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mCP X Blade Micro CPx Helicopters Information and Help


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Old 09-08-2012, 01:29 PM   #241 (permalink)
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Quote:
Originally Posted by Lupusprimus View Post
@litehawkdown: Here you have the base for it:
http://www.heli-scale-quality.com/co...170/Itemid,43/
http://www.heli-scale-quality.com/co...art/Itemid,43/
Of the kits you can build any version of Hughes 500th.
Looks like a good quality kit. Might go that way. The Revel models look heavy. Thanks for the heads up.
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Old 09-08-2012, 08:32 PM   #242 (permalink)
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Well, I have not given up on the MIA 500 fuselage yet. I finally assembled the landing gear and installed it into the fuselage this evening. Tomorrow I'll look at figuring out the tail-boom issue and work on swapping the components over to the spare stock frame that I managed to keep. As confident as my flying has become with the MCPX and finally getting nose-in's, it would be nice to fly a scale bird.
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Old 09-09-2012, 01:21 AM   #243 (permalink)
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Originally Posted by Varc View Post
Well, I have not given up on the MIA 500 fuselage yet. I finally assembled the landing gear and installed it into the fuselage this evening. Tomorrow I'll look at figuring out the tail-boom issue and work on swapping the components over to the spare stock frame that I managed to keep. As confident as my flying has become with the MCPX and finally getting nose-in's, it would be nice to fly a scale bird.
Bravo! Never give up.
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Old 09-09-2012, 11:40 AM   #244 (permalink)
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Originally Posted by Coco66 View Post
Bravo! Never give up.
Never give up, NEVER SURRENDER!

I think instead of messing with my yellow birdy, I'm going to take my second MCPX that had the Xtreme head that didn't work so well, and convert it back to stock and use that as my scale bird. For the Military Hughes 500, I think the black plastic head will probably look better on it anyway. More, stealthy.
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Old 09-09-2012, 11:59 AM   #245 (permalink)
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My scale UH-1N based upon italeri 1/48 kit.
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Here are the components
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Basically the battery goes in the nose.
The crew platform fits over the battery and
The roof clips on top
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The side doors slide to connect the battery and remove the roof.
Flies pretty good with mild brushless set up.
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Old 09-09-2012, 03:50 PM   #246 (permalink)
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Well crap. Gonna have to scrap the project. I have lost one very vital MIA part that holds the tail-boom up. It's a gonner, can't find it anywhere!
Besides, I think I'm going to be selling ALL of my MCPX's and parts for the new NCPX!
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Old 09-10-2012, 07:14 AM   #247 (permalink)
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Lovely job Ians. Arf
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Old 09-10-2012, 10:09 AM   #248 (permalink)
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Thanx. Forgot to add photo of the original.
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Old 09-10-2012, 02:30 PM   #249 (permalink)
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Thanx. Forgot to add photo of the original.
Attachment 347950

How about a couple shots or video of yours in flight, I love the UH-1N Iroquois, in fact once I get this CP flying down I will be dressing my 600 up in some sexy UH-N1 Canadian goodness, but I am from a small town called Iroquois in Canada hence the Canadian dress
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Old 09-10-2012, 04:42 PM   #250 (permalink)
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@Ians99: Nice to see. What weighs on the flight?
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Old 09-11-2012, 10:27 AM   #251 (permalink)
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Sorry guys can't video or weigh it.
At the moment the heli and me are in different countries and I won't be back in UK until November.
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Old 09-11-2012, 11:26 AM   #252 (permalink)
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Quote:
Originally Posted by Ians99 View Post
Sorry guys can't video or weigh it.
At the moment the heli and me are in different countries and I won't be back in UK until November.
Beautiful work Ian! I just bought a bunch of stuff from Varc, so planning to get my Huey back in the air...
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Old 09-11-2012, 12:05 PM   #253 (permalink)
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I want to see it flying




When you get back to your heli you will have to try remember to get both the weight and a flight vid for us
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Old 09-13-2012, 03:57 AM   #254 (permalink)
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Will do. Just need someone who doesn't know how bad a pilot I am to hold the camera.
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Old 09-14-2012, 09:30 AM   #255 (permalink)
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i moved the tail rotor where it belongs. the tail motor should be cooler now, too. and the battery went into the cockpit. now the balance is better, not tail heavy any more.

h.
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Old 09-15-2012, 12:23 PM   #256 (permalink)
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i moved the tail rotor where it belongs. the tail motor should be cooler now, too. and the battery went into the cockpit. now the balance is better, not tail heavy any more.

h.
Looks amazing!
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Old 09-17-2012, 01:51 AM   #257 (permalink)
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@badfrog: thank you!
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Old 09-28-2012, 01:14 PM   #258 (permalink)
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First post, here goes. This isn't exactly mCPx, but I think it's relevant.

