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Author Topic: Graupner - Azimut Atlantic Challenger  (Read 5856 times)

James321

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Graupner - Azimut Atlantic Challenger
« on: October 13, 2021, 05:00:37 pm »

Hey guys, newbie here, both to the forum and to building boats so please go easy on me if I'm making any ridiculous mistakes along the way with this build. I'm an aircraft engineer by trade and have built several rc aircraft so I've been using that knowledge and skill set in this build.


I picked up the kit from eBay, the kit has been previously built and then disassembled but the seller had included the majority of parts needed for the build, pretty much everything except for the bulkheads, structure and deck.  I'm guesstimating the kit is around 20 years old, the running gear and building methods certainly seem from a previous generation but as I said, I've never built a boat so not qualified to answer that. The bow of hull had sustained some damage during shipping which had caused the shape to distort, the hull appeared to have had a previous repair or had been re-skinned at some stage, however the resin was still tacky and didn't appeared to have fully cured. I set about sanding it out which was an experience! If you've never tried sanding uncured resin then I would advise against it, you spend more time de-pinning the sandpaper than removing material.

Once the hull was flattened out enough it was pretty flimsy, a quick order to easy composites had a selection of carbon fibre cloth and resins to put some strength back in the hull. I cut a front deck section out of MDF to help form the damaged hull, applied the carbon fibre and taped the deck section down. 



* no idea how I post pictures on here?


https://flic.kr/p/2mzS8hk


https://flic.kr/p/2mzZLRw


 


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James321

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Re: Graupner - Azimut Atlantic Challenger
« Reply #1 on: October 13, 2021, 05:28:38 pm »

Once the carbon fibre and resin had cured, I sanded it back to make life easier when it comes to attaching the bulkheads, etc, it doesn't look neat but it will when it's all finished and gets a final coat of resin.


https://flic.kr/p/2mzS844


*If someone could explain how I can post pictures on here it would be a great help, I don't see any instructions?


https://flic.kr/p/2mzWjBF


https://flic.kr/p/2mzWjFd


https://flic.kr/p/2mzWjK1


https://flic.kr/p/2mzWjAt


The bulkheads weren't included in the kit and the plans are pretty poor, they are more of an instruction sheet than a plan so making the bulkheads was a lengthy process of folding and cutting paper until it was approximately the correct shape and then transferring that to MDF so I could file away until I had a good fit.




It was a long process made easier by my friend who had recently purchased a CNC machine as a project, I made good use of his untested machine to carve out some pretty good (for a first attempt) bulkheads.


https://flic.kr/p/2mzWjHH


https://flic.kr/p/2mzWjHs


Once the shape was finalised the CNC was again put to use in cutting out some carbon fibre sheet. The whole structure will be built from carbon, we use it on full size aircraft so why not employ it on this boat, it's strength to weight ratio is difficult to match.


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tica

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Re: Graupner - Azimut Atlantic Challenger
« Reply #2 on: October 13, 2021, 07:57:33 pm »

I believe that the Admin has put a minimum of post a newbie needs to load before one can add pictures. But I can't find the post about it anyway keep posting  :-))
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Stuw

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Re: Graupner - Azimut Atlantic Challenger
« Reply #3 on: October 13, 2021, 09:05:53 pm »

Looks very neat and tidy!
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James321

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Re: Graupner - Azimut Atlantic Challenger
« Reply #4 on: October 14, 2021, 07:00:32 pm »

Well I've tried numerous ways to get my Flickr pictures to show up on here but no luck so I either just post up links or just forget about sharing a build thread, I've wasted too many hours trying to get this working and its becoming annoying.
The insert image doesn't work, the add image to post doesn't work and the upload image....doesn't work.

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RST

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Re: Graupner - Azimut Atlantic Challenger
« Reply #5 on: October 14, 2021, 08:07:17 pm »

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Re: Graupner - Azimut Atlantic Challenger
« Reply #6 on: October 14, 2021, 08:17:46 pm »

Well I've tried numerous ways to get my Flickr pictures to show up on here but no luck so I either just post up links or just forget about sharing a build thread, I've wasted too many hours trying to get this working and its becoming annoying.
The insert image doesn't work, the add image to post doesn't work and the upload image....doesn't work.

