Boatmad.com


Reply
 
Thread Tools Display Modes
 
Old 19-04-2006, 08:48 PM   #1
Registered User
 
MrRob's Avatar
 
Country: England
Location: Birmingham
Occupation: Scratching
Interests: Big Dinners
Boat name: Never Enough
Boat make: Seaquel 600xs
Engines: 225hp Merc ProMax
Cruising area: Anywhere! I prefer Weymouth

Join Date: May 2005
Location: Birmingham
Posts: 3,232
Send a message via AIM to MrRob
Cutting down a 20" mid

Anyone know the score on cutting down a 20" midsection to a 15" midsection?
__________________

__________________
I got jumper cables!
MrRob is offline   Reply With Quote
Old 19-04-2006, 09:10 PM   #2
Registered User
 
Tony Davis's Avatar
 
Country: Job Centre
Location: In a box
Occupation: Chaos's gofer
Interests: Skiving
Boat make: Spectre 30
Engines: 2 x Promax 225
Cruising area: In the bath

Join Date: Mar 2004
Location: In a box
Posts: 5,201
don't be ridiculous!
__________________

__________________
Chaos for Moderator.
Tony Davis is offline   Reply With Quote
Old 19-04-2006, 09:16 PM   #3
The Doc
 
Captain Chaos's Avatar
 

Join Date: Mar 2004
Posts: 8,265
I'm not sure exactly but whats involved, but I reckon you'd need a bloody great saw and say "20 minutes"
Captain Chaos is offline   Reply With Quote
Old 19-04-2006, 09:19 PM   #4
Registered User
 
scottyboy's Avatar
 
Country: United kingdom
Location: West Sussex
Occupation: Grease Monkey
Interests: Makin my boat faster!
Boat name: S.B Racing
Boat make: Ocke mannerfelt canopied B23 / Zapcat
Engines: Merc 200XS Gen 2 / Tohatsu 50
Cruising area: littlehampton/Southampton

Join Date: Jan 2005
Location: West Sussex
Posts: 2,652
Re: Cutting down a 20" mid

Quote:
Originally posted by MrRob
Anyone know the score on cutting down a 20" midsection to a 15" midsection?
WTF?? Heard of cutting down a 20" shaft to a 15" but not a complete mid section??????
__________________
Class 3C Mono EPA National speed record holder 95.35 mph Avg!
scottyboy is offline   Reply With Quote
Old 19-04-2006, 09:21 PM   #5
numbskull
 
Jon Fuller's Avatar
 
Country: United Kingdom
Location: South
Occupation: none
Interests: none
Boat name: Leviathan
Boat make: Phantom 28
Cruising area: South Coast

Join Date: Mar 2004
Location: South
Posts: 15,959
Re: Cutting down a 20" mid

Quote:
Originally posted by MrRob
Anyone know the score on cutting down a 20" midsection to a 15" midsection?
I did it about 15 years ago, but the downshaft kept breaking on the weld which was just below the spline..The mid section itself stayed together OK, even tho' i welded it using oxy-accetylene (great skill required)

Gave up with it in the end.
__________________
.

"I Agree with everything you say really!" - John Cooke to Jon Fuller - 26-01-2013
Jon Fuller is offline   Reply With Quote
Old 19-04-2006, 09:25 PM   #6
Registered User
 
Country: england
Location: the grim north
Occupation: robot
Cruising area: tyne

Join Date: Nov 2004
Location: the grim north
Posts: 904
search around on scream and fly theres quite a bit on this topic.
__________________
Speed costs weight so what do we cut off first
sinkunit0 is offline   Reply With Quote
Old 19-04-2006, 10:05 PM   #7
Registered User
 

Join Date: Mar 2004
Posts: 6,862
Re: Re: Cutting down a 20" mid

Even if you do say so yourself!

Quote:
Originally posted by Jon Fuller
i welded it using oxy-accetylene (great skill required)
Matt is offline   Reply With Quote
Old 19-04-2006, 10:10 PM   #8
Registered User
 
MrRob's Avatar
 
Country: England
Location: Birmingham
Occupation: Scratching
Interests: Big Dinners
Boat name: Never Enough
Boat make: Seaquel 600xs
Engines: 225hp Merc ProMax
Cruising area: Anywhere! I prefer Weymouth

Join Date: May 2005
Location: Birmingham
Posts: 3,232
Send a message via AIM to MrRob
I have been looking a lot on S&F about it. They cut the shafts and respline them rather than cutting a section out and reattaching the spline.
But I have not been able to find a guide on the subject.

