Go Back  RCU Forums > RC Boats > Speed - Electric
Reload this Page >

STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Notices
Speed - Electric For all your electric boating needs.

STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Old 09-19-2012, 01:45 AM
  #26  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Ok... guys i need your opinion about the hardware for this Cat...soon as please

I posted pics of the Hydro speed drive from Graupner, wanting to use two of them....cheap way out
1st pic
Or

Modify two Graupner GTX650 outdrives like in the photo....these i still need to buy..total cost of $207 for 2.
2nd pic
Or

Two stingers set left and right with a rudder in middle of transom... maybe $50 each seen running fast in this video
http://www.youtube.com/watch?v=Q2k1QG8Pfmk
3rd & 4th pic
Or

very expensive idea...
5th pic
http://www.wd200-modellbau.de/?Antri...FDirektantrieb
http://www.wd200-modellbau.de/?Antri...kbarer_Antrieb

One outdrive is not an option...i want this like the real Cat...and will modify where ever needed..!!!




Attached Thumbnails Click image for larger version

Name:	Zx71994.jpg
Views:	34
Size:	10.8 KB
ID:	1802682   Click image for larger version

Name:	Wr56135.jpg
Views:	46
Size:	38.9 KB
ID:	1802683   Click image for larger version

Name:	Af90439.jpg
Views:	58
Size:	56.9 KB
ID:	1802684   Click image for larger version

Name:	Jd88667.jpg
Views:	43
Size:	19.2 KB
ID:	1802685   Click image for larger version

Name:	Ge96439.jpg
Views:	48
Size:	23.5 KB
ID:	1802686  
Old 09-19-2012, 06:54 AM
  #27  
expresscraft
 
Join Date: Dec 2008
Location: COCOA, FL
Posts: 723
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

if I was going to go that way, I would use what you have, do not lengthen it, wax up the deck.then use Formica to make a 1" ledge around the deck.To use as a flange. Fill in gaps with clay and trim as needed, wax every thing again, then again ,and wipe off with a clean rag. Then spray gel coat on just the deck,(you can brush gel on as well). Matter of fact, mask off the hull once the flange is complete. Then put 1 layer of well wetted out mat over the gel coat. Using polyester resin. Mix your polyester resin with micro ballons to make a putty and fill in sharp corners where needed, like the ribs on the deck, you will never get your mat or cloth to conform to that.After your first layer has dried over night, add a few more layers the next day.Let dry over night again. and pull your mold off the original boat.Remove the mask and formica flange and all clay from the hull, and wax it 3-4 times, each time removing the applied wax with a clean cloth.Now put your deck mold back on you boat, and wax the exposed flange, as it will now be the ledge to create you hull trim edge and will fit perfect, repeat the same process used on your deck, now you will have molds to reproduce a working piece that you can lengthen and work with.I have been building models 5-7 days a week for 23 years full time for a living.You are going to create a mess working with abs,not saying you cant do it. Just saying you will not be happy with the results, this procedure I'm giving you will take a little work, but its nothing compared to what you will get yourself into by cutting and lengthening what you have, you have no real foundation.I am saying this in the most helpful means I can and do not mean to put it out there as a challenge to what you had in mind.you will have some time in this, but it will be good enjoyable time with great results. and you will have the boat you want.if you go this way just post if you get into trouble and we will help you through it.
Old 09-19-2012, 07:20 AM
  #28  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Thanx so much for all that info..this will help me a great deal

I think i will do as you said...i spoke with my dad and he almost said the same..when seperating the hull from the mold..would i need to drill a hole in the hull and blow compressed air into it to release it ?

What do you think for the hardware i stated in last post ???
Old 09-19-2012, 09:34 AM
  #29  
norbique
Senior Member
 
norbique's Avatar
 
Join Date: Feb 2003
Location: Europe, HUNGARY
Posts: 388
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

i use the stingers in the 4th photo on my twin cat. they're cheap but if greased well they last long. bushings can be replaced etc.
Old 09-19-2012, 10:50 AM
  #30  
expresscraft
 
Join Date: Dec 2008
Location: COCOA, FL
Posts: 723
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

you should not need to drill a hole, just make sure you wax and wipe about 4-6 times,letting the wax dry about 10-15 minutes before removing, its really best if you do this over 2 days, to allow the wax to gas off, its not really needed, but its not a bad idea.you can use masking tape to hold the reasonably cut to shape formica, in place and brace it with thick cardboard. or even better if you dont mind the work use a board and set your boat on it and glue blocks of wood arount it cut just below the seam line, then ca your formica to those glued in place blocks,then seal your gaps with clay and trim as needed. and wax.when you are done. wax one more time lol.keep us posted. one more note, the formica should end up even with your seam, that joins the deck to the hull.
Old 09-19-2012, 11:36 AM
  #31  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

This is great stuff....now i'm getting somewhere....

