Reddit mentions: The best socket head screws

Hello, fellow Canuck! :D

Amazon is my goto for parts as well. I live in a smallish city so local resources are few and far between.

M3 kit - I bought capped hex M3s for no other reason than I like the look of them. This is the one I bought. Whichever kit you decide, make sure it has a 25mm bolt. The 25 is long enough to go through the stack, the 40x20 fan, and into the shroud.

Fans: you may have to do detective work to find static pressure ratings. I found the Sunon specs somewhere else other than Amazon. I'm sorry I can't remember where or what the spec was other than it was higher than the Noctua.

Velocity Stacks: like fezzes, velocity stacks are cool.

Settings etc.: I saw your note about the fan being installed backwards. Ack! I accidentally did that, too, but I caught it before I started to print. Hold off on the flow percentage change for now until you've got the fan sorted out and/or installed the new shroud, fan, and velocity stack. You may find that's enough to get the results you like or you may want to experiment with flow to see if you can edge the quality up higher. I run at 92/92 for my flow, sometimes changing it to 92/94 if I've got a first layer adhesion issue.

Physical mods: of all the ones I've done, replacing the extruder to an all-metal one was the best. I know you said you're budget conscious, but if you have the money for it, it's a great upgrade. This is the one I use. I know it says Ender 3/CR10 etc. all over the listing, but it will work for the mini with a small modification. If you dig around in my comment history you'll find a guide of sorts that I wrote for someone on how to do it.

Bed curling: After you get the quality sorted out, you can investigate why it's curling. If you need to use a brim or raft in the meantime that's okay. One problem at a time ;)

I'll chime in... had my kit for about 2 weeks now and will share my experience:

Tools

If you don't have some of these, I HIGHLY recommend them.

• Flush Cutters. Fantastic for snipping and trimming zip ties, and great for cutting filament. They're inexpensive at less than $5. https://www.amazon.com/Hakko-CHP-170-Stand-off-Construction-21-Degree/dp/B00FZPDG1K/
  
• Digital Calipers. You'll use these alot. Will come useful in the construction of the printer as well. Can find a decent pair for $10-$20. If you have a harbor freight nearby, they sell some decent ones that always have a coupon.
  
• Bondhus Ball Hex Screwdrivers. I don't know people do it, but using those L shaped hex drivers are annoying and uncomfortable. Don't cheap out on these. Bondhus makes some of the best hex drivers in the business and are fairly inexpensive. https://www.amazon.com/Bondhus-10687-Balldriver-Screwdrivers-ProGuard/dp/B0006O4ADI/
  
• M3 Tap - I don't know how widespread it was, but a few people received frames where the holes were not tapped (or if they were, they were covered in powdercoat afterwards), and had screws snap inside of them. You don't want this to happen... happened to me and is a pain to fix. I didn't want to deal with customer support and wait for a new frame, so I tapped the holes myself. Even if you don't need the tap, it'll come useful for a lot of projects since a lot of stuff uses 3mm screws. https://www.amazon.com/Tonsiki-Adjustable-T-Handle-Reversible-Threading/dp/B01M4J4GWL/
  
• 3mm hardware kit - Again, you'll likely need some extra 3mm hardware if you plan on modifying the printer or adding on to it. https://www.amazon.com/Hilitchi-210pcs-Stainless-Socket-Assortment/dp/B014ONCP88/
  
  Assembly isn't too hard, and the directions are pretty good. My main complaint with the directions is that sometimes they don't explain what's important and not important all the time. I spent a lot of time building, taking apart, and rebuilding the base y-axis frame because I thought I did something wrong (it wobbled) to find out that you fix that wobble as one of the last steps.
  
  The 100mm distance that you're required to thread double nuts early in the assembly is absolutely critical by the end of the build for many different reasons. It would be nice if prusa included some kind of printed spacer to make that step foolproof.
  
  Again, assembly is straightforward. I took a span of 3 days to finish mine while dedicating a few hours each night to do it.
  
  Upgrades
  
  A couple of things can be improved on the printer. The printer isn't terribly noisy, but you can make it damn near silent with a few upgrades.
  
