Thanks Mike,
You are correct. As I told them I didnt want to go to the hassle of adding a fillet, they did confirm that I was better off to go with the flat tab.
Dean
Thanks Mike,
You are correct. As I told them I didnt want to go to the hassle of adding a fillet, they did confirm that I was better off to go with the flat tab.
Dean
Brett, don't know if this site helps.
http://www.thehulltruth.com/tabmans-...discussion-15/
Yeah Brett,Originally Posted by fishfeeder
It was about 9 years ago when I did my Victory Tabs fitup.
I just double checked as I still have the off cut from the material I used and it is 20mm. I cut it in a wedge from 20mm to zero across the 12" width. They seemed to work well at that.
My current boat, tournament 2100, I made 25mm. I may have said 30mm earlier and 25mm for the Victory but just a bit of old timers disease.
There are a lot of angles that come into play and it seems complicated to work it out.
You also need to determine at what point of trim you actually want them to be running parallel because it changes as you go up or down.
I decided that I would try and have them with a very slight toe in when fully up and running parallel with about the first degree of effective trim.
It is very hard to determine the water flow too while in the shed. I found the easiest way is to take the boat for a run with someone else at the helm, carefully go to the stern at cruising speed on calm water and running straight. Eyeball the water flow with a straight edge, looking straight down to approx where the tab will be, just a piece of timber will do and put a pencil line on to somewhere on the stern as a reference for later. Just don't rub it out.
So then all you have to do when home in the shed is to set up the tab in place, think I used a short plank with a jack pressing up lightly under it extending a bit past the stern enough to sit the tab on and then angle it around while sighting it with the stick you used earlier placed back on your reference marks while on the water. Line it up again and look down at the tab and set it where it looks parallel, or you could slightly toe in.
The water flow is not parallel with the keel out near the chine where the plates are to mounted and the further you go out the more the angle of the flow.
When mounting on a boat such as a CruiseCraft 625 with a straight across transom and mounting tabs with no wedges you are in fact mounting your tabs with toe in , because the transom is angled at about 12 degrees to the vertical, looking straight down it forms a shallow Vee and this is also what you are doing by installing the wedges on a transom that is angled like the Seafarer or my Tournament and many others, so then when looking straight down you get a straight line across the boats width more or less where the transom meets the bottom.
That's probably as clear as mud but I hope you get my drift, but as I said before many just plonk them straight on and they work fine for them and the loss in efficiency may be negligable.
Or just plot that water flow angle and take it as being correct and set them at that fully up and you will be close enough.
I should mention too that I have only ever mounted either flat plates or ones with a slight turn up.
I would be concerned that any significant downturned tab may affect steering if running with just one side or the other down to any degree by being angled outwards. It would seem that efficiency would be affected too if not running at the best angle, as they would be fighting each other and or the engine for not only lift but direction as well. although I see some comments here that they have no problems and that may depend on the boats weight and power fitted, maybe other factors, not sure but i would think that it would have to have some effect.
I feel my motor load up as I apply just flat tabs running fairly parallel.
Flat plates may be the go anyhow.
I am going to have a go on the weekend to fit them up, I am going to start with the 20mm wedge and see how that works, If it needs to be changed later I can.
I will take some pictures as I go and post them on here.
Cheers and thanks for all the help and Ideas
Brett
Mikeys, Just got Photobucket to work and nice job. That would have drove me nuts trying to that work out, But its given me confidence to get in and do mine.
Cheers
Brett
Great thread, thanks for all the info from everyone. I'm installing tabs soon too, so this is very usefull.
Just checking to make sure you guys are sealing up all those screw holes properly. I've seen what happens to a transom when water gets in. I'd be drilling the holes out oversize and filling them with resin before redrilling the holes to suit the screws.
A bit of extra work, but cheaper than replacing a transom in a few years time.
Matt
Brett
I probably should mention that there was more than one quiet ale consumed, sitting on my butt, staring a the transom, over a period of several weeks thinking how the hell I'm going to do this. Not quite as easy as the instruction manual.
If you can get away with using a single piece of Starboard (you might like to try buying from here http://www.buckwoodcraft.com/king_st...0Price%20Chart ) At one stage I was contemplating using starboard and getting these guys to cut it with their bandsaw. I used plenty of cardboard templates and duct tape to get the angles right with mock-ups. The thinking bit was the hardest. When it comes to fabrication, it's all just one step at a time. Good luck.
Matt, definately sealing the screw holes. Makes the final assembly exciting when there's different types of goop hanging of all sorts of bits and pieces, trying to keep everything clean and neat before it's all tweaked up.
And countersink any holes drilled, too!
Mike
Anyone know where I can Buy Starboard or ????? in Brisbane Southside ???
Cheers
Brett
Hi all.
Just got back from the beach and had a good test on the new tabs.
They are mounted flush to the transom and so turn out a bit. They are M80's batwing.
The boat is a Seafarer Vagabond with twin 90 etecs (but this is not about etecs). They are not counter rotating.
The tabs worked a treat and with no noticable effect on steering. That is the boat did not want to turn in big circles. It did not want to veer to port.
I ran the speed test without the tabs and with for a 1 km/h change (63km/h v 62km/h) so this is not an issue to me and i never ran both ways.