I love scale helis. I have a dream of the ultimate indoor scale micro heli. And by indoor I mean living room (not gymnasium) and by scale I mean down to the rivet, not some 'fun scale'. I'm not there yet, but I've been exploring available hardware and construction. The mCPx is a little too big for my indoor tastes (the nano may prove to be the bomb as soon as I can get my hands on one), so I've been focused on the mSRx. The flybarless head and size opens a world of great helicopters to model.

My plan is to mold fuselages. From model kits for now, probably my own scratch built molds in the distant future. I've attached pictures to show you what I mean. Starting with a 1:48 Bell Huey kit I created latex molds for the the main body halves. Once you have a mold, then it's a simple matter to recreate the part using either built up tissue and glue, or nothing more than a coat of paint and then spray foam (window insulation in a can). When it works, the detail is absolutely fantastic, right down to the rivets from the plastic kit (I guess the scale accuracy is only as good as the kit). When it doesn't work, it turns out like crap. I have much to learn yet, and soon I'll be switching to silicon molds instead.

To give you some idea, a model kit plastic body half weighted in at 5.15 grams (no paint). A reproduction, molded (and painted) tissue body half weighed in at only 2.9 grams. And that was my first attempt. The detail on the reproduction is identical to the original plastic part, and I'm sure I could cut the weight down even more. I'm not working on a 'final' fuselage yet, just feeling my way around the materials. With more practice I believe I can make an exact scale, foam body with all the detail of a plastic kit.

Another area of 'scale' concern for me is the tail motor. I just can't stand for a metal can sticking out of the tail. So I've been experimenting here two (pictures attached). Using a gear set from a Losi micro car differential and nothing more than a stock mCPx tail boom plus a little carbon fibre rod, I moved the tail motor from a direct drive hanging off the back to shaft and gear drive. The tail now has a proper slim profile that can be hidden in any number of scale heli profiles. I also flipped the tail blade to the other side (where it is in most of the heli's I'm considering). Just for fun I also created a scale'ish Bell Huey tail rotor to go with it (same scale as the 1:48 kit tail rotor) from some scrap carbon fibre. I don't have a picture of it, but I've been using the scale tail rotor for testing.

Despite costing probably less than $15 in parts, the tail conversion is working really well. The mSRx tail holds well and is nearly as responsive as the stock tail (it might be a little more sluggish, which doesn't matter). This tail mod is still very rough. The gear mesh isn't great, the bushings are sloppy. Honestly, it's a wonder it works at all but instead it flies great. With more tuning I can clean up the gear mesh (got some micro bearings coming) and streamline the gear box into an even smaller profile. Since it's not a direct drive anymore, the gears are different teeth counts, the tail rotor is now turning slower (1 to 5 ration maybe?). Different gears might be better.

Moving the tail motor forward is a serious change in CG. That's a lot of weight to just hang way out there on the end of a boom. The CG shift will be a tremendous advantage when it comes time to add the scale fuselage, they're always tail heavy. This mod will do nicely for a Hughes 500 or a jet ranger, but not for any heli with a bent tail (like the Heuy or a Cobra). I'm still thinking about how to do a bent tail. At the risk of more gear losses, maybe a second gear set at the bend.

Anyway, not quite mcpx (sorry) but I hope it's relevant and sparks more ideas
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Old 09-28-2012, 04:51 PM   #259 (permalink)
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Originally Posted by fightingmosquitoes View Post
First post, here goes. This isn't exactly mCPx, but I think it's relevant.

I love scale helis. I have a dream of the ultimate indoor scale micro heli. And by indoor I mean living room (not gymnasium) and by scale I mean down to the rivet, not some 'fun scale'. I'm not there yet, but I've been exploring available hardware and construction. The mCPx is a little too big for my indoor tastes (the nano may prove to be the bomb as soon as I can get my hands on one), so I've been focused on the mSRx. The flybarless head and size opens a world of great helicopters to model.