Is it easy enough to do Jon? Problem with S&F is no one ever seems to detail whats actually involed with these things.
__________________
I got jumper cables!
MrRob is offline   Reply With Quote
Old 19-04-2006, 10:15 PM   #9
Registered User
 

Join Date: Mar 2004
Posts: 6,862
Because if you have to ask.......
Matt is offline   Reply With Quote
Old 19-04-2006, 11:09 PM   #10
Registered User
 
RossM's Avatar
 
Boat make: Phantom 23

Join Date: Mar 2006
Posts: 1,650
Send a message via MSN to RossM
Search marty powell on scream and fly!
RossM is offline   Reply With Quote
Old 19-04-2006, 11:11 PM   #11
..
 

Join Date: Jun 2004
Posts: 1,567
Quote:
Originally posted by MrRob
They cut the shafts and respline them
when i was involved in race cars ( Gartrac ) we used http://www.quaife.co.uk/ from sevenoaks for all our halfshaft mods, re-splining included
Foolish is offline   Reply With Quote
Old 20-04-2006, 08:48 AM   #12
numbskull
 
Jon Fuller's Avatar
 
Country: United Kingdom
Location: South
Occupation: none
Interests: none
Boat name: Leviathan
Boat make: Phantom 28
Cruising area: South Coast

Join Date: Mar 2004
Location: South
Posts: 15,959
Quote:
Originally posted by MrRob
Is it easy enough to do Jon?
I think this is probably the right time to add, that the motor in question was a 7.5hp merc twin, for use on a 12' aluminium dinghy.
__________________
.

"I Agree with everything you say really!" - John Cooke to Jon Fuller - 26-01-2013
Jon Fuller is offline   Reply With Quote
Old 20-04-2006, 09:08 AM   #13
Registered User
 
MrRob's Avatar
 
Country: England
Location: Birmingham
Occupation: Scratching
Interests: Big Dinners
Boat name: Never Enough
Boat make: Seaquel 600xs
Engines: 225hp Merc ProMax
Cruising area: Anywhere! I prefer Weymouth

Join Date: May 2005
Location: Birmingham
Posts: 3,232
Send a message via AIM to MrRob
Quote:
Originally posted by Jon Fuller
I think this is probably the right time to add, that the motor in question was a 7.5hp merc twin, for use on a 12' aluminium dinghy.
I see!
__________________
I got jumper cables!
MrRob is offline   Reply With Quote
Old 20-04-2006, 09:08 AM   #14
BananaShark Member
 
Cookee's Avatar
 
Country: UK
Location: Salcombe South Devon
Occupation: Racer and builder
Interests: Winning races
Boat name: BananaShark
Boat make: BananaShark 34' Race
Engines: Twin Yanmar BY 260's

Join Date: Mar 2004
Location: Salcombe South Devon
Posts: 4,632
Quote:
Originally posted by Jon Fuller
I think this is probably the right time to add, that the motor in question was a 7.5hp merc twin, for use on a 12' aluminium dinghy.

__________________
Cookee



British Champions! RIB Formula 1 2005
National Speed Record Holder at 90.15 (still)

www.bananasharkracing.com
Cookee is offline   Reply With Quote
Old 23-04-2006, 08:52 AM   #15
Senior Member
 
Country: netherlands
Location: Mijdrecht/holland
Occupation: truck repair
Interests: fast boats/porches
Boat name: bernico cat
Boat make: bernico 26 cat 2x 2,5,s
Engines: merc,s 2,5 EFI,s
Cruising area: ijselmeer

Join Date: Dec 2005
Location: Mijdrecht/holland
Posts: 382
Find an old Hot Boat magazine ,10 years ago or so ,there was a complete artikel by John Tiger that shows you by a lot pics what to do and where to cut,and lots other things.