  
• The vibration dampers mentioned previously (https://www.thingiverse.com/thing:1707045) work damn well to eliminate a lot of sound. I've also seen people claim that putting the printer on a concrete paver block and then putting that block on rubber feet eliminates most of the sound as well. (http://shop.prusa3d.com/forum/improvements-f14/best-usd7-buck-improvement-you-can-make-t3051.html)
  
  
• After the vibration dampers, the hotend fan becomes the loudest thing about the printer. I ended up buying a 40mm Noctua fan and printing an adapter (https://grabcad.com/library/mk2_40mm_fan_duct-1) to mate it to the extruder assembly. Now the only thing I hear is linear bearing noise. Wiring in the noctua fan isn't plug and play though. I cut off the stock fan and crimped some dupont connectors on the leads and connected the wires that way. Soldering works too.
  
  
• I don't care what you do, but find a new solution for a spool holder. The one prusa includes is terrible. Easiest solution is to print or use a pvc pipe to connect the two spool holder brackets. I went another route and printed a spool holder that used 608 skate bearings to make the spool holder buttery smooth. http://www.thingiverse.com/thing:1832235
  
  
• The method to mount the y-axis bearing is not great. Print these out (http://www.thingiverse.com/thing:1819779) and switch out the zip ties when you get a chance. No rush to do these... just something to do when you want to tinker. Look up the igus drylin bearings too... a lot swear by them.
  
  
• Also software. If you can swing the $150, I highly, highly, highly recommend simplify3d. Their slicing is second to none, and their support structures don't make a mess and require a ton of print cleanup.

Thanks man!

Locally, Lowes is pretty good for basic 1/4-20, 5/16-18 and 3/8-16 nuts and hex bolts. Then everything else, Amazon. Like the 5/16-18 x 1" button cap screws. Love that 2 Day free shipping with Prime.

It's pretty easy to make your own "kit" if you have the BOM and access to Amazon or a site like it. I'm biased because I've always gotten good service from them. Some people have said that I'm biased because they pay me, but I really do try not to recommend places of business that I don't frequent myself.

Anyhow, here are the x upgrade and the y upgrade that I was looking at when I went searching.

Both use 608 bearings and a 10 pack should take care of it and give you several spares for further upgrades or replacements in the future. (want a spool coaster?)

Next you need the GT2 belt and 2 pulleys. Done.

The BOM doesn't say it, but you might need some m3 screws

Edit: Full disclosure: Amazon pays me something like 4% on items that aren't sold by third parties. If everything on this list qualifies and you buy it all I expect to make about a dollar.

I'll try and cover a few of these extra questions:

Lasergist can do a 1.2mm plate - but I think the site only has 1 and 1.5. For Alps, 1.2 is ideal. If you contact them directly through email, you can still get a quote for a 1.2mm plate. I did this for my Alps build, and I'm glad I did.

Any of the "universal" plates will probably not work. By universal, they mean ANSI or ISO. I haven't seen any that will work with Alps as well, due to the thickness issues.

Also, I'm guessing 3 screws would probably be okay. The only issue I could think of is if you had any material between the PCB and case (such as wires from a hand wire or sound dampening foam), it might be difficult to get the board to lay uniformly flat. From a security standpoint, I don't think the weight of plate and switches will be such that 3 quality screws won't hold it in place. The screws that come with most 60% cases are trash. I'd recommend something like these, which I use for all my builds. They're tough and won't strip.

There are sets on Amazon with M3-M5 hardware. Here's the one I started with, but note I'm not saying it's the best deal at this time. It's a good place to start. For long fasteners, or larger amounts of just one size, it's usually better to go to Aliexpress or Ebay.

In my own designs I also use a lot of 1/4"-20, although that's mostly because I already had a lot of fasteners that size, plus all three types of taps, plus dies.

A hardware store is your best bet. Take the sliding nuts (or threaded rail) with you to make sure its a good fit. Personally, I like the M3x8mm hex bolt with washers. Definitely cheaper at your hardware stores.

Sorry, had a storm a few days ago and the power went out. I got distracted and forgot.

​

I used 10-32 machine screws like these for the trunions. You'll need ten of them but buy plenty of extras. You'll have to cut the six for the front trunion very short since they will hit the barrel if left to long. The easiest way to that is to put a nut on the screw and then cut it to length, when you take the nut off it helps fix the threads that were damaged from cutting. DO NOT OVER TIGHTEN THESE! Since there isn't a lot of material for them to screw into it's easy to strip them. Put some Loctite on them and get them snug.

For attaching the trigger guard I used socket cap screws since the heads on them are smaller, there isn't much room for them. You will need five of these along with nuts.

