Monday, 30 August 2021

A Look at Automating 3D Printer Bed Leveling, and First Layer Calibration

My latest article, in which I explore the auto-leveling features in the Anycubic Vyper 3D printer, has been published at Hackaday. I found the idea of integrating a strain gauge into the hot end to look well done, and in short, it works as advertised and gives perfectly serviceable results.

In the article I talk about why bed leveling and first layer calibration remain a pain point for 3D printers and users, discuss some ways people have tried to make the problem go away, and take a close look at the method implemented in the Vyper.

One thing that is unusual for 3D printers -- compared to other CNC machines -- is that there is a strong trend toward using build surfaces that are coated (or textured), and swappable. This makes the problem more difficult, because these swappable build platforms are never completely flat, and no amount of adjustment with screws will adjust out the imperfections in them. It's up to the machine to work around them.

Tuesday, 27 July 2021

Thermal Cameras Are More Hackable and Affordable Than Ever

 

I recently wrote this article about the tCam-Mini wireless thermal imager and I am deeply happy with it. However, it's important to know what the unit does and doesn't do, which I cover in the article.

These kinds of tools are great, and the fact that they can be hackable is making me get idea after idea about how to use it in different ways.

One of the challenges for this not-quite-plug-and-play device was that the information about it is sprinkled here and there. I round up all the necessary resources at the end of the article.

Monday, 28 June 2021

How to Give Yourself Some Wins When You Need Them

 My most recent article is all about how to give yourself the occasional "win", and it's particularly significant for the self-employed, entrepreneur types, indie developers, and similar types.

Those kinds of people are often doing many different jobs at once, and feelings of progress or success in some areas is often offset by failures or stalls in others. That can lead to burnout, so setting yourself up for some easy wins can be a lifesaver.  Be sure to check it out. 

Friday, 25 June 2021

3D Printers Are Fantastic For Weird One-off Fixtures Like This One

I'm in the process of turning part of a shelf into a 3D printer enclosure, and I ran into an issue that having a 3D printer really helped me solve. It illustrates how making custom objects for a specific purpose is a really useful purpose.

I wanted the front panel of my enclosure to be mountable at different heights, exposing different amounts of the enclosure depending on where it was mounted. A little rail or "mini-shelf" that the front panel could rest on like a canvas on a easel would do the trick nicely.  Multiple rails at different heights would allow me to pick and choose a height easily.

The problem with making multiple little rails at different heights is this: they get in the way of the panel.  If the panel mounts low, then it's laying ON every other little rail in between. That might be a bit hard to picture, but the end result was that I needed a rail that could push itself out of the way when it wasn't needed. To solve this problem, I made the piece shown in the picture here.

Wednesday, 16 June 2021

Tips When Selling on Amazon via FBA

 I have made two products sold on Amazon so far (the latest is my fun RPG-related product, the Dungeon Master's Advice Dice which started as a very successful Kickstarter campaign) and I have a few tips to share about what to expect from the Fulfilled By Amazon (FBA) process, and how best to use it.

  1. Be proactive about restocking (but don't overdo it.)
  2. Understand your costs really well.
  3. Amazon changes their policies sometimes, be prepared for that.

1. Be Proactive About Restocking (but don't overdo it)

When selling on Amazon via FBA, you send Amazon a box full of your product and they stock it into their warehouses for sale. When a customer buys your product, Amazon fulfills the order. That means Amazon does the sale and ships the product from the stock you sent to them.  

You ideally want to send a new box of product to Amazon before they run out of the previous stock, but be aware that this can take a while.  Once your box is delivered to Amazon, it must be processed before it can be made available for sale, and this can take days or longer.  During peak times, it might even be much longer.

How much to send to Amazon (and how often to restock) depends on how well your gadget is selling.  My first box to Amazon held 35 units, partly as a test to gauge demand.  They sold fairly well and I sent another box to Amazon a month later once they were down to 1 item left, but I should have acted sooner.  My restocking box has been delivered to Amazon for nearly a week now, but they're busy and haven't processed it yet.  As a result I'm looking at probably another week (or maybe more) before my product is back in stock, and there's no way to expedite this process.

Don't overdo it on being proactive if it leads to dead stock. Space is money, and no fulfillment company wants to waste shelf space on stuff that isn't selling.  Having too much stock sitting on a shelf and not selling well enough to justify the space may lead to a fee.  

