Introduction: DIY F1 RC Race Car! a Complete Beginners Guide to Building Your Own R/C Race Car
Hi! My name is Dogoman, inventor and creator of the first ever DIY 1/18 F1 Remote Control car!
Have you ever wanted a really fast on-road R/C car that looks and works awesome, and doesn't cost a fortune? If so, then today is your lucky day! In this Instructable I will be showing step-by-step how to make your very own high speed R/C race car, without the need of any fancy machines, advanced technology, or really any previous experience in R/C! If you do happen to have a laser cutter, a lot of the parts cutting work using my templates will be easy for you. I don't have an expensive laser cutter (I wish!), so these instructions use basic tools anyone can easily access.
About two years ago I started this project with the vision of making my own mini R/C car, that I could have fun with in a small area, but what I got was much more!
The first design idea I had was a 1/24 "rally" style car using a Tamiya universal gearbox with a mini 4wd plasma dash 130 motor, but when I did the calculations I found out that it would only go around 7 mph! So after that I left the Idea for about six months and started looking into buying a cheap off-roader, but the prices led me right back to my homemade R/C car. Then I started to look for ideas on the internet, and I came across a style of on-road R/C car that does not have an actual transmission, but uses a direct drive style of "transmission". Basically it has a solid rear axle with a spur gear directly on it, and the pinion gear on the motor meshed up against the spur (as seen it pictures 7 and 8 ). So I started brainstorming some more and drew a new design that was an "1/18"scale IndyCar with a pan car style drive train, but then I realized that it was actually a 1/24 scale car, so I started to work on a new design.
(sorry about how short this test run is. The camera was apparently not recording, and i did not get another good test run in because Hobbyking sent me a faulty power system. They sent me a new one but it has not got here yet! :( I will post a good test run as soon as I can.
So after a few months I finished my third and final rough design, and this time it was an actual 1/18 IndyCar. After months of saving money, designing, and changing designs over and over again, I finally finished it on October 7th 2015! The final v.1 design runs on a 6100 kv motor (76,000 RPM on 12.5 volts) and a 25-90 amp car ESC, with a 2.4 GHZ radio, and it runs on 25-50c 2-3s LiPo battery.
Absolutely all the electronics and some of the hardware in this car comes from http://www.hobbyking.com/hobbyking/store/index.asp.
I got the tires from http://www.amainhobbies.com/rc-cars-trucks.
I got the rest of my parts from my local Home Depot. There are absolutely no salvaged junk pieces used in this project, so its 100% reproducible!
I would like to give a big thanks to http://flitetest.com/ for inspiring me to do this project!!
When I saw how Flite Test makes their own scratch build R/C planes, I got to thinking. If they can make their own R/C planes, why can't I build my own scratch built car? Without that inspiration I would have never designed, made, or finished the v.1 design for my 1/18 F1 R/C car, and believe me I really cant tell you how many times I've changed the little design details, and how many times I just gave up on the idea! So THANKS FLITE TEST!!!! :)
If you are interested in making your own super awesome scratch built rc planes, please do visit their website and their YouTube channel to learn more!
I would also like to thank Hobby King for having all the great quality products at really low prices. I would have never been able to get into this hobby without Hobby King's great products at low prices, so thanks!:)
NOTE: If you look at the price this project costs and think, "wow! thats expensive!", and "why the heck would I make one of those when i can go to Walmart and buy a 1/18 car for $20-$30?", please consider that this isn't a "robot" or cheap "toy grade RC car". This car is built for high speeds and racing, and is not your every day cheap toy-grade RC car.
Step 1: Tools
The tools you will be needing for this instructable will be:
: 1-2 adjustable wrenches
: files ( preferably small files )
: hack saw, and/or dremel with cutting bit
: dremel with cone grinding bit
: x-acto knife
: metric allen wrenches
: drill and drill bits
: hot-glue gun
: soldering iron and solder
( for soldering battery leads)
: small screw driver
: ruler ( with mm )
:infrared digital thermometer ( optional, but recommended )
: and finally, the scissors!
: Optional...laser cutter if you're lucky enough to have one. Lucky for everyone else, I don't have a laser cutter, so I'll show you how to do everything cutting manually!
Step 2: Electronics
If you don't have any "hobby grade" RC parts, then follow list one, but if you do have the basic parts
( transmitter/receiver, LiPo battery charger etc.) then follow list two.
