I have started, then later rejected, many ideas in building my latest homemade CNC machine - I am moving them to this post to clean up my build post and still keep track of the ideas I have tried...
I will list an explaination for why I rejected the ideas as well - Use "Next" or the index to the right to view the rejected ideas...
Rejected Because: Since I started my own Aluminum Foundry I just decided to not make any parts out of MDF...
Here's a look at the motor mount that I designed and cut with machine #1 :) You can see the six holes that will bolt the motor mount to the t-slot aluminum extrusion. Since I used the first homemade CNC machine to manufacture these - they are perfect! These particular mounts will hang off the bottom of the Y Axis - I will make two more of these (I think) for the X and Z axis. On the other side of the motor mount I will need two bearing mounts that hold the lead screw bearings.
Rejected Because: This Idea still showed racking and was just not tight enough...
I've decided not to use Angle aluminum for the linear rails of my homemade CNC machine this time - because it was proving just too difficult to attach it to the T-Slot... Basically the screw heads were getting in the way of the bearings... So I looked for something that would sit in the t-slot channel and I found some 1/2" galvanized pipe that fit fairly well and should give me a nice rail for the bearings to ride on... I might have to sand it smooth if it's rough - I'm not sure about that one yet - but here's a look at the rails and a preview of the base so far... Don't mind the 2X4 legs - they are temporary :)
Rejected Because: I thought that adding an extra bearing I'd avoid the racking I was seeing with the homemade CNC Machine - I was wrong
Here's a shot of the four linear bearing trucks I made last night - came out pretty good... Basically I wanted to have room for 6 bearings so that's what determined the length of these (which is 100mm by the way) - the T-slot aluminum is 60mm so these hang over the edge by 20mm on each side... I'm figuring that's not going to be much problem - but we shall see... The next picture is the over all shot and then a close up of trucks installed, and finally a video of the gantry moving :)
Rejected Because: This idea racked as well and really just took up too much space for it as well...
Well... I got the linear bearings installed and started working more on the gantry and they still rack :( even after adding another bearing from the original idea... So something is flawed with that idea... maybe it's because they're not exact - or maybe the idea just isn't totally good - I dunno... So... I started working on a new linear bearing idea! :) Basically I'm taking regular L-Brackets and rounding one side down with my grinder and installing two bearings two washers and the L-bracket make it just right to ride on the pipe - so far without racking :) Here's some pics of how that looks... basically I was trying to make my own V Bearings and I think these came out pretty good... if these don't work on the pipe like I hope, I know that a similar design will work really good on angle iron (with a point at the top) - but the pipe is already installed :) so I thought I'd give these a try... The last picture is a current look at the machine - I've got the motor mounts and linear screw mounts installed :)
And here's a video of the gantry moving with these new bearings : Video
It seems a little tight and hard to move - but I think I can loosen that up a bit but I want to see if it loosens up with use...
Rejected Because: This idea was close - but in the end I decided that I didn't want the bearings to ride on the aluminum - I figured I'd get too much wear - and also the parts were made from MDF and I've decided against ANY MDF in this build... it was close though! :)
Ok - sorry to take so long between the last update and this one - but i wanted to really work out this linear bearing idea before I kept posting things that I eventually change :) so this update is (I hope) the last in this "Linear Bearing Idea" saga...
Needless to say - that last idea racked too :( so I started looking at solutions I could buy instead... But that's just not my style ;) hehe - so after searching through a bunch I came across a few that I could try to re-make for my purposes and here's the latest linear bearing idea...
Basically I used my first homemade CNC Machine to cut me some parts again - which means these are made from MDF (as that's about all I can get away with cutting on machine #1) but they should suffice until I can #1 make sure they are exactly what I want and #2 until I can use my second homemade CNC machine to make them from hard plastic (like Delrin) or aluminum... I might be able to machine Delrin (or the like) with my first homemade CNC machine - and I got a piece to try - so that update will be coming soon ;)
Without further ado - here's the pictures and videos of the latest (and hopefully the last) linear bearing idea!
and here's a video of that Y-Axis moving HERE
Ok - so that seems to work really well and I've got ideas to stiffin it up if it does rack - but so far (after 100 or so slides back and forth trying to loosen it) it's not racking...
Next we have my idea for the X Axis and I'm not 100% sure on this one yet - it seems solid - but I'm not sure about having the trucks on the inside... I think I'll move them to the outside - anyway - here are some pics of it and a video :)
Rejected Because: Previous Idea was expanded on, and I thought about making the MDF parts from aluminum - but decided against that because it's just going to be really difficult to get accurate results from my hobby foundry right now - and I've thought of another linear truck idea that so far looks like a keeper and is easy to assemble...
OK - been working on this linear truck idea for way too long - the last idea was pretty solid - but I've expanded on it a little bit connecting the two pieces with a piece of threaded rod rather than being two separate pieces - they act as one piece now... This makes it so that I don't need a piece of extruded aluminum right on top of the top piece and that gives me more table room :)
Also is a picture of the bed I put together that the sacrificial MDF will rest on... More updates coming tommorrw and make sure to keep an eye on the site as I will be posting about my NEW latest hobby very soon! ;)
Rejected Because: I think it will be too difficult to cast perfectly dimensioned parts in my hobby foundry - I just don't have the skill yet :)
It's been a long time since I've updated with any progress - I've been working on the Aluminum Foundry so I could cast parts for this project out of aluminum :) Finally I've had sucess with that and have made my first custom part ever :) To check THAT project out - go HERE
and here's a picture of the unfinished part straight out of the sand :) - it's not pretty - it has to still be machined - but I couldn't wait ;)
Rejected Because: MDF Parts...
Ok - Started working on the X Axis today as I think the Y Axis is pretty solid so far... Basically these X Axis trucks are wider than the Y Axis ones - basically running on the width of the extruded aluminum. I still kept the idea of bolting them together to keep it so it moves as one piece. I also bolted on what might be the beginning of the Z Axis - but I have to figure out it's linear motion so there's a good chance this idea will change... More than likely I will add an X Axis bar to stabilze the Z Axis as well which will really stabilize the X Axis too - we'll see :)
Without furthur ado - here's the pictures and one video :)
Check out the video of the X and Y axis moving :) Click Here