My JRGO machine build (a ways to go yet)

[badmoonrizn]

Hi all...
I must say first of all that this is by far the greatest site on the web.

Now with that being said, I hope I can count on all you masters to help me through this project. I may need lots, cause I'm cornfused by much of this.

I have bought my steppers, drivers, breakout board, and power supply, as a kit through probotix. It's the 4 axis monster kit.

I have my pieces all cut out and ready to start drilling what seems to be an endless amount of holes in all ten billion pieces(<---- slight exaggeration) of this mdf.

First off, do not cut this stuff in a closed up garage with all windows shut without a respirator!!! I'm still hacking up stuff that CSI wouldn't be able to identify!!

I want to go with 1/2-10 lead screws instead of the 1/4-20 all thread. If anyone has done this, and would like to share with me a good place to purchase everything all at one time, thanks in advance! Like the lead screws, the abn's, flanges, etc...


Anyhow, here are some pics. of really nothing much, but I thought I would post my first build from the ground up.

[CarveOne]

Definitely DO NOT use all-thread for the lead screws!! Using 1/2-10 single start will run 2x the speed of 1/4-20 and have less tendency to whip. These will make a very usable machine but you will eventually think that it is also too slow. www.use-enco.com sells these 6' utility grade rods for around $9 or less, which is less than 1/2" x 10' all-thread in some cases.

Using 1/2-10 5 start ACME is highly recommended for the higher torque steppers like 425 oz/in and will run even faster with 1/2-10 8 start. These come at a higher price but they are well worth it. McMaster-Carr has these and the last time I looked the 8 start was a couple dollars cheaper than the 5 start. These are precision rods. Use DumpsterCNC anti-backlash lead nuts with these lead screws.

CarveOne

[badmoonrizn]

Thanks CarveOne for the reply and the tips. My motors are only 400oz. but will hopefully still work out with the five start??

I seem to already be starting out wrong. I used the parts list and cutout list I found posted on here somewhere, and for the base top piece and bed top piece, it calls for 1/2 x 24 x 39.5 & 1/2 x 20 x 39.5, If i'm not mistaken, I believe they should both be 40.5

I sure hope I didn't cut all kinds of parts wrong

[CarveOne]

Originally Posted by badmoonrizn Thanks CarveOne for the reply and the tips. My motors are only 400oz. but will hopefully still work out with the five start?? I seem to already be starting out wrong. I used the parts list and cutout list I found posted on here somewhere, and for the base top piece and bed top piece, it calls for 1/2 x 24 x 39.5 & 1/2 x 20 x 39.5, If i'm not mistaken, I believe they should both be 40.5 I sure hope I didn't cut all kinds of parts wrong

5 start will work fine with 400 oz motors. Take a look at the Joe's 4x4 forum to see what size motors they are using with the 8 start screws. 400 oz should be fine with those also, particularly if you will be using Gecko drives.

Looks like you need to check into the latest update before cutting more parts. The problem with lists of materials is that once posted online revision control is lost.

CarveOne

[badmoonrizn]

Well... I ended up only having to re-cut the two pieces so far. The base top & the cutting bed top. They were wrong by 1" length wise in the cut out list. Of course these were 2 of the biggest pieces of the build, and had to use another sheet of MDF. My fault for not checking every detail first. I wish a moderator or someone could pull it and modify it to save others from doing the same as me.

I managed to get the base and cutting bed all pieced together without too much trouble, and started drilling holes, and tapping some of the other parts.

Wow!!...... This is going to take some time!!! It has taken dang near a full day to get 4 pieces completed. I'm trying to do everything as accurate as I possibly can.

I also ordered 1/2-10 rod, because it's that or nothing, as I am at my budgets end. At least it will be twice as fast as 14-20 and a bit more stable. I am planning on making my own couplings, and whatever else I can out of whatever I can, to get this thing to move.

I just have to keep on thinking (or hoping) of what satisfaction I'll have once this thing is built.

[CarveOne]

You will need to analyze how the change to 1/2" diameter rods will affect other things needed to implement the change. Bearing ID, and maybe also OD, will change. The bearing OD change may require that the bearing hole size be made larger and the center location be moved on your bearing mounting blocks so that there is no interference fit issues. You'll need the correct ID ACME lead nuts or anti-backlash nuts.

