colosus

Hi guys, i have an old Robbe Diabolo Deep Vee laying around for about 10 years, i never had enough money at the time to make this boat go fast, at that time i tried the standard motors from Graupner as brushless was not invented then...they were the 700,700BB & 700 Neodyme motors...the motor that every body used back then was the Ultra 1300-9m this is the motor for my boat..i recently got hold of a secoundhand one for nothing and thought of putting this in the Diabolo so my son has a fast boat to use, back a few years i had major probs with the prop shaft vibrating, as its a normal ballbearing shaft and never finding the right adapter from motor to shaft so ending up with either bent shafts or broken shaft connectors.
Ok heres the questions... i want to change the shaft for a flexi, plus change the rudder system to a single rudder, i have no idea on which to use either a straight stinger type with rudder inline with shaft or the rudder set to the right ?? ( see photos, Red Flame color is mine ) i dont have much money so using what i have at the moe..this motor is still high priced today at 291euros, i dont have the money to put a brushless in & change the speed controller...that comes later..this is a good size hull at almost 1 metre, so dont want to throw it away, i'am an Englishman in Belgium and not one model shop here is interested in converting and getting more speed, please guys see wat u can do...cheers.

garfieldmsn

single rudder will be great
I prefer the rudder set to the right
you need used more powerful motor Base on you want to let this boat get more speed,so pick a one

colosus

Hi & thanx for a response.... well i have that Alu rudder set in the photo and can modify it to be set to the right, or should a buy another system ?

Thing is i have no idea what measument it must be, what distance from the shaft to the right of the hull...i cant do it once and find out its no good cos it'll have too many holes in the boat to repair... another question is what length should the shaft be sticking out of the hull ?? same length as rudder, inline with rudder length, after rudder or just before rudder length...??
This is a boat that not many people know of except in Germany, thing is the forums are in German plus i got no responses...lol
They speak of this boat being very very quick & wining competition 8 year ago...looking at other deep vee's we can make the modifications but how to begin is the bit i'am stuck on..i know the Traxxas Spartan is amazing at 400+ dollas but i didnt want to buy a new Vee as i want a Mystic 114 or 135...

The photo with my boat doing a jump is using the Ultra 1300-9m motor.... i never even had this boat reach 30mph...

sundogz

In my experience, offset rudders work best on hulls that don't heel over such as hydros, riggers and cats. That inline rudder in the pic would be my choice. Just get a cheapo stinger that will provide clearance with the largest (longest) prop you will likely use. A 4mm (or larger) flex shaft will do nicely.

colosus

Thanx for the info... did you have any idea on what distance to place the rudder from the shaft ?

what if i use this shaft with my Alu rudder...see photo ?

sundogz

My bad - I was confusing the inline system with a stinger drive. That inline will work as-is, or you can use a stinger and a rudder as well. The strut will work as well, I have one on my Foki in an arrangement like that. It's a little more difficult to adjust - but once adjusted, it stays there. Offset rudders are usually placed slightly behind the prop.

colosus

Thats a nice boat you have there....

Well if using this inline rudder + strut system wont my Vee hull have serious wobble at high speeds...?

sundogz

If you do experience wobble or porpoising, trim tabs should keep things steady.

colosus

Cheers m8.....but before i make the changes would it be better to get this stinger here in these photos...its from China....and 35$ cheap
I can wait as not in a rush, i want it to be right .....and not have to remove all and repair holes again....already its a mess after i removed the shaft and steering gators..
Its a 70mm stinger with a 300mm flex shaft & stuffing tube...

sundogz

Did you want to do this on the cheap? What do you have that you can use?

colosus

well i got 50 euros left to buy that stinger if its for a good cause, it will work with the Alu rudder i got..

I was thinking that if i had a stinger i can use either inline combo or with rudder set to the right...but if i dont get a stinger then iam stuck with the inline combo....but the stinger combo will work with any boat i buy in the future..

Its because i also dont have the 4mm flex...the one i have is an old Prather flex no stuffing tube & no teflon tube, no DDdrive just a flex, this one is difficult to get the right size prop and stuffing tube for...so the one in the pic is complete plus i can adjust the up/down angle if ever needed although i know normaly the stinger should be level with base of hull so moving stinger down will not do anything..

