Forum Replies Created
-
Posts
-
We finally launched #150 this week at Codorus State Park in southern Pennsylvania with a Tohatsu 6hp motor. We need a better way to transport and launch it, will probably get a trailer.
Our CLC remote throttle kit for OMC outboards was not installed and not used, is for sale for much less than the CLC price, in the “Parts” section of the classifieds.
I agree. It looks like you need to trim back the “king plank” so it drops behind the nose block, although it’s not totally clear from the picture you posted. This assumes that the deck in the picture is properly aligned front-to-back.
Epoxy in some wood pieces where the screws for the handle will enter to ensure that it’s strong enough. I added a 3/4 x 3/4 scrap to each side of the center frame but bigger than that might be better.
My boatbuilding partner Jack and I have finished the Tohatsu thrust bracket modification for a CLC kit boat. We have test-fitted it to the boat, with the bracket assembly screwed into the motor clamp, and the wooden wedge screwed into the transom.
The bracket now lands above the small cavitation fin on the propeller shaft instead of below it.
If you want a more detailed e-mail with photos, reply here with an e-mail address or phone number, and I’ll send it to you. I’ve not been able to post photos here for a while.
We’ll be at the Maryland Yacht Club race this saturday with the wedge and the bracket for anyone who is interested in seeing what we did. Look for our “150” tee-shirt.
If you post an e-mail address here, I can send you a longer description of what we did, with some photos.
Here is the answer I received from CLC, in response to my inquiry about CLC making wedges in various angles available for purchase by CCR builders:
Thank you for your suggestion. We can fabricate a motor pad for the CCR. It would cost the same as the one that you had made for your boat [$75].
We have a black Tohatsu MFS6DS. I think the “W” in yours might be the color, white. The vendor I bought it from (not Annapolis Inflatables) told me that it’s the current version.
Alan Brown’s Tohatsu 6hp thrust bracket was developed on a non-kit boat with a 10-degree angled transom section and no drain plug at the bottom, as you can see on his web site photos of it. The bracket sits under and against the cavitation fin. Our bracket will sit above the cavitation fin so as not to foul the drain cock. We’ll eventually find out how well that works.
We might get the boat launched and the motor broken in later this season so we get some real-life experience with it.
I sent an e-mail to CLC suggesting that they make wedges and offer them as an optional part. I’ll post the response here.
Andy, depending on where you are in NC, if you can get to Fredericksburg VA next friday, you can stay with me and ride up to Pasadena MD (near Baltimore) with me on saturday for the boat races.
All of this is good input.
Given the difficulty of making a decent wedge without a table saw, radial arm saw, or power miter, plus decent carpentry skills, I think that CLC should offer them in various angles as an option. I’ll contact CLC and suggest it.
Keep in mind that the Tohatsu motor is bigger, heavier, and likely more powerful than the old OMC two-stroke motors.
Fred Allerton mentioned to me the risk of the motor coming off the transom while operating it. Jack and I took a look at the clamp to see if there’s a way of bolting the motor to the transom, but there’s no obvious way to do it. We’ll consider that issue later.
The wedge is another issue. I could probably come up with several slices of wedge to epoxy together if I spent a day in the garage with the tools that I have, but I’m not interested in doing it. I found a local (Fredericksburg, Virginia) woodworking shop to make one for me.
How long is the wedge (top to bottom)? That is a good question and will require a long answer explaining how we got to this point. I apologize for not posting photos, but I’ve had no luck with doing that here recently.
Per instructions from Alan Brown, I had a wood shop make a 10-degree wedge. The wedge was sized to fit under the Brown 4095 thrust bracket base plate, from the angle to the top. The base plate is bent to a 10-degree angle to fit around the wedge. The top of the base plate is flush with the top of the transom. I don’t remember the height of the wedge. It should be at least 7 inches wide, but a bit wider might be useful. You can always trim it.
We ran into several interconnected issues with the Brown thrust bracket on our CLC kit boat. Note that the photos on his web site show the prototype on a boat with the transom built to an angle without a wedge and without a drain plug at the bottom.
The base plate of the thrust bracket from top to bottom is equal to the full height of the transom, i.e. the bottom of the base plate is flush with the bottom of the transom (and the top is flush with the top of the transom, as mentioned).
Problem number 1a: There is a protruding drain plug just off-center on the kit boat. The base plate cannot mount over the drain plug.
Problem number 1b: The thrust bracket needs to sit close to the bottom of the transom to land in the intended location just beneath the cavitation fin, so cutting off the bottom of the base plate is not a solution because then there’s no support directly beneath the bracket.
Idea for solution 1a: Close off the drain hole during construction and relocate the drain a few inches farther away, but still in the same cavity. This is not hard to do if you haven’t installed the cockpit floor yet. Cut a plug of plywood to fit the hole, epoxy a wood backer behind the hole, and epoxy the plug into the hole.