Any hardware store should have these, I'm pretty sure I bought them at Lowes or Home Depot. You'll also need some type of threadlocker, I used Loctite Blue #242. The tap for threading the holes is a 10-32 tap (obviously) and it uses a #21 drill bit (5/32 will also work fine). If you've never used a tap before watch some youtube videos or something first. Go slow, use oil, and back it out to clear the chips frequently.

​

Here are some pictures of mine -

https://imgur.com/a/v4oDgAO

15 years and thousands of rounds without a problem. Rivets look better but screws work fine. It's currently painted with BBQ grill paint, I want to Cerakote it but I keep telling myself I'll do it when I eventually get around to replacing the screws with rivets. Chances are I'll never get around to it.

​

If you have any problems or questions along the way feel free to send me a message.

The majority of the build used 8020's so-called "economy" T-nuts: in slide in profiles. I bought a fair amount of the roll-in or twist-in type for the accessories like the electronics boxes I was adding to the frame after it was built, where I might not already know where they'd go to pre-load or be able to slide in later by just removing a plastic end-cap.

I also found a fair number of generics with longer hex head bolts for add-ons in black, such as:

https://www.amazon.com/gp/product/B00WW50A3I/ref=ppx_yo_dt_b_asin_title_o01_s02?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B015A3FC40/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

Most of my bolts for the actual assembly are I think M6 x 16mm, 8020 has the blue-anodized or zinc coated ones, cap head / domed like your link.

Anything in the 40-series is waaaay over-strength for just a single human-weight type application - compare that profile cross-section to your standard office chair that just uses a curved angle-bracket type or tube for stiffness. So I wasn't too worried about the hardware being the "higher strength" type connections.

Buy

($6)Wires:For the MOFSET mod

($1o)MOFSET

($6)Wire spades:For the MOFSET mod

($8)Assorted M3 Bolts:You need some for a few mods and for the bolts you will inevitably strip on this cheap wonderful machine

($13)Longer assorted M3 Bolts:For a few mods

($9)M4 Bolts:For one of the mods

($9)Metric allen wrench set:Had to order one of these since metric tools aren’t common round these parts

(~$20) PLA of preferred choice- You’ll run out of the sample bit quick so go ahead and order a roll or two to be prepared. You will note some upgrades require ABS so a small spool of that to your order will also help.

($6)M3 Lock nuts:Critically needed for a simple mod

($10)Threaded rod and nuts:Please note that this item seemed difficult to find online. I recommend going to your local hardware store and getting two 5/16” rods of at least 16” in length. They should have an assortment of threaded rod in various lengths available. Also note that the pitch of the threading matches the nuts you buy. Further instructions regarding this can be seen in Azza’s Z-Axis braces below.)

($6)9mm Wrench for the nozzle: Don’t wait for your first clog, go ahead and have this on hand to remove/change the nozzle. Note to only tighten/loosen the nozzle when heated.



Below is the order of printable upgrades I recommend but I suggest you mix in a few other prints along the way because this is a hobby after all and you should be having fun. It helps to have your quality as tuned in as much as possible for some of these so be patient and keep trying if you need to.

Print

Spool holder- temporary : Until you can mount your spool on top of the enclosure or any other personal preference.

Belt tensioner- print x2

Z-brace

Shielded stop button

Cable relocator : It’s a pain, but if you spend the time to do this and turn your extruder motor 90 degrees then you can get the full Z height without ruining your cables. It does involve opening all the cables to the PSU and feeding a few extra inches back through the cable chains.

Cable shroud : Looks nice if you do the cable relocator.


The following need to be printed in ABS:

M3 Bed Nut retainer: 10/10 upgrade. I know they look worse than the nice metal stock ones, but these help keep your bed level longer.

CiiCooler

Glass bed Holder


Now that the first major round of printed upgrades is done it’s time to shift to a few more supplies to pick up to really fine tune the machine.


Buy

($5)Radial fan: For CiiCooler

($5)Glue sticksThis and a glass bed is magic

($25)Borosilicate glass 8” x 8”

($26)Y-Carriage plate upgrade: This has been a nice upgrade as I now only need to relevel the bed every couple weeks instead of every print. Check out this guide for a ‘how to’ as well as a free upgrade by shifting your Y pulley over.