...a ha it does work from flickr but a bit fiddly as they don't make it easy for sharing or doing anything with pics unlike other image hosting sites!  I think I had to show someone how to do it similar way for imgb or something like that a while back.  For me the "attachments"option is much easier but here's how I think figured out one of your pics (if I can do it, anyone can).  Unless of course image links are restricted during the early stages of a new user also.  There's a post on how to do photos at the top in "chit-chat":

  • Seems to work from the desktop site rather than mobile ('tinterweb says similar)
    In FIREFOX:  Right click image and go to "inspect (Q)".  Normally I'd just right click and select "copy image location" but that doesn't seem to work for flickr
    Go to the line where the .jpeg is.  DO NOT try to right click and copy, it doesn't work.  Just use ctrl + "C".  You can't copy this directly into a new post here for whatever reason -looks like something is restricted in the programming.  I pasted into powerpoint (just because I had it open anyway).  Select the text i.e. //live.staticflickr.com/65535/51579871276_a3063f1740_4k.jpg  ....actually I just re checked and you can paste to the forum but the coding can go a bit screwy and the forum can put in extra code so you need to be careful your text doesn't re-size, go bold etc.
    Go to "Insert image" icon in the post reply section.  In the pop-up window paste the above image text but add in "https:" at the start
...See if that works for you!, it just did for me.  Should be easy enough to master, it took about 2mins for me to try and I'm no expert or have much patience.  If that works for you someone can show me how to get bullet points to work because it never seems to on SMF forums!

Hope that helps, worth a try anyway.

Rich
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Re: Graupner - Azimut Atlantic Challenger
« Reply #7 on: October 14, 2021, 08:26:12 pm »

PS:  Just noticed in the way I got it to work there's no note at the bottom to say it is "Jim such and such's photo feed from flickr".   Makes little difference but when that message is there you can usually get to the persons flickr page and mooch around any other public photos in the album.  Not sure if I'd worry about it either way, and I know it's terribly unpopular to have to click on a link on a forum these days, but the photos are there regardless.  Anyone interested would hopefully still look like I was.  It's still better to use an image hoster if you can find one with amicable t's and C's these days, in my opinion it takes the load off the forum plus photos show when you're not logged in.
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Martin (Admin)

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Re: Graupner - Azimut Atlantic Challenger
« Reply #8 on: October 14, 2021, 08:57:23 pm »

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James321

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Re: Graupner - Azimut Atlantic Challenger
« Reply #9 on: October 15, 2021, 03:07:06 am »

Thanks Rich, let me give that a try. Life used to be much easier with photobucket until they became thieves, Flickr was a reasonable option but the UBB code which is the usual way of posting pictures on forums didn't seem to work here.  When I get some more time I'll sit and try and work through it.  Thanks again.
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Re: Graupner - Azimut Atlantic Challenger
« Reply #10 on: October 15, 2021, 03:25:11 am »

Quote
Thanks Rich, let me give that a try. Life used to be much easier with photobucket until they became thieves
....yes I know but I was always a photobucket user also and niavely lost all my photos also  -they changed how long ago, the gripes about photobucket are very long gone, dusted and buried by now.  A Prime example how we fell into a free service then they started to charge so we simply stay or move on.  Do you want to upload everything on-line or just chose a few pics?  (Facebook users need not apply)


That process for flicr works and it takes about 30s a picture to pull from yours to here so can't be that bad?  As I said I explained to a different user but they continue to post just links ever since which is their choice.  We can all wax lyrical about photobucket forevermore but it won't come back! and you must be many years to complain about it so not much sympathy now as we were all in the same boat.

PS:  In the background I also asked martin / admin to include the ability to post from flicr on the image posting thread I siad before as it's not mentioned there but is in reality pretty simple or -if in doubt just attach a picture to be straight and threy couldn't male it much easier just to "attach"


I also used to have an on-line gallery with a digital camera magazine.  I made it to front page, then they changed and went to social media type posts.  I lost everything trying to log-in afterwards and was told tough love by the magazine: new system like it or lothe it. Reminder that wherever you post to for free or cheap is not in your control, it's just all a balance of whatever t's and c's you accept but they will probably change regardless. Post away but never, ever be afraid to lose a picture you post is a good rule to follow.  Pics uploaded as attachments on here are just the same -chose who you upload to and take the terms.
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James321

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Re: Graupner - Azimut Atlantic Challenger
« Reply #11 on: October 15, 2021, 05:08:38 am »

