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: 804

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

wes malone replied to wes malone's discussion rd424 to E 80
" Thanks.  Now I know what i am looking for.   Wes"
6 hours ago
Brian replied to Brian's discussion Going to previous software version (E80 classic)
"I haven't been able to get to the boat yet to check the cable resistances.  I do know that the cable was cut and then spliced.  Because of that, what I would like to do is bring a new cable with me to troubleshoot/replace the old…"
8 hours ago
Dave McMakin replied to Dave McMakin's discussion power up out of water....
"Thanks, That is exactly what I was looking for,,, "
9 hours ago
Helios replied to Helios's discussion P70 wind shift alert?
"Yes the masthead wind instruments are connected to an iTC-5 and the Seatalk NG backbone.  Is there a timeframe in which the 15 degree wind shift needs to take place to activate the alarm? or will it sound the alarm regardless of time?…"
12 hours ago
Bruce Cutting replied to Bruce Cutting's discussion AIS on RL70RC Plus system
"Thank you for the reply.  One additional question.  Which chartplotters will support my existing RADAR RL70RC Plus radar."
12 hours ago
Mike Klaubert replied to Mike Klaubert's discussion Pathfinder smart heading system with e127
"Thanks for your help, that is what I needed to know."
13 hours ago
Robert Bell replied to Robert Bell's discussion C80 won't read CF card
"Thank you for the quick response. Since I have no idea of what it might cost for the repair I am considering just upgrading. Do you know what would be the latest replacement for the C80? Thanks!"
13 hours ago
ray roberts posted a status
"what is the button battery for in my RL9 display"
13 hours ago
Bill Martin updated their profile
14 hours ago
Profile IconDave Warwick, Andrea Lake, Mike Klaubert and 6 more joined Raymarine Technical Forum
15 hours ago
Moderator - Raymarine, US replied to Tyler Hudson's discussion C140w - Loose internal component
"Welcome to the Raymarine Technical Forum Tyler, The MFD should have no loose internal components.  In such cases, it would be recommended that the MFD be sent to Raymarine's Product Repair Center to be bench tested / serviced."
15 hours ago
Tyler Hudson posted a discussion

C140w - Loose internal component

On one of my boats, I have a C140w MFD that for the most part has been working fine.  I am currently in the process of re-painting the interior of the boat.  While getting prepared, I removed & disconnected all my electronics from the console to help in painting.  After I unplugged & removed the C140w display I noticed something very odd.It sounds as if a screw or some sort of part inside the unit has come loose.  If I shake the unit you can hear whatever it is bouncing around inside.…See More
15 hours ago
Moderator - Raymarine, US replied to Mike Klaubert's discussion Pathfinder smart heading system with e127
"Welcome to the Raymarine Technical Forum Mike, Unlike the retired MFDs which preceded the a/c/e/eS/gS-Series MFDs, Raymarine's currently manufactured MFDs do not feature a user interface to linearize (for deviation) and align the Pathfinder…"
15 hours ago
Mike Klaubert posted a discussion

Pathfinder smart heading system with e127

I am upgrading my e120 Classic to an e127.  I had the Pathfinder Smart Heading System with Fluxgate Compass on the e120 for radar overlay and weigh point display convenience.  Do I need it with the new e127 and HD Radar for the radar overlay on the charts, and if so will it work?  Or does the new software not require the Smart Heading system for the overlay?See More
15 hours ago
Moderator - Raymarine, US replied to Robert Bell's discussion C80 won't read CF card
"Welcome to the Raymarine Technical Forum Robert, As the problem occurs with two CF memory cards, both of which had been successfully used with the MFD in the past, then it would appear that the MFD has experienced a problem with its memory card…"
15 hours ago
Robert Bell posted a discussion

C80 won't read CF card

I have a 2006 C80 Multifunction display. It will not recognize the Navionics CF card or the blank card that I use to transfer data. It was working but just decided to quit. Would appreciate any thoughts! If I need to replace could someone recommend the newest replacement for the C80?Thanks!See More
15 hours ago

© 2016   Created by Moderator - Raymarine, US.   Powered by

Badges  |  Report an Issue  |  Terms of Service