($15)rechargeable dehumidifier: For keeping in the bin with your opened filaments

($9)Extruder gears: Might be able to hold off on these, but will need eventually. If for some reason you have a Maker Select with metal X-axis blocks (V1 and V2, but not V2.1) then this is a must. You can follow this guide for a how to.

($28)Metal extruder plate and lever: Not needed, but nice.

($14)Noctua 40mm fan: Not needed, but makes the printer a lot quitter. A LOT quieter.

($50)MicroSwiss All Metal Hot End: The destruction of my PTFE tube by this point pushed me to doing this upgrade. If needed you can follow this guide for replacement. Remember to tighten/loosen when the nozzle its hot.

($6)Ceramic cotton: Tore off the stock one when replacing for the all metal hot end by accident. At least its thicker than stock

Now that the printer is in its final form, its time for the enclosure which is a stacked Ikea Lack hack.

Print

Spool holder

Pi Case

120mm fan cover

Fan grill

120mm fan PSU modification: I edited this to fit upside down since my PSU is mounted on the underside. This was nice since I blew the 40mm fan anyways so it made everything a lot quieter than before.

IKEA Lack filament guide

Webcam holder: This is one I designed specifically for the webcam I happen to have lying around. The camera mount piece can be changed out no problem though for what ever webcam you have or buy. The SketchUp file is included on Thingiverse for such purpose.

Buy

($20)2x Ikea Lack: Luckily there is one right down the street from me. I am located in North America though, so we do not have the STUVA, if you live literally anywhere else you may check in to this as an alternative.

($80)Plexi glass for enclosure: Could be cheaper alternatives, but it looks cool

($9)Foam pads for feet

($42)Raspberry Pi3: For OctoPrint. I also suggest using a different USB cable than the stock one provided by Monoprice or you will have issues.

($9)2x 120mm fans: Used for the power supply cooling and enclosure

($6)Rocker Switches so that the enclosure fan can be on for PLA, but off for ABS

($15)Dimmable LED lights

($10)8mm LED light connectors


Total:
$250 printer + $452 upgrades/parts + ~$80 PLA/ABS to date

Sure!
Dein Username prüft übrigens aus.


The Light Units


The Chips x4: 98.6$

The Driver x1: 74.9$

CPU Cooler
x4: 55.96$

Thermal Adhesive Paste x1: 7.9$

4way pin for the coolers x1: 9$

Lights Total: 246.36$

Framing and stuff
Most guys build their framing out of aluminium profiles. I bought mine here from the %%% section: https://www.alu-verkauf.de/ALUMINIUM-ALUMINIUMPROFILE

Every country has its own manufacturers for these. Mine cost about 30$.

You also need cables. The veros are pretty flimsy. so take pretinned gauge x1: 9,95$

In order to screw the frame you might wanna cut holes swith a thread. This will do x1: 8.43$

Be careful these drills suck and break easily.

Screws x1: 12.98$

Wago Connectors
x1: 6.35;$

Were at about 315$.

Lets see what we can do with it.

1. Glue the COBs to the CPU cooler.
   
2. Drill the holes into the frame. You should plan that very carefully. Where to hang the frame, where you place the COBs...
   
3. Assemble and screw the frame. It should be a nice and tight framing.
   my frame is build with 6 L-Profiles in which the COBs just lay around and one center piece: Link to Pic
   
4. screw on the driver and check the cable lengths.
   
5. measure your needed cable lengths.
   
6. cut the cables, strip them and connect them to the veros. Watch this video, if you need any help. I wired mine in row, because i chose this particular driver.
   
7. Connect the driver output to a Wallplug using three of the wagos. PLEASE BE CAREFUL WITH THE CONNECTIONS!. I had one of these lying around. Everyone should have a cold device cable lying around somewhere.....
   
8. Connect the COBs to the driver. Please refrain from plugging in the driver while doing this :)
   
9. for testing, place the COBs in your direction on the floor and plug in the driver. U might need sunglasses, im not joking, its bright as hell. literal hell.
   
10. Connect the CPU coolers 4way y-cable to a sufficient power supply. Any Smartphone loader should do the trick. You need a few more wagos here.
    