OK, I think Ive got this figured out (thanks Rich!) so let me start again with the pictures and I'll continue the build thread from here:So here's the kit after it was unboxed, you can see the difference in colour in the hull where the resin was poured in the rear end only, the cabin had the original decals or actually they are vinyl stickers, these have all been removed and rubbed down:
The new parts included in the kit saved my bacon as these aren't available anywhere:

So as i mentioned previously, there were no bulkheads or structure included and the plans aren't great for determining the shape of the bulkheads at a given point in the hull so I set about making paper templates, these were then transferred by computer magic into a digital image for the CNC machine:
 


With the bulkhead shapes finalised we put the carbon fibre sheets in the CNC and let the black dust commence, the finish was a little rough but after a quick run over the edges with sandpaper they looked great:


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Martin (Admin)

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Re: Graupner - Azimut Atlantic Challenger
« Reply #12 on: October 15, 2021, 05:43:48 am »

   
     :-))
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Re: Graupner - Azimut Atlantic Challenger
« Reply #13 on: October 15, 2021, 06:38:02 am »


   
Quote
     :-))

Hi Martin, did you update the photo guide to add for flicr?

Rich
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James321

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Re: Graupner - Azimut Atlantic Challenger
« Reply #14 on: October 15, 2021, 09:13:19 am »

Continued

The hull interior looks messy here because its sanded back so the adhesive bonds better, I'm using Voduglue which is an Easy Composites product, it gives an incredibly strong bond, you could literally glue aeroplane wings on with this stuff, its down side is a very short working time, you have less than 10 minutes before its staring to cure so the aligning, application, aligning and fixing has to be rehearsed a few times before you commit to the fitment.



I added some more strength to the forward bulkheads, it isn't really required but once the deck is fitted these areas will never be seen again so what looks very messy in the pictures is purely function over form. I used some 25mm carbon cloth, its the same method for glass cloth, paint on the resin, allow it to cure to the A stage (tacky but not wet) then apply the cloth and using a paint brush or roller, push it in to the edges and leave it to cure, I usually give it a good 24 hours but the temperatures here in Dubai are quite a bit higher so I'm being excessive on that cure time.
This picture is with the cloth applied but without the top coat of resin:
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James321

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Re: Graupner - Azimut Atlantic Challenger
« Reply #15 on: October 15, 2021, 09:31:55 am »

Attaching the Jet drive was a messy experience, due to the previous owners resin coat and then my addition of carbon skin, the dimensions were all askew so it took some time and a lot of adhesive to get them watertight and in a position that would line up the impeller, prop shaft and suction tubes without the impeller binding, again this was a process that required several dress rehearsals before committing to adhesive

The original Graupner plans have the servos mounted on sections of ply which are attached to the sides of the suction tubes at the very rear of the hull interior. I'm a little concerned with my weight distribution on this build as the original runs with 2x 6V 8mAh motorcycle batteries which weigh in a 2kg per piece, I'm going to be running 2x Lipo 4s 5000mAh which weigh in at 450g per piece so the CG of my boat is going to need to careful consideration.I drew up a single servo mount tray and made it from MDF to see how it will fit, it had a few design changes until I had the two steering servo and two reverse servo servos in line with the holes in the transom.


Here the servo tray is straight off the CNC machine so its got rough edges, the small L shapes are for L Section carbon to become the servo mounts.
A bit of cleaning and sanding later and I attached the L Sections using the Voduglue

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James321

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Re: Graupner - Azimut Atlantic Challenger
« Reply #16 on: October 15, 2021, 10:04:06 am »

My next job is installing the motors, I've gone for a pair of 3660 1460KV motors to go with the 4S LiPo, that should give me approximately 16,000rpm on the impeller if I did my maths correctly, I can always go up a size to 6S on the batteries if this setup doesn't work so well but I wanted to keep the current/heat down as much as possible.
Here's a question for the experience out there on the forum; Motor/ESC cooling - Dubai is a salt water environment, there's no fresh water lakes if you exclude the swimming pools, I really REALLY don't want to use the sea water as coolant, carbon fibre and aluminium are not galvanic table friends in a salt water environment, the aluminium will literally dissolve! I was considering running a water tank and using that as coolant, it would also probably help with getting the weight back in the boat that I lost through the batteries. Is an onboard water reservoir something commonly used on RC boats, will it have the capacity to keep the motors cool?
Anyway, back to the motors and mounts, I considered making the aft bulkhead the motor mount but it just got too complicated in having everything lined up, it would have had to be perfectly aligned on both sides for it to work and this 20 year old model is far from perfectly aligned so I went for two separate motor mounts:


These will be attached using the same adhesive as the rest of the build. I think I've got them lined up well enough, I can slide the motor in and out and it connects straight in to the coupler, I'm not at a stage where I can run the motors yet, I'd like to do that to ensure there's no vibration from misalignment but it looks good by eye.Next job is to design the battery trays and ESC trays, I also think I'll have to mark out the water line and pop her in the bath to figure out where those should be positioned. I also have a bilge pump and coolant pump to work out where to position.
That's this thread up to date, I'll be working on completing the servo tray today and then hopefully be receiving material for the deck next week, I'm still undecided on staying with ply as per the original or switching to a 1.5mm thick plasticard deck, I'm thinking the latter as it's an easy product to work with and I would assume has better longevity.
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derekwarner

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Re: Graupner - Azimut Atlantic Challenger
« Reply #17 on: October 15, 2021, 12:05:49 pm »

So taking an alternate thought, many combustion engined vessels use surface cooling [under the hull bank of radiator tubing] and circulate hot engine cooling water through the surface cooler & attain cooling from the cooler sea water


Seawater temperatures Dubai appear to range from ~~24 to 35 degrees C throughout the year


a. So this appears a little problematic unless you can see the electric motors cooling water jacket being at least 10 degrees C over the water temperature, and then have sufficient flow through the closed loop to take advantage of the heat differential


From your background, I am sure you realise any exotic [expensive] cooling fluids are either water + colour die, or ethylene glycol etc
What type and flow do you have planned for water cooling?


b. Air cooling again through a closed loop radiator would at first appear questionable, with the ambient air temperatures approaching or as high as the fluid in the motor water jacket


c. Brushless motors are available with a dual output shaft [one at either end]......a 20 mm diameter fan in a close-fitting circular trunking wizzing around at 16,000 RPM would appear to be a consideration in blowing ambient air directly over the motors......an alternative to this could be a similar sized fan mounted on each of the motor couplings, however reversed to direct the trunked air back over the motors

[I find the subject interesting as I am considering using 2x 25 mm diameter/square cooling fans to blow air over a small tube radiator with circulating boiler water & so add some preheat to a twin cylinder steam engine to minimise condensate at startup]   

Keep us posted with your thoughts & progress

Derek       
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James321

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Re: Graupner - Azimut Atlantic Challenger
« Reply #18 on: October 15, 2021, 01:07:21 pm »

Hi Derek,
I considered air cooling but there's not going to be much air flow through the hull without drastically changing the design to allow a thru-flow of air.
You're right on the air/sea temperatures here, also the salinity is off the chart, possibly a byproduct of the desalination plants on the coast pumping as much brine back into the sea as they take out clean water but it's very salty. If i ran the sea water through the motors I'd have to rinse them with de-salt flush after each use and I'm not looking for something high maintenance.My thought was a water tank of approximately 1/2 litre, I could add ice to this if required to keep the water temperature down. No fancy additives are required for the water, as you say they are just dyes to make it look pretty but probably reduce the waters cooling efficiency.
I got the servo tray finished up, I just need a few more nuts to complete it:

 The pushrods line up nicely, I will have to drop the height of the rudder/steering pushrods on the servo arm but thats simple enough to do

I've a set of new pushrods on their way from Cornwall model boats with the bellows to seal up the holes.
I now need a set of 4mm bullet connectors for the ESC's and break out the soldering iron and then hopefully see if i can get motors turning.
I'll hopefully get an hour of so later today to get some adhesive on the motor mounts, that looks like it will be a 8 stage process, one motor at a time, attach the outside of the feet first, then remove the motor once that's cured and apply the adhesive to the inside of the feet, repeat for motor number two.

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derekwarner

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Re: Graupner - Azimut Atlantic Challenger
« Reply #19 on: October 15, 2021, 01:34:49 pm »

This is a very tidy build James.....


With the salinity so high, coupled with the sea temperature, you may need a pump with a pressure capability as the vessel in still water for any length of time would cause salt build to clog up in small bore tubing!


