DFC!? Pah! ......

[raptorheli2]

align did have bolt failures on the 700 DFC correct.

cheers

[tonystevens]

align did have bolt failures on the 700 DFC correct.

cheers

Nothing scince the bolts were upgraded 12+ months ago though?

[raptorheli2]

i'm sure there will be the odd few about but in general the issue was fixed yes.

cheers

[panosg]

Are you Nigerian?

joe.jpg

[Benjbrit123]

you are all saying ohh but the bolts can fail! well I trust them more than an even cheaper peace of plastic that we use on a ball link :S and you use 2 cheap bits of plastic on a HPS head ! I heard far more storys of links coming off that bolts snaping! Infact I have not heard a report of a bolt snap in over a year!

Ben

[Ross Northcott]

you are all saying ohh but the bolts can fail! well I trust them more than an even cheaper peace of plastic that we use on a ball link :S and you use 2 cheap bits of plastic on a HPS head ! I heard far more storys of links coming off that bolts snaping! Infact I have not heard a report of a bolt snap in over a year!

Ben

Ben you were at grassroots, on the Sunday right? at Phoenix? Harry, James son had his snapped, brand new kit less than 5 flights old, can you remmember, also damaged his swash plate and other items?

[heathy]

Ben you were at grassroots, on the Sunday right? at Phoenix? Harry, James son had his snapped, brand new kit less than 5 flights old, can you remmember, also damaged his swash plate and other items?

He didn't see it because he was blind from where someone popped out his glass eye,lol

[Benjbrit123]

Ben you were at grassroots, on the Sunday right? at Phoenix? Harry, James son had his snapped, brand new kit less than 5 flights old, can you remmember, also damaged his swash plate and other items?

Im fairly sure what happened was the ball link failed which backs up my point... I might be wrong I will ask james now but im sure that was the ball link :P

[Benjbrit123]

Yep I was correct I just asked james the link failed so like I said I much rather trust a steel bolt than a plastic link!

Oh and did I mention how well a dfc head flys lol

Thanks Ben

[waveydavey]

What a load of rubbish. Material selection is down to the designed loads that particular designer has calculated he requires. No bolt whatever is meant to take any shear or bending moment which is what you get with the dfc links, period. A ball link is less likely to shear because of the rotation designed into it funnily enough that's why they're called ball links.

By using a stronger tensile strength bolt align have sort of solved the problem but not eradicated it because the shear is still there unlike a plastic link. Pointless debate over a design flaw, don't understand why people are trying to justify it

[trillian]

Yep I was correct I just asked james the link failed so like I said I much rather trust a steel bolt than a plastic link!

Oh and did I mention how well a dfc head flys lol

Thanks Ben

I think you'll find the plastic ball links used on everything are very well proven over many years. The difference when comparing a ball link with the bolts on a DFC head (as I'm sure you're aware) is that a ball link is omnidirectional, it has no side loads on it. Yeah, anything can (and does) fail sometimes. What would be absolutely bullet-proof for normal link situations (not for DFC obviously) is something like this;
Metal_Ball_Link_rc_accessories.jpg

But then you'd really need to have a turnbuckle for any adjustments and the cost goes up etc.

[heathy]

What a load of rubbish. Material selection is down to the designed loads that particular designer has calculated he requires. No bolt whatever is meant to take any shear or bending moment which is what you get with the dfc links, period. A ball link is less likely to shear because of the rotation designed into it funnily enough that's why they're called ball links.

By using a stronger tensile strength bolt align have sort of solved the problem but not eradicated it because the shear is still there unlike a plastic link. Pointless debate over a design flaw, don't understand why people are trying to justify it

Exactly the reason why Compass use a delrin drive tube with normal ball links on the ends, never heard of a failure yet. Even their chief crash pilot ( me ) has had many crashes where they have just popped off and saved a mess.

You can also buy these heads for most large helis....

CompasFbl Head Conversion (Atom 500)

FBL Conversions & Parts

[Benjbrit123]

Ok I dont know why I bothered :S The DFC design is good for so many resons in flight, and then to add to that the bolts have a very good history of not failing compared with ball links, That is enough for me to be able to feel very safe flying and I feel my 700 DFC is an amazing flying machine which I have not changed even after being offered to fly some helis for free, the reason being because the 700 DFC is such a good all rounder! You can shoot me down tell me Im wrong but what is the point :S This forum is a bit of fun yet all the time I come across people saying things I know and have tried are crap and maybe I would be better to just say nothing but im sorry but I feel I should stick up for what I have tried and tested and has been great for me

[KevDavies]

Ben I dont think anyone is denying that the DFC system works. Thats a proven quantity. They are out there, they are working and not failing FACT

But if you were to approach the situation as an engineer, there are shear loads on a bolt where no shear loads should be. Im pretty convinced that there is a solution to fixing the dfc arm to the blade grip and to remove the shear loads from the bolt in question. Im going through ideas myself to see if it could work.

Theres no need for anyone to be getting irate, arguing etc. everyone has a valid point.

[waveydavey]

Absolutely Ben whatever works for you is absolutely fine and good luck with it. However, exactly the same goes for many others on here who have been in the hobby a long time and have an awful amount of knowledge. The forum is more than a bit of fun it's a place for discussion on all things Heli related. You don't need to justify everything and saying that others opinions are crap is in my opinion a bit disrespectful. I've been in engineering all my working life and don't need any opinions on what's right or wrong from someone like yourself, not saying your opinions aren't valid nor valuable I just can't see the point in debating it further. You have your opinion even if it is wrong : D