REK Lower units and Snapped Cables

[LiPo Power]

Ran the tunnel today and guess what............................


Any way, I think I found a soluton to the problem....I picked up a OS complete lower unit today.

REK=Trash.

...no way, so on my way out of there, when you went to pick it up it was the cable again??? Great you have the other one....

[rek]

Last week he had a big bulk bag of them, these ones seem good i did not shorten it at all. The rek unit have the most harsh angle on them than any other unit. I was looking at the other setups at the race this weekend.

I do not get on the forums much. But I do have to comment on this: REK lower unit has the harshest angle is incorrect. K&B has the greatest degree of bend in the cable, it is 90 degrees. My lower unit is 83 degrees. Lawless is the least transition angle , close to 75 degrees.

Doby,
Sorry that you experienced shaft problems with one of my lower units. After 4 years and several hundred units sold for both electric and nitro, I have not gotten any reports on flex shaft problems. There are a few things to keep in mind. The flex shaft does come long and has to be trimmed. This is because of the differences in motor shaft length and coupler placement. You trim the shaft till the motor can be set down with out the shaft lifting it up and having any gap, then trim about 1/32" more off. This will ensure no bind.Some times the square ends do need to be sanded to free up the fit into the coupler and prop shaft. There is an oil hole at the top flange of the unit. Important thing to keep in mind, because of the brass liner, you should pump some lube into the lower unit before every run. Just greasing the cable once before the weekend running will not provide enough lubrication. I use a STP with about 25% never seize before each run. This was the same when I ran K&Bs with a brass liner. Do not drill any holes at the prop shaft, this allows water to wash lube away from prop shaft and let existing lube to run out to quickly.
Best regards,
Richard Konnen (R.E.K.)

[Doby]

I tried every trick to get it working...two othe club members have had similar experiences...I got rid of it,,,got a real OS lower unit and the boat now runs as it should,,,,run after run....

[AlanN]

John,
I am sorry to hear your opinion on the REK unit. I would not have recommended it had I thought there were issues with it. But I wouldn't call it trash since it did not work for you. Remember your hull is pretty heavy in comparison to other tunnels. I fully advocate Richards REK units.

I have only used the REK units and no severe issues with any of them. Run after run after run.

[Doby]

Hey, no problem Alan...lets hope Howard has better luck.

[AlanN]

He's been using the REK also with no probs. I know of a 2 others in the area with also no probs.

[Darin Jordan]

Same thing out here, Alan... We have 5 or 6 at least, in our club... and I have yet to hear of any issues.

[ryan_t888]

John, I have the same REK unit sitting here that I ran with you guys 2 or 3 years ago. I have never snapped a cable in that unit. Not one. Must have 100+ runs on it by now.

I used the SV motor, trimmed down the shaft and placed my coupler in the appropriate spot. You have to keep the coupler as close as possible to the motor otherwise it will make the flex cable appear to be too long. These flex acables are standard length and should not ever have to be cut down.

Ryan

[Doby]

3 members in the Toronto club had similar issues to mine with the REK. I'll never recommend it and I know some others who would't either.

Personally, I'm glad its gone.

My last comments on this issue.

[properchopper]

I've used the REK lower for over a year with weekly use and only snapped one cable. It's a good and widely used unit, IMO. Switched to the Hyperformance Angle Drive with a modded [see picture] REK adaptor and haven't snapped a cable yet with weekly use for over a year. I trim the end-play exactly as Mr. Konnen posted, very important. I modded the REK motor adaptor by drilling the outer and inner wall , fitted a tube to inject lube [ Harley Synthetic motor oil] before and after each run. After about three uses I open the access hatch and smear grease on the cable. Good to go !

[daveives]

Use a better grease?

I have bought over 20 REK lower units, assembled about 15 with various motors, and have run about a dozen so far. In 4 years, I have snapped only one cable. I use 6XL motors, KB45 motors, and others. I trim the cable for clearance, but do not bother to re-grease after every day of running. What am I doing different? For most of my builds I use "Starbrite PTEF Trailer Hitch Lubricant" from West Marine (or other retailers). This is a TEFLON based grease. I tried Prather and ProBoat and Mercury "Quicksilver 2-4-C" grease on a few. I suspect (but do not know for sure) that the one that broke did not use the TEFLON grease. Just my 2 cents worth.

[daveives]

Another Cable Snapping Thought

Maybe the brake setting in the ESC can snap cables. If the propeller is rotating and the brake is applied, the rotational inertia of the prop acts to unwind the cable, the cable expands, the cable locks in the tube, and then snaps. The propeller mass is small, but the RPM is large. I cannot remember if the rotational inertia torque is linear or quadratic in RPM. If quadratic, it could be very large. So the question is "did you have the ESC brake enabled when your cable snapped?" Lets hear from those of you with snapped cables. I do not enable the brake. Now I can go back to sleep after thinking about this for half the night.

[ozzie-crawl]

thats a very good point about the brake, i use a bullet drive no problems so far,but after seeing the trouble doby had from his first posts i have always removed my flex after each run then spray with wd40 ( and inside the leg with wd40) and leave it till next run before greasing and placing back in the lower unit