Idea for solution 1b: Place the thrust bracket on top of the cavitation fin instead of beneath it. This is complicated by a not-quite-flush rubber plug on the propeller shaft that will foul the thrust bracket cam. That might or might not be an issue in the real world, but the way around it is to raise the thrust bracket far enough over the fin to clear it, about an inch. Otherwise, I’d worry about that rubber plug being beat up by the bracket.
It seems to me that the physics of raising the thrust bracket will reduce its effectiveness, but it’s still better to have it than to not have it.
BUT …
Problem 2: We discovered that the thickness of the full-height wedge, plus the transom, plus the 1/8-inch bracket base plate, plus the two Brown 10-degree mini-wedges on the front side of the transom (to keep the clamps at the correct angle), was more than the span of the motor clamps, i.e. too thick to get the motor on at all, even if we were able to do something about the drain plug problem at the botttom.
Solution 2a: Keep experimenting with it and see if things can be arranged so the motor clamps will fit. We weren’t interested in fiddling with all those loose parts and a 60-pound motor any longer in a stinking-hot garage and decided to not pursue this.
Solution 2b: Reduce the height of the wedge by trimming the top (the angle stays the same), and reduce the height of the bracket base plate at the top by the same amount. This way, the base plate and the wedge will stay flush with the top of the transom, the top of the wedge is thinner, and it raises the bracket closer to where we need it to be anyway (more about that later).
2b is what we did. We cut approximately 2.25 inches off the top of the base plate and trimmed the top of the wedge to match. This coming weekend, we will install the whole business again for a final confirmation of fit, take some pictures, then take it apart so we can take the pieces to the Pasadena race the following weekend to discuss with Fred Allerton and other Tohatsu owners.
More notes about this process:
There is also the issue of the vertical alignment of the bracket itself. The original thrust bracket set that Alan Brown sent me had a bracket with a base that positioned the bracket low enough to get it below and against the cavitation fin. This is the bracket shown in the photos on his web site. Later, he sent me a bracket base that did not sit low, i.e the base is shorter in height and locates behind the bracket cam. (It looks like the #4005 thrust bracket on his web site.) Combined with the available vertical adjustment from the slots in the bracket base, we confirmed that we could get the bracket at the height we want it after our modifications.
Then there is the issue of the forward to aft alignment of the bracket. Will it end up where it belongs, snug against the propeller shaft? As far as we can tell, from our clamp-on mockups, it looks like it will fit. This is with the motor clamp angle set to the second hole from the lowest on its pivot, which makes it more or less parallel to the transom when mounted with a 10-degree wedge. Note that this is with the shortest side plates that Alan Brown makes for the bracket, shorter than those shown on his web site photo.
And finally, there is the issue of the countersunk holes on the base plate. They are intended to screw to the bottom of the motor clamp to attach the base plate to the motor. Apparently the intention is to fasten it to the motor rather than the boat. When you hold it in place against the motor you can see how it is intended to fit. The screws are already in the clamp. With our modification, these holes don’t land in the right place, so we will duplicate them farther down, which will take some careful measuring and drilling.
In closing, these are the points I take away:
1. We want the thrust bracket as a precaution to prevent the motor from breaking the transom loose.
2. The thrust bracket as supplied by Alan Brown won’t work with the CLC kit boat without making changes to it and/or the boat.
3. We have figured out how to modify the bracket to make it fit, but we don’t know how well our changes will work in the real world because we haven’t launched the boat yet.
4. Per Alan Brown, the motor should be strapped down against the thrust bracket to prevent movement in the other direction (and to prevent the cam from sliding out!). We haven’t figured out how to do this yet, but compared to the time spent on the thrust bracket so far, it will be simple.
Sorry this was so long.
Andy, we have both an Ultraflex kit and the Tohatsu remote control parts.
The Tohatsu cables are 3/8-inch diameter, the Ultraflex are 1/4-inch. That doesn’t mean much, but it does mean that the Tohatsu cables are more substantial than the Ultraflex.
We compared the cable ends of the Ultraflex with the ends of the Tohatsu, and they were different, although I don’t remember what the difference was. This means that the Ultraflex will not be a direct fit in place of the Tohatsu cables in the motor. I don’t know what that means in the real world, because we decided to use the Tohatsu control box.
If you are within range of Central Maryland (Baltimore), we can arrange to have you come over and have a look at what we’re doing. We’re in the process of modifying the Brown thrust bracket and installing the remote control, wedge, motor, and thrust bracket. We’ll be working on it next weekend (17-18 July 2021).
We screwed our handles into parts of the transom that were doubled. With the wisdom of hindsight, they should be farther apart, but we’re not moving them.
The bow handle should also have some backer, which we installed before the deck went on. We epoxied strips of wood to both sides of the longitudinal frame under where the handle would mount.
The following notes apply to our Tohatsu installation. We know nothing about doing it with any other motor, and we’re learning as we go with the Tohatsu.
Wedge for Tohatsu should be at least 7 inches. A bit wider might make it easier to work with.
