jrlawman

Hawk problem...Can anyone tell me why my Century Hawk clutch lining keeps melting down? I have replaced it twice and dont want to do it again until I know why. It's an older hawk heli and I've gotten about 5 minutes of start up time before it melts down. Any ideas would help. Thanks guys

rotordoc

Did you buy it used?

jrlawman

I did buy it used so I dont know it's history. I have seen a couple others who have the same problem however I cant seem to find anywhere where they have solved the problem. Any ideas you may have would be great.

rotordoc

Probably the most popular forum for Century helicopters is the one on R un Ry der. And clutch problems seem to be relatively non existant there.

The only time I have ever had a problem, after over 500 flights on one, was after starting it a number of times in idle-up or with the throttle stick not at idle, so it starts at full or half throttle....these are called "hot starts". By the time you figure it out, and brought the switch back to normal or the throttle stick down, you have worn out a lot of the liner and you have "heat treated" the clutch a little more then you should have (causing it to loose some, or all, of the tension that was built into it). After a couple of hot starts, the clutch liner would definitely require replacement and the clutch wings are definitely over stretched. If you only replace the liner, your clutch will now drag at idle and slip a lot, so the liner again will wear very quickly.

Like any clutch, on any heli, if you have to replace the lining, you should also replace the clutch because your clutch wings will have stretched outward beyond their design limits.

Once replaced, you should have learned to always check that your throttle is at idle and your mode switch is in normal. Then you will find the clutch will last a long, long time...probably longer then your motor.

rotordoc

If you want a good idea of how durable the cluch etc. is on an old Hawk Sport, check out this thread from way back in 2004.

http://www.runryder.com/helicopter/t...ght=40+gallons

jrlawman

thank you for the advice. A hot start sounds like the probable cause and I cant think of any other reason for it. If something else comes to mind please let me know. I just ordered two new clutch bells with the lining. so I have spare should I need it. Thanks again, it's appreciated.

rotordoc

DId you not order a new clutch????

As I tried to explain earlier, I think your clutch wings/shoes are "oversprung", so the same thing will happen again in short order unless you replace the clutch also...not just the bell or liner.

jrlawman

Hi, actually I did. Probably should have articulated that earlier. Thanks again.

Arcnsparks

Also make sure you don't over oil your clutch bearings! Very easy to do when putting that brand new bell on. The slightest bit will smoke a lining in a matter or seconds. How does your clutch shoe look on the wings are they all shiny or are they still black and the burned liner actually transferring material to the wings? If they are shiny are they equally shiny on both wings?

jrlawman

Hi, the clutch shoes are definately sprung. One side bent out and the other fairly straight. As far as color etc goes, it looks the same all over. The clutch bell obviously wore into the bottom of the fan. Once I replace the shoes, bearings, bell etc other than the previous advice given, is there anything else I need to know other than watching my throttle/idle control sytem? Thanks

jamesc43

My Feedback: (2)

Check for the proper clearance from the clutch shoes to the clutch lining. I have had several Hawks and my oldest one burned
the clutch up when it fell over while running. I didn't do alot of damage at first but I never really realized the clutch was toasted until
I saw small black parts flying from under the heli while attempting to learn to hover. I replaced the clutch lining and the clutch. I used
JB weld to install the clutch lining into the clutch bell and I also installed a high volume fan. I don't think the fan really did any better
than the stock fan but it was aluminum.

jrlawman

I got the new bell with lining. Do I need to remove the lining from the bell and glue it in with the JB weld?

jamesc43

My Feedback: (2)

If it is already glued in then do not remove it. When I replaced my clutch, I only replaced the lining. I reused the clutch bell.

jrlawman

Thank you, thats what I thought but was'nt certain. Being from the Springs area, are you aware of any really good hobby stores in the Denver area? One that may not only carry a good variety of planes but heli's as well?

jamesc43

My Feedback: (2)

The last time I was in Colpar they had a pretty good selection of airplanes and helis. We have a local internet store at coloradoheli.com. The heli's are not very popular here for reasons I do not understand. I think it might be the altitude.