New Machine Build- Big Orange jgro

[pbeamtn]

Been spending the last couple of weeks building. I wanted to build a Joe 2006, but without a CNC and without cash, I figured JGRO was the way to go. I did, however, implement Joe's changes that makes the unit a little bigger.

I have most things figured out. I'm using the Hobby CNC controller, but I found some 160 in-oz steppers at Marlin P Jones for only $12.95 each, so I decided to go with those even though it will affect my speed. My lead screws are 5/16 threaded rod, which fits nicely in the skate bearings. I fashioned some motor couplers from 1/2" aluminum rod, which is drilled and tapped, then I used 1/2"ID rubber hose and hose clamps to fasten them together.

Things are mostly good, but I'm fighting with the bearings on the long Y axis. I just cannot get one bearing on each side to make contact. I was pretty sure my pipe was flexing in the middle, and I think supporting it there will help, but I'm thinking I am going to have to take it apart and shim to get everything to make contact. X and Z were mild problems, but I could adjust the pipes enough to tighten things up.

Here are a few pictures on my progress:

[Jason Marsha]

If you can, use 5/16 stainless threaded rod it won't whip as much as the standard rod. Although I used a much stronger option than the pipes I supported the entire length of the axis. I also used threaded rod running under the pipes to pull the sides together and keep them from pushing out as the gantry moved along the axis.

[pbeamtn]

I am using 5/16-18 threaded rod since it fits the skate bearings and can be gotten easily. I know many people use acme 1/2-10, and I may do that eventually, but I am starting with what I can get at Home Depot and Tractor Supply.

With Joe's variation, the linear bearings ride on the outside of the pipes, and the lower front of the gantry has holes that go completely around the pipe. I concluded that my problem was the pipes getting squeezed together in the middle, so after some tinkering, I came up with center supports. I am going to have to modify the gantry a bit so that I don't have interference.

I am now able to get all the bearings to make contact. I will post pictures this weekend when, hopefully, I will have all three axes assembled.

[Glidergider]

Congratulations on your build. You're going to love the JGRO. I know I loved mine, I cut a lot of stuff on it too.

Once you get up and running, you will want to go faster then the 5/16"-18 threaded rod will allow. Just like gears in a car, you will be cruising along everywhere in first gear. You won't go very fast in first gear either.

Eventually, speed will become more important, and the easiest way to increase speed is to upgrade the threaded rod to an ACME 1/2"-8 (2 start) [4.5 times faster]. Or even the 1/2"-10 (5 start) [9 times faster].

Hope this helps later in your JGRO experience. You're going to love it. Get some good software too. Mach3 and VcarvePro are my favorites.
Take care
Dave

[pbeamtn]

Glidergider,

Thanks for the advice. I have looked through many of your posts, which helped me get started in the first place. I will probably move to an ACME rod when I get the thing done, but I wasn't sure how far I would get, and ordering then waiting is not a lot of fun. I wasn't sure a 1/2" would fit on the Z axis, but I have seen how slow the Y axis travel is with a drill -- it seems like it takes forever to get from one end to the other.

I have been using linux for years, so I have initially installed EMC2 and have been able to at least jog the Z axis. I feel pretty confident I can get it to work. In this forum, it does not appear as popular as Mach 3, but it is free.

I have watched others progress from simple and cheap to more complex and expensive, and I may follow when I get experience, or I may decide that slow, simple, and cheap suit my purposes. I should at least be able to get a couple of Christmas presents done. Then I will have to decide whether to upgrade the jgro or use it to build something like the Joe 2006 in which case I would definitely make it faster.

[pbeamtn]

I couldn't get all the bearings on the Y axis to make contact with the gas pipe, so I added a couple of supports to the middle. Now, I can adjust the width at each end and the middle, which allows all the bearings to make contact. It also stiffens the pipe quite a bit. I fear, however, that alignment may be more tricky, but I am as close as I can get without the table attached.

I had to modify the lower front of the gantry to clear the new center supports. Perhaps, there is an easier way to do this, but this works for me.

[voltsandbolts]

Nice work, I like the modifications.

My wife wanted me to paint my jgro orange, but I just couldn't do it...

[pbeamtn]

Thanks. If this week goes as expected, then I'll need it to start manufacturing points for Tennessee. Perhaps, basketball season will be better.

[pbeamtn]

Just an update on my progress. Sorry, no pictures.

I built a torsion box for the table, and I think it turned out pretty well. I drilled holes in all the internal parts, so I could potentially attach a vacuum to it to hold parts down. I have seen this concept in other posts, but I have not seen where someone has actually done it. I'll just need to drill a series of holes in the top and do some external plumbing to try it out.

I mounted the router -- an old Craftsman 1.5 hp. I took the base off the router and bypassed the switch so it is always on. I am not thrilled with the appearance of the MDF bracket, but it works. I had problems with the MDF wanting to split on the narrow sections, so I coated the whole thing in thin cyanoacrylate ("super glue") to hold it together and make it stronger. (My old company had a 3-D printer that made parts out of powder. We would soak the whole thing in super glue and it was really strong.)

I do have all 3 axes working, but I have decided to take some time and make a rolling stand for this beast and mount the electronics instead of just having them sit sprawled out on a table. Perhaps, this week I will actually cut something!

[pminmo]

Looking good! Don't expect much speed with the 5/16-18 all thread. http://pminmo.com/mechancial-power

[pbeamtn]

Just jogging it with EMC2, I'm around 40 in/min. EMC2 does everything in in/s, and it seems pretty reliable at .6 in/s. I might be able to .7 or .8. Right now, I'm just thrilled the thing moves! Eventually, I'm sure I will move up to an ACME rod.

[pbeamtn]

A few more pictures to post. I got the router mounted and the electronics "mounted." You would think that a EE would do better, but I just screwed the electronics to a piece of OSB on the roller base I made. I will eventually make a dust cover, but for now, it keeps everything together and gives me some more room.