DIY hydraulic trim/tilt

[Badburn]

I decided I really need a trim/tilt setup for my 35 johnson. Did some research and concluded that the CMC aftermarket unit seems to be a nice piece. I checked out a few other brands, looked at pictures and thought to myself- That looks like it's pretty easy to build.

One of my friends commented to me- "You cant just make one of those"-- Sounds like a dare to me.

My work is slow and I don't really have the spare bucks to spend $700 on a boat part. I am thinking I can build this for around $200. So here I go................

I'm not the worlds best fabricator, nor do I have any fancy CNC shop equipment. I could probably benifit from any tips, tricks or ideas you guys have so fire away.

Best I can tell, they didn't make a factory trim/tilt for Johnson motors under 40 or so HP. I couldnt really figure out how big these units are or what interchanges with what.

I finally got tired of searching ebay, google, etc and just ordrered this from ebay. $155 delivered to my door.

Its way too big to fit into the motor bracket of my 35 horse motor, so I guess I have to figure out how to make this work. I started by measuring it, locating the mounting holes.Three on each side indicated by red arrows.

 

[Badburn]

Re: DIY hydraulic trim/tilt

This is the boat and motor as it exists now. It has this manual jack plate that doesn't really work because it's already all the way up, if you lower it the steering hits the bracket and the motor won't tilt. I think the motor needs to go down a little bit anyway, the prop blows out when you turn.

I'm thinking that my best option is going to be to build it into the setback/jack plate somehow.

 

[Badburn]

Re: DIY hydraulic trim/tilt

I took the jack plate off, dissassembled it and just started stacking the parts around the hydrauluc unit to try to get ideas how it could all be put together. The unit has a very odd shape, so I decided to make brackets and spacers to square it up and make it the right width to fit into the jackplate and hopefully use the existing mounting holes in the transom.

Here are the brackets and spacers I came up with using my table saw, drill press, and some scrap aluminum I picked up at the local metal supply.

 

[ajgraz]

Re: DIY hydraulic trim/tilt

DIY be awesome.

Where's Shingle Springs?

 

[Badburn]

Re: DIY hydraulic trim/tilt

DIY be awesome.

Where's Shingle Springs?

Shingle Springs is east of Sacramento.

Anyhow, I made a bit more progress. The brackets I made ended up being too short, so I had to make longer ones. This way I can drop the unit down farther and still have plenty of surface to bolt to. The aluminum channel I have is 4 inch. I have not not been able to locate 4 or 5 inch material. I wanted to use 5 inch and cut the pieces a bit longer. I settled on using what I have since I'm trying to keep this inexpensive.

I've been doing lots of this............ These will be the tabs that connect the hydraulic ram to the plate that will tilt. I made them side by side(bolted together) so that the holes are in the same places and they are the same shape.

 

[5150abf]

Re: DIY hydraulic trim/tilt

You certainly won't be lacking strength, that is some mondo huge aluminum.

I have to say,I saw the title DIY TT and though ya right, most guys think you can make one with some 1/8'' angle and an air assist cylinder they have laying around not having a clue of the forces involved but you are doing it right, very ambitious project.

 

[RRitt]

Re: DIY hydraulic trim/tilt

i would have just bought the center ram or one similar and hooked it up to a volvo AQ290 pump assembly using either CuNi brake tubing or braided hose. Probably a 2-4 hour job from start to finish. It 35HP so you'll need something like 1-1/2 to 2" diameter piston hitting about 3-4" from pivot axis.

 

[Badburn]

Re: DIY hydraulic trim/tilt

i would have just bought the center ram or one similar and hooked it up to a volvo AQ290 pump assembly using either CuNi brake tubing or braided hose. Probably a 2-4 hour job from start to finish. It 35HP so you'll need something like 1-1/2 to 2" diameter piston hitting about 3-4" from pivot axis.

Good Call.

You may have something there RRitt. I was sort of thinking the same thing, the 3 ram setup I have is heavy and probably overkill for the 35 horse. I bet the ram alone would be plenty if power to tilt it. A quick google and ebay search for that volvo pump shows it to be about $300 for a used pump. It looks like a nice compact unit. Then you have to buy the ram, and it seems like the cost starts to really get close to a new CMC unit. With a bit of research I bet it could be done on a budget though. Unfortunately, I started this knowing almost nothing about trim/tilt rams and pumps. Like any other project, I will know what I did wrong by the time I get to the end.