Aluminum back plate won’t easily work with the thrust bracket. We have one (12 x 12 x 1/4-inch) if someone wants to buy it at cost, $30.
Before you put the deck on, install wood backers everywhere you might want to attach anything to the cockpit sides.
Jack and I got the Tohatsu motor (a whole other story) long after boat construction was finished. The remote control is big and heavy enough that it was not feasible to just screw it into the thin plywood. We made a hole for a 4-inch inspection port just to the rear of the remote control location, and reached in to attach the screws. The whole process for this was hours and hours of aggravation.
Some pointers for anyone who does this:
Take frame members into account if you cut a hole. Also take into account the fact that the heavy cable from the Tohatsu control will come straight out of the rear of the control box. They cross directly over our inspection port, but it works, more or less.
Take the available length of your arm’s reach into the hole into account. Trust me. About 12 inches was as much as I could manage, and everything in there had to be done by feel. Imagine fumbling for 2 to 10 minutes for each washer and nut you want to install. I used stainless M6 wing nuts to make it a bit “easier”, then held them while jack turned the screws.
If you decide to use threaded inserts, be aware that they need to be aligned VERY accurately or you won’t be able to get the screws in. If you want to do it anyway, McMaster-Carr has stainless M6 inserts. We ended up using one of them and gave up after that. We have two left if anyone wants them.
If I had to do it with inserts, I’d put the bolts through the control box, jam-nut the inserts in place on the ends of the bolts, and use that to mark the holes and turn the inserts in. That’s just an idea that came to me later.
If we had to mount the remote control box again, we’d replace the M6 bolts with large (#14?) stainless flat or oval head wood screws of a suitable length and diameter. If there’s enough thickness of wood epoxied to the back of the cockpit side, you can drill and screw right into it, it’s easily removable, and MUCH LESS work than what we did.
Finally, the Brown thrust bracket will NOT work with a kit boat for two reasons, which I won’t go into now. Jack and I are modifying it to work with our kit boat.
Jack and I will be at the race on 24 July 2021, wearing “150” tee shirts if you want to find us and discuss. We’ll have the wedge and thrust bracket with us, but not the boat.
Alan Brown sent me another aluminum piece to correct the vertical misalignment, but I can’t visualize how it’s going to fit in with what we already have.
I’m going to Baltimore next week to see what we can do with it, and I’ll report the result here.
Jack and I plan to be at the race on 19 June (without a boat). I’ll have a T-shirt on with our number 150 on it. Please find us if you’re there. We’ll bring the thrust bracket pieces with us.
More information if anyone is reading this thread:
The Tohatsu 6hp thrust bracket we got from Alan Brown doesn’t work with our boat and our motor for two reasons:
First is that the aluminum backing plate for the bracket goes from the top of the transom to the bottom and fouls the drain cock. We’ll probably have to close that drain hole, and drill a replacement for it more off-center in that space.
I’ve inquired of CLC if they have any suggestions for how to close that hole. My idea is to enlarge the original 1-inch hole toward the next larger dowel size (5/4 inches?), epoxy a piece of dowel and jam it in there with epoxy. I’m not sure if that’s a good enough fix, given the need for that repair to be absolutely secure.
The second problem is that the bracket itself, at the bottom-most range of its adjustment on the backing plate, lands more or less on TOP of the cavitation fin instead of under it, where it belongs. Alan has sent me another piece to relocate the bracket to lower on the backing plate. I haven’t had an opportunity yet to take it to the boat and see if we can make it work.
Note that the second photograph on Brown’s web site shows a prototype setup that is not on a CLC kit boat with the drain in the way.
I’ll report my findings here.
The Tohatsu remote control box is big and heavy, definitely too much to entrust to the thin plywood of the side of the cockpit. What to do? The boat is built and the inside of this area is not accessible.
I examined all the toggle bolts I could find on-line and in my hardware stash, concluded that ALL of them except the old fashioned split-wing model would not work because they require more depth in the mounting surface that the 3 or 4mm that is there. I didn’t want to use the split-wing style because I don’t think it will be a satisfactory solution, not to mention fiddly to install, and we would probably need some bushings in the holes to keep it from shifting around under stress. Sounds like a bodge.
We decided that a 4-inch access port in the area directly behind where the control box will go will provide enough access to the inside to be able to epoxy a piece of wood there. Size might be a piece of 1×4 or a wider piece of 3/8 or 1/2-inch plywood, whatever we can find in our scraps. We’ll cut the 4.5-inch hole for the port, install the remote control box, then install the access port, which reduces the opening to 4 inches. We’ll have to take the frame locations into account when we position these things. Any wood that’s installed there, and all cuts and holes will be thoroughly epoxied before the point of no return.
The control box comes with 3 M6-1 x 90mm oval-head bolts, nuts, and washers. We might have to get longer bolts or use similar-size wood screws instead, but we’re not that far yet to decide.
I’d like to post pictures when we do this, but that hasn’t worked for me in this forum for a while. I’ll return here with comments after we get this done.
