Author Topic: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?  (Read 1528 times)

wingdingjoe

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Ok even though I try to restrain myself from overtightening when I change front wings... I think over time the aluminum threads just can't withstand the constant stress.. And I change between the hps 1050,880,and the ART999 quite a lot depending on Conditions.

Why doesn't AXIS build the fuse with ssteel Helicoils already installed? At least for the M6 holes? Weight? Cost? Problems with ssteel bolts in ssteel threads?

Already paid a local machin shop to fill, redrill, tap this once.. Totally screws up the anodizing (any suggestion on what the best PAINT is after the anodizing gets f@cked?)

Now it's the OTHER M6 (on the front wing attachment) that has stripped and I'm thinking to buy a an M6 x 1 helicoil kit on Amazon.. Any comments please.. It's there any reason I should NOT repair all stripped M6 holes in the axis black fuse with these?
I GUESS they are 1cm long? Can't tell for sure from the article description..

Hoping the STAB holes will last longer (honest I only tighten with moderate wrist pressure.. Never CRANKING them down as I do the fuse/mast M8s) but.. Not ready to buy another fuse just yet so..

Advice from the fixit gurus please.

https://www.amazon.com.mx/Helicoil-5546-6-Metric-Coarse-Thread/dp/B0002KKPXK/ref=pd_aw_di_ci_int_rm_ing_dp_m_cn_p_0?pd_rd_w=lboK7&pf_rd_p=cf89587f-f199-4236-8c0d-2d36a198e7da&pf_rd_r=86A27FTSGP4J933M0WQM&pd_rd_r=9bc8ca92-367e-4c79-ad43-061c6a491ac6&pd_rd_wg=nYUh9&pd_rd_i=B0002KKPXK#immersive-view_1650648826981

Califoilia

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #1 on: April 22, 2022, 01:26:42 PM »
OK, so a couple things. The mistakes I've seen most often with stripping a 6mm fuse thread is not necessarily from overtightening, but rather putting the wrong length screw in with a different wing. Yes, while all of the black fuse wings use the same 8mm x 20mm screws in the rear, they do not all use the same 6mm screws in the front. Now not saying that you did that, but those wings you listed don't all use the same length fronts screw screws, and.....

I inadvertently made that mistake when demoing out a BCS 890 to a guy, and then later in the day handing him the BCS 810 when he felt the 890 was a tad too big...and forgot to give him the shorter 14mm screws to go with it. So him not knowing any better (I wish he would have said something when he was starting to feel a little resistance) started cranking on the longer screws trying to get them to snug into the thinner wing, and he stripped the holes. So I know it can happen.

But not the worst thing to have happen really, because I just purchased a "Tread Repair Kit" (Helicoil) from Amazon for less than $15, and it took me all of about 30 minutes to get the fuse back into service a couple days later once the kit arrived.

The only thing I wished I had was a drill press to drill the new, larger hole precisely vertical. Because in one to the holes I apparently had the drill at an ever so slight angle that I didn't realize, and it's tad bit harder to get that screw started w/o wiggling, jiggling the wing slightly in the process.

Hope that helps, and gets you back on that fuse again.
Me: 6'1"/180...5'1" Kings Foil Board...5'4" Kings Wing Board...9'6" Bob Pearson "Laird Noserider"...14' Lahui Kai "Manta"...8'0" WaveStorm if/when the proning urges still hit.

jondrums

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #2 on: April 22, 2022, 04:03:33 PM »
yes you can definitely drill out the ruined threads, retap with the heli-coil tap and insert the steel helicoil.  Not hard to do, and there are youtube videos on this if you've never tried it.  A drill press is nice but not required.

More importantly, invest in a little bottle of lube.  TefGel works wonderfully.  Just a tiny dab on the screw each time you swap or every few times and you'll probably never strip the threads again.  Also, don't use the ball-end allen keys - a nice t-handle with flat end allen will help you get the screw in straight.  And stop using your battery drill driver...

PonoBill

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #3 on: April 22, 2022, 05:16:37 PM »
All the stuff people have already said: Tefgel, be gentle, be precise, screw length, square-ended Torx, etc. I'm a bull in a china shop and I use an impact driver all the time. And so far (knock on wood) my black fuse hasn't been stripped. I do know how to use that impact driver, and I'm careful with it, but still, the problem isn't aluminum threads, 99.9% of the time it's the nut behind the wheel.

When and if I need to install repair threads in a black fuselage, it probably won't be helicoils, it will probably be a timesert. Way more expensive, total pain in the ass to install, but restores the threads to full torque. It's VERY easy to screw up a Helicoil, especially ones smaller than 8mm without a compressive installation tool, which the cheap sets don't have. And you can and will fuck them up even once they're installed. If you spin the screw in a fraction too fast when it isn't properly lubed it will weld the screw to the insert, and you'll back it out the next time you take the wing off. Overtighten just a bit or use a slightly screwed-up bolt and the top few threads break out. If you ignore the problem the screw will eventually seize in the hole or strip it out. The only repair after that is to finish stripping out the Helicoil, TIG weld up the hole, redrill, and retap it. Helicoils are NOT a universally good thing, or the answer to every problem with steel screws in aluminum, as any motorcycle mechanic will tell you. Yeah, I know, Armstrong does it, and they supply titanium screws. I won't go into all the reasons that is not the best idea ever.
« Last Edit: April 22, 2022, 05:20:54 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

finbox

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #4 on: April 22, 2022, 07:25:06 PM »
Here is a thread repair insert that is similar to a helicoil - it is a threaded insert - it requires the 6M hole to be redone to a M10 hole with threads. I doesn't need a special tool to install
https://www.mcmaster.com/thread-repair/316-stainless-steel-easy-to-install-thread-locking-inserts/

Welding on the fuse to fill the hole for the threads will mess with the heat treat on the aluminum.