 

[Badburn]

Re: DIY hydraulic trim/tilt

Brackets made- and sizing everything up.

Next comes the tilt portion of it. I went with 3/4 thick aluminum for most of this because is looks like it's thick enough to drill and tap and use 3/8 bolts to bolt all the pieces together.

Stainless bolts on everything. They gall really easily, I've already ruined one bolt from assembling and disassembling it so many times.

 

[RRitt]

Re: DIY hydraulic trim/tilt

the two trim pistons will need strike plates. If they just push on the bottom of your engine bracket then it may cause the aluminum to split. A single ram system is usually the best method for 70Hp and smaller. It does not need strike plates and most outboards have the upper shaft mount built into the default swivel bracket. You can use nylon or bronze oil-lite bearings to shim the shaft size to match your shock-eye. CuNi tubing can be bent and flared with hand tools and has better corrosive characteristics than stainless. Aluminum tubing will swell with age and burst. A hydraulics shop can make you braided flex hose but it can get pricey. For $3 your can buy a 3500PSI hose from harbor freight and use NAPA brass fitting to make it fit. Carefully bent CuNi is best overall. A volvo AQ290 pump is standalone and you can mount it in any convenient spot above the waterline ($200 new). It is 3w and can be directly wired to a heavy duty switch. The center ram from your pictures should be more than adequate to the task. Use ISO hydraulic oil whenever possible.

 

[Badburn]

Re: DIY hydraulic trim/tilt

the two trim pistons will need strike plates. If they just push on the bottom of your engine bracket then it may cause the aluminum to split. A single ram system is usually the best method for 70Hp and smaller. It does not need strike plates and most outboards have the upper shaft mount built into the default swivel bracket. You can use nylon or bronze oil-lite bearings to shim the shaft size to match your shock-eye. CuNi tubing can be bent and flared with hand tools and has better corrosive characteristics than stainless. Aluminum tubing will swell with age and burst. A hydraulics shop can make you braided flex hose but it can get pricey. For $3 your can buy a 3500PSI hose from harbor freight and use NAPA brass fitting to make it fit. Carefully bent CuNi is best overall. A volvo AQ290 pump is standalone and you can mount it in any convenient spot above the waterline ($200 new). It is 3w and can be directly wired to a heavy duty switch. The center ram from your pictures should be more than adequate to the task. Use ISO hydraulic oil whenever possible.

Good Info, it sounds like you've been through this before. I did look at the factory tilt bracket with intentions of trying to build the mechanism into it. It really looked too small to accommodate the ram. The factory manual tilt locking mechanism looked like a 1/4 or 5/16 rod if I remember right. I'll look at it again today. As of now, I plan to make strike plates out of the 2" round material in the background of this picture.

More to come later today.

 

[RRitt]

Re: DIY hydraulic trim/tilt

Good Info, it sounds like you've been through this before. I did look at the factory tilt bracket with intentions of trying to build the mechanism into it. It really looked too small to accommodate the ram. The factory manual tilt locking mechanism looked like a 1/4 or 5/16 rod if I remember right. I'll look at it again today. As of now, I plan to make strike plates out of the 2" round material in the background of this picture.

Most strike plates are shoes made from 1/8" stainless plate. They are typically held in place on the original swivel bracket with a few screws or bolts. It won't help much - if any - to make your strike plate from aluminum rod.

 

[Badburn]

Re: DIY hydraulic trim/tilt

Most strike plates are shoes made from 1/8" stainless plate. They are typically held in place on the original swivel bracket with a few screws or bolts. It won't help much - if any - to make your strike plate from aluminum rod.

I had to space the strike surface out about an inch or so with aluminum. I think facing it with stainless is an excellent idea. I'll have to pick some up. For now I got it all put together. I'm certain that there will be a bit of fine tuning and/or trial and error(mostly error) involved here, but it's working and installed on the boat.

Next comes the wiring. I'm waiting for a pair of Bosch relays to show up in the mail to make the control box with.

One thing I didn't plan for was the transom not being tall enough for this setup. I'd say I lucked out. If it was 1/4 inch taller, it would stick down past the bottom of the boat.