My plan is to mold fuselages. From model kits for now, probably my own scratch built molds in the distant future. I've attached pictures to show you what I mean. Starting with a 1:48 Bell Huey kit I created latex molds for the the main body halves. Once you have a mold, then it's a simple matter to recreate the part using either built up tissue and glue, or nothing more than a coat of paint and then spray foam (window insulation in a can). When it works, the detail is absolutely fantastic, right down to the rivets from the plastic kit (I guess the scale accuracy is only as good as the kit). When it doesn't work, it turns out like crap. I have much to learn yet, and soon I'll be switching to silicon molds instead.

To give you some idea, a model kit plastic body half weighted in at 5.15 grams (no paint). A reproduction, molded (and painted) tissue body half weighed in at only 2.9 grams. And that was my first attempt. The detail on the reproduction is identical to the original plastic part, and I'm sure I could cut the weight down even more. I'm not working on a 'final' fuselage yet, just feeling my way around the materials. With more practice I believe I can make an exact scale, foam body with all the detail of a plastic kit.

Another area of 'scale' concern for me is the tail motor. I just can't stand for a metal can sticking out of the tail. So I've been experimenting here two (pictures attached). Using a gear set from a Losi micro car differential and nothing more than a stock mCPx tail boom plus a little carbon fibre rod, I moved the tail motor from a direct drive hanging off the back to shaft and gear drive. The tail now has a proper slim profile that can be hidden in any number of scale heli profiles. I also flipped the tail blade to the other side (where it is in most of the heli's I'm considering). Just for fun I also created a scale'ish Bell Huey tail rotor to go with it (same scale as the 1:48 kit tail rotor) from some scrap carbon fibre. I don't have a picture of it, but I've been using the scale tail rotor for testing.

Despite costing probably less than $15 in parts, the tail conversion is working really well. The mSRx tail holds well and is nearly as responsive as the stock tail (it might be a little more sluggish, which doesn't matter). This tail mod is still very rough. The gear mesh isn't great, the bushings are sloppy. Honestly, it's a wonder it works at all but instead it flies great. With more tuning I can clean up the gear mesh (got some micro bearings coming) and streamline the gear box into an even smaller profile. Since it's not a direct drive anymore, the gears are different teeth counts, the tail rotor is now turning slower (1 to 5 ration maybe?). Different gears might be better.

Moving the tail motor forward is a serious change in CG. That's a lot of weight to just hang way out there on the end of a boom. The CG shift will be a tremendous advantage when it comes time to add the scale fuselage, they're always tail heavy. This mod will do nicely for a Hughes 500 or a jet ranger, but not for any heli with a bent tail (like the Heuy or a Cobra). I'm still thinking about how to do a bent tail. At the risk of more gear losses, maybe a second gear set at the bend.

Anyway, not quite mcpx (sorry) but I hope it's relevant and sparks more ideas
Very nice work!!! the shaft drive is brilliant! I would like more detail on the paper bodies... steps, qty, etc.
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Old 09-29-2012, 12:31 AM   #260 (permalink)
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Very nice work!!! the shaft drive is brilliant! I would like more detail on the paper bodies... steps, qty, etc.
Thanks. The shaft drive was really easy to do and works very well, considering it was just a test. A better bearing at the gears (either ball or block) will make that a no brainer. I did have trouble with the rotor blade hub. It's two short pieces of Aluminum tubing joined in a tee and bound with thread and CA. It's really fragile, I'd like to find something simpler and more robust to do the job.

As for the bodies, I'll detail what I've done although it's not where I want to be yet. This is my initial attempt. It's all about getting a good mold first.

I started with a 1:48 Huey kit. I think 1:48 might be a bit small for an mCPx. It's just about right for an mSRx. I thought a 1:35 kit might be a better fit for the mCPx frame, but even it's a little too big I think. Somewhere around a 1:40 would probably be about right for an mCPx, but nobody makes those. Anyway, I cut the side body halves along the door tracks and the floor under the first skid mount. My thoughts are that I would make it a two part fuselage with a lower and back half and an upper and front half with the split crossing the main rotor shaft. That way the mechanics could be mounted in the back half and the front could be magnetically stuck on without having to dismantle the head and blades to get things in.