PonoBill

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #5 on: April 22, 2022, 08:07:39 PM »
That's a mighty big hole to fix a little 6mm thread. I've used those kinds of inserts for larger threads, but I wouldn't trust them with little stuff like 6mm. They rely on a very aggressive pre-applied locking compound to hold them in place.

A 6mm timesert is drilled to 6.248 mm and threaded whatever 2X the thread depth + 6.248mm is--probably no more than 6.5mm. There are a lot of reasons for liking these inserts--they're solid, they lock into the hole, and they're available in a variety of metals. The only thing they are not is inexpensive. I'd have to measure the thread depth of the black fuse holes and I'm too lazy and a little sick to get up and do that to say exactly what to buy. If you buy a kit, do that and make sure it includes the length insert you need. Kits are about 70 bucks for one diameter, which is way better than the $400 I paid 20 years ago for a kit for 12 and 14mm spark plugs that I only used once.

Yes, welding will mess with the heat treat, and any good welder can retain most of the strength. the trick is to preheat the aluminum lightly if at all, and use enough power to get the bead done and the hole filled before the heat-affected zone spreads very far. While the Axis fuselage is heat-treated, probably to T6, the 6mm screws are in a heavy section of the fuselage. It's the skinny bits, especially around the mast that I'd be scared of. I'd just clean the part really well with Acetone, warm it to 120C or so to drive off any residual water or solvent, crank the welder to 200 amps and weld it like I knew what I was doing--quick and determined.

The anodizing would be hosed, but it's just cosmetic. Paint it flat black if you like, but I'd just leave it. I can actually do black anodizing. I've got a setup and all the dyes. But no, it's a messy, fussy job and always comes out blotchy when I do it.
« Last Edit: April 22, 2022, 08:38:15 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

wingdingjoe

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #6 on: April 23, 2022, 08:15:14 PM »
Thanx for all the great answers everyone!
This fuse will not last forever so I guess I'll go with the helicoil solution for now and use a drill press as recommended.

And for sure I understand that some wings are thicker than others.. But I never forced these m6 "too deep" into the hole so in this case I dunt think it was that.

Can ANYONE comment on if the standard helicoil M6 kit that l included the link in my first question are the correct depth /length of inserts? I think they are just one cm long... But from the helicoil info pages I can't be sure. Thanx again!

PonoBill

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #7 on: April 23, 2022, 11:35:21 PM »
You can cut Helicoils to whatever length you need, but they are probably ok as is. One cm is, of course, 10mm and I think the holes are about 12mm deep. If you cut them, use strong diagonal cutters that are new enough to be sharp. Helicoils get a little longer as you thread them in the hole because uncompressed they are bigger than the hole. You can also cut them once they are installed if they're a bit too long. Notch the helicoil with a triangular file and bend it lightly back and forth until it snaps off. The kit will probably come with a flat punch that's supposed to break the insertion tang off. It won't work with something as small as 6mm in a blind hole. You can use a much smaller rod or punch to push the tang back and forth until it breaks off--the tang is scored at the base to let it break. Remember to fish out the broken bit. I generally use red locktite to lubricate the Helicoil for insertion which then locks it nicely. I've done zillions of Helicoils. I'm not a fan, but they're cheap and work OK.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

wingdingjoe

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #8 on: April 24, 2022, 07:25:17 AM »
You're a rock star Bill! You answer the questions that bubble to the surface of my mind before I even see them breaking the surface!  ;D

Thanx a gazillion.. Just ordered my helicoil kit.

wingdingjoe

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #9 on: May 09, 2022, 11:47:15 AM »
I guess anyone who's read this far probably has stripped their M6 front Foil threads in the fuse as well... So just to finish the story..

Bought the Helicoil full kit for like 30 bucks (Probably cheaper in the states)... It comes with like 10 "coils" plus the tap and an interesting little applicator device for "screwing" the coils in.

Since I dunt own a drill press I decided to pay the Local machine shop guys to drill and tap. And insert the coils.. I guess they added locktite red in hopes that the coil will never back out.. Who knows if that's even an issue... And they used a punch to break off the little tab at the bottom of the coil.

It seems that "deep end" of the coil is NOT quite as deep a the original holes... By maybe a mm or 2..so my hps 1050 and 880 the original M6 countersinks perfectly but with the 999 installed they dont QUITE get all the way flush.. So I'll have to grind a tiny bit off the end of the bolts to make it perfect.

I guess in writing this to confirm that there seems to be a VERY SLIGHT difference in the thickness of the hole in the wing ART compared to the HPS.. and also to say that the Helicoil Option worked out great for me.. Have had some epic sessions since the repair.

Califoilia

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #10 on: May 09, 2022, 04:50:14 PM »
Axis has the 1050, 880, and 999 all using the 6mmx14mm screws up front. But I've found the same thing that you did, that the 14s are just a tad too long for the ART wings.
Me: 6'1"/180...5'1" Kings Foil Board...5'4" Kings Wing Board...9'6" Bob Pearson "Laird Noserider"...14' Lahui Kai "Manta"...8'0" WaveStorm if/when the proning urges still hit.

jondrums

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Re: Axis black fuse M6 thread repair.. Helicoil stainless? Depth?
« Reply #11 on: May 11, 2022, 12:09:03 AM »
I use M6x12 on my 899 and 999

 


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