11. In my case, i just placed the COBs losely on the frame, and connected the cooling units.
    
12. Plug in wall and grow weed.
    
    You might additional hangers, cold device cables and another power source for the cooling fans. If you decide to buy the MeanWell HLG-320H-2100B you will need to connect a 10kOhm potentiometer to the Driver. This is to dim the light and safe money in vegphase. The HLG-320H-2100A has a build in dimmer which you can access via a screwdriver. I would recommend A, since its easier to operate. You can also regulate the fans of the cooler via a 150Ohm poti. If you dont like the sound, you can run them at 1/3 to 1/2 speed.
    
    have fun!

I am on my third psu now. Yes, that is the correct fuse and it supposed to be slow blow. It's an exact replacement.

Bad news is, I'm almost certain It's not just the fuse that is blown. The mk3's psu's are well known to fail, and while some people say that there are just bad apples, I think the psu can't handle the higher draw when printing higher temp materials. If you were to open up your psu, I'm almost certain you would find the permanent on board fuse soldered to the board to be blown as well, and possibly also one of the components busted and burnt where it failed. Prusa will replace the psu under warranty, but in my case it just happened a second time. Same thing.

So here is what I would do if I were you. Go on Amazon and buy this. Not only is this psu way more reliable than the cheap Chinese one prusa ships with, it is capable of much more and will not fail you. Well worth the 30 bucks. This is the mount you will need to print to attach it to the printer. This fits perfectly, and uses mostly the screws and nuts from the stock psu except for one kind of screw you need 5 of. I made the upgrade and it is so much better than the stock psu. It has a fan that makes the printer slightly louder and it runs intermittently, but it also gets rid of the ticking from the heated bet and makes everything run a bit smoother. You can either hook up the replacement prusa sends you temporarily in order to print the mount, or you can do what I did and hook the meanwell up next to the printer to print the mount then mount it properly. Just be careful if you do as there will be exposed terminals that could shock you.

There is a great write up on the prusa forum detailing exactly how to do this and everything you need

Yes, they are handy to have. I bought this and Im glad I have it. Better quality steel than the chinese stuff I have used. I hate when I strip out a hex head because the metal its made from is garbage. You may want to get a kit with some washers and some longer bolts (35-60mm) as well. I find myself needing those. The washers are handy if you are bolting printed parts together, helps to prevent the bolt head from sinking into the plastic. I have also bought little variety packs of different wire plugs/pins for wiring up steppers, controls boards and other things.

Shouldn’t be too hard to find a replacement screw. I took a quick look on amazon and found this:


https://www.amazon.com/Socket-Screws-Thread-Stainless-Quantity/dp/B01A9EJJIK



In the meantime, assuming there is enough meat left of the top of the screw, you can always use a hacksaw to cut in a straight line across the top of the screw, effectively making it a flat head screw instead of a Philips or whatever it was before. Hope that helps.

First I center punch the rivets on the bottom with one of these-

Bastex Steel Automatic Center Punch For Stable Hole Drill Indentation. with Adjustable Tension, Push-to-strike Function. https://www.amazon.com/dp/B072HSWV3B/ref=cm_sw_r_cp_api_i_6smvCb6ZKRCC8

Then I will use a 1/4” drill bit to take the head of the rivets off so the body and base can be separated. Just be slow and careful at this point so you don’t damage the base. Sometimes you may need to use a smaller bit on this part so just check and see what works best for the application.

Then I drill down about 3/16” into the rivet with one of these drills and then tap the hole with the tap-


Du-Bro 360 2-56 Tap And Drill Set https://www.amazon.com/dp/B0006O4GYG/ref=cm_sw_r_cp_api_i_KrmvCbDECZ061


Then I install one of these to make sure it fits correctly and holds everything together properly after all the work is done. You could also do a 2-56x3/16” screw if you want one a little bit longer-


2-56 x 1/8" Button Head Socket Cap Screws, Allen Socket Drive, Stainless Steel 18-8, Full Thread, Bright Finish, Machine Thread, Quantity 100 By Fastenere https://www.amazon.com/dp/B00YSS9CYA/ref=cm_sw_r_cp_api_i_ormvCbP5S7Q34

I think that’s about it. Send me a DM if you have any other questions.

It's pretty straight forward. Here are the parts I'm using:

1. I bought this ATX plug so I didn't have to splice my power supply.
   
2. Using this PWM controller
   
3. Using these female banana plugs
   
   Those are the things I bought specifically for this project. The things I already had that helped are:
   
   
4. I really like this flexible silicone wire.
   
5. I use these USB connectors for various projects. Their pinout is .1" (2.54mm) and it comes with all kinds. Works well for slimming down a raspberry pi.
   