(Note: if you are in the US be sure to buy from the US warehouse not the international warehouse because large orders can be expensive.)
List 1: The total comes out to $155 at 2015 prices. If you feel really bad about spending this much money I'll try and ease your mind. :) Most of the expense in the RC hobby is TX-RX (transmiter & receiver), battery charger, and accessories. You can do a ton of stuff for way cheaper once you have your Tx-Rx and battery charger. Even if you get very little money to spend on this it's really not that much. I'm only 14, and only get around $10 per month, and iv'e already spent over $200 in this hobby (not only cars but also planes and other things)
or a better and nicer radio
: battery and charger
and this for safety
:motor and esc
The motor and ESC combo I used is the 6100 kv setup, but any one of these will work (lower kv = more torque, higher kv = less torque & more speed), or if you already have a motor and ESC you can use that too just as long as the motor is around 20-24mm in diameter.
List 2: The total comes out at $110 .
:motor and esc
The motor and ESC combo I used is the 6100 kv setup but any one of these will work (lower kv = more torque, higher kv = less torque and more speed), or if you already have a motor and ESC you can use that too just as long as the motor is around 20-24mm in diameter.
Or you can use any 2-3s battery around that weight and size if you already have one.
Step 3: Materials, and Accessories, and Hardware
When you go to the store, you may want to take some calipers with you so you can measure the loose hardware so you don't get the wrong stuff.
3/16in threaded rod. Be sure to get one that is straight and not bent in any way.
3/16 nuts (2)
M4 bolts and nuts
tiny brass washers (2)
1/4 (7mm) in inner diameter washer, and for the outer diameter anything thats not under 11/16 in (17mm)
nylon washer ( but in stores single)
You can buy these at your local hobby shop for cheaper.
1.4 mm music wire
and 1.4 mm linkage stoppers
dollar tree foam board( NOT THE ELMERS STUFF !!!)
spur gear 50turn (50 teeth) 48pitch
pinion gear 18turn (18 teeth) 48 pitch
Team Associated RC18 tires (for rear) buy here
Traxxas LaTrax rally tires (for front) buy here
ball bearings 4mm
motor heat-sink with fan
Thermal Heat Transfer Compound
xt60 connectors, or your favorite style battery connector
yeeeeah! sticker sheet! because its just not complete with out the stickers!
Step 4: Understanding Your Electronics
Understanding your RC control system is very crucial. The more you know about your power system, the easier trouble shooting will be further down the road. If you already have an RC power system and know how it all works, then you can go ahead and skip steps 4-5 and move on, but if you don't, it is very, very, very important that you watch the videos and read this section! Now you will notice that these videos are for understanding RC airplane electronics. Thats ok because there are only some minor differences. The most important differences are the motor and speed controller. The motors used in RC cars (including this one) are in-runner motors. Most RC planes use out-runner motors. Both of these motors are covered in the video. The other difference is the ESC (electronic speed controller). The main thing is the ESC for a RC car can reverse the motor. This allows the car to go in reverse. An RC plane ESC only goes one way . To better understand what I'm talking about, watch the videos. The only other differences are you only have one servo for steering, and the motor is spinning a propellor not wheels.
There are five main components that make up your RC power system: TX/RX (transmitter & receiver), battery, ESC, and servos. The esc motor combo that I recommend comes with a good manual read it! I include a picture of the wiring, note this is not a picture of the same power setup. however it plugs in the same way. All 2.4 GHZ radios work the same, other than the number of channels. and the shape they take. You can use a stick transmitter, but its a lot better to use a pistol grip, but they both do the same thing.
Step 5: Safety
LiPos are the most common battery for RC. LiPos are not your normal everyday batteries. If you don't take care of them they will go bad. You never want to over charge your batteries. If you do, they will heat up and smoke! In some cases they will even burst into flames!! The same goes for draining the voltage too far.
Now that I covered the bare basics on liPo safety, watch the video for more detail on what to do to protect your batteries. To better understand how liPos work, watch the liPo video in the last section.
Cutting safety is an important thing to remember when using an X-acto knife or any other sharp tool. Never cut towards your body or any body parts, especially fingers. When using a Dremel or hack saw make sure to keep your fingers clear of the blade. I know you have heard this before, but it never hurts to be extra cautious! As always, use common sense!