Could i use Styrene sheets for the hand made flange .. ? or is Formica an American term for plastic Styrene ?
I created a Sailing barge ''Thames Kitty'' all out of Styrene sheets with rail sail cloth..back a few years..those sheets are strong stuff...


Thanx Norbert...i can get those for 35 quid each now....so dead cheap there normaly more..maybe there too big 110 mm to end of stinger and 150 mm to end of prop nut...
but then again i really love those Arneson drives at 392euros is 315quid : $511 for the duel kit..ouch...but then again every boats hadware is expensive..it always has been..


The pic is not mine, but its exactly the same creation..(mine is with ex gf lol, have to pick it up next year)
Attached Thumbnails Click image for larger version

Name:	Nk27769.jpg
Views:	47
Size:	68.0 KB
ID:	1802928  
Old 09-19-2012, 12:06 PM
  #32  
norbique
Senior Member
 
norbique's Avatar
 
Join Date: Feb 2003
Location: Europe, HUNGARY
Posts: 388
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Matt, those stingers come in two lengths! there are shorter ones with 4mm shafts.
the ones you say are for bigger 4.7mm shafts.
Old 09-19-2012, 01:10 PM
  #33  
expresscraft
 
Join Date: Dec 2008
Location: COCOA, FL
Posts: 723
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

formica is what you cover counter tops with, plastic sheets would probably work, just make sure the resin does not attack it, and remember when drying there will be some heat, that's why only one skin coat to start with, so it does not warp your part,even after one skin coat you can't go crazy layering it up in one shot, the more resin, the more heat.
Old 09-19-2012, 11:37 PM
  #34  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

great stuff guys, thanx, this will take time, i will not rush it so be sure to check back every so ofter..i need to find all info before i do anything to this Vintage machine..

I still need more help on final decision for Hardware...
Take a look at the post with 5 photos and tell me what you think...please

Norbert i know used the stingers in the 4th photo for his Cat and they work, i also posted a video of another guys creation, only problem is there not so scale..and are not steerable..the cheap Grauper drives will look more scale in the water than those stingers but maybe break with Leopard motors...i might just go with them for a test build..

What about modding the GTX650 motors ? its never been done but i could make it work, they may have to be set on a bracket to distance from the transome so the flex can turn more...but i think it will work..but $200 for 2
Old 09-20-2012, 12:55 AM
  #35  
Rebel bay
 
Rebel bay's Avatar
 
Join Date: Jan 2010
Location: Boulogne-Billancourt, FRANCE
Posts: 144
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Here is what I will use on twin setup mono, with Scorpion 3026 1400kV (2x6S) motors.Stingers come from HOR 30$ each, the rudder have a long bracket and the blade is shorter. Stinger lenght is adjustable 85mm to 105mm. Very good hardware and cheap

Old 09-20-2012, 01:25 AM
  #36  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Yep those look great ...are they 1/4 or 3/16 or less ...sry inches im not formiliar with..i wouldnt know unless i had them in my hand..lol

1/4 is for boats 45'' 114cm - 62'' 157cm and 3/16 is for 29'' 73cm - 39'' 99cm...so i take it the 3/16 is wat i need..but there's two version one at $30 and other $45