The tabs did just what they were supposed to do, unless of coarse I dont know what I'm looking for.
We had 5 on board one day and three another so the weight was up with all the gear and people.
It could be that twin legs may be enough to counteract any steering problems that could have been.
Cheers, Stu
Hi Stu
Now all you need to do is fit foils to the motors and you can lift the bum another inch or so up and really enjoy the "Vee"
Good to hear the tabs did the job, on mine they added to the bum lift even when they were full up. The foils went on first and there was a noticable bum lift as witnessed by the fact that the rear side spray pattern was lessened and also moved further rearward.
This was good esp when traveling at a slow plane side on to stiff breezes the spray no longer can occasionally, as it previously did, get into / onto the rear seat and the four batteries and two oil storage bottles.
Maybe there is a little weight back there, not to mention the two 115 HP Evinrudes at about 167kgs each!
Cheers
Chimo
What could go wrong.......................
[QUOTE=stue2;1278125]Hi all.
Just got back from the beach and had a good test on the new tabs.
They are mounted flush to the transom and so turn out a bit. They are M80's batwing.
The boat is a Seafarer Vagabond with twin 90 etecs (but this is not about etecs). They are not counter rotating.
The tabs worked a treat and with no noticable effect on steering. That is the boat did not want to turn in big circles. It did not want to veer to port.
I ran the speed test without the tabs and with for a 1 km/h change (63km/h v 62km/h) so this is not an issue to me and i never ran both ways.
The tabs did just what they were supposed to do, unless of coarse I dont know what I'm looking for.
We had 5 on board one day and three another so the weight was up with all the gear and people.
It could be that twin legs may be enough to counteract any steering problems that could have been.
Cheers, Stu[/QUOTE
Geez Stu. That's bound to get it all started again!
I'm glad to hear that yours also work fine without the fillet.
Again I can see the logic in the fillet, but they really do work fine without( on my boat )without noticeable loss of speed or increase in fuel usage , and the boat definitely steers straight.
Here we go.
Brendan
Ha. Yeah it might get em going but it was a good read and some good pics as well.
Yep chimo I'm looking into foils. I have heard of one on each side. stay tuned.
Brett if you see this I'm working on a pic or two for you just got a small camera problem at the present.
Cheers, Stu
Hi Stu
"I'm looking into foils. I have heard of one on each side. stay tuned."
When Lindsay at Seafarer fitted my Lencos noticed they had fitted foils to a twin motored Vag with only one foil on the outside of each motor. Mine already had a full set on each and the difference had been observed over a number of trips. I asked about the alternative and seem to recall the response was related to cheap. Same thing as to why tabs were not fitted as standard given their benefits.
If you want slower planing and to gain extra bum lift why wouldn't you fit foils to each side of the motor and also get a better balanced result?
Cheers
Chimo
What could go wrong.......................
I just thought that one on the outside would be the one thats on the water.
I think you can get them to fit without drilling holes in the cav plate now. Which would mean one on each side of each motor.
My mechanic is trying to talk me out of them.
So I shall research them for a while and yes I know you like yours Chimo.
I have lifted the motors a hole and I think i need to go another so I'll do this first.
Cheers, Stu
OK guys I just wanted to let you all know I finally pulled my finger out and Installed my Trim Tabs and thanks to all who offered there advise. I ended up getting Bennetts to replace my M120 planes for flat planes so I never had to make a Fillet/wedge.
Well the installation was a nightmare with one problem after another with mounting the Top Ram to the transom. The major problem was that the shorter ram's top mountings lined up with the level of the step so after trying everything possible I ended up having to cut holes in my steps. This caused the problem of what should I use to cut the holes in the step as the shape needed to be a half moon. I thought a air Die Grinder with a Fiberglass cutting bit would work, well it did but was way to hard to control. Then I thought of a Dremal die grinder, well this thing was fantastic and cut perfect and sanded even better, it Just took hours to get them to sit perfect.
Ok next problem was how do I drill the holes for the top mount with the step in the way.... another trip to Glenfords Tools, well the young bloke there was fantastic and was really helpful, ended up with a 12inch extender for my drill with all the bits and pieces needed . After getting this it was pretty simple to drill the holes and seal it and screw it all to the boat.
Next problem was with the Hydraulic Pump trying to find somewhere to install it that would hold it flat, to do this I needed to make a wedge and screwed it to the transom... Hooking up all the wires and the Hydraulic lines was pretty straight forward.
Fitted the controls to the dash was simple except for trying to work out which wire on the key to use for the Auto Retract without a test light, ended up and wired it to a switch on the dash for now but will need to get that sorted ASAP.
Next problem was I forgot that I would need to add more fluid to the Hydraulic pump after bleeding the system, mounted it about 5mm to high to get the cover off, SO had to remove it from the transom to top up the fluid level then screw it back onto the transom...
OK so Yesterday was my first outing after installing the Trim Tabs and it was a good test day with it blowing a constant 15-20 knots and I have to Agree they work fantastic at leveling the boat from wind or weight in the boat. But now I am getting cavitation when in messy condition (prop slipping and motor reving up but no forward propulsion).
I am planing on going to Solas Props in the near future to get a new prop to lower my offshore speed and I hope fix my cavitation issue.
I will put some pictures of the installation up as soon as I get the photos off the camera.
Cheers
Brett
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