Step 6: Cutting Out Your Templates, and Marking the Pieces
Step 1: Cutting out your templates and marking the pieces
The first thing you need to do is print the template. Once you have printed your template, start by carefully cutting the pieces with your x-acto knife and scissors, using the scissors for the straight cuts and the x-acto knife for the rounded cuts. After you have cut the pieces, take the motor mount and bearing holder template and crease it straight down the center on the black line (see pictures). Now you will need to get out your aluminum L bracket and tape your plans to it (on the outside of the bend), making sure that the crease line is on the corner of the L bracket. With the plans taped down, mark the circle and each corner of the rectangles. Then take off the tape and remove the plans, and connect the dots to form the rectangle. Do the same for the other one. Next turn around the bracket and mark your two steering plates, re-enforcing plate, and chassis, using the same techniques you used for the motor mount.
Step 7: Cutting Out the Parts
Step 2: Cutting Out the parts
Once you have marked all the parts, its time to cut them out. Start by cutting the motor mount/axle holders with a nice sharp hack saw, making sure that you keep your arm and hand straight holding it firm but not tight with your forefinger extended to keep the saw pointed straight. Here's a good article and video on how to properly use a handsaw.
The next part you need to cut are the steering plates, and they are small, so you will need to hold them down with either a vise, workbench, or some good old clamps. Once you have clamped you bracket down to a solid surface, you can begin by cutting the top angled cuts. Since Its angled its extra hard to keep the blade right on the line, so what you need to do is grab the hack saw with both hands and slowly give a couple nice long strokes until you have a nice straight kerf going, then you can continue with the back and forth movements. Next cut the straight cut all the way down. Then clamp the piece down again, and cut the two bottom angled cuts. Now just cut the remaining piece of and file down the edges then repeat for the next one:) .
Now get out your 10-24 threaded rod and cut from the straightest part a 16mm length of it. With that cut mark a line 75mm away from each end with a Sharpie or any sort of marker. Next hold down tightly the rod on a flat surface and take a small file or dremmel and start filing the thread down where you just marked until you have a nice flat area in between the two lines. Then flip it 360º degrees and do the same thing, but be careful not to file to far. The only reason in doing this is to make a flat spot for the adjustable wrench to hold on to without slipping, while you screw on the nuts, so you only need to file down enough on each side to get rid of the roundness.
The only part remaining to cut now is the wood chassis, cut this out using the hack saw and files, or just use you dremmel with cutting disk and sanding bit( I would recommend using the dremmel because its much easier and faster to do ). What you need to do is first cut all the straight edges, and where there are rounded cuts draw a straight line from one point of the arch to the other point. Cut on the line and just use the sanding bit or a rounded file to sand down to the curve.
Step 8: Drilling Out the Holes
Step 3: Drilling out the holes
You heard it, it's time to drill the holes! You're going to need get out your drill and 3/8, 5/32 (or as close to 5/32 as possible) drill bits, and two other bits (exact size doesn't matter: one larger than the 5/32 and one smaller than 3/8). Ok lets begin, the first parts we will be drilling are the holes in the motor mount brackets for the bearings. Take your two aluminum brackets and clamp them down on the edge of a table, workbench, or vise, with a piece of scrap wood under the bracket so you don't drill into your work table. Then take your drill with the 5/32 bit in it, and put the bit on the center of the circle and slowly give it throttle until you have a nice indentation for the bit to go into. Then start picking up its speed until it goes all the way through. After you have drilled the pilot hole move up a couple sizes up and use the previously drilled hole to position the next one and drill the hole. If you notice that your bit is starting to get too hot you may need to use some cutting oil to help it go through. Keep doing this until you get up to the 3/8 bit and you're done, Repeat for the other one!
The whole point in doing this instead of just starting with the largest is because if you where to do that it would be extremely hard to keep it in the right spot without it going allover the place, not to mention it would most likely get stuck and you could break the bit or even damage the drill. Have you ever heard the saying "don't bite off more than you can you can chew"? It's much easier to to slowly move up a size until you get up to the right size, than try to go straight to the large one. If you notice that your bit is starting to get too hot you may need to use some cutting oil to help it go through.
