ST7002 Autopilot
While we were in the Amazon Delta last month our ST7002 autopilot quit working. The unit made a loud grating noise - it sounded like spinning gears which were not fully engaged. The fly in the ointment is that the unit started out life as an Autohelm 7000. We have replaced the control head, but the computer and the type 2 long linear drive unit are the original Autohelm components. We think that the unit was manufactured around 1991 - this is based on the motor label which indicates DATE 2/90.

I dismounted and opened up the linear drive unit. The inside of the linear drive unit had a large amount of black dust - it appeared to be brush carbon, but could have come from the black plastic gears. The drive belt (300 3M 12 469D) had some wear, but it appeared to be in serviceable condition. I disassembled and inspected the components. I connected a source of 12VDC to the motor - it ran fast and smooth. The resistance between the leads of the motor is .6 ohms (measured with a Fluke Model 23 Series II digital multimeterI). I connected the 12VDC source to the clutch coil and it had a strong magnetic field. The resistance of the clutch coil is 27.3 ohms. The clutch coil seems free to slide axially on its mounting pin. Both the small motor drive gear, and the large belt driven gear on the drive shaft seem to be serviceable. When I pull the tiller arm in and out, the planetary gear unit rotates freely. However, there is quite a radial wobble in the 4 planetary gears, which allows the clutch top / planetary gear housing to have a radial wobble.

I removed the circlip on the shaft end and pulled the steel clutch plate / plastic drive gear assembly. Both the shaft bushing and the plastic ring gear teeth on the clutch appear to be serviceable. I removed the roll pin securing the brass planetary gear base to the output shaft. The wobble in the planetary gears is as a result of excessive wear of the small drive gear which engages the 4 pinion gears. The planetary gears do not seem to be excessively worn.

I called the Raymarine Technical Department and spoke with Mark - he was quite helpful. He told me that the problem was that parts are not available for units built before 1989. The motor-side of the baseplate has a three box label with the following numbers: (upper two boxes) 2029 and 12V, (the lower box) 400004. There is a label on the FRACMO motor (serial 3666/366) with "DATE 2/90" - which indicates that if the motor was manufactured in February 1990, then this unit was built sometime after that date. Attached are 10 photos for ID purposes.

Mark told me to set up an account on this forum and post the information I had so that the folks in England can try to establish the date of manufacture for this unit. Then we can order the correct replacement parts. It is my understanding that there is a bronze gear replacement kit to upgrade the plastic gears. I would like to not only replace the broken components, but anything else you think we need to do. We are headed for the Panama Canal, and it is a long way across the South Pacific. I started out my career in the US Navy as an electronics technician, so with some guidance and the needed repair parts, we ought to be able to repair the unit.
Warm regards,
Tom Service
S/V Tiger Lilly
Spanish Waters, Curacao

Views: 326

Attachments:

Reply to This

Replies to This Discussion

I apologize for the delay, wanted to speak with our linear drive technician about your issue.

He explained that you will need planetary gear kit N021, this will come with the brass gears. He also suggested due to the age of the motor, he would recommend a new motor, and keep as a spare in case you get into any issues in the future, motor part number N002.

Are the part numbers the same for a type 1 linear drive?

Rodney,
I am the wrong guy to answer your question. I am just another boat owner who needed information from Raymarine.
You need to open a separate topic, and wait for the Raymarine technical wizzard (Underway - Raymarine, US) to answer you. It took them a couple of days to get back to me.
If you do take the same brass gear kit (N021), and you are in the Caribbean, Budget Marine carries these parts.
Tom Service
S/V Tiger Lilly
Spanish Waters, Curacao, N.A.



Rodney Kidd said:

Are the part numbers the same for a type 1 linear drive?

The brass gear kit is the same, N021.  The motor part number is different, for the Type 1 the part number is N001.

