prerotator improvement

[LARRYEBOYER]

I had mentioned in an earlier post that a friend from Canada had given me a tip on how to get more rpm on prerotation. I took some of his advice but made a few changes. I found a supplier on the internet that sold teflon spiral wrap . I purchased 9 ft of 3/8 inch teflon spiral wrap like they use to prevent chafing of wires. I pulled out the flex cable and wrapped the tefflon onto the shaft. There is enough room for the 1/4 inch shaft and wrap to easily slip into the sheath.I regreased the whole shaft and wrap.To conduct the test I used the standard configuration(without the wrap) and got 156 RPM in a 5-10 MPH wind. I inserted the teflon wrapped shaft and got 195. I think I could have done better ,but I have to adjust my cable back to the joystick as the handle was hitting the stick and would not allow me to exert more pressure. Any way, if you are looking for 25% more RPM with $35 of teflon wrap and 15minutes you can do it. Another benefit was that the sheath appears to flex alot less with the space inside the sheath smaller and aparently the shaft can't move around and create the vibration as before. So there you have it from the Skunk works in Reading, PA.

[Texas Armadillo]

How do you get the tape to stick to a greasy flex shaft? I can't imagine trying to get all the grease off of mine.

[LARRYEBOYER]

The teflon is not a tape. It is a spiral wrap material. let the grease on and put grease over the wrap, also.

[Texas Armadillo]

Ah, thanx! I'll get some and try it.

[rehler]

That sounds great! Thanks!

"I found a supplier on the internet that sold teflon spiral wrap "

What is the website address?

Also, do you think it makes a difference which way the cable turns? Mine turns opposite to most and I am wondering if it would "untrist" the wrap and jamb it up.

[gyropilot]

Guys,

A little word of warning...

When using Teflon for various projects around my workshop, I've found that while it definitely has a low coefficient of friction, it's not very wear resistant.

A couple of examples...

I've tried using it on my rotor head as a washer between the teeter bearing inserts and the teeter towers. I found the constant rubbing causes the Teflon surface to shed in little particles. After noticing this phenomenon, I switched to using the MDS filled Nylon that Bensen recommended, which works perfectly without shedding.

I tried using Teflon sheeting as a thrust washer between a measurement dial and the table on my small horizontal milling machine. It didn't last very long. The result was particle shedding and ultimately shredding to pieces. I replaced it with UHMW polyethylene and it's been holding up fine for years now.

Your mileage may vary of course!

Good luck,

John L.

[Harry_S.]

Larry, A 1/4" shaft?? I think mine is 1/2" or at least 3/8". I'll have to check it, but I know it's more than 1/4".


Cheers :)

[LARRYEBOYER]

My apoligies on the shaft thickness. I purchased 3/8 for the 1/2 inch shaft. I have only test time on this idea and I will monitor the wear every 10 hours of use on the hobbs. The other poster said he found a better material in nylon. I think any material that reduces friction will be a benefit. I think nylon is cheaper than tefflon and I would welcome the lower cost of 3.98 a foot. I think the ideal way to wrap it would be that It would tighten against the rotation of the shaft . That is how I did mine.Also remember that if you purchase the 3/8 inch material, you should buy 7ft to do the 4 ft shaft. I purchased 9ft thinking I would have enough to do 2 shafts. After wrapping it from one end of the shaft to the other, except the insert areas on both ends, it used more than I thought because you are wrapping the 3/8 around a larger surface.(you knew that didn't you?) :rolleyes:
P.S.
Send $25 through paypay for a more detailed explanation on the proper technique to wrap the material.Enclosed in your information packet will be a picture of the greasy hands properly wrapping the tefflon counterclockwise against the rotation of the shaft. There will also be included a free pair of surgical gloves to the first 1000 responses.(to avoid the greasy hands) Be the first to order your information kit NOW!!! Or call toll free 1-800-upyours. :p

[Chuck Roberg]

Uh,,, Larry! I called your 800 number. All I got was a recording about talking to horny women all around the world. :p (NO kidding it's really a porno number). :eek:

It didn't give me the option of leaving a message except for my credit card number. :cool: So please let me know if this is the right number for your business or not. :D :D :D

[LARRYEBOYER]

I sure hate it when I get found out!!! You got me. I was trying to make a buck on the spiral wrap idea and also sucker you into paying $3.95 a minute to talk to a sweet talking porn queen.If you don't want the spiral wrap, at least call my 1-800 number and she will give you an idea on spiralwrap using body oils.

[Harry_S.]

I like it!! That's a good one Larry.


Cheers :)