No Room for Trim Tabs, What To Do?

[DixieBoatN]

I have no room on my transom for trim tabs. I was thinking of purchasing a set of Smart Tabs SX series, but I found the measurements listed on the Nauticus web site and I do not have room for them. The transom is not smooth all the way across and the outer edges are angled a little but also the surface goes in and out. It is very difficult to describe. I do have room closer to the center, but I only have just enough room. On one side, I have a kicker motor bracket, so the motor would interfere. I also have scuppers in the way that would prevent me from mounting the top of the shock anyway. The mounting bracket for the gas shock would actually fall exactly in the middle of a scupper on each side. What do I do?

I have a porpoising problem. The boat is a 1985 HydraSports 1800 SS Center Console. The motor can not be trimmed in any further. I am not sure what else to do for the porpoising. Smart Tabs seem like the best option, but I just do not have room for them. I can provide pictures if necessary, but either way, I just do not have room without making custom sheets for the gas shock or something.

Does anyone have any suggestions?

 

[NW Redneck]

Re: No Room for Trim Tabs, What To Do?

Pictures would help us see what you have to work with. Also, try contacting Nauticus and sending them pics. They are very helpful and have seen alot of different applications. The owner is a member of this site (JDiegro) and a great guy.

 

[DixieBoatN]

Re: No Room for Trim Tabs, What To Do?

Here are some pics. This first one I added some pathetic drawings to show the measurements I am dealing with.
Here is a link to the entire album:
Full Album

 

[MikDee]

Re: No Room for Trim Tabs, What To Do?

In your case I would suggest a Doel Fin, it is the smallest least intrusive hydrofoil design, that was designed by an aeronautical engineer, and the first hydrofoil design ever made I have used one on almost all my boats, I was very happy with it, and had no problems over the yrs. All the rest are copies, and some are bizarre

 

[Gary H NC]

Re: No Room for Trim Tabs, What To Do?

Thats going to be a tough one to put any tabs on....
Maybe JDeagro has some ideas.....
I wonder if you could build those outer edges out flush using some star board..?

 

[DixieBoatN]

Re: No Room for Trim Tabs, What To Do?

Thats going to be a tough one to put any tabs on....
Maybe JDeagro has some ideas.....
I wonder if you could build those outer edges out flush using some star board..?

I wonder what, if any, changes it would cause in the hull dynamics to build out the outer edges? I had considered building aluminum frames to mount the Smart Tabs to that basically bolt to the transom at the outer edges and would create a situation effectively similar to building out the outer edges. Would that put too much leverage on the transom mounting points? I'd probably have to bolt the aluminum brackets completely through the transom and not with machine or coarse thread screws.

 

[DixieBoatN]

Re: No Room for Trim Tabs, What To Do?

I forgot to mention that I did send an email to Nauticus, but have yet to get a response in more than a week. I'll bet those guys are really backed up, so I thought it best to get some opinions here. I can try emailing them again if needed. I'd also like to avoid using a hydro-foil. I just don't like the idea unless there is truly no other option. I used to be a welder and metal fabricator, so I can build whatever I need to build, I am just not sure about whether I should build something or not.

 

[Varago]

Re: No Room for Trim Tabs, What To Do?

Dixie take a look at the st1290 drawing on the smart tabs web site, they have a special mounting for restricted space mounting, it only takes 7.5". I dont know if they make the same on the next smaller size or not but worth a check.

Dave

 

[Gary H NC]

Re: No Room for Trim Tabs, What To Do?

I was thinking the starboard material because its like a hard plastic the could be cut to size and the contour of the off set.You could screw it down with 5200 and mount the tabs to it no problem.
I doubt you could through bolt anything that low on the transom.
I don't think it would cause any bad effects as far as handling.

John Deagro's number is 800-233-0194.
He is a great guy and very helpful on the phone.

 

[tashasdaddy]

Re: No Room for Trim Tabs, What To Do?

i just asked John to look at this one. interested in his suggestion.

 

[DixieBoatN]

Re: No Room for Trim Tabs, What To Do?

i just asked John to look at this one. interested in his suggestion.

Thanks for that. I do intend to call them when I am ready to make a purchase.

 

[Jdeagro]

Re: No Room for Trim Tabs, What To Do?

Dixieboatn

Call me 800-233-0194

We may be able to provide some tricks to get the tabs mounted.

 

[micel]

Re: No Room for Trim Tabs, What To Do?

I was wondering what you ended up doing,trim tabs or what?I have the same boat and was considering the Bennett sport tabs,but I do not have the kicker bracket issue.

 

[TheLucille]

Re: No Room for Trim Tabs, What To Do?

Just saw this since it got bumped, but if you haven't solved it yet i would go get some simple white PVC trim from the hardware store, which will be easy to work with common tools. Make a piece which has the angle and goes on the outside most part of the transom to make it a flat area to mount the tabs to and 5200 it on. Purchase new QUALITY ss screws (tensile strength will matter a bit here) to reach through the PVC into the transom for a solid grab and you should be good.

Mount them as outboard as possible. With this positioning, it appears that the scuppers will be 2-3 inches inboard of the tab mounts. If they fall on the angled part of the transom create new brackets again for the mounts, 5200 on and be sure to THROUGH BOLT through the material (PVC trim if you dared to try it... it has good compression strength!) and get a big stainless fender washer on the other side of the transom.

Should work well, be cheap and you can do it with locally-available parts and material.

 

[DixieBoatN]

Re: No Room for Trim Tabs, What To Do?

Micel,

I apologize for not responding sooner. I have had a string of mechanical repairs that I have been dealing with. I think I have all of the bugs worked out now. I will likely be calling jdeagro and figuring out what to do within a week or two. I'll post up what the solution is.

BTW, if you have the same boat, are you having porpoising problems too?

 

[Jdeagro]

Re: No Room for Trim Tabs, What To Do?

WE have a bass boat series (MoBster Tabs) that should work. MT1080-60

I can show you how to install them so that the transom bracket will mount just under the drain hole on the port side.

 

[DixieBoatN]

Re: No Room for Trim Tabs, What To Do?

WE have a bass boat series (MoBster Tabs) that should work. MT1080-60

I can show you how to install them so that the transom bracket will mount just under the drain hole on the port side.

Awesome! I will be hopefully calling you up by the end of the week once I am ready to order a set. I have had to put it off due to mechanical issues that should be resolved now. I am actually dwon to 2 items on my list, finally. SmartTabs and a new Prop. I hope to be ordering both this week!

 

[Jdeagro]

Re: No Room for Trim Tabs, What To Do?

Unless you are changing the prop because it is dammaged, You may want to get the tabs on first, then re-prop. You may find that you can move up in pitch and get more top speed, more fuel economy, and still get on plane easily. Make sure you stay within the recommended RPM range.