I have no knowledge in the construction of those anodised aluminium motor water jackets you show...do they have any sophisticated internal porting or are they just a tubular shell with an inlet & and an outlet?......if so, the actual cooling capacity is limited the heat mass transfer of the aluminium as opposed to any secondary internal flow?!


Have you considered any of those copper tubular coils type conductors over thebdiameter of the motor?, that way you eliminate any of the corrosive issue, but again not the clog up 


I must admit I had not considered that the Atlantic Challenger would have a waterproof deck to hull with limited breathing


Do you use liquid nitrogen at the Aeroshop?.........you could consider a self-designed cooler complete with a miniature peristaltic pump?  %)


Don't you just love word spell...when I typed die  :embarrassed: 

Derek
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Martin (Admin)

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Re: Graupner - Azimut Atlantic Challenger
« Reply #20 on: October 15, 2021, 05:21:05 pm »

   
Hi Martin, did you update the photo guide to add for flicr?

Rich

No..... but James seems to have worked it anyway!   :-))
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James321

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Re: Graupner - Azimut Atlantic Challenger
« Reply #21 on: October 15, 2021, 05:50:04 pm »

I used Rich's "inspect Q" method to get the jpg link, it's a long winded way of working it but it works. Flickr does give the ability to select the picture size and then gives a UBB code for that size picture, that's how I've worked it on forums in the past, not sure if the "image location" tab above can be adjusted to accept a UBB code?


I'm not so good with computers and software, give me tools and I can build it or fix it but I'm a rabbit in the headlights with computers.
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Re: Graupner - Azimut Atlantic Challenger
« Reply #22 on: October 16, 2021, 03:18:54 am »

Hi James321;


I also used to be annoyed with cooling a power source of RC tank.
For instance,in my case the tank was 1/10 scale(actually 67cm long)0.7mm steel made one weighing about 25kgs.
This was powered by OS 2 stroke 45 class nitro engine which was,OF COURSE,enclosed mostly by the steel made hull that
became toooo hot naturally under the violent sunshine in the mid-summer in Tokyo where it became normally around 35degreees C. {:-{ :(( <:(  The engine was running in the very narrow and abnormally hot conditions.!! O0 {:-{ :((
I finally came to succeed in running the tank for continuous 30 minutes under such circumstances by water cooling system,
when the fuel tank had been exhausted completely.
The tank was equipped with a water tank of 400cc ,a simple handmade radiator with a primitive fan and a micro pump.
Instead,the brass water tank became hot with a touchable level like a bath water after the running. O0
I added a certain level of a coolant for car at that time.
I thought in those days about 30years ago that water cooling be so effective for severe circumstances such as the above. O0 %)
A running tank in the pic below was taken in the winter.!
Even I once thought to challenge building the Azimut Atlantic Challenger.....
Wishing you a successful work of the superb boat.!!! :-))
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Re: Graupner - Azimut Atlantic Challenger
« Reply #23 on: October 16, 2021, 12:08:12 pm »

Hi Backerther, impressive tank, 25kg of steel, wow! I looked at an RC helicopter cooling system for electric helicopters, it had a small radiator/heat exchanger with a built in pump and the water jacket for the motor, a very neat design but sadly no longer produced.


I went to my not so local RC store today (1.5 hours round trip) to look for a solution to the cooling problem, the store is geared up mainly for RC planes but it seems that's where I found my answer, I walked out with a 24oz (~700ml) aircraft fuel tank complete with clunk and hose, this should work perfectly as a header tank for the cooling system.


More pictures to come soon, I've been working on the two water pump mounts today, they will live in the stern behind the rear bulkhead, one is a bilge pump with water sensor, the other is the coolant pump for the motors and ESCs.
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Re: Graupner - Azimut Atlantic Challenger
« Reply #24 on: October 17, 2021, 01:29:04 am »

Glad my method worked for you, it's only a few mouse clicks at the end of the day.


As for cooling, carrying around  freshwater coolant on a model is just plain daft to me. Much better to just use the sea water.  Flush it out afterwards like you should do on any boat with an outboard.  You'll maybe find you have to pull and strip out the drive shafts and anything exposed anyway like others who run in salt water do?


I don't know what an r/c tank has to do with a model boat sitting in the biggest heat sink possible.
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