://www.modelboatmayhem.co.uk/forum/index.php?topic=23.msg2630#msg2630

[gregk9]

thanks for the thread link for photo imaging, but have checked the link, but it does not support windows 7, only XP at present. Ive tried to download tha application anyway, but it locks up and freezes, so will have to uninstall and look for another program that will work with win7.

thanks for trying anyway.

[dougal99]

Serif have a free version of their software http://www.freeserifsoftware.com/software/photoplus/ which will allow you to resize your photos if you dont mind the odd reminder about the paid for version. I've used it for the last couple of years with no problems.

[pugwash]

Greg If you are using windows 7 nothing couild be easier for re-sizing photos - go into your photo gallery
select your picture to be resized right click and and select the resize option - thats all I do - you can take
a series of photos of your build and have them on the forum with some text in less that 15 mins.
Geoff

[Perkasaman2]

Hi greg, It seems Win7 has 'resizing ' built in?.............. anyway I chose twin Speed700 BB Turbo motors. The motors I have (model Nr 3307  4.8 - 16.8v) seem to have been replaced  by model 6317 running 7.2 - 19.2 v. This replacement would seem to be more suitable for the latest megga nimh battery packs and will easily spin a 45X rated prop or two.
It's also worth considering model 6316 if you don't wish to exceed 12v since this model probably won't require the additional cost/fitting of cooling coil and plumbing/scoop fittings which will also may need to be bought and fitted to each of the 6317 versions on megga voltage packs............................ food for thought?  (My engines did'nt require additional cooling.)
It's worth studying this dealer's link which lists the specs of the whole Speed 700 range of models currently available and their price/service/reputation is very good. The 820 is OTT and twin 900s would respectably power a surfboard. 

 http://www.cornwallmodelboats.co.uk/acatalog/graupner_motors.htm

 

[gregk9]

"Hopefully  and fingers crossed, have attached some pics of my perkasa ive just aquired. as you can see the engine bay is virtually a blank canvas.

[gregk9]

Thanks perkasaman for your info and suggestions on powerplant, 700's sounds good, but what about mfa 800's?  would the 700's be ok for a long term fit, or would the 800's be better, with that bit more "capacity" if needed so to speak. im not looking for  full throttle 100% of the time, but when i do, open her up, id like it to lift its little skirt and make a sure dash for the horizon! [ha ha].

yes, can get 700 turbos for around £18.00 ea, but can also get a twin 800 kit pack, with all mounts, u/j's esc and wiring for £100 all in, yes, ok still have to get a couple of props as the kit comes with a pair of 50mm's jobs, which i appreciate are to big for this craft.
rudder replacement is no problem, I dont know if to leave the central one in and just fit an extra 2 covering the new prop's and link all 3 together for extra handling.

[Perkasaman2]

Hi greg, the Speed700 BB Turbo's are far superior to MFA 800/850's in both performance and quality. These Graupner motors are ballraced and run with less friction and will deliver the 'brushed' power you want with long service. They will quickly swop in/out for use in future models....... your motors/esc's and batteries are all transferable................a real future cost saving.

A triple shaft/prop setup would likely use 3 non-turbo Speed 600's but I have no experience of a successful triple high performance brushed motor setup in our hull. The 49" Perkasa is a great favourite and there are a lot of other threads on Mayhem which explore alternative power options and ideas which could be helpful. Triple engines can require quite sophisticated control extras to aid steering and power control and I would be cautious and research thoroughly before buying ANYTHING until you fully know what you want and have thoroughy understood the options and the costs involved.  

Great pics - well done. 

[gregk9]

Thanks again Perkasaman for your suggestions and guidence. I will be using only 2 motors, not 3, but was wondering about leaving the originally fitted "centre rudder" in place and linking up to the 2 new rudders behind the new motors. Wondering if it would give that better edge on handling, having 3 rudders on a  turn instead of 2.

My robbe dusseldorf uses 4 rudders as standard and that turns on iself if you let it !

i do also have  an Italeri PT596 which I followed a certain ",magazine conversion" and fitted that out with 3 x speed 400's and triple rudders, that runs a treat and planes well. i did use  some micro switches to deactivate the inner motor on sharp  rurns on the rudder servo, so it did not run 3 motors on tight turns.

[Perkasaman2]

Hi greg, triple rudders?........ why not if you fancy them. Your Italieri PT looks great. (This Elco kit is perfect for rc/motorizing and your success with a triple 400 is very useful and valuable experience.)
I could'nt find any suitable (45X) and  inexpensive  'handed' props at the time, although the speed motors work equally well in either direction, so my hull 'crabbed' a little at full power, so an additional centre rudder may improve this issue. I converted my Tx to 'twin stick' to enable 'tank steering' with twin esc's on seperate channels to get excellent low speed handling/control.
I could have managed to get my propshafts slightly more horizontal, but I left clearance for trialling twin props up to 50mm but found, after extensive trials, that the 45X's were ideal. I contemplated shaft supports (P frames) but decided to add struts later, well away from the props to avoid disturbing the water flow close to the props.   

[gregk9]

Thanks Perkasaman,
The PT596  is a treat to use I do admit. I run it on an 8.4v cell stick, or if wanting to "impress", drop an 11.1v lipo in! and then watch it fly !!!!!

I do have a fairly complete set of construction/modification build pics of this kitbuild, so can post all of the build on this site if anyone is interested, like all my builds/ mods. I always document anything i do, for my own reference later if need be, or for others to either learn from my mistakes or experiences.

I will post the mods to the perkasa once I have sourced all the bits and do a build post if you think it may be wiorth seeing for others, too, feedback from some of the "quiet watchers" would be good please guys, let me know if you wanna watch the mods take place too.

Best wishes.

gregg

[gwa84]

yes please 

[Perkasaman2]

Hi greg, I also think that your offer to post a thread on your triple prop Italieri build is a great idea.  

[sarge257]

Hi Gregg, Yes please me to 

[gregk9]

Ok, I will start a new thread and call it "Perkasa 49in renovation". I have some jobs to do on the boat right away before I even place an order with anyone for the bits required, as the original centre propshaft has to be removed completely to reduce underside drag. the water scoop has to come out also, as well as some othwer items im not entirely happy with from the original build, but thats for the thread, not here, so once again, many thanks to Perkasaman" for the guidance and inspiration so far and hope that he will follow my new thread and pop the odd suggestion and tip in too [pretty please] as I will be following his helpful suggestions for the powerplant and bringing in some of my own ideas on some of the modifications to the superstructure and "operational bits" so to speak.
This wont be a quick build, as kindly appreciate this thread will be updated as and when i get to do some work on the boat. I am also currently building a pusher tug from scratchbuild from plasticard, so thats is taking some of my time up too, but I like to be busy and only work well with at least 3 projects on the go at once, so whilst one bit is drying, i can be attacking another one [ha ha].