Reply to Discussion

RSS

Events

Videos

  • Add Videos
  • View All

Photos

Loading…
  • Add Photos
  • View All

Latest Activity

Roko replied to Roko's discussion No bottom at all with E120s, CP300, and B164
"Due to the non existent performance with the CP300 I have sourced a used hungary made DSM300. I'll be changing over from CP300 to DSM300 and possibly updating the software. Can you please provide install instructions and latest software…"
8 hours ago
Frank M. Clemente replied to Carl Hawkins's discussion Boat Heading
" "
10 hours ago
Brett Densmore replied to Brett Densmore's discussion C120 connection to an EV-200 pilot system
"Right now i am in the process of installing the pilot. Mostly installed  and now its time for the seatalk connections. Currently the only thing in the seatalk port on the C120 is the gps. It is spliced in and out of a block. System also runs…"
10 hours ago
Roger Cowles replied to Roger Cowles's discussion Wind Transducer Not Working
"Sorry, a few more pics that failed to upload...."
13 hours ago
Mrbill419 replied to Mrbill419's discussion MFD's
"The pic#1 is the AirMar tag on the B-60 transducer cable. The #2 pic is the B-60 transducer plug that plugged into the bottom of the old DSM300. The #3 pic is the back of the E127. I have connected the CPT200 to the CP200. I then connected the CP200…"
13 hours ago
Roger Cowles replied to Roger Cowles's discussion Wind Transducer Not Working
"Hello again, Good news is the new wind transducer has arrived.  Bad news is I still cannot get it to work. I was able to get a hold of some brand new Raymarine cable with connection for the vane, so before climbing up the mast again, I figured…"
14 hours ago
Profile IconBob Billeci, Sean, Luis Ruiz and 12 more joined Raymarine Technical Forum
14 hours ago
Moderator - Raymarine, US replied to Brett Densmore's discussion C120 connection to an EV-200 pilot system
"Welcome to the Raymarine Technical Forum Brett, Unfortunately, I don't have a system diagram to offer, but its very easy to interface these items using a SeaTalk to SeaTalkng Converter Kit.  Is the EV-200 autopilot system already…"
14 hours ago
Brett Densmore posted a discussion

C120 connection to an EV-200 pilot system

Is there a drawing of the wiring hook up to connect an older c120 plotter with the new EV-200 pilot system? I am told I need a seatalk to seatalk ng converter kit but not sure how to hook it all up? I want my new pilot to read and follow my existing courses.See More
14 hours ago
Moderator - Raymarine, US replied to J.R. Farrar's discussion e7 with GX2150, T122, ST4000
"You're welcome."
16 hours ago
Moderator - Raymarine, US replied to Peter Korten's discussion How to determine if the trim tabs and outboard motor lower units will interfere with side vision chirp transmission
"You're welcome."
16 hours ago
Mark Duncan posted a blog post

Help with compatability of Raymarine sytems

HiI have a Raymarine RC425 Chartplotter that I need to replace due to UV damaged screen.Obviously that model is no longer available, so what could work and be compatible with;ST60+ Tridata, ST60+ Wind and ST7002 Autopilot.I am also limited in the space on the console, so needs to be of a similar size. 6 1/2" x 7 1/4". Could maybe go a fraction larger.Can anyone advise?ThanksMark See More
17 hours ago
Vladimir posted a discussion

Autopilot 100\300 and ST 7000+

I have Autopilot 100\300 with ST7000+ control plus ST60 wind - close hauled wind instr. , ST60 tridata  and chartplotter c120.A few month ago speed stop working on tridata -I think because of problem with  weel sensor.  A few day ago ST60 wind stop working( display is dead but power goes thru unit to tridata with seatalk cable). On Tridata  deap line show 000 and ST7000+   NO link.I check wires-  one Seatalk line runs from computer to ST insruments and chartplotter and second line to ST7000+.…See More
17 hours ago
James Burgess replied to James Burgess's discussion What nema sentences does the s-1000 need to follow a route?
"Underway, Garmin suggested raymarine would know what sentences were needed.I sent them the four you sent me but have not received a reply.The garmin sentences seem to be the same as the standard nema sentences I found online.      …"
17 hours ago
Peter Korten replied to Peter Korten's discussion How to determine if the trim tabs and outboard motor lower units will interfere with side vision chirp transmission
"Thank you. I know it will encourage people to purchase both the down vision as well as the side vision. Hopefully they will have it by spring. Thanks again."
17 hours ago
J.R. Farrar replied to J.R. Farrar's discussion e7 with GX2150, T122, ST4000
"Thank you!  I verified with Standard Horizon that their output on the GX2150 CAN support 2 listeners so that should not be a problem."
18 hours ago

© 2014   Created by Moderator - Raymarine, US.   Powered by

Badges  |  Report an Issue  |  Terms of Service