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: 199

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

john bailey replied to john bailey's discussion e120 classic plotter
"Sorry just like to add, that when I power up the plotter I see the heading and tidal vectors, but then they vanish. Likewise if the plotter is on and I plug in the seatalk cable into the seatalk/alarm out socket, the heading and tidal vectors appear…"
2 hours ago
Tomas Själander updated their profile
3 hours ago
Jack R Wilken posted a status
"I have a SPX-5 Autopilot tiller drive unit & i60. The SPX-5 wants Sea Talk 1 wind direction info & the i60 is Sea Talk NG. Any suggestions?"
10 hours ago
TJ replied to Bill Fernandez's discussion C70 with scanner weirdness
"If you don't have a dedicated groundplane then connect it with the negative going to the ground for the battery."
11 hours ago
mike hoyt replied to Crockers Boat Yard's discussion i 50 questions
"Same with mine. brand new. Just installed. Want raymarine to come on board with this discussion Yesterday worked well for  few hours after leaving dock with battery freshly charged.  Then started its game. Wondering if could be…"
11 hours ago
Bill Fernandez replied to Bill Fernandez's discussion C70 with scanner weirdness
"Thanks tj, I will upgrade the wire to 10 awg.  Also, there is a third wire from the c70 power connector.  I have the red and black for power but the 3rd wire is not connected.  Where should that be connected and would that cause this…"
12 hours ago
Steve Dudka replied to Chas McKeown's discussion MMSI: Change or add a second
"The Ray240 does not have a DSC button or a function button.  There is a Menu and 16/9. Is there an alternate procedure for the Ray240?"
12 hours ago
TJ replied to Bill Fernandez's discussion C70 with scanner weirdness
"Under voltage can absolutely cause it. I'd expect a 10ga pair to be sufficient to extend a factory cable to the distribution panel."
12 hours ago
Patrick Shanafelt and Ric Murray are now friends
12 hours ago
Bill Fernandez replied to Bill Fernandez's discussion C70 with scanner weirdness
"Also it doesn't matter if I am on shore power, engines running, engines off and direct connected to a battery.  Could the guage wire I am using cause this issue?  My power cable has a short run and I have attached 6' of extension…"
12 hours ago
Bill Fernandez replied to Bill Fernandez's discussion C70 with scanner weirdness
"So I am back with the same issues as before.  I traced power and have a clean connection to the mfd both pos and neg.  The power from the mfd hits my terminal block, then heads right down to the bridge breaker, then right to the…"
12 hours ago
Peter Capobianco replied to Peter Capobianco's discussion AIS Reprogram
"After looking at the manual, it seems to me that the software can only be used to configure the original static data. I am trying to change the original static information: "Once static data has been programmed, you must not change it. If the…"
12 hours ago
Eric Mercer replied to Eric Mercer's discussion Dragon Fly loses bottom
"Anyone have any ideas?"
13 hours ago
Glenn McKibben replied to Glenn McKibben's discussion e7D with st-2000 tiller pilot
"In hooking up the NMEA signal lines in the ST1000 I noticed there is a Seatalk pin.  What is that used for in the ST 1000?"
15 hours ago
Tom Winegar replied to Tom Winegar's discussion ST50 wind Instument
"Update: I've confirmed that the transducer is working, the problem is with the instrument. So, is there an updated instrument that will work with this existing transducer that is mounted at top of my mast? "
17 hours ago
Peter Capobianco replied to Peter Capobianco's discussion AIS Reprogram
"I own AIS650. When I try to download the ProAIS2 software, I cannot open proAIS2.dmg using OSX. "Image not recognized". "
20 hours ago

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

Badges  |  Report an Issue  |  Terms of Service