HPR C5009 Bulletproof Animal build.

[KillerDave]

Ok chaps, I have a question....
If you have a look up there ^^^ to post number 41, you will see I have some support bearings and flex savers....
Here's the problem... The "support bearing" is sized at 5mm but the 3/16" flex is 4.75mm so it's not so supported is it.... The saver is spot on though??? Any ideas???

[nata2run]

Ok chaps, I have a question....
If you have a look up there ^^^ to post number 41, you will see I have some support bearings and flex savers....
Here's the problem... The "support bearing" is sized at 5mm but the 3/16" flex is 4.75mm so it's not so supported is it.... The saver is spot on though??? Any ideas???

Yep not worth using :) lol .... rather invest in the MBP collets and you'll never loose a flex again "kinda" but they are awesome!! and easy to get cables out from every run. I dont think the bearing is ment to be tight around the flex anyway, mine never was.

[KillerDave]

To be honest, I've never lost a flex but then, this will be the fastest boat I have.
I did get an email from MHZ and they say the bearing should be loose... Why have the bearing there then???

[ManuelW]

The sense of the bearing is in combination with the flex shaft security ring. Imagine there is no bearing and you need the flex shaft security. It might spin still around 30.000rpm and then imagine the friction between the stuffing tube and the flex shaft ring! In that emergency case all the load gets on the inner ring and it can also spin free. Therefore the security ring should also have a little offset with the right diameter that fits to the bearing.

regards,
Manuel

[KillerDave]

I think I understand Manuel...
Do you mean that the security ring should fit the bearing inner race?
I have been looking at making a shim to take up the space between the flex and the bearing and I have made a VERY thin tube spacer and it looks like it would work...
Would that be a bad thing?

[KillerDave]

THE MOTORS HAVE LANDED!!!! Oops! Sorry for shouting but it feels like I've been waiting so long for them!!!

They are TP Power 5040 2200kv Pro Competition spec' I don't know what they do to make them "Pro Comp" but I have read they run very cool....
So now I can move on a little! I do have a very busy weekend this week and I might be able to get some done if I'm lucky????

[KillerDave]

I can't believe my luck! I get the motors and have just been told I need to go away with work!!! Aghhhhhhhhhhhhhhh!!!
Anyway, I have made a small start moving forward...


And I'm afraid that's it for a while as I am off to Spain at the end of the week Germany 3 weeks later and Japan in 8 weeks!!! Joy!! Jet lag time for me.... I wonder if I can take the boat with me???

[Chrisg81983]

I have ran many 2200 kv leos on 6s without a single problem. Thats if the rest of the rig is set up correctly. Generaly mostc people toast them due to the wrong prop/props at those rpm's. Second what size brass and flex are you using because my brass for 3/16 fit perfect into the single nut drives. I actually had to bore them up to 10mm to fit the correct brass for 5mm flex. I didn't feel comfortable with 3/16 switching to the 5mm was the best thing I did for my 115

[KillerDave]

I have ran many 2200 kv leos on 6s without a single problem. Thats if the rest of the rig is set up correctly. Generaly mostc people toast them due to the wrong prop/props at those rpm's. Second what size brass and flex are you using because my brass for 3/16 fit perfect into the single nut drives. I actually had to bore them up to 10mm to fit the correct brass for 5mm flex. I didn't feel comfortable with 3/16 switching to the 5mm was the best thing I did for my 115

Hi folks!

So, I'm done with Spain but at the weekends, I have spent time with my family so no work done on the boat....
After Easter, I am off to Germany and my trip to Japan is delayed... So after Germany, I will do some more but family time is a must!!!
Chris, I have swapped over to TP's now at 2200kv, I think I will start with Octura X440 props on 5 or 6s... What do you think??? Also, I will be taking it easy on the ESC's timing and not just run but also test run and see how things go......
As far as the flex and tube go... I have Octura 3/16 flex and the tubes are Teflon lined 6mm ID 7mmOD brass tube.
I have centred them into the drives with a very thin bushings I made and it looks all lined up great! :-)
BTW, I got the tube and lining from MHZ in Germany....

http://www.mhz-powerboats.com/category-11/category-25/Brass-Teflon-Tube-3-16---4-75mm-.html

How did you get the 5mm flex into the stub shafts?

[ManuelW]

You have to use a lathe and drill the stub shafts to a bigger bore, something around 4.9mm would be fine. But for normal applications the 3/16" flex shafts work fine when aligned well. Only in highest performance applications they fail from time to time.

regards,
Manuel

[KillerDave]

You have to use a lathe and drill the stub shafts to a bigger bore, something around 4.9mm would be fine. But for normal applications the 3/16" flex shafts work fine when aligned well. Only in highest performance applications they fail from time to time.

regards,
Manuel

This is why I made the small bushing, to align well. When I get a chance, I will post more pictures and you should see that everything will line up as perfect as I can get it.... I am taking a short holiday with my wife and daughter over easter and I'm home next week so I should be able to spend some time on it then....

Thank you for the input.... :-y

[iridebikes247]

Don't make a shim spacer for the flex shaft.

http://www.mhzusa.com/Flexshaft-Saver-and-Support-Bearing-m-2256.htm?categoryId=-1

There is your explanation for why it is the way it is. I run one as does Bruiser77 on here, they work very well. I'm not so sure its a needed part but it looks cool comes with a flex saver and allows you to oil the flex easily. Running an oiler is great.

[KillerDave]

It still doesn't explain why there is a gap???
IMO, If the is a vibration in the flex, you would do your motor a favour by using the bearing to stop it.
On top of that, having the extra mass of the collar would exagerate the forces....
I am at the moment thinking of not using it.. Not sure???

[nata2run]

There is good and bad with those units. The good "all in my own opinion" is that if the collet lets go you won't loose the whole drive. When I ran the MHZ 114 the first time I lost the cable, shaft and prop all in the first 5min. LOL man was I angry!!!

The bad I guess would be that you are spinning that little collar/clamp, and it can run uneven coursing some vibration throughout the whole drive. I don't think it's a good idea to run this past 38k rpm. One of the clamps came lose one day! I can just imagine if it flew off and shot into the electronics. (That would have worked nice with my luck)

Both my HPR and MHZ don't use it for the simple Fact that I trust the MBP collets and they clamp really well. Also my cable runs perfectly in the center of the Teflon liner, so no grinding and little wear. If you decide to use them place the collar as close to the motor collet as you can to avoid too much vibration.

[iridebikes247]

I think its cool and its worked for me if you have doubts then I wouldn't use it. Many high end builds have been completed and run well without this item. I suppose you could make a shim but it will probably make it more difficult to remove the flex when you want to. If something works I don't re engineer it as new problems may surface down the road. If installed you can still use the grease fitting definitely tricks out the build a bit and having a flex loaded with grease quiets everything down a lot