After you drill out the holes for the bearings it's time to make the mounting holes for the motor! With the 5/32 drill bit, start drilling a row of holes as close to each other as possible in the area you marked so you can turn them into one slot. Make sure that the middle holes are centered on the line, that the bottom of the top holes are aligned with the bottom of the line, and that the bottom holes are aligned with top of the bottom line (as seen in picture 7). After you have drilled all the holes get out a small flat file and start filing out the holes to make it flat. It doesn't need to be perfect you just need to file it down enough to fit your motor mount screws in, and the motor shaft fit through without rubbing up against the mount. Then just flip it around and drill the mounting holes on the bottom with your 5/32 drill bit, and you're done with the aluminum brackets!
Next just drill out the holes in the chassis, suspension upper deck, steering plates, and reinforcing plate with the 5/32 drill bit and your ready to move on to the next step!
Step 9: Gluing in the Rear Axle Bearings
Step 4: Gluing In the rear axle bearings
For this step you will need to get out the two aluminum brackets and your two 3/16" ball-bearings. What you need to do is push your bearings into the holes you drilled, and make sure that the outer part of it is flush with the bracket. You may need to file out the hole just a little bit to make it fit, but be careful not to file too far or you'll ruin it, you want the bearing too be tight but not so tight that it takes an excessive amount of force to push in. With the bearings pushed in making sure that they are flush, slowly pour on small drops of super glue, being very careful not to get any inside the bearing. Once you feel you have a good amount of it on there, get out some baking soda and cover all the glue and around it in the baking soda. This step is optional but highly recommended, because what the baking soda does is it instantly cures the surface of the super glue, and will prevent getting your fingers or anything else stuck to it. You will need to do this a few times until the glue is piled up enough to get a good hold on the aluminum and the bearing. Then just clean the baking soda off and do the exact same thing to the other one.
(Note: I did this step with the brackets mounted to the chassis but you don't need to do that.)
Step 10: Assembling the Rear Axle
Step 5: Assembling the rear axle
Once you have cut and drilled out the holes in all the pieces, and installed your bearings, it's time to assemble the rear axle. Start by getting out four of your 15mm long M4 bolts and nuts, and insert them into the holes in the chassis and, carefully slide your bracket on and thread the nuts on (see pictures). If your bolts are too long you may need to cut them down with a hacksaw or dremmel. Be careful not to cut them down too far. You want at least 3mm extra sticking out, but not more.
After you've tightened that down it's time to assemble the axle. You're going to need the 3/16 threaded rod, four locknuts, 3 washers, one 3/16x1/2 nylon spacer, and your spur gear. Start by threading on one of the nuts 55mm in from one of the ends, then slide on the spacer, spur gear, three washers, and then two nuts (see pictures). Make sure that the nuts are all tightened down and you're ready to mount the axle!
To mount the axle you will need four washers, three locknuts, and four regular nuts. First slide on one of the washers onto the axle, then partially insert the axle into the bearing on the left side of the car and slide on a washer, four nuts, and another washer (see pictures). Then start screwing in the nuts until the axle is in as far as it can go, and tighten up two nuts up against each bearing (see pictures). After they are all the way in and tightened, put a washer and locknut on the opposite side than that of the spur gear assembly, and tighten that up against the bearing (see pictures). Next thread on another locknut, but not all the way stop it 10mm away from the other nut (see pictures).
Now to complete the rear axle, you just need to install the wheels. What you're going to need to do is get your two tires and drill the small hole out with the 5/32 drill bit, then ream out the large hole out with an x-acto knife (or dremmel with sanding bit), just enough to allow a locknut into it (see pictures). With it now reamed out, thread the tire onto the axle until its all the way up against the nut. Then thread on a locknut, but this time put it on backwards. If you can't thread it on backwards, you may need to file the edge of the axle so you can get it on then screw it in. Once you get the nut on, thread it on as far as you can into the tire as you can get it. Then get your super glue and slowly pour it in the gap in between the tire and nut, being carful not to get it on the axle itself. Keep pouring on the super glue until you have a good amount of it on there, then put baking soda on it to cure the surface. Let it cure over night and then you can thread on another locknut to fasten the tire down.
Step 11: Assembling and Mounting the Front Steering Hub and Tires
Step 6: Assembling and mounting the front steering hub and tires
For this step you will need your two steering hubs, two aluminum steering plates, two M4 bolts, two large washers, four 4mm bearings, four small washers, two nuts, and your two front tires.