2. Understand Your Costs Really Well

If you don't have a cost-of-goods (COG) spreadsheet worked out for your product, get that done as soon as you can.  Without it, you won't be able to calculate an accurate idea of your costs, and therefore won't know how much you make per sale.  The worst thing would be to discover you are actually losing money on every sale.

Here is how costs work with FBA: Amazon will charge a fee for every sale, which is a combination of fees including the actual fulfillment (shipping). Whatever is left is what you get.  Subtract your own cost, and you're left with your profit.  Example: One of my products is a small and lightweight item that sells for $16.99 and out of this, Amazon keeps $7.01 in fees from each sale.  That leaves a little under $10 for me on each sale.  If my total cost per-item can be $5 or less in the end, that's not bad.

Your costs should also include the cost of shipping the box of stock to Amazon FBA.  For example, if you send a box of 50 gadgets to Amazon and shipping was $22 and the box and packing materials was $3 for a total of $25, that adds an extra $0.50 to the cost of each item (which by the way ignores the labor involved to pack the box and use Amazon's FBA tools to create the shipment.)

Note: Occasionally a package will have a delivery problem. If this happens, you will be on the hook for it, not Amazon.  Your cost should include maybe 2-3% to allow for lost packages and other unforeseeable issues.

3. Amazon Changes Their Policies Sometimes

Amazon sometimes changes how they do things, or changes what kind of information they require from you about products before they can be advertised or sold.  I recommend that whenever something like this happens, don't waste time trying to find out why something changed; instead focus your energy on how it affects you and what you need to do to stay compliant.  Amazon's help documentation on their policies and actions is usually pretty good, so do some reading to find out what they need, and try to provide it in exactly the way they say they want it.

This also means that any guide you read from somewhere online might be slightly out of date regarding some details by the time you read it, so try to expect that.

You Don't Need Everything Solved at Once

It's okay to not have every blank filled out at once.  Just try to make sure to record everything, and when you get better data, update your records.  For example, when you add a product to Amazon they will give you an estimate on their fees, which will turn more concrete once you actually start selling.  It's okay to send a small box at first to see how well it sells and get some good solid numbers before committing to more.  Don't worry about having an incomplete to-do list, it's okay to focus on getting the process down first, and refine things later as you learn more.

Tuesday, 20 April 2021

3D Scanning and 3D Printing: How to Use Them Together

 Check out my latest article, all about how to most effectively use 3D scanning, in which I explain a few gotchas that lurk in wait for the average 3D printing enthusiast who wonders whether 3D scanning can help make a project a bit easier.

This is a dense topic that I distilled down to a short, practical summary by picking three common use cases: 

  1. Using 3D scanning to make copies of an object with 3D printing
  2. 3D scanning as an alternative to designing something from scratch in CAD
  3. 3D scanning as a way to digitize important shapes that would be a huge pain to make or create any other way
Check it out if any of that sounds relevant to you. It's part of a series of articles called 3D Printering on Hackaday.com, which focuses on 3D printing and things related to it.

Sunday, 29 November 2020

Low Effort Fan Repair for GPU (broken graphics card fan)

A household computer got a few fan blades broken off the graphics card when using compressed air for cleaning. Turns out it still seemed to mostly work okay, but over time more of the blades broke off until the fan couldn't do the job any more.

The usual way to fix this would be to buy a replacement fan but two things made that seem like a not-great idea:

  1. The GPU is old (GTX 750) so parts aren't easy to come by.
  2. The fan looks integrated in to the enclosure and doesn't look like it can be easily replaced.
I instead opted to fix it in a dumb but effective a low-effort way.  I printed a replacement fan, snapped the remaining blades off the hub, and glued the new fan blades on top. Having it hollow helped center it visually so it's not off-balance.

Obviously this isn't optimal, but considering how long the GPU trucked along with a fan whose blades were nearly 50% gone, I think this might be okay.
  • Fan 3D model downloaded from here: https://www.thingiverse.com/thing:3620483
  • I scaled it down a little so it would fit on top of the hub
  • I glued it down, gave it a spin with my fingers and adjusted until it looked centered.
Fan blades nearly 50% gone. It surprisingly trucked along okay for quite a while.

Snap off the old blades. Instead of trimming the little bits off I just opted to glue the new fan right on top.

3D-printed Replacement

A few spins by finger verify that it is centered.

This is obviously not as good as mounting it to hug the hub, but this way I didn't have to 1) clean all the little nubs smooth, and 2) I didn't have to worry about matching the size of the printed part to the fan spindle.  Whenever 3D printing replacement parts that mate to existing pieces, there's always the challenge of getting dimensions just right.  This way I didn't have to.