how to make snowflake heart my youtube: https://www.youtube.com/channel/UCnvoThr2-6rfWITzEUQWTJg
Topic by duongjiangnan | last reply
ok i have the following parts to ue for this: (all leftovers from former project..) :) 1x mosfet IRF510 power transistor 5,6A 100V 9x 2N3904 amplifier transistors 40V 0,2 A .0.625 W ~16x 1uF capacitors 50V ~99x recifier diodes 1A 50V ~35x 2k resistors 0.25 W the idea is to charge a battery pack consisting of 4x 1,2-1,25V = 4,8-5V 3000mah AA nimh batteries using my 5v usb wall charger that has 1A output! i tried connecting the battery pack directly to + and - and 'i think' its starting to charge but after 1-2 hours at full rate (5v 1a) it should be at least 50% charged (3 hours would be full charge -> 5W x 3 = 15W), but if i connect them they last for about 2 -3 minutes and then empty again!! so after this im concerned that i might need at lest 6V-10V to achieve the desired effect !! -> charge 15W NIMH batterpack with wall charger (nokia ac-60e.. 1-1,5A) i nless than 3 hours (as like a phone would need !!) therefore i need a cuirciut (ONLY DC) to double my 5V OUTPUT to 10V (yiou shouldnt apply more than twice the curent of a batter pack) or ideally 6-7 V but i dont know if thats possible without a swiching IC or more different resistors.. so just doubling would be nice at the moment!!
Topic by sblocc10 | last reply
Hello instructacles, I'm trying to build a simple contact-based set of sensors embedded in card board, paper or thin plastic sheets. I want to make a simple game for my kids that could detect/react to the presence/absence of some random items positionned on such a board? (empty glass bottle of coke, cereal box, shampoo bootle, you name it) Ideally i would use something like those books for kids where they have metallic threads "printed" on think plastic sheets and when you press them, it triggers a music. But i dont know how to print metal basically. don't really know how to get started. I was thinking of sewing conductive thread but i'm not really sure it would work. I have seen many attempts with aluminium foil (ex: https://www.instructables.com/id/Interactive-Art-With-Scratch-and-Makey-Makey/) but those are based on the fact that a human finger touches them (basically it uses the conductivity of skin), whereas in my game i was to use the weight of random objects from the house (in the 50g to 500g range typically) Any idea how i should get started ? thanks fourchu
Topic by fourchu | last reply
Hello guys i'm building my first drone using the arduino pro mini , i'm following this tutorial https://www.instructables.com/id/SpeechVoice-Controlled-Arduino-Drone/ on how to build it but i have a problem with the wiring , i've connect the battery to the arduino and also the hc-05 but i'm having problem with wiring the rest i've uploaded a picture of my wiring so far can someone please help me wiring the rest. http://imgur.com/dK4cRFy thanks!
Topic by omarb22
I am making a personal plea to contributors to Instructables to please, refrain from using acronyms! The same goes for submitted comments. I am not a total novice in computer hardware or programming, but I frequently get caught struggling to understand an instructable or comment because of a needless use of acronyms. Think how someone new to instructables , with little or no background, must feel. I understand that there are times acronyms are used for brevity, but surely a simple explanation of the acronym when first using it would be a help for all readers. In fact a list of acronyms to be used and the meaning of each wouldn't be a bad idea! The purpose of an instructable (in my opinion) is to pass on a tip, a procedure or even to teach your reader how to do something that you think is worthwhile. An excessive use of acronyms with no explanation/definition strikes me as counterproductive. That makes me feel better, nothing like a good RANT!
Topic by cobourgdave | last reply
I will make very small robot with wheels+ display + color sensor .Wheeles will be remote controlled and I need to manupilate info from color sensors and write it to display with stopwatch . For example robot goes and stands on brown surface and displays "You are on ..brown.. surface for ..10.. seconds " or when it reaches to 1 minute it displays "You are on ..brown.. surface for ..1. minute and you should leave " Questions - 1 -Can arduino handle this much work ? If yes which model should i prefer? 2 -Is raspberry pi a better choice? Again if yes which model ? Little note Coding wont be problem .I have worked with c languages.Im just inexperienced with mechanical stuff. I want my robot to be fast from all aspects( obviously) . i might add some features like voice or camera in the future.