For each hub do the following. First start by getting out your steering hub, insert the arm into the hub, and make sure that its all the way up against the hub, then turn it around and mark with a sharpie the inside of the rectangle (see pictures). Then remove the arm and file down about 2mm of the area that you marked (see pictures).
The whole point in doing this so when you mount the axle the bolt head will have enough clearance to fit flush with the hub to allow the steering plates to be mounted. After you file that down get your steering hub and steering plates, and mount the plates on the hub. If you didn't have a drill bit small enough to drill the hole for the servo screw, you can also use the tip of an x-acto knife to start the hole. Then you should be able to screw in the servo screw and mount the steering plate with it. Now put the 4mm long M4 bolt into the back of the hub in steering plate hole, and slide on a small washer, 4mm bearing, large washer, tire, bearing, small washer, then a nut (see pictures). When you tighten up the nut try and center the large washer on the axle so the inner ring of the bearing is not touching the washer, otherwise the wheel will not move freely. You may need to loosen the nut so you can adjust the washer using a small screw driver, and move it around until the wheel moves freely.
After you assemble both the wheel assemblies, its time to mount them to the chassis. Start by mounting the aluminum reenforcing plate, with a M4 bolt and nut, cut it down if needed. Then put on the bolt, small washer, steering hub and arm, small washer again, and a nut (see pictures). You want the nut to be on firmly but not so tight that the hub won't move, you may need to lubricate it to help it move better.
Step 12: Gluing in the Servo and Placing the Steering Links
Step 6: Gluing in the servo and placing the steering links
For this step you will need, your servo and servo arm with screw, three 1.4 linkage stoppers, and two lengths of 1.4mm music wire, one 65mm long and another 95mm long. Step one, get your 65mm long wire, and make a horizontal bend 10mm in, then make a vertical bend 15mm away from that one, this is called a modified z-bend (see pictures). After you are done with that, cut out a 10mm x 10mm foam board square and peel off the paper on both sides, then take your hot-glue gun and glue the foam board square to the chassis up against the aluminum (see pictures). Then get your x-acto knife and cut down the foam board so that it's flush with the aluminum and glue down your servo with a generous amount of hot-glue. Be sure to configure it as seen in the pictures! Next get your servo arm and ream out the second to the last hole so that the linkage stopper will fit on. Next put the linkage stopper on and wiggle the modified z-bend wire into the hole that you made on the steering arm (see pictures). Now slide the wire into the linkage stopper and screw on the servo arm (see pictures). Then flip the car upside down hot-glue the bottom of the z-bend so that you won't have too much wiggle room (see pictures). Now it's time to link the two steering arms. Get the two linkage stoppers and put them on the last hole on the steering arms, and link them with the 95mm long wire (see pictures). Now all that's left is to plug in the servo to make sure its centered, and tighten the linkage stoppers so that the tires are straight, and your done with steering!
Step 13: Mounting the Motor and Adjusting the Gear Mesh
Step 7: Mounting the motor and adjusting the gear mesh
If you decided to use a heat-sink and fan, before you can mount the motor you need to put on the heat-sink. The heat sink i chose was not actually made for a 21mm motor, it was actually made for a 28mm motor. So what you will need to do is use some pipe wrench pliers and carefully bend the heat-sink inward until it can slide on the motor snugly. Now just squeeze on some heat transfer compound and slide in the heat-sink and wipe off the excess.
With that on, you can now mount the motor and adjust the gear mesh. Get your motor mount screws and washers. I used two of the screws that came with the fan and cut them down to 10mm long with a hack saw , and used the same small washers. Now you can go ahead and pour out some locktite onto something, and dip the screw in it. Then put the washer on it and screw it in the holes that are the farthest out. Now put on the pinion gear and tighten it, but be sure to align the grub screw with the flat part on the motor shaft. Once the pinion is on get regular old paper and push the pinion up against the spur with the paper in between them and tighten the screws down, this is the most common technique for adjusting the gear mesh. If your gear mesh is adjusted properly, the gears should have a little bit of give, but not too much or the pinion could slip on the spur and strip the gears, but also not too tight, because if it's too tight it will bind up and not work correctly. See the video to best understand this step.
Step 14: Building the Body!
