Pro-flex woes...

[Hammertime]

Posted - 03/07/2005 : 23:32:40
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Well guys and gals, it happened to me. :arggg:

I have been flying my Fury Expert with YS .61, and more recently an Extreme with YS .80 for several months now. Love the ships, building, flying all wonderful. Purchased the MA Pro-flex starting wand from the same dealer as the helicopters. My flying buddy has a Fury expert with OS .61 in it. He called to ask me if I had ever had problems with the one-way bearing in my Proflex. I had not, and told him that. He had his toss out a bunch of the little rollers after locking up on the start shaft. Well, I head out to the field and get a couple of flights in, then MY proflex does the same thing! Our local MA rep is there, (Dusty Barron) graciously lends us his spare Proflex, and it pukes on my buddies bird after a couple of starts. Now, bear in mind we have all been flying these birds for several months. We have our starting routines down, and always run the fuel out to prevent a hydrolock.

Question, is this a known problem? Is there a fix in the works? Or, must we convert to a hex adapter and associated 6mm wand? I really don't want to do this, as I don't want to put a flat on the starter shaft and make it hard to dis-assemble.

Seems like a funny coincidence that three drives would frag on two different airframes over a one week period....

Sure could use some help with this, as there are a couple of grounded fliers in Las Vegas this week...

MA guys, if you read this, you can contact me direct
tim.beghtol@earthlink.net
(702)369-4092

[DavidH]

Or, must we convert to a hex adapter and associated 6mm wand? I really don't want to do this, as I don't want to put a flat on the starter shaft and make it hard to dis-assemble.


I am been using hex adapters for two years now. I never had a problem with the flex shafts. But since most of the other brand helis are set up for hex systems. I switched over to hex in case I need to borrow a starter at the field.
I don't put a flat on the start/clutch shaft. I have never had the hex adapter slip, even trying to start flooded engines.
The procedure I use to install the hex adapter. I clean the clutch shaft and the inside of the hex adapter good with acetone. I then smear red loctite on the tip area of the clutch shaft. I slide the adapter down on the shaft. I use set screws that have flat tip or cupped tip. I use blue loctite on the set screws. Insert the screws and snug them good. Let the loctite cure couple of hours and ready to go.
DO NOT use set screws that have a point on the tip. They will not hold.

When I get ready to take the hex adapter off, I just heat it a few minutes with a heat source and it comes right off.

There is several of the MA Team Pilots that use this same setup and technique.

David

[ausheli]

mine seem to crap out about every 6 months but the last set of replacements i got, I found a place here in Aus that stocks small bearings and stuff specifically for RC and they had some the exact same size but with a metal cage instead of the standard plastic one

[rc30fan]

Ausheli,
care to tell us who this bearing supplier is?

I noticed a little piece of something fell out of my flex starter after starting my Tempest this past weekend. I checked the roller cage and there are several pins missing. I dont mind spending $50 for another flex shaft but I would rather fix this one with a quality bearing if I can get one.

ps Isnt your town spelt with an R? And great quote - Love the Oils.

[capebob]

After suffering through several bearing failures, I got some bearings from Boca Bearing. They seem to be holding up well so far. I bought an extra set just in case.

Metric 6.0000 10.0000 12.0000 HF0612 (FC6-K)

Bob

[lucky]

I have two of them that craped out on me . This last one I got has lasted About three months now and still going strong. I think after the moter breaks in then they stop breaking. Now that you mentioned it I am going to buy a spare

[rc30fan]

Okay, now I have my replacement bearing from Boca, how do I get the original out?
When I couldnt unscrew the tip from the flex shaft I heated it nice and gently with a soldering iron but still no luck. Is the thread reversed or conventional?
Does anyone have any tips they can share on how to disassemble this flex thing?

Shaun.

[Hammertime]

The end that contains the two bearings is a REVERSE thread. It is not held on with Loctite or anything else, but is pretty darn tight from use. Use two good wrenches that fit the flats well, and remember, reverse thread....


tim

[rc30fan]

Okay i've finally managed to remove the tip from the shaft. Now I see that there are in fact two bearings in there - one that has shed its rollers and another one thats intact. Now my problem is removing both. I hope that the undamaged one will last.
If I'd known there were two I would have been more inclined to replace the whole unit for only $25 more than the cost of the replacement bearings...

Hammertime - did you replace your bearings or the whole tip?

