Another Joe in GA

[BobF]

I posted a link in post 6 to another thread showing a machine with a "hole" through the bed and a way to clamp a board vertically so you could machine the end for dovetails. I studying a way to do that to may machine.

[TCGliderguy]

O.K.... Now I understand. I wasn't sure if you were talking about cutting dovetails into the top of your machine for holding fixtures.... or something else.

I had a similar thought about my machine, although I was just thinking of some sort of a "Black & Decker Workmate" vise arrangement that would hold vertical pieces for boring and dovetailing. But, of course, the leadscrew underneath would get in the way of doing a wide piece that way...

So then I thought about some sort of a bolt-on adapter, that would hold the router with the bit parallel to the base (horizontally).... but I don't know enough about the software to know if the computer could figure out how to do a horizontal bore..... ?????

-Taylor

[DeWalt58]

I'm thinking that no software change would be needed if you swapped wires to your steppers to do horizontal boring....what do you think Bob? Might be a problem getting the work high enough with the router in horizontal mode. Hummm.....hinged router holder so it flips from vertical to horizontal!!! Just a thought.

Cheers
dewalt58

[BobF]

Seems like it would just be an X or Y movement instead of a Z movement. You could probably make a new router mount to hold it horizontally. This would allow boring the end of a large piece, but coudn't you do the same thing with my dovetail adaptation? Just make the "hole" large enough to clamp the work piece. The only limit would be how high you are off the floor.
There is a little over 7 inches between the frame sections in the inside of the X torsion box. I am trying to decide if that is enough space, or do I want to risk cutting one out and adding another brace or 2. I added one, but still haven't decided to cut any. Don't know If I would need to mount a board wider than the 7 incehs I have.

[BobF]

Well it cuts air.
I loaded the G-code of one of the side plates and it follows the tool path it draws on the screen. I guess I need to buy my license for Mach now.
I have not mounted a router yet. Thats next. I think I will set the max motor speeds down to a lower number for the first few cuts. I also need to complete the wiring for the limit switches. I think the recommended way to setup is use the NC contacts so if I cut a wire or break one it shuts down.

[BobF]

I have my Y and Z limit switches wired in. I have the all connected normally closed and wired in series. They are connected to the board on pin 15 and ground. If I run Mach3's auto setup it sees me trigger each switch, but if I leave them in the config, it immediately says limit switch triggered and shuts down. I think this is telling me I need an additional resistor in the line.
Correct?

[BobF]

OK I think I got the limit switches working. Needed some "debounce" in the Mach3 setup.
Now I need to make a dust collector before I cut the top of the table, since I know the dust cloud will rival Mt St Helens.

[joecnc2006]

Can you take some pictures and do a simple explanation on how you hooked it all up so others can benefit from it. maybe add to the mod sections?

Thanks, Joe

[BobF]

Sure, Joe.
I'll get some pictures this weekend if not before and post them. I'll also write up a little explanation of how I set everything up.

[BobF]

Ok here are some pics of the limit switches. I still have to add some to the Xaxis. This shows Y and Z. The micro switches I bought have 3 connections. There is a little diagram on the switch that shows how to connect them for NC or NO contact. I wired mine NC (normally closed) meaning they normally make a circuit. When trippped they open the circuit.

I used alarm system wire that I got from HD. I bought a 500' spool when I built my house and had some left. The wire is 4 conductor with a foil shield. I wired the switches in series. This lets me put the whole string on 1 input pin and the ground pin of the HobbyCNC board. I used pin 13 as the input pin. If the machine contacts any one of the switches, it stops. I also setup the top switch on Z and near switch on Y as home switches. If I click the "zero Y" button under diagnostics, the machine slowly moves to near side on Y until it contacts the switch and reverses just to the contact point of the switch.

If you look at the pictures, you can see where I split the outer jacket and pulled out the wires to make connections. In most places I used heat shrink tube to close the split back. There is one still open at the top of Z. All of the connections are soldered. You could also use small spade connectors on switches like mine.

The switches are mounted with 2 finish nails through 2 holes and held to the machine with a dab of thick super glue. This seems to provide enough support but still allow them to be removed. You could use small screws as well.

For the Y axis I bent the contact arm out a little with needle nose pliers, and added a contact block to the Z carrier. The block is about 3/8" thick and provides clearance for the all thread ends that protrude from the sides. Adjust the thickness to make the machine stop where you want it to.

[calgrdnr]

Thanks for the pictures and info, Nice color like the hammered silver. You might look into bracing the gantry. I used bed frame nice and stiff heck to drill. braceing helped a lot also anchoring to the wall.
You are doing great job. bet you are having lots of fun. Just wait till you start carving

[flyon]

I really like your build. I'm in the final stages of my build as well. One thing that I haven't figure out is how I'm run the wires to the carriage. It looks like you came up with a possible solution. I can kind'of see a hinged arm running from the gantry side to your carriage. I was wonder if you can explain what you did alittle. I went to HD last night looking for something like what you used and didn't find it.

Thanks,
Flyon

[BobF]

Hi Flyon,
What you see is the wire management piece off the back of an old server rack that I got at work. If you work around computers and servers, maybe you can find one.
If not, here is a suggestion. This is hinged in 3 places: the middle. and a spot about an 1 inch or so from each end. You should be able to make one out some hinges and hardwood strips. This one has velcro to hold the wires. I'll take a better picture of it and get some measurements.

[dshowalt]

Flyon
check out the picture in this thread.
http://www.cnczone.com/forums/showthread.php?t=41826

[joecnc2006]

Those are good ideas, but the only concern I would have over long term, is flexing the wire in one spot, with an energy chain or using some Blue electrical conduit you distribute the bend over the length of the wires, Like Kent did on his.

Joe

[BobF]

I had a problem with loosing steps and the motors making a "grinding" sound. I posted this in the Mach section and I think I found the solution. Here is a link to that thread.
http://www.cnczone.com/forums/showthread.php?t=47594

[BobF]

I also had some issues with noise on the limit switches. Setting the debounce up to 3000 in the config helped reduce the false triggers. Next I plan to add a .01 cap to accross the connection. As soon as I get the cap and try it I'll report the results.
If this works, I think all the little issues are solved and I no longer have excuses for not making lots of sawdust.

[joecnc2006]

interesting on the board, i will try the 1/2 set setting and turn current reduction off on my 4x4 machine, I have it at 1/4 and jog at 200ipm with no problems, but i am using 1/2-10 5 start, so 2tpi is a little different i am turning the motors probably 1/2 the speed as you are.

Look forward to some cutting from you. lol

Joe

[gacrwell]

I had a problem with loosing steps and the motors making a "grinding" sound. I posted this in the Mach section and I think I found the solution. Here is a link to that thread.
http://www.cnczone.com/forums/showthread.php?t=47594

The board would be pretty easy to modify to use the current reduction output of Mach3 to control both the current reduction and sync. I'm going to give that a try just as soon as I get my table wired up.

Gary

[BobF]

Not sure I know what you are talking about.
What "sync" are you referring to?
I disabled the current reduction and changed to 1/2 steps and that seemed to fix things. I have not tried each one separately to see if it is just one of the 2. I need to try that and see if I can isolate it to one. I noticed that the motors get a little hotter than they used to, so current reduction helped some.