Remember the splines from a drive shaft are hardened for wearing out soon.
so cut it 5 inch ,respline ,and harden the metal again.
Resplining I usually pay 100€ (65 GBP)

sterling
sterling is offline   Reply With Quote
Old 23-04-2006, 08:21 PM   #16
Registered User
 
Hydrostream's Avatar
 
Country: Ireland
Location: Dublin
Occupation: Boatbuilder
Boat make: Hydrostream V-king, 650SS OCR ,Ring 21, Ring 18, Phantom 18.
Engines: 300Hp Mercury 2.4, 130 Yamaha, Bridgeport EFI, XR6, Merc 200.
Cruising area: Malahide, Dublin

Join Date: May 2004
Location: Dublin
Posts: 1,803
Mr Rob....

http://forums.screamandfly.com/forum...ht=cutdown+mid

http://forums.screamandfly.com/forum...ht=cutdown+mid

I'm halfway through my 15" mid project but am out of time for this season so I'll finnish it next winter.

Alan
__________________
www.powermarine.ie

[SIGPIC][/SIGPIC]
Hydrostream is offline   Reply With Quote
Old 23-04-2006, 08:39 PM   #17
Registered User
 
MrRob's Avatar
 
Country: England
Location: Birmingham
Occupation: Scratching
Interests: Big Dinners
Boat name: Never Enough
Boat make: Seaquel 600xs
Engines: 225hp Merc ProMax
Cruising area: Anywhere! I prefer Weymouth

Join Date: May 2005
Location: Birmingham
Posts: 3,232
Send a message via AIM to MrRob
Quote:
Originally posted by Hydrostream
Mr Rob....

http://forums.screamandfly.com/forum...ht=cutdown+mid

http://forums.screamandfly.com/forum...ht=cutdown+mid

I'm halfway through my 15" mid project but am out of time for this season so I'll finnish it next winter.

Alan
Are you cutting down your mid?
__________________
I got jumper cables!
MrRob is offline   Reply With Quote
Old 23-04-2006, 10:33 PM   #18
Registered User
 
scottyboy's Avatar
 
Country: United kingdom
Location: West Sussex
Occupation: Grease Monkey
Interests: Makin my boat faster!
Boat name: S.B Racing
Boat make: Ocke mannerfelt canopied B23 / Zapcat
Engines: Merc 200XS Gen 2 / Tohatsu 50
Cruising area: littlehampton/Southampton

Join Date: Jan 2005
Location: West Sussex
Posts: 2,652
Rob,
Why dont ya just buy a 15" mid and gearbox???
__________________
Class 3C Mono EPA National speed record holder 95.35 mph Avg!
scottyboy is offline   Reply With Quote
Old 24-04-2006, 01:30 AM   #19
Registered User
 
Hydrostream's Avatar
 
Country: Ireland
Location: Dublin
Occupation: Boatbuilder
Boat make: Hydrostream V-king, 650SS OCR ,Ring 21, Ring 18, Phantom 18.
Engines: 300Hp Mercury 2.4, 130 Yamaha, Bridgeport EFI, XR6, Merc 200.
Cruising area: Malahide, Dublin

Join Date: May 2004
Location: Dublin
Posts: 1,803
Quote:
Originally posted by MrRob
Are you cutting down your mid?
I bought a cut down tower off a member on S&F to see how it was done etc, and do the rest myself.
I will be cutting down another mid too.

You may (probably will) need to remove a section of leading edge from the top of your nosecone to allow the leg trim under the tiller and transom assembly, and run a new hose up at an angle to plumb the cooling water into the pump area.

Alan
__________________
www.powermarine.ie

[SIGPIC][/SIGPIC]
Hydrostream is offline   Reply With Quote
Old 24-04-2006, 08:03 AM   #20
Registered User
 
MrRob's Avatar
 
Country: England
Location: Birmingham
Occupation: Scratching
Interests: Big Dinners
Boat name: Never Enough
Boat make: Seaquel 600xs
Engines: 225hp Merc ProMax
Cruising area: Anywhere! I prefer Weymouth

Join Date: May 2005
Location: Birmingham
Posts: 3,232
Send a message via AIM to MrRob
Quote:
Originally posted by Hydrostream
I bought a cut down tower off a member on S&F to see how it was done etc, and do the rest myself.
I will be cutting down another mid too.

You may (probably will) need to remove a section of leading edge from the top of your nosecone to allow the leg trim under the tiller and transom assembly, and run a new hose up at an angle to plumb the cooling water into the pump area.

Alan
I have a proper 15" trim ram so that wont be a problem
Got any pictures of your cut down you want to share?
__________________

__________________
I got jumper cables!
MrRob is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3

All times are GMT +1. The time now is 08:04 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×