[Hammertime]

I actually sent in both of MY tips, and two other tips from Pro-flex users at our field. Minair replaced all the bearings in them for the cost of bearings, (about $20 per unit.) I thought that was a pretty good deal.

You can carefully drift out the old ones with a properly fitted brass or aluminum punch, along with a little heat on the outside of the case. Clean the inside of the case well, then put the new ones in carefully. (It is pretty easy to screw them up, but if you go slow you should be OK)

[rc30fan]

Well that was fun.
I replaced the failed bearing with one from Boca, started my c-spec twice and on the third attempt both bearings shed rollers. Lucky for me I had a hex adapter handy and was able to borrow another starter at the field.

This proflex lasted a little over a year, about 4 gallons a month. Thats not bad for a $50 part. I'll be ordering another from my lhs on monday.

[Clintstone]

I have been starting my 91's and several other folks for quite a while....... I have found that the 2400 nicads are making the Dynatron work great. I am running 2- 6 cell packs in series. I have been running this setup for over a year with alot of luck.

If I had trouble I would switch to the hex..........

[rc30fan]

I found an interesting coincidence with my Shogun electric heli today; I was in the process of converting it to eccpm when i noticed that it uses the one-way bearings from the pro-flex in its main gear.
I had a spare main gear so I went to the LHS and bought a spare bearing for $13. Both now reside in my pro-flex. I also bought a Sullivan one-way hex start wand just in case the Shogun bearings fail like the Boca ones did.
As I mentioned above I was planning on replacing the entire Pro-Flex but it seems MA are redesigning it (I hope they do a better job than they have been doing lately) so they are no longer available.

[wattybotts]

Those of you using the hex...

I just ordered the Freya Hex Shaft adapter. This seems to be pretty solid and on center. Any tips for mounting it?

Bobby

[DavidH]

Bobby,
Hex adapter are easy to attach and will stay secure if you follow instructions.

First, if the hex adapter uses a allen hex screw with a pointed tip. Throw the screw away. Only use a screw that has a flat or cupped tip on it.

Clean the inside of the adapter that goes on the shaft and the shaft with acetone.
Apply red loctite to the inside of the adapter before sliding on the shaft. Apply blue loctite to the set screw and then tighten it firmly.
Let the loctite setup 12-14 hours. Once the loctite sets up, the adapter should not slip even if the motor is hydro locked and you try to start it.

When the adapter needs to be removed, just heat the adapter with a small torch and it will come right off.

This is the way I have been installing hex adapters for several years. I DO NOT and never have ground a flat on the start shaft.

David

[bigrcr]

As for the Pro-Flex starting wand, there are several things that will make it fail. If you use it in the following fashion the Pro-Flex will last much longer. The one I use has been in use for several years without failure starting .80 glow motors and gas motors as well.(I'm setting myself up on this one!! :DOH )

1-Always fully insert the Pro-Flex onto the start shaft before hitting the starter. The needle bearings should be fully supported with the start shaft. If not, the bearings can "cock" in the bearing holder. This will dislodge the needle bearings (then they fall out) or break them.

2-Don't jerk the Pro-Flex off of the start shaft immediately after starting while it is still spinning fast. This can cause the needles they may be "dislodged", to fly out of the Pro-Flex. :oops:

3-DON'T keep hitting the starter when the motor is hydro-locked!!!!!! This will almost guarantee that you do damage to the needle bearings. This is usually what locks the Pro-Flex onto the start shaft, then you damage the Pro-Flex trying to get it off of the start shaft. :arggg: The cage that holds the needle bearings gets malformed and then releases the needle bearings.

4-Do not drop the Pro-Flex onto the ground and get sand, grit and dirt into the bearing. Make sure you keep the dirt out of the bearing.

5-Periodically clean out the bearing with low pressure air or by flushing it out with light oil (Tr-Flow will work) and lightly oil it (If you did not use oil to flush it).

6-Do not spin the starter without the Pro-Flex engaged on the start shaft as this can spin a needle out that has been dislodged as well. You can look to see if any are dislodged by looking in the bearing and if any are carefully push them back into their cage.

7-DO NOT lend your Pro-Flex to someone with a short start shaft in their model or to someone with burrs on the start shaft!!!! :WOW They will break your Pro-Flex for you.

I am not saying that if you do the above you will never have a problem, but if you do not do the above I guarantee YOU WILL!

It looks like this is a bunch of maintenance, but it really is not.

Hope this helps!