Topic by ShadowL5 | last reply
I have a project where I very simply need to raise and lower a flat board with a 50 lbs drill press 35-40 in. and have it stop at the same specific place every time going up and coming down. I've seen TV lift mechanisms and things such as that, but they cost $500 - $1,400. I need this project to cost very little. <$100 if possible. I have a scissor design that I will be made from wood that I already have, so all I need is a motor that can lift 50 lbs up and down, slowly, quietly, and only once or twice a week. But I know nothing about motors. Here are all the parameters that I can think of. 1.) It will be stationary, i.e. — not require a battery or ever need to be moved. 2.) It must move slowly. Lift the surface approx. 1 in per second. i.e. — around 30 seconds to raise the surface 30 in. or so. 3.) It must be as quiet as is reasonable. It doesn't have to be whisper quiet, but def. not power-drill loud. 4.) It must be as inexpensive as possible. I do not care about... 1.) Motor weight 2.) Dimensions 3.) Power consumption 4.) Heat production 5.) Longevity... it will be used very rarely so wear & tear is a non-issue really I very much appreciate any help you guys can give.
Topic by Dolmetscher007 | last reply
was doing a bing vs google test and found this. what is it? its my photos and text from my instructable on another website , my identity or username are not there? http://www.diyourself.ru/technology/pc-power-supply-on-ps3-slim-do-it-yourself.html being brief because it written it 4 times now and it keeps being glitchy and loosing what i just wrote.
Topic by crazyg
Hello, I am currently developing a wireless PIR motion sensor for my home with Arduino and I need some advices (I am new with Arduino). The product will send a signal everytime it detects someone but I need to switch on/off when I am at home. For instance, before switch on/off on the device, it will detect a movement (and I don't want to). Is there any way to switch on/off remotely (right before entering in the house for instance) ? 1/ Infrared ? Is it consume a lot of battery ? 2/ Bluethooth ? Is it consume a lot of battery ? 3/ Other ? Thanks for your help,
Topic by arduinodev
Hello! A good friend of me, who happens to be blind, posted an interesting question on facebook earlyer today, and it got me thinking. He wondered if it would be possible to get alarm feedback from a usb key when a file is done saving. So I was thinking, could I somehow do something with a transistor or a relay on a usb cable, to sound an alarm for 1.5 seconds when the voltage turns to absolute zer0. I know how to solder and i did projects before, but never something like this, with this kind of tech. so tips and feedback could be welcome.
Topic by Shaddorry | last reply
I can't seem to log in to the site when using Firefox 54.0.1. After clicking on the "log in" button and entering my username and password, I get redirected to the homepage. I can log in using Safari, so I don't think the issue is with my account. I also tried clearing my history and deleting my cookies, but the problem still persists. Any ideas as to what's going on? Thanks!
Topic by M3G | last reply
Hello everyone, First time here, found lots of info but have question about using this type of piping. I've noticed most people use either black hose or irrigation pipe. I have extra black radiant heat hose and was thinking it would be much better. Its black hose shell with a thin aluminum shielding then thick white pipe inside. It says rated for 200F - 100psi and is 1/2 thick. Brand name caked Weil-Mclain Alumipex for Radiant 1/2nom 1216 PEX-AL-PEX. Can someone please let me know if this would work. Thanks. Brian
Topic by fst2011 | last reply
No time and no pics for a proper Instructable, so I just put out some word of warning ;) Around here bad people take advantage of the fact that a lot of new houses have the garage right next to the house. With these you usually also get a door so when you park your car you don't have to get out of the garage again. All controlled by the press of a button on the remote... Some fancy guys got a device working similar to the IM-ME Open Sesame hack a few years back. But unlike the original author the new guys found ways to make money by providing working "universal garage door openers" on dubious websites. Problem with the new model is that it not only fakes a remote with dip switches but also the newer models with so called "rolling code", "intellicode", "changing code" and so on. The old remotes with dip switches should actually by phased out years ago by any owner who values his stuff... But the new models are still deemed secure and next to impossible to hack - well if you trust the advertisement... How does the code hacking work? The old dip switch models allow for a maximum of just over 4000 different codes and come in just 3 or 4 frequency bands. No real problem for anyone with basic electronic and coding skills to hack these - as shown with Open Sesame. The new models all use a so called rolling code, here the remote and opener are paired through 32 bit of ID code and an encrypted part that changes every time. Both remote and opener calculate the next code once a button was pressed or a code received. To overcome reception problems the base usually calculates the next 256 codes in advance - and that is the entry point for