The more I look at my project and the fact that it TECHNICALLY does in fact roast coffee now… and the more I think about it the more I feel I need to work on a better project enclosure for my project. While the Radio Shack case is fine I have concerns with the layout I had to use for the in-progress prototype plain taking up too much space. I feel like I need to move on to building something that is (at least on the outside) more permanent.
When I look at the schematics and all the wiring involved I keep seeing situations where I need to shrink it all down onto a custom made board. The more I think about a board (as rendered a few weeks ago in a previous post) I realize I need a box that it will go in figured out. Once I know the box shape the better I can layout a board since I will finally have “internal dimensions” to try to squeeze it all into. How to build a case, however, is not entirely easy.
Sure there are blogs all over about people building cases for their projects but most of them assume a standard rectangular box. The sides all interlock together and you anchor it with some slots cut into the box and a set of bolts/nuts for each corner/side/whatever. Outside of those sort of cases there are very few options as a DIY case unless you have welding capabilities or other more advanced tools at home like a mini-CNC or something like that.
There are plenty of sites that offer to fabricate stuff for you. Ponoko tends to one of the more popular ones. There are also other more “professional” ones that allow much more advanced cases to be built. These sites include those such as Protocase and Front Panel Express. Both of those offer free software that you can use to design a case. Protocase offered a pretty interesting tool that actually creates a 3D case made from various metals and are quite impressive. The issue is they are also VERY impressively expensive. The deal is, however, that they do offer “console” type cases that are customizable quite a bit and will allow you to see a complete all around view of the case. The problem is that you cannot do anything with the file they give you other than to send it in and buy it from them.
Front Panel Express offered a much more open proprietary tool. This tool you can export the completed panel to a DXF file which can be imported into many other software packages, including those used on the suggested list for Ponoko. While they don’t really want you to use their software to build a panel at another vendor, of course, it DOES actually work out.
Another issue with the Front Panel Express is that it only allow you to design one panel at a time. Each side Left/Right/Rear, Front, and Back in addition to your Top control area needs to be built separately. They make a lot of their panels out of aluminum or steel and have quite a lot of capability to build most anything you want.
The issue? The following:
At the cheapest this seems to run around $65 for only this panel. You can save a bunch of money by drilling your own holes for the countersunk screws and the round holes and instead just having them marked using an engraving to help center your drill bit. I’m not against paying $65 for it BUT I feel that I need something cheap so I can confirm the layout REALLY is good even if I’ve rendered it in 3D. I need to mount everything in the holes and confirm that yes it DOES fit properly and there are no heat issues or anything else to make me need to move anything.
Enter Ponoko. When I import the DXF into Google Sketchup it does all sorts of weird things with the text and a few other things depending on the design. When I try to raise/lower the material it does some odd things as well because of some of the lines etc. What works better? I dug out CorelDraw and found I could tweak the Front Panel Express file in there quite well, export it, and load it into Ponoko’s system. It appears to look ok in there and allows you to use wood, cardboard, plastic, and a variety of other items.
I took the outside dimensions of the FPE designed panel as well as the other measurements from some of the cut outs and dropped them into a few shapes in Google Sketchup. I then rotated the “rough” panel up 30 degrees since that seemed like a good amount and then attempted to measure the size of the effective foot print. I then threw together a small 1 inch base and then raised the top edge up the two sides up 30 degrees as well. I then slid them together and came up with this rough case package.
Using the exported DXF for Ponoko in Acrylic after modifying a few items to make it compatible to Ponoko the front panel ended up around $15. At this time I haven’t purchased it since I need to make sure all the measurements are correct. Additionally I need to add the sides now that I’ve gotten measurements confirmed in Sketchup to a layout. I’m expecting the entire thing to run around $45 at Ponoko for the initial testing versions.
The version in the rendering of course isnt entirely right. The LCD is actually slid up a little bit and the buttons go up as well. Each button ACTUALLY is supposed to be rounded on one of the sides and the two round holes on the left and right are for the potentiometers that should have an LED above them. The top needs an LED and there needs to be screw holes in a variety of places as well as some engraving to label things.
At this time I intend to figure out the distances to the LCD edges and adjust the base width as needed when I find the ACTUAL dimensions of the LCD panel that will be used with a mount designed to secure it. I will then come up with a back panel and then start having this made. I will have plastic panels made by Ponoko and when I’m certain that I am pleased with the dimensions/shape and fit I will have FPE build an anodized aluminum case for whatever it costs.
Due to the 30 degree angle and the fact I did not want to use tabs to lock it together I wanted to be sure of my decades old “trig” knowledge when calculating triangles. The Sketchup Layout works well to see if the dimensions look good. As long as it all fits together a Ponoko build will let me see a physical model for final confirmation and showing it off before I get a permanent case made.
Anyway I’m thinking for the buttons I’m going to use some MultiMec 1V16 white buttons for the directions, The middle button is currently planned as the 1T type buttons for an “OK/Select”. I’m don’t think I can get them pre-labeled though so I might have to switch to a different button or do without labeling. Then the two at the top that are round would be for some sort of Escape/Cancel and perhaps a dedicated stop/end/cool/whatever. I need to confirm out which buttons to use so I can get whatever I need labeled well enough.
In the position of the potentiometers I might switch them out for rotary encoders to help setup things a different way. Where the LCD is I will start with a panel that will fit in place of the full sized LCD using a smaller 4 line LCD until I start building the PIC32 system into it. Once I get to that stage I need to mount the LCD panel onto a backer that screws in place.
If I could scrape together enough cash I’d get some sort of mini CNC machine and perhaps etch some buttons with ESC / OK / COOL or something like that as well as arrows and then infill them with some black. Totally way involved for a few buttons but would probably look pretty impressive. If I could make my own panels that would certainly negate the need for another vendor making the final panels. Too bad those machines are so spendy.
I had ordered some motor controllers from a company in China back at the very beginning of the month. They shipped from the seller after some Chinese holiday or something. Apparently they went to some company that handles shipping things to the US or something before it went to their post office. It left China about a week ago and arrived in the international mail portion of some facility in Los Angeles a few days ago. It appears today it made it to the REGULAR Los Angeles post office sort facility. It should probably arrive in one of the Northern California sort facilities tomorrow and MAY make it my local post office. As I’ve come to expect anything coming from China seems to require a signature 9 times out of 10 so I will probably need to go to the post office on Monday to sign for it. So we’re around 20 days from when it was ordered. I’m trying to see if I can control the fan motors differently in some way that would make it more stable and give me a few options for actually building my own roaster later on using much larger blower fans and some other motors for opening/closing vents.