 

[RRitt]

Re: DIY hydraulic trim/tilt

wiring diagrams

 

[Badburn]

Re: DIY hydraulic trim/tilt

wiring diagrams
View attachment 83825View attachment 83827View attachment 83826

Thanks RRitt. I think I'm using the two relay system. I have an OMC control with the rocker switch in the handle.(3 wires). The trim motor I have is a two wire. I think I can use two Bosch style 5 pole relays to reverse the polarity for up and down. The only thing I am unsure of is the amperage. I have 2-20 amp relays here. I can tell from just touching the trim motor wires to the battery while testing that it uses a fair amount of current. Do you think 20 amp is sufficient?

 

[Cadwelder]

Re: DIY hydraulic trim/tilt

I've been following this one, since it's very interesting, and good work too I might add. On the amp draw I can tell you, that my 115 Mariner pulls 32 amps while tilting under power, but that being a smaller unit you may be okay, but it sounds like a bare minimum to me.

 

[RRitt]

Re: DIY hydraulic trim/tilt

Thanks RRitt. I think I'm using the two relay system. I have an OMC control with the rocker switch in the handle.(3 wires). The trim motor I have is a two wire. I think I can use two Bosch style 5 pole relays to reverse the polarity for up and down. The only thing I am unsure of is the amperage. I have 2-20 amp relays here. I can tell from just touching the trim motor wires to the battery while testing that it uses a fair amount of current. Do you think 20 amp is sufficient?

Use mercury wiring if you have the choice. Mercury got their 2w relay wiring scheme from Force (Prestolite design) and even after 23 years it remains the most trouble free system available. As an added bonus it only costs about $10 to build a home-made version and $30 to buy a clean used one. Any 1988 and up Force or any 1990+ mercury/mariner will work. Relays are available on Ebay for $2 each. Shipping will cost you more than the relay.

oh, the switch is the same for 2w or 3w. You can use any brand on any engine with any wiring system. It's just a matter of picking connectors.

 

[64osby]

Re: DIY hydraulic trim/tilt

Badburn, Great job, I love the work you have done on this. I might have to resort to this type project in the future.

I would be interested to know what your expenses totaled and how much time you put in to it.

 

[Badburn]

Re: DIY hydraulic trim/tilt

As of now, I have about $225 in materials, and I'd say about 10 hours into this.

I'm having a bit of difficulty locating the electrical parts I need, maybe you guys have some ideas.

First, the Bosch style relays I got are the 5 pole type. They are rated at 20 amps at rest, and then 30 amps when activated. I really wanted to have a 30 amp rating on both sides, but have not been able figure out what part number I need. I'm using Echlin part numbers from Napa/Riebies as of now. I may end up just using them and hoping for the best, since they are not really continuous duty part.

Next- I need some kind of trim limiting or stop switch to stop the up-travel of the unit before the steering bracket on the engine hits the back of the boat. There is a bit of an interference issue, and I figure thats the best way to prevent any damage. I have checked out the Mercruiser style ones, but is seems like half of the info I found was people complaining about how they are unreliable. Maybe best to stay away from those.

It needs to be a waterproof -normally closed type switch that can be mounted where it will get wet. Any ideas guys?

 

[RRitt]

Re: DIY hydraulic trim/tilt

don't worry about part numbers on relays. If they are 5pin bosch then they are correct. It is a universal standard like the threads on a light bulb. They were invented for auotmotive headlights and only found their way into boats because some clever engineer at prestolite thought of using them. Thanks to him, trim wiring for US outboards is miles ahead of the japenese.

20A rating is plenty unless your trim motor is defective. If you draw too much current then the voltage loss in connecting cable becomes excessive and it is a poor design and you need to start thinking about beefing up your anodes.

The relays have a mounting ear. Drill and tap a couple of small holes in bottom of cowling near starter. Pull relay + power from starter feed and tie relay ground to engine block. If the inside of your engine floods with water you then will have bigger problems than non-waterproof trim relays.

Just buy a used Mercury.mariner/force trim harness. It is the best trim wiring on any brand outboard and it is dirt cheap. You're thinking too much and making it hard. So just go buy a used merc/mariner/force harness off ebay and be done with it.