Im going to make the mold then build the original and do tests with it...top cover will be modified so you can get to both motors

i suppose just buy the complete set from HOR..whats the length of the rudder arm & blade ? that rudder is not on HOR site..and cant find it anywhere...
Old 09-20-2012, 04:51 AM
  #37  
martno1fan
Senior Member
 
martno1fan's Avatar
 
Join Date: Jan 2005
Location: blackpool, UNITED KINGDOM
Posts: 11,390
Likes: 0
Received 1 Like on 1 Post
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Any hardware props motors ,esc,s you need talk to me i can get almost anything you need if i dont allready have it in stock.
Mart
Old 09-20-2012, 05:12 AM
  #38  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Thanx Mart

well that complete system that Rebel Bay has in the picture is what im after but cant find the same rudder...there is a simular one on HOR but its not the same...
Old 09-20-2012, 06:02 AM
  #39  
martno1fan
Senior Member
 
martno1fan's Avatar
 
Join Date: Jan 2005
Location: blackpool, UNITED KINGDOM
Posts: 11,390
Likes: 0
Received 1 Like on 1 Post
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

one thing ill say about a cat is you dont want the rudder so far back it creates handling issues,best to have it nearer the transom in my experience.As for rudders and drives i sent you a pm.im not allowed to talk business on here lol.
Mart
Old 09-20-2012, 06:20 AM
  #40  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

yea thats why i was going to mod two GTX650 drives

LOL if i could just use stingers and no rudder and have it setup so that when one side motor stops or slows down it causes it to turn..using a flight transmitter and setting the left and right sticks both forward thrust...just pull back on one and she will turn....but that not what i want to do..
Old 09-20-2012, 06:25 AM
  #41  
martno1fan
Senior Member
 
martno1fan's Avatar
 
Join Date: Jan 2005
Location: blackpool, UNITED KINGDOM
Posts: 11,390
Likes: 0
Received 1 Like on 1 Post
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Why not go with a single drive much simpler ,something like this would be perfect for something like a 4082 or 4094 motor on 6 s lipo it would go really well.
Mart
Attached Thumbnails Click image for larger version

Name:	Ge95932.jpg
Views:	41
Size:	78.7 KB
ID:	1803175  
Old 09-20-2012, 06:28 AM
  #42  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Naaa.... i want this almost same as the real thing, it had two Mercruiser zdrive's then later went to two steerable stingers...that rudder you picture is almost like my alu rudder i pictured in first post

eveybody uses single....because of too much work to transform to twin...and there not sure if it will work...I know it will work..
for me ..i dont care if this takes me 6 months or 2 years...i will still do it..
Still no one has remarked about the other hardware i posted pics of...
Old 09-21-2012, 12:10 AM
  #43  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Ok i spoke to a professional boat builder from datelinemarine.uk last night who has 15 years model boat making running competitions and then Racing real powerboats...

My Stretch will work but so much needs to be considered, already he recons the ABS will melt just by putting the gelcoat on, then theres the steps in the hull...by me making it longer the step will be in the wrong place, which will throw the balance out and will make it handle real bad..
Not a problem, this can be delt with, but the time and money will be a problem, he said if he was to do this for me it would be more than 300quid...
So i'm on hold for the stretch, he recons paint the outside of the hulls in 2k paint polish to a shine, use release agent and then make a mold..

I will be building this original Graupner boat for now with twin stingers, so just getting hardware sorted out before hand.
Old 09-21-2012, 12:52 AM
  #44  
martno1fan
Senior Member
 
martno1fan's Avatar
 
Join Date: Jan 2005
Location: blackpool, UNITED KINGDOM
Posts: 11,390
Likes: 0
Received 1 Like on 1 Post
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Thats why i said you need to use epoxy,it will not melt abs but heat may distort things another reason i said leave it alone lol.Im a profesional boat builder by trade and been building rc hulls for 5 years but never used abs i only use glass.
My advice would be build from wood or buy a glass hull and modify it or buy Toms big gasser at expresscraft and go BIG,his hulls only $350 plus about £150 shipping so total cost would be close to £ 364-£370.With customs charges probs arround£450 ish.
Mart
ps 2k paint would probs melt abs lol
Old 09-21-2012, 04:16 AM
  #45  
expresscraft
 
Join Date: Dec 2008
Location: COCOA, FL
Posts: 723
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

I dont know if gel coat will hurt the abs or not,it comes in a plastic bucket, and i do not think the heat created by it kicking off would be that bad, of course I would try it on a sheet of abs first,Remember the whole idea behind making molds, was just so you would end up with something to work off, as abs is not it.on a glass hull you can fill and move the steps where ever you need them.plus with your mold you could lay up a heavy part to have a really good foundation to work with. or just use yours for reference and build one out of wood.
Old 09-21-2012, 12:05 PM
  #46  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Yea i know...i listened to you all...but when you got a bug its almost impossible to let someone tell you otherwise...

