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: 527

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

Michael goldberg replied to Tony O's discussion dsm 300 - the saga continues
"They are giving you a new unit, be happy. Download the Navionics app on your cell phone and it will get you by for the week. Good luck."
3 hours ago
Moderator - Raymarine, US replied to John Pecora's discussion ST800/B120 SPEED DATA NOT RECEIVED
"John, Should the MFD's NMEA 0183 buffer include sentences which are populated as 0.0 when underway, then it is recommended that you check the Speed and Log data items reported within the MFD's Databar, Data application, or Databoxes.…"
5 hours ago
Peter Christis updated their profile
14 hours ago
John Pecora replied to John Pecora's discussion ST800/B120 SPEED DATA NOT RECEIVED
"Okay, that explains why I could not access the data source--I was thinking that the ST/STNG converter was a problem & preventing speed data display since I could not access the transducer set-up menu, but it appears my network is working as…"
15 hours ago
Moderator - Raymarine, US replied to Greg Pfleger's discussion Disposal of old radar equipment
"Noted."
15 hours ago
Moderator - Raymarine, US replied to Ken Peckham's discussion Classic C-80 and Digital RADAR compatibility question
"You're welcome."
15 hours ago
Moderator - Raymarine, US replied to Bob Kurtz's discussion Problem connecting e125 video out to hdtv
"You're welcome."
15 hours ago
Moderator - Raymarine, US replied to Glenn Morrison's discussion C90W and ACU-200 on SeaTalk NG - Two Power Sources Acceptable?
"Noted."
15 hours ago
Moderator - Raymarine, US replied to Kenneth Watson's discussion Dragonfly 7 Slow Boot Time
"You're welcome."
16 hours ago
Moderator - Raymarine, US replied to John Pecora's discussion ST800/B120 SPEED DATA NOT RECEIVED
"John, The Multiple Data Sources (MDS) feature is intended to permit more than one instance of a NMEA 2000 data source to be interfaced to a new a/c/e/eS/gS-Series Data Master MFD, i70 Multifunction Instrument Display (MFID), or p70/p70R Autopilot…"
16 hours ago
Brian Tilley replied to Brian Tilley's discussion Tridata
"Good morning. I went back to the boat to try the test you described, and am perplexed by a new result.   When I take the speed/temp sensor out of the thru-hull, the instrument works sensing temp in a bucket of water and reading speed if I…"
17 hours ago
Heath Hooper updated their profile
21 hours ago
Bob Johnston replied to Bob Johnston's discussion EV-200 failed seatrial calibration
"Another update a month (and a couple sailboat races) later: It's reassuring to see that in the interim, several others have had similar experiences commissioning the EV-200.  Those of us who read manuals (vs. the commissioning summary in…"
yesterday
Jean Gauthier replied to Jean Gauthier's discussion SR50 SiriusXM interface
"Try the unzipped version Same fatal error Please advise as to the proper course of action"
yesterday
Chris Lambert replied to Chris Lambert's discussion Autohel 7000 - rudder angle referance is off
"Hello again, After solving rudder angle issue I now have a new problem: boat speed instrument shows zero speed... This problem started right after I changed DRIVE param as per my note above. Is there a param value which affects speed…"
yesterday
larry nanni replied to Adam's discussion Dragonfly 4dv
"thanks  anyways..the virtual view is just a extra that cost more and weather or not i needed it to hunt fish...  heres one  try u tube and type trying to add transducer to trolling motor? u just don't know..."
yesterday

© 2015   Created by Moderator - Raymarine, US.   Powered by

Badges  |  Report an Issue  |  Terms of Service