An easy (cheap) way to make molds is to use liquid latex. It comes in a tub from the craft store. It's thick and goopy, but don't lay it on too thick. As it dries it skins over and if it's too thick it takes for ever to dry. I started with each heli body half (left and right) laid flat on an cutting mat. You have to cut down the alignment pins on the one half that has them so it will sit flat on the board. Then I simply painted the latex on with a brush. It's easy to apply, taking care to avoid bubbles. There's no need for mold release or anything like that. Dried Latex doesn't stick well at all to plastic, and the kits as they come out of the box still have some factory mold release on the surface anyway. You have to go one painted on layer at a time and let it dry over night before continuing or otherwise it will never dry in the thicker parts. It's a slow process. After a few layers had dried, I added drywall mesh (fibreglass mesh tape) on top and then gooped it into the mold with a few more layers to give it a little bit of rigidity. After the latex is completely dry, I used plaster of paris and burlap to create a hard shell over top. The latex picks up all the detail, but it's not solid enough on it's own to hold a consistent shape. The plaster 'cast' over top is what keeps the latex mold in shape for later use. The cast doesn't stick to the latex, but being plaster it takes the shape of the latex mold outside. So later I just lay the latex mold in its plaster bed to continue.

The latex picks up the plastic part detail perfectly, no complaints. Every rivet, every nook and cranny, every simulated screen mesh, all perfect. In fact after looking at the results carefully under a magnifying class I've learned a lot more about how 'crude' the plastic kids can be. Of course there were many open parts and holes in the kit side pieces. I filled in and built up those areas with modelling clay first and just latex-ed over top of them.

First lesson learned here (learning curve) was the the edge where the plastic part meets the cutting mat (edge of the mold). I thought I was doing OK, putting a weight on the part and latexing the edge to seal it before getting heavy into the coats. But it left a very thin 'lip' in the latex at this point that either tore away to create a rough mold edge or got left behind, also making a rough mold edge. I was trying to preserve the original model kit but not assembling anything, which was a mistake. Also, since I made each mold half separately, on a flat cutting board there are no keys in the mold flange. Needless to say trying to line up the halves later is hit and miss.

For my next attempt at molds I'm going to glue the two kit halves together first, then fill and sand and prime them so that the finished piece is perfect with no join seams. Then I'll use modelling clay to create a mold divider so I can create each mold half properly with keys. I'm still taking a two half (front and back) approach, although, I wonder if it would be easier yet to build the whole kit fuselage in one piece and then make the appropriate parting lines in the mold only.

Once the molds are done and the plaster is dry the fun part starts. I use Armour All car vinyl polish as a mold release (paint will stick quite handily to latex). Just squirt some on the latex and rub it around with my fingers until there are no more wet spots. Then I spray the inside of the latex molds with olive drab paint to give them a good coat. I don't have an air brush, so I've surely added more weight in paint than needs to be there. The paint will lift right out of the mold with the finished result.

My first test was to apply tissue paper directly to the (painted) molds. I'll call this the 'shell' technique. I used water based polyurethane crafters 'varnish' to wet the inside of the mold, then lay down some tissue and wet it again. This was all done very sloppily (experimenting). You need to be careful about tearing the tissue (common gift wrapping tissue) into small pieces that can follow the curves of the mold. Any corner or detail the tissue doesn't make good solid direct contact with will just crumple away when you pull it from the mold. I actually learned this from reading about micro airplane guys doing the same. There are all kinds of formulas for doing this, watered down white glue being another popular 'sticking' method. I placed several layers of tissue, one on another like this. Then I thought the drywall mesh tape I used making the molds might help make it even stronger. So I laid down a layer of that too, and more tissue. I suppose the drywall mess did make it stronger, but when it dried it left a mesh imprint in the final surface. It doesn't show so well in the pictures, but it was really noticeable. My final pieces were much heavier than they needed to be, but it costs next to nothing to make piece once you've got the mold so there's no where to go but up

When the tissue dried completely, I just peeled back the latex mold. Then I used common paper scissors to trim the excess tissue around the edges. Where I didn't get good contact between the tissue and the mold, details crumbled. In the future I'll be very careful to take my time and make sure the first layer of tissue gets forced into every little feature. I think I'll let the first thin layer dry well first before continuing. I kind of went gung ho and applied layer after layer while it was all wet.