Step one, print the plans that are provided, and cut them all out using the same technique. Once you have cut out the plans, you can start tracing them out, as done before. Now its time to cut them!
The most important trick when using foam board, is to use a sharp x-acto blade! If your blade is dull it will just tear through it and leave nasty edges on your cuts. Now you may think well why does it have to be an x-acto knife? The answer is, you don't have to use an x-acto knife. You can also use razor blades and other cutting tools, but I would highly recommend using just your x-acto knife for a couple reasons. One, because it is the most maneuverable when cutting small and curved edges. Two, it is easiest to hold and move around. Third, the blade is normally thinner than most razorblades, so it will make a thinner, cleaner cut. It may help to get a scrap piece of foam and draw some straight lines and boxes using a ruler for practice. This will help you when you cut the actual pieces out. Also draw out some curved edges. Do some cuts that go all the way through and do some scoring cuts.
After you have gotten used to cutting you are ready to start cutting out the pieces! The score lines will be marked with a polygon. The rest just cut all the way.
Ok once you have cut all your pieces out, it's time to assemble them. We will start with the nose. What you need to do is bend it over and make an angled cut all the way down it. Now you should be able bend it vertically. Then fill the gaps with hot glue and quickly put it on over the servo (see pictures to better understand). Once the hot glue has dried take it off then put hot glue on the inside and bottom and slide it back on making sure that its on all the way. Then turn it upside down and glue on the front wing. But be sure that it's on straight and that the score cut is pointing down. Then fill the score line with hot glue and push it up a little bit. Then glue on the the little wedges right next to it, and you're done with the nose!
Now it's time to build the main body! Start by getting the side plates, and bend the part with the score line outward ( as seen in the picture). Now glue it down to the main body piece, with the non straight edge down. There is an arch marking what side is the front. Once the straight part is glued, glue down the curved edges. Do this for both pieces. Then take the piece you cut of of the nose piece and glue it down to the main body piece. Then put a small piece of foam board under it, and glue that down to it. Now get out the piece with all the score cuts, and a triangle on it. First, make sure that all the scored lines can open up. Second, fill them up with hot glue and hold it down, against the rectangle with a half circle. Then glue it down to the rectangle and the main body (as shown in picture).
Now it's time to form the cock pit! Take the main cockpit piece and peel of part of the paper ( as shown in picture). Then put it on the edge of a table, and start bending it. Once your done bending it, it should be able to bend, and stay rounded, but not just bending in one spot. Now put a good amount of glue on the bottom of it, and place it. You will need to hold it down for a few seconds to let the glue dry enough to hold it down. Now just glue on you half circles to the back of the cockpit, starting with the largest and ending with the smallest.
Now the only piece left to the body is the rear spoiler! All you need to do is pour some hot glue into the score cut and make it bend upwards slightly. Then just slide on the slotted squares and glue those on. To mount it just get a BBQ skewer and spear it into the spoiler, and into the foam board in the rear! Then just glue it in and you're done with the body!
I will leave painting and decorating, it up to you! Use your creativity!
(note: I will probably be doing a build video, and better body design, soon.)
Step 15: Mounting the Electronics
Step 8: Mounting the electronics
Now the final step is mounting the electronics! You will need to cut out a 60mm x 30mm, a 20mm x 30mm, and a 20mm x 25mm piece of velcro ( both sides of it). Cut all those and place the spiky part on the electronics and the soft part on the chassis, using the electronics positioning template. Next, get a regular old coffee stirrer, and cut a 20mm long slot down the middle so that the antenna can slide through it easily (see pictures), then just zip tie it on to the motor mount and you're done. This will be our antenna holder. Now all that's left is to put them on and connect them together (see pictures), and your ready to race!.
( Note: you will want to pad the small bolt sticking out behind the battery, so that the battery won't slam back and hit that.)
Step 16: Extras!!
Here are some extra videos that will help you better understand, and use your RC power system and car! These are optional to watch, but I would recommend watching them! :)
Step 17: Now You're Ready to Race!
This project was not only a lot of fun, it was bringing my dream to life! I hope you have just as much fun as i did building and using this car! Thanks for reading, and I hope my instructions were easy to follow. If you find something that is missing, or you don't understand feel free to comment and ask!
I will be entering this Instructable in the first time author contest, and the epilog VII contest. So if you liked this instructable please vote!