bad boys. The illegal device scrambles the frequency detected while storing the code received by the orignal remote. As the door did not open the owner will try to press the button again. Still scrambled to opener does nothing - until the device sends out the first recorded code! Now the owner can drive in and is happy. Of course he still needs to close the garage - again all is scrambled and the code stored as before. You see where this is going.... It is even possible to set the amount of required tries to capture, so in theory a bad guy could get the next 10 or codes in advance for use once the owner is gone out... Worst thing however is that these illegal devices not only open garage doors but also cars as a lot of them use similar systems for their remotes - up to the point of starting the car with it. Took me only 2 hours with Google translate to find a website outside the usual search results that offers these "gadgets", along with WiFi and cell phone jammers, credit card copy devices and more things I don't want know about... What can you do to protect yourself? First check what type of remote your system uses - if there are DIP Switches than replace the remote system or the entire device in favour for something more secure. If you already have a rolling code model that you are far better off but sadly no longer totally safe here. A lost remote should not only be replaced but the old one removed from the system as well - you never know if you just lost it or someone took your remote ;) Alternatives exist, especially if you are not afraid of doing some open heart surgery on the electronics of a garage door opener. You can add a WiFi module and use your mobile phone to open the garage - search Google if you like the idea ;) Another very neat way is using a second transmitter that keeps the relay for activating the opener from working. This can be anything from a BT module paired with your phone or cars BT system over a keycard to numberplate recognition cams. A good system also allows for a "holiday mode" or similar. Here you can set this mode with one remote until you deactivate it with the same remote the system will not react to anything. Great if you leave the house for more than a day or two... As a last resort you can always get a big and angry dog to sleep in your garage.... What if you are renting or a bit limited with the electronics and soldering skills? Not all is lost if you can accept a second remote for added safety. These days you can get plug in converters for your mains voltage outlets that work with a remote control. Unless they use Infra Red for this they are great to disable your opener. Simply plug it in where the power cord for the opener is and then plug the cord into it as well ;) Now you can fully shut off the opener with the press of a button and only if the power outlet is switched on the opener will work. If in doubt you can use a double outlet adapter an extension cord and a night light to indicate wether or not the opener has power. Ok, and what about the door lading from the garage into the house? Well, of course keep it locked and if you are home also keep it locked. At least this way you have some extra time in case someone tries to enter through your garage while you are sleeping ;)
Topic by Downunder35m
I am trying to make a desk out of a hollow core door. I want to fill in the hinge areas before painting or put something there after painting to make them look nice. any ideas? I haven't found any online and I've spent hours looking.
Topic by BrookeF | last reply
I am willing to PayPal $30 for someone to write this Sketch. I have an Uno board, a motor control board L293D Motor Drive Shield and a 5 volt 4 wire motor NEMA17 Stepper Motor. I'm using #include . I can make the motor run any speed in both directions in a loop. That's all the further I've got in two weeks. I would like it to start idle (hold) and when I touch (momentarily) power to a pin, I need it to run in reverse until another pin is contacted, a switch, and stop (or run forward a small amount). Let's call that home. Then I would like to touch power to a different pin and have it reverse to home and then run forward 200 steppes. 3 more like that, 200 steps, 400 steppes, 600 and 700 steppes. So, i need 4 pins, one the run the motor to home. The 3 others will run the motor down to home and the up to a predetermined spot. The "Stop and stay home" can be a couple steppes up from the home switch. Think of it as running blinds full open & closed with 3 available open positions in between. If you can do that, I'll pay $30. But I don't want 10 people to make it and each expect to get payed. How do we do this? Scott Goldsborough Thank you!
Topic by Scott GoldsboroughG | last reply
I have been watching a lot of YouTube videos of building your own LED bulb using a scrap CFL bulb. Since I have watched a lot of those videos, I want to build one. However, almost all of those videos are about making one that runs on 240V AC, and where I live I use 120V AC. Take this video for an example: I also noticed that in that circuit diagram, there is a 5th diode that is unnecessary. So I want to build an LED bulb similar to that one in the video above. But I am not so good with electricity, so I am not so sure how I can modify the circuit so that it will run with 120V AC instead of 240V. Can someone help me with this?