These things do take considerable time to build.

CarveOne

[badmoonrizn]

Originally Posted by CarveOne You will need to analyze how the change to 1/2" diameter rods will affect other things needed to implement the change. Bearing ID, and maybe also OD, will change. The bearing OD change may require that the bearing hole size be made larger and the center location be moved on your bearing mounting blocks so that there is no interference fit issues. You'll need the correct ID ACME lead nuts or anti-backlash nuts. These things do take considerable time to build. CarveOne

Yes, that may be a trial and error thing there. I have most everything ordered and should be coming soon. I'll just have to get things fitted together, and see what I need to do.

I ended up having to re-cut a few other pieces due to the errors on the cut out sheet, you'll have that I guess. I actually used my band saw to cut them in stead of the circular saw, and they turned out sooooooo much more accurate anyhow. I was surprised at how smooth the cuts came out even with the 6 tpi blade i have in it.

I have 14 more pieces to go, and I can see how I did with my cutting/ drilling accuracy, should be close I think???

If nothing else... This is a great project for any machinist to take on, novice or veteran, in my opinion. I feel I'm better educated already.

[badmoonrizn]

Thought I would post a couple more pics of my progress. Lots to do still.

[badmoonrizn]

Well.... I have been working on this non stop, and have gotten quite a bit done. I have some issues to work out on it though. It seems no matter how accurate I tried to do things, some parts just did not come out right.

I have lots of slop in both the x and z axis, and no more adjustment left, so I'm not sure what I'm gonna do about that yet. Also the x axis is binding up when moving to the far left which in turn stripped out my lead nut already. (bummer)

I ended up doing the lead screw supports a little different by making up some bearing blocks out of mdf, and pressing some bearings into them and turning the lead screw ends down to fit the inside of the bearing. I'm actually pleased with the out come of that.

I also made my own coupling from 5/8" steel rod, drilled out to 1/4" and drilled and tapped for two 1/4-20 set screws. I'm using 1/2-10 ACME threaded lead screws so I turned down the other end to .250 to fit my coupling. That also worked out good.

Now if I can get the play out of this thing, find out why this is binding up, and make my spindle mount, I can start learning how to use it.

[badmoonrizn]

I finished making my spindle bracket for my generic router. I have no idea what make it is, but it runs. It only has a 1/4" spindle and 1 speed, but will have to do for now.

I was playing with Mach 3, and am starting to figure it out a little bit. I don't have any physical limit switch, so I hope the soft limits are reliable in Mach? They seem to be. I had a heck of a time getting them set right too.

Instead of firing up my router, I figured I would do a test run with my trusty, and less hazardous pencil first. The (A) turned out a little light because my rails still need some fine tuning, but I was very happy to have gotten this far.

Almost time to cut some chips.

[badmoonrizn]

I did some text engraving because that is all I can figure out how to do at this point. While doing that I found I was a bit disappointed with the amount of travel in the X axis 14.750" So... I am thinking of making some changes already.

I believe I read about other people doing something like this. If I take the gantry sides and just reverse them so the bearings are riding on the outside of the rails, it should give me an additional 3 1/2" of travel. Doing this however, will require me to lengthen (re make) a few MDF parts, X axis guide rails, and lead screw. Fortunately, I should have enough stuff left over to do it.

I really wish I would have done this to begin with. I guess that's what it's all about

[badmoonrizn]

Well, like I said I was disappointed with my travel on the X axis, so here's what I did about it. I first ripped everything apart, and just moved the bearing assemblies to the inside of the gantry sides.

Then I cut a new, longer, gantry front with two 1.5" holes for the rails to go through. I also had to cut another, longer, gantry back, made basically the same way as the original minus the access hole.

I then figured out it was no longer possible to have the same kind of gantry bottom due the bearing blocks in my road. So... I improvised, and used a piece a laminate flooring that I just happened to have laying around for the new bottom (without this it was very flimsy) The flooring is very thin, so it still clears the base support, but is super strong, and worked great! I drilled 6 holes through it and counter sank them, then anchored it to the gantry with 1.250" wood screws.