Go Back   RIBnet Forums > RIB talk > Trailers & towing
Click Here to Login

Reply
 
Thread Tools Search this Thread
 
Old 15 June 2015, 12:29   #1
Member
 
Country: Other
Town: Stanley, Falkland Is
Boat name: Seawolf
Make: Osprey Vipermax 5.8
Length: 5m +
Engine: Etec 150
Join Date: Mar 2006
Posts: 3,726
Multi roller trailers - fine tuning

So, I've got the DeGraaff trailer now with lots of rollers, and I've finally got around to fine tuning it so the boat sits exactly where I want etc - just need to move the axle back a bit to increase the noseweight and I'll be done with the setup.

The only issue that I have is that the weight isn't evenly distributed across all the rollers in the banks. In fact, on the 5x2 banks, most of the weight is on 2 pairs of rollers, there isn't much on another 2 pairs, and at least one pair on each bank isn't touching the hull at all (you can rattle it back and forth with a few millimetres of clearance from roller to hull).

Is this 'normal' with multi roller banks? The DG rollers are quite hard (polyurethane or something), so there is no squish in them. I'm not sure if the issue is the shape of the hull, or slight variations in the height of the mounting holes that the rollers go through, or maybe a bit of both. The boat rolls on and off like a dream, if you lift the drawbar of the trailer about a foot it will start to roll backwards just with gravity, so I'm happy with the setup, but I'd prefer the load to be distributed more evenly.

I figure that one option is to take the weight of the boat and then file out the holes slightly on the highest rollers, to sit them down a bit further and spread the load more evenly when the boat is right on the trailer in the towing position.

Any other ideas please?

(Note the photos are not the boat as sitting on the trailer now - I have moved it forward so the rear roller is closer to the transom)
Attached Thumbnails
Click image for larger version

Name:	DSCF0795.jpg
Views:	329
Size:	170.3 KB
ID:	106073   Click image for larger version

Name:	DSCF0791.jpg
Views:	312
Size:	177.7 KB
ID:	106074  
__________________
A Boat is a hole in the water, surrounded by fibreglass, into which you throw money...

Sent from my Computer, using a keyboard and mouse
BogMonster is offline   Reply With Quote
Old 15 June 2015, 12:39   #2
Member
 
Phil M's Avatar
 
Country: UK - England
Town: Whitehaven
Boat name: Cerberus
Make: Destroyer 5.8
Length: 5m +
Engine: 115hp Merc 4st
Join Date: Oct 2012
Posts: 462
Mine is the same. The only way you will ensure all are in contact is to only have 2 sets of rollers per support. essentially the rollers are on a flat bar and you are trying to support a curved shape, so even loading on all won't happen. My back rollers are fairly evenly loaded, as the profile is flat, but at the front I also have gaps between rollers. The keel is well supported though so not a concern.

Phil M
__________________
Phil M is offline   Reply With Quote
Old 15 June 2015, 13:23   #3
Member
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 12,178
RIBase
Quote:
Originally Posted by Phil M View Post
Mine is the same. The only way you will ensure all are in contact is to only have 2 sets of rollers per support. essentially the rollers are on a flat bar and you are trying to support a curved shape, so even loading on all won't happen. My back rollers are fairly evenly loaded, as the profile is flat, but at the front I also have gaps between rollers. The keel is well supported though so not a concern.

Phil M

Like wise, I've never been able to get even loading on every roller, even with the superduper new trailer. You would need fully independently adjustable rollers/arms/cradles. With a bit of tweaking you can get it pretty close. A common mistake is having too much weight on the winch post, try backing the post away from the boat when the boat is fully on the trailer, you might find that the boat will drop into the cradles a tad further. Then move the winch post to the boat.


.....sh1t happens.......
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4:Don't feed the troll
Pikey Dave is offline   Reply With Quote
Reply


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




All times are GMT. The time now is 05:17.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.