6. I used one of these prototype boards to solder the usb receptacles and the LED to.
   
7. I'm using a pink LED from this pack of assorted LEDs along either a 100ohm or 220ohm resistor, I can't remember.
   
8. I use one of these DPDT switches to switch between power on w/ PWM and power on w/ power to the solder fume extractor.
   
9. I used a JST connector from this JST kit to put a male header on the side so I can plug in accessories like the solder fume extractor.
   
10. Lastly, the front panel is bolted on with some M3 screws from this assortment.
    
11. The case was modeled in Rhino 5 and printed in a CR-10 using Silver eSun PLA+
    
    This post has made me realize I have way to much electronics stuff just lying around...

I use these ones for 3.5" disks: https://www.amazon.ca/gp/product/B01E5EOIWW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 I've used them in Dell, HPE and Supermicro trays. They fit them all

and these ones for 2.5" disks: https://www.amazon.ca/gp/product/B00NQ06EOC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Yep. Just check it for you. Its M3 6mm countersunk screw.

Something like this

https://www.amazon.com/uxcell-M3x6mm-Carbon-Countersunk-Socket/dp/B01E5EOIWW/ref=sr_1_26?s=hi&ie=UTF8&qid=1506218941&sr=1-26&keywords=M3+6mm+screw

Trencher Shovel:

Manufacturer's site for specs: https://www.crkt.com/trencher.html

Amazon link for a better price: https://www.amazon.ca/gp/product/B01M0G10O4/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Mounting Pieces:

Quickfists: https://www.amazon.ca/gp/product/B000CQPANY/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

T-Slot Nuts: https://www.amazon.ca/gp/product/B009SWGLHW/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

Screws: https://www.amazon.ca/gp/product/B00IZFS0VI/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

You will need a Drill and a 3/8" or 1/2" drill bit. Drill out the stock hole in the bottom of the quickfist to make the hole larger, the screws will then fit through. Put the T-Nut in the bed-rail and slide it down to where you want it. Screw the Quickfist to the T-Nut and you get what you see above! Insert your tool of choice!

Get this or something similar: https://www.amazon.com/Hilitchi-210pcs-Stainless-Socket-Assortment/dp/B014ONCP88/

Theres a bunch of mods that require various sizes of m3 screws, having a variety pack around great.

Drill out original rivets, which I assume you did in order to take it apart. Drill pilot holes for tap, be careful not to go too far. Use tap tool to cut threads, make sure to use lube (wd40 works). If you’re unfamiliar with tapping maybe look up a vid on you tube.

Button head screws -
Tap and drill bit

I also ordered all these to complete the set up
5-Pack of T-Slot Nuts - Ideal T Slot Nut for Toyota Tunda & Toyota Tacoma Pick-Up Truck Bed Deck Rails - By Mission Automotive https://www.amazon.com/dp/B07739WXJB?ref=yo_pop_ma_swf
The Hillman Group 44018 3/8-16 x 1-Inch Button Socket Cap Screw, Stainless Steel, 5-Pack https://www.amazon.com/dp/B00IZFS0VI?ref=yo_pop_ma_swf
Quick fist clamps https://www.amazon.com/dp/B000CQPANY?ref=yo_pop_ma_swf
Plus Washers at my local hardware store

You have to really watch those cables under your Mini. They can bump into the belt easy.

I just printed the following; you will also need some screws.

https://www.thingiverse.com/thing:2302588

https://www.amazon.com/dp/B014ONCP88/ref=cm_sw_r_sms_c_api_l3BkzbJ4XBJ9Y

motor screws are m3 screws, this is a good place to start but i can't tell how long the screw is so you may want to measure it's length in mm before buying. or if you need it sooner, a local hardware store should be able to match one up for you.

I have a few boxes of misc nuts and bolts, which happen to include M3x20 (it's a fairly common size)

Something like this: https://www.amazon.com/Hilitchi-210pcs-Stainless-Socket-Assortment/dp/B014ONCP88/ref=sr_1_1?ie=UTF8&qid=1468998197&sr=8-1&keywords=m3+assortment

not exactly cheap or all encompassing but i'd probably go with this assorment

VIGRUE M2 M3 M4 1080PCS Stainless Steel Screws and Nuts, 1080 Pcs Hex Socket Head Cap, Silver https://www.amazon.com/dp/B071KBVZVV/