Let me know wat you think about that stinger cos if its best then i need to buy it quick cos it will take some days to arrive from China...look at photo again...cheers

Looks like no one else is putting themselfs out to help me here...

sundogz

I was asking because I didn't see an aluminum rudder pictured - just the inline combo. Sounds like you have a plan!

colosus

well i thought i could use that inline Alu rudder set and just remove the flex drive support making it just a normal rudder, then either using it inline with that stinger i pictured or using the stinger and setting the rudder to the right of the stinger...what you think ?

sundogz

Now why don't you want to use the inline setup? It would seem to be a most suitable solution. That and trim tabs and whatever flex & prop shaft fit the strut. You can make it more complicated and spend more money, but won't attain much better results. That's just my humble opinion.

colosus

well you said about just get a cheap stinger, so i was searching for one...all the Mono hulls/Deep Vee's are using the stinger & rudder set to the right..
I am remaking this boat, it was in top condition untill i ripped off that spoiler and will be changing the way the hatch looks, filling up the holes in the Aft, and a all new paint job, i all ready started so i need to finish now... but first things first is that rudder & stinger system..i think i will get that stinger for future mods, after all i will put a brushless in this one for my son, iam not after this boat breaking speed records but i do want it to get past its manufacture speed, u can see that little pic of my boat in red & black with a modified rudder that is doing some serious speed...its actually using that brushed graupner 1300-9m with 24cells 2400mah

Here pics of paintjob in mind theres Hydros [8D]

My real model boat is a T-4 Twin Wing Hydro from Hydro&Marine Germany thats not finished as no money for the speed controller...damn Lehner 2250 9winds needs a 500euros+ on a speedcontroller [:@]

pompebled

Hi Colosus,

A large 920mm hull doesn't 'need' a flexshaft, a solid shaft will work just fine, as long as it's long enough to keep the propshaft angle at a minimum.
The angle doesn't need to be 0°, as these hulls need a bit of propangle to keep the boat on the water.

Check out the Arowana thread here: the yellow and purple boat is the one I set-up:
http://www.rcgroups.com/forums/showt...hlight=arowana
I know, a lot of reading, but a lot of info too on the various ways to set-up a V-hull, both with solid shafts and with a stinger.
The shafts in our Arowana's are 420 mm long.

The shaft needs a few mm clearance when the hull sits flat on the table, like this:


While I'm at it, I assume you've read this one:
http://data.robbe-online.net/robbe_pdf/P1122_1-1067.pdf
Specially the part where it says to flatten the rounded edge at the transom.
As you have a more powerful motor now, the underwater hull needs to be flawless, or you'll experience very 'interesting running charactaristics' when the boat picks up speed, in other words it'll be a bad handling hull.

As a rule of thumb, the front of the prop is 10-13% of the hull length from the transom, which is between 92 and 120 mm in your case.
The rudderblade should sit next to the prop to counteract propwalk as shown in these pics:




Let me know if you need more info.

Regards, Jan.

pompebled

Hi Colosus,

I assume you know the 1300-9 needs watercooling on both can and brushtabs, to keep is alive on 20-24 cells NiMH or 7-8S Lipo?

I added a picture of my 1300-7 with a custom made waterjacket and brushtab cooling, very efficient, but I strongly advice agains runtimes of more than three-four minutes continuously, as these motors were not (I repeat: NOT!) designed to run for much longer under max load (as they are designed for (sail) planes).

If you run longer, the motor will overheat and the commutor will shed solder, which effectively ruins the motor, as the segments of the commutor will fly off.
Plettenberg can repair the motor, but at considerable cost.

Before the brushless motors took over, a lot of German boaters running Plettenbergs, had huge radial fans coupled to the cooling slots of the commutor, blowing a lot of air through the motor in an attempt to keep the temperature down for 5-6 minutes.
They also had watercooling on the can and brushtabs, so the whole set-up was quite elaborate.

Regards, Jan.

colosus

thanx for all the info guys, i'am so happy some more guys are sticking there necks out to help me here...cheers

Ok..... i've already changed my solid shaft with bearings four times and each time have bent them slightly because of a bad connector to motor also can be slightly out of place too...but i made sure with measuments to get all lined up before gluing all hardware parts inside....thats also why i want to go flex.

No i did'nt know about the extra cooling for that 1300-9m...cheers for that advice m8...
and yes i did see the thread on sanding the transom...that i did before anything else

I realy need to just know with the photos i've posted here which system and size i should use......thats the problem realy....i have the single inline 115mm rudder but no flex and its hard to find exact one... i can buy the stinger which is 70mm long with flex 300mm ( my solid shaft sticks out by 50mm ) very cheap....and then of cause knowing the distance between rudder and shaft if not using inline system.....or even using a stinger with that same 115mm inline system...... so much to choose from

colosus

" I realy to know with the photos i've posted here which system and size i should use......thats the problem realy....i have the single inline 115mm rudder but no flex and its hard to find exact one... i can buy the stinger which is 70mm long with flex 300mm ( my solid shaft sticks out by 50mm ) very cheap....and then of cause knowing the distance between rudder and shaft if not using inline system.....or even using a stinger with that same 115mm inline system...... so much to choose from "

ok no more news here...you must all be working..
I've ordered that stinger drive..now just need to wait for it to arrive from China..if anything it will be useful with either this boat or another.....
This weekend i will repair the holes in the Aft and the hatch after ripping the spoiler off....damn super glue is well tuff....

will post a photo soon

Doctor ES

hello from germany.

iv'e found an interessting pic in this tead here; its the orange mono in post no.6 from sundogz. does anybody know what it is?

thanks to you all,

doc :-)

sundogz

It is a Foki SX Evolution.