I want the Systems Hull from Expresscraft but i dont have that cash, plus it needs a lot of mods to make it like the Reporter Cat, which i can do, plus the price of the hull is almost the hardware needed for this Graupner Cat what with it being twin motor, twin controllers and twin stingers...and then Expresscrafts cat is bigger meaning bigger hardware meaning double the money..just aint got that cash..not yet any way..

So while i research an accurate wooden base plan of a Cougar Cat, i will build this one with twin motors and do tests', i will be making adjustments to the sharpness of the underside and get it running fast, think of this as your Days of Thunder Beta.. then afterwards we can all have a laugh...hehe
If i came across some money then i would buy the expresscraft Cat and do the changes to the deck...as i would have time to save up for the hardware lol.

Old 09-22-2012, 11:57 AM
  #47  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Ok i had a thought...

What if i used the wooden Lithium Cat plan and modified the back so that it was straight, the same as Cougar hull ?
This has kinder taken over my Lithium Cat build, i will build both of them...but just not sure which one first..but i have a good idea it will be this Cougar Cat..
Lol im gunner have to rename this thread...
These are Norbert's pic's of his Lithium cat, so hope he dont mind me showing you guys, to see what you think..
I think i can do the transformation to the tappered sides and sloped transome..and looking at the top view pic of the frame work you will see the transome can be made straight...
then just create the top using foam & resin ...

Oh my plan is now made to 135 scale...ouch..i think i can pull it off
Attached Thumbnails Click image for larger version

Name:	Qo39868.jpg
Views:	50
Size:	90.3 KB
ID:	1803805   Click image for larger version

Name:	Ez82276.jpg
Views:	51
Size:	92.8 KB
ID:	1803806   Click image for larger version

Name:	Fd93298.jpg
Views:	54
Size:	107.2 KB
ID:	1803807  
Old 09-22-2012, 01:08 PM
  #48  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Damn i may be wrong about the Reporter Cat...

Although it was raced by Steve Curtis in the 80s and won Key West championship...the Cat was a former Seahawk 38 Cougar..so they claim here :
http://www.offshoreonly.com/forums/c...-cougar-2.html

Anyway i still want to build it. it had 4 pilot seats....i just cant find any more photos of it anywhere...only video racing and the photos ive already shown..
Attached Thumbnails Click image for larger version

Name:	Ge96366.jpg
Views:	52
Size:	138.0 KB
ID:	1803834   Click image for larger version

Name:	Xt60253.jpg
Views:	48
Size:	83.8 KB
ID:	1803835   Click image for larger version

Name:	Gl21646.jpg
Views:	73
Size:	101.5 KB
ID:	1803836  
Old 09-23-2012, 04:57 AM
  #49  
colosus
Thread Starter
 
colosus's Avatar
 
Join Date: Jul 2005
Location: London, UNITED KINGDOM
Posts: 108
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build

Just incase people are thinking its not worth it, just get another hull....well take a look at this video :

http://www.youtube.com/watch?v=dTG1lSjilJc

I want to beat this speed in the Vintage Cat...i want it 100kmh + and im sure with my twin setup and all running right, i will beat it..
I will More than likely be using 2x 1600kv's ...this Cat is gunner scrEAM.....
Old 09-23-2012, 06:22 AM
  #50  
Rebel bay
 
Rebel bay's Avatar
 
Join Date: Jan 2010
Location: Boulogne-Billancourt, FRANCE
Posts: 144
Likes: 0
Received 0 Likes on 0 Posts
Default RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build


ORIGINAL: colosus

Thanx Mart

well that complete system that Rebel Bay has in the picture is what im after but cant find the same rudder...there is a simular one on HOR but its not the same...
The most difficult parts to find are the T center bracket and the blade mount with two arms, here are some links

mbp-rc.de/MBP-7075Alu-157-127mm-lang_1

www.arrowshark.com/standard-drive.php

cgi.ebay.fr/RUDDER-BRACKET-ONLY-150mm-LONG-gas-rc-boat-/120757651556

For the center rudderlong bracket I took parts here and here... Here is the complete twinsetup for a deep vee 39" long





Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.