[TravisR100]

I've watched these forums for quite some time over the last year. I finally got around to actually buying and retrofitting a machine. It's still a work in progress but I thought I'd go ahead and start a log for anyone else who might be working on one of these.

First of all, a few links. I would not have gotten nearly as far as I have if it weren't for a thread started by Alex Cole regarding his retrofit of a Dyna 2400. Here is a link to his thread:

http://www.cnczone.com/forums/showthread.php?t=33770

I've also made many other posts here regarding various components, questions, or problems as they've come up. Instead of trying to include all of that information I'm posting links to my other posts. Here they are.

Stepper wiring RE shield/ground/connector
CNC4PC C3 Index Pulse Card - Help
Stepper Motor "cogging" issue
CNC4PC C23 Power Connections
Speed Controller Wiring - check me
12vdc from 5vdc
Spindle Motor Help
Dm2400 Line By Line Execution????
Source for metric Delrin nut

[TravisR100]

I found the mill on Craigslist. I went and took a look and it was in decent shape. The first thing I did when I got it home was to remove all the stock electronics and clean it up.

I'm not sure what the difference is between the 2400 and 2100. The 2100 doesn't have the built in oiler that the 2400 has. Other than that, not sure.

I'm going to post some pictures. A note on these pictures - while they are reasonably good size pictures you can click the link below each picture to go to the full size image. BEWARE: The full size images are 12MP images and range in size from 2MB to 6MB.




http://www.travisreese.net/dyna/P1000870.jpg

This is a view of the base of the machine with x and y axes removed. They look like hand scraped ways.

[TravisR100]

http://www.travisreese.net/dyna/P1000872.jpg
Here's an overview of the machine with the axes and spindle removed.


http://www.travisreese.net/dyna/P1000873.jpg
Here's one of the axes. You can see the housing for what dyna calls a "supernut." It's their anti-backlash nut.

[TravisR100]

http://www.travisreese.net/dyna/P1000876.jpg
Here's a view of the Z axis with the electronics cabinet removed from the back of the mill.

[TravisR100]

http://www.travisreese.net/dyna/P1000877.jpg
A close up of the z axis.

[TravisR100]

http://www.travisreese.net/dyna/P1000881.jpg
A close up of the ways.

[TravisR100]

http://www.travisreese.net/dyna/P1000882.jpg
The oiler port on the bottom of the table which lubricates the ways.

[TravisR100]

http://www.travisreese.net/dyna/P1000885.jpg
The spindle.

[TravisR100]

http://www.travisreese.net/dyna/P1000886.jpg
Bottom view of the table and the lead screw.

[jpgmoreno]

looks good, is this a 2 1/2 axis machine, or you can actually put 3 stepper motor for 3d machining?

[TravisR100]

http://www.travisreese.net/dyna/P1000888.jpg


http://www.travisreese.net/dyna/P1000889.jpg

These are both views of the "supernut" anti-backlash nut removed from its housing. You can see two tangs on the leftmost metal fitting in the bottom picture that sit in the two keyways on the left half of the plastic nut. You'll notice that the right side of the plastic nut only has one tang on it. The other is broken off. This nut had to be replaced.

The leadscrews on this machine are M12x2.5 which is not a standard size. I couldn't find any source for them other than going back to Dyna to get a replacement.

[TravisR100]

http://www.travisreese.net/dyna/P1000909.jpg

Here is the replacement nut sitting below the original.

[TravisR100]

http://www.travisreese.net/dyna/P1000912.jpg
Here I'm starting to reassemble everything. If you look inside the nut housing you'll see the