The resulting parts are much lighter than the plastic they replaced. But lining the two halves up is next to impossible (there's no flat glue edge). For fun I cut a profile shape of a Huey tail from a foam dinner plate, and then glued the two halves to it on the top and bottom (foam plate back bone). It certainly was strong, but it will take a lot more finesse than I was prepared for to make it look good.

My second test I wanted to try working with spray foam. So back to lubing up the molds with Armour All, and a good thick coat of olive drab. This time I laid down just a single layer of tissue. Then I closed up the two mold halves lining them up as best I could with a little more polyurethane along the edge. This sealed the tissue along the joint. The molds (surrounded by their plaster casts) were wrapped with stretchy sticky bandage roll. I don't know what the bandage roll is called. We got it when our dog needed treatment. It's like a tensor bandage, but it sticks to itself when its stretched and wrapped (sort like reusable tape). Great stuff for this application. Then I shot spray foam, into the tail rotor hole until it swelled out the opening at the other end.

This attempt failed for many reasons. I didn't do a good job with the tissue layer. I tried to work with a 'single' big piece that didn't make it into the corners well at all. Some how I thought the foam would force it the rest of the way, but that didn't happen. I didn't let the polyurethane dry completely first, thinking that the moisture in the polyurethane would help kick the foam into curing. In the thickest parts, the foam took a long time to cure, and when that happens it gets messy as foam bubbles merge into uneven cavities. When the 'single' piece came out of the mold, some areas were really good, but many other areas just didn't make contact with the paint and the mold surface at all. With more testing and care I think this is probably the best way to go. The tissue layer would have to be done in many more smaller pieces with much care to follow the curves of the mold.

For my third test I was getting rather annoyed with the whole fiddly tissue work. So this time I lubed and painted the molds as usual, but skipped the tissue and varnish. Instead I just wrapped up the two mold haves and shot spray foam in the tail rotor hole.

This attempt showed a lot of promise (if for no other reason than the utter simplicity of it). There were some problems. For example the main body part (thickest foam) ran in to the same problem of foam not curing in the middle. In the thin parts (the tail boom and fin) the foam set up quickly and the detail came out perfect. But in the thicker parts, again foam would inconsistently merge small bubbles into big bubbles and then the big bubbles would collapse leaving pock marks in the final surface. If you look closely at the last picture you can see that parts of it look like they have been through a meteor storm. But it sure is easy! For fun I did another foam test (no paint at all) so I could see the foam results directly. I loves me the spray foam!

Spray foam will stick to pretty much everything, so you have to be careful not to let it touch the latex mold directly without some kind of protection.

What have I learned?

I've learned that the molds should be made directly against each other on a one piece part with a keyed flange so they can be accurately aligned each time. Don't try to make separate halves and line them up later.

I've learned that spray foam, in any thickness will suffer from bubble collapse leaving pock marks. I think I can reduce, if not eliminate, this by using an 'inner plug' to force the foam to fill a consistent wall thickness, say no more than a 1/4 inch. If the foam isn't allowed to get too thick, it will cure nice and smooth. Plus you'll have some hollow interior room to play with (and again, less weight).

I've learned that a single layer of tissue, properly attached and dried to the entire mold surface first (with some kind of water based adhesive) in combination with a foam filled core will probably do quite nicely and weigh a fraction of what the plastic kit did to begin with. The tissue layer will provide some protection against foam bubble collapse and give the surface a wee bit more strength.

My plan is to eventually mold the tail rotor drive shaft and gear box (and running lights) directly into a single piece light weight foam 'back end' that the rest of the hardware can be attached to.

My next set of molds I want to make using silicon (bathroom caulking). They will be more durable and not require 'lubing up' every time I use them (nothing sticks to silicon, but more silicon). I want to get a decent set of full Huey molds so I can turn out heli after heli until I get the process nailed. Then I'll sweat the small stuff like durable landing skids.

I have yet to try making molds of the 'front' half. The kit parts are all ready to be fitted and molded, but I'm not quite sure what to do about the glass areas yet. The clear parts can be vacuum formed easily enough, but the window/screen frames are going to be too thin to mold in foam. There just isn't much room for foam filler in the front half, so except for the nose, the whole front half might have to be formed from nothing more than layers of tissue.
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