Topic by ADRIANT28 | last reply
Not sure where to post this, but it's something that will be of interest to others and use one often comes here for ideas and to get help for this guys project as it has massive potential as its Open Source Tech. http://go.farmbot.it if anyone has any ideas or wants to see about forking some stuff back and forth suspect that the Designer will be happy to chat. One was thinking that he hydroponic groups, lighting groups, ardeno enthusiasts, raspberry geeks, hardware hackers etc. However, its getting word out and getting the right people to hear about it... It has potential one feels to help change how we approach Open Source.
Topic by mattadlard | last reply
Hey everyone, I would like some help finding some fpv goggles for a big project I am working on. I am looking for something that has two eye pieces (a display for each eye) so I can get depth perception out of it, with a rather small profile something like this: Example Goggles:https://www.aliexpress.com/item/In-Stock-Skyzone-SKY02S-V-3D-5-8G-48CH-FPV-Goggles-With-Transmitter-Camera-Head-Tracking/32813350842.html?spm=2114.search0104.3.16.Hw9RjX&ws;_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10068_10084_10083_10119_5400015_10080_10307_10082_10081_5390015_10110_10137_10175_10111_10060_10112_10113_10155_10114_10154_10056_10055_10054_5370015_10312_10313_10059_100031_10099_10078_10079_5380015_10103_10073_10102_10120_10052_10053_10142_10107_10050_10051,searchweb201603_2,ppcSwitch_5&btsid;=a608c8aa-657c-4a80-bb79-3a6fe633d1c0&algo;_expid=d18d9248-7548-44db-95a6-3cb9578d9ebd-2&algo;_pvid=d18d9248-7548-44db-95a6-3cb9578d9ebd But I don't need all that wireless circuitry, just the displays and ideally an HDMI port for each one, thou one would suffice. If any one can make a recommendation to one that is already on the market place, or point me in a direction to make my own (type of displays, and where to get them ect ect) I would much appreciate it. PS. I do have a limited budget hence me not buying that particular set and getting it over and done with =P
Topic by HannesB8 | last reply
Hi, I am considering a project in creating input buttons to send requests to my iPhone so that on Spotify I can change track forward and back, start and stop the track, and hopefully use spotify SDK to display track name on an LCD screen (not essential). As far as I am aware for this I would need a bluetooth module for Arduino and i already have an LCD screen with combined input buttons (tell me if anything else might be required). I have tried understanding this article - https://davidfindlay.org/weblog/files/2009_09_07_ipod_remote.php - but a lot of the stuff goes over my head because I am a programming/arduino/electronics simpleton/beginner - does anyone know of some simple ways I might be able to send requests to my Iphone to be interpreted by Spotify? Thanks in advance
Topic by Tech10007
Can anyone suggest the best mini laser cutter machine to purchase for creating greeting cards and paper napkin rings and is user friendly? Thanks. Andrea
Topic by andreasievert | last reply
Hello, I am trying to automate the windows and doors in our barn using NEMA stepper motor and Lead screw and would like to exert around 20 Kg force for opening or closing. The windows are fairly old and made of wrought Iron. I am wondering if somebody can advise and help me selecting the motor (based on torque) and the appropriate diameter of the Lead screw for this instance. The idea being that when the lead screw rotates, the ball nut flange moves left or right and pushes the connecting rod out or in thus opening or closing the window I have attached a rough sketch what I had in mind and please pardon me for any mistakes. Many Thanks Ash
Topic by AshishJ61 | last reply
I'm scouring the web for a tested design for a 2 wheeled (+caster) robot with an arduino and 3 sensors, left, right, forward and a line following sensor. Can anyone recommend a specific design (not a kit, but just a tested configuration?) Thanks!
Topic by pitosalas | last reply
Hello! A couple months ago, I posted an Instructable on how to build an electric ukulele and I entered it in a contest. everything was going great until recently. Now, whenever I click to view my instructable, I get an error message saying instructables is down. The weird thing is, I only get this error message when I click on that particular instructable; i can still view my other instructables as well as other people's instructables. Has anyone ever had this happen to them? Thanks in advance for any help. I really appreciate it!
Topic by Ace Gambit | last reply
Can we have an option to sort the forum topics according to dates? It'll be helpful to find the most relevant ones. I was surfing the "Free Stuff" category where I found tons of posts on the top that were posted some 5 or 7 years ago. Those are not even relevant!
Topic by alamtania | last reply
Hi, all. These days, I plan to DIY a drone. In the drone, I want to make a PCB which integrated control unit, ESC, Gyro, barometer, and etc. Specially, I want to use blue series 12A ESC as that on my drone. As all of us know taht the blue series 12A ESC can be flashed by BLHeli by myself. However, it is difficult to find the schematic drawing(Eagle file, althium file, or PCB layout) of the ESC. So, could anyone give some help about this? Thanks in advance.
Topic by 373996214
I would like to make circuits using paper and a conductive ink pen, but there's not way to "attach" the components to the paper. I'm looking for a conductive glue, like epoxy or super-glue, I can apply directly to the point of contact between the paper and the component. Can anyone suggest a product, or how to make such an item? Thanks, Kevin
Topic by kevin.t.stein.3
Story be this my friend. I have a few 1000watt grow light inverter/ballasts. Turns out i can't afford the electricity needed to run these. Soooooo I'm wondering if i can convert them into a dc-ac inverter. For use in a mobile home or in my car for....something I'll figure some use for it. Could also just be a fun project. Point being Id like to see these re purposed for something useful. I didn't pay much for them (lucky thrift shop find) And i dont want to use it for running lights on 12v or whatever. Thats all i can seem to find on this subject in google. And i can solder and very well..i think.
Topic by williamb349 | last reply
Hi, I've just activated a premium membership but can't seem to be able to download any PDFs of Instructables. When I click 'Download PDF' it asks me to buy a pro membership when I am still logged in to my account. On previous Pro Memberships this has been fine. Any suggestions/help welcome. Thanks, theRedBryophyte
Topic by theredbryophyte | last reply
When logged in and viewing a personal Instructable there is a keyword list. We can add and delete words very easily. Nice feature. Until very recently we could also click on any of the keywords in the list and it would take us to a page of similar projects based on that keyword. This was very useful to track all teammates for the Makerspace contest. Why does this click option no longer work. Now every link defaults to the "everything" category. Would be nice to have that link feature back. DIYWATERDOG
Topic by DiyWaterDog | last reply
Hi all, I did try and search for the answer to this but did not find it. Someone was (very kindly) attempting to vote for my project in a contest via mobile but the voting button is not there. Or is it and I missed it completely when I looked for it myself? Seems odd that someone would not be able to vote while looking at an Instructable on their phone especially since most folks are mobile-oriented. If someone could clue me in, that'd be great. Thanks!
Topic by Humboldtartdept | last reply
I've noticed that the images and the "I made it" header have disappeared from all of my Instructables where people had posted them in the comments section, the comment itself remains, but no images. I've also checked on I'bles where I posted an "I made it" and those images have gone too, any idea what's going on here? The problem only occurs when I am logged-in, if I view anonymously they appear as expected. The following I'ble is a good example as it contains a few "I made it" comments: instructables.com/id/Enchanted-Rose-Beauty-and-the-Beast UPDATE: This issue now appears to have been resolved, everything is behaving as expected.
Topic by ThirdEarthDesign | last reply
I've been umming and ahhing about what to do with this for the couple of weeks since I accidentally invented the thing (I was working on a solar energy device), and I thought you guys may be your usual well-spring of help and advice. Basically I seem to have designed a device which will collimate an extended light source. Any light source. So you could, for example, turn a 100 Watt light bulb into a 100 Watt laser. Or a square meter of sunlight into a kiloWatt. I haven't made it, but simming on the computer gives an optimal blow out rate of about 1/2 meters per kilometer, so over a range of meters or tens of meters it's pretty much as accurate as a normal laser. The only upper limit I can see on how much power you could put through this thing is when the materials start melting, which would probably be pretty high. There's really nothing fancy about it, it's just a shape. You could print it out easily on a 3d printer and fill it with some kind of settable glass for the total-internal-reflection. It would weigh about as much as a 2 litre bottle of water and be about the same size. I was concerned about it being weaponisable, but even at a kiloWatt the lethal range would probably be less than 100 meters, in which case you might as well just get a gun. I don't know if anyone's already done something like this, I can't find anything online, and people kept telling me it was supposed to be impossible. So, um, yeah...
Topic by SolarFlower_org | last reply
After reading some explanations about Collections, I still don't get. Could anyone please explain what is Collection in instructable, and what is used for? Why I can edit the collections, which are someone's published instructables? Is there any official guide about how to use Collection? Thanks.
Topic by penguin007 | last reply
Hello all! I was just looking through various Maker projects, here and elsewhere, and was reminded of a collage engineering exercise I was told about growing up. Apparently, they don't do it any more. My education is only up to an Associates Degree in Drafting and Design, and I never got this at that level. This exercise (near as I can remember) consisted of a student being given a piece of aluminum (I think) and a set of files, a caliper, and a few other small tools. The student then had to turn the piece of aluminum into as near a perfect cube as they could, using only those tools. Has anyone out there heard of this exercise before? Maybe done it themselfs? Namely wanted to through this out there, see what people thought.
Topic by ProfCoppersmith | last reply
Magandang araw sa inyo! - Good morning guys! Want to learn Tagalog or Filipino? This is helpful if you want to visit my lovely country the Philippines! You can message me or use my contact details if you want to learn English or you want to be my friend. If you're planning to visit the Philippines don't forget to contact me so you're not alone when you're in my country. I am willing to help! (If I'm not busy). My Contact Details: Email: email@example.com Facebook: fb.com/warengonzagaofficialpage Twitter: @waren_gonzaga Instagram: @waren_gonzaga Patreon: patreon.com/warengonzaga Comment down your questions, thoughts, opinion or what ever you have. Thank you!
Topic by WarenGonzaga
I originally posted about converting a John Deere Power Wheels tractor to remote control powered through the RPi. I decided not to for various reasons. Time was one of those reasons. Now, I have been able to come up with a large scale electric remote control vehicle. I'm looking to hook that up in a collaboration with the Raspberry Pi. I have some ideas but just wanted to get some opinions and maybe even a difficulty rate as for as programming and so forth. Any help will be much appreciated!
Topic by SMILEY4242
I've started an I'ble and saved it but can't find it anywhere... Thanks!
Topic by perec3 | last reply
Hello, Does anyone know how I can replace my monitor's LED Backlight to an RGB LED Backlight? RGB (Red Green Blue) LED Backlighting is superior to W-LED (White LED, which is just Blue LED without Green and Red). I don't even know why the mainstream LCD makers are trying so hard for superior picture quality, when CRT & Plasmas all used RGB light. It's not rocket science: they should just switch to RGB backlights, and replace them when they decay at their different rates. Anyway, does anyone know where I can find RGB LED Backlights for my PC Monitor? I know how to open up my PC Monitor's LCD panel, and remove the LED Backlight, but where can I buy RGB LED Backlights? Does anyone know where I can buy RGB LED Backlights?
Topic by davidwinst | last reply
Hi all, May I suggest to establish a new achievement: I made it! Because we are makers and makers actually MAKE things. We share our I'bles but we also make I'bles from others. This would be also a good way to avoid million of I'bles about the same objects. what do you think about this?
Topic by BaptisteL8 | last reply
I understand that people want to ask for things, and want maximum exposure of their request but, to the best of my knowledge, that's what the Wanted category is for. The free category is for things you are giving away, not things you're asking for. The forum is all messy with Free Pro Membership Giveaways, and Wanted posts, and it's difficult to sift through to see any actual posts for free items. Is there a way we can better avoid this, or be more strenuous about enforcing or self-enforcing this? Thanks! Sorry, not tryin' to be a jerk, but if you can put any kind of post in the free section, it shouldn't be a separate section, ya know? -Mike
Topic by mikemenzie | last reply
While in the comments section of a post, the user's own profile is displayed when hovering over the profile picture of another user's comment. Precondition: logged-in Steps: 1- Select a post with comments. 2- Scroll down to the comment section. 3- On a comment, hover over the user's profile picture. Expectation: - Commentator's profile is displayed Result: - The user's own profile is displayed instead of the commentator's profile Extra Details: Browser: Google Chrome - Version 59.0.3071.115 (Official Build) (64-bit) Post used in pictures : https://www.instructables.com/id/Arrow-Through-Coke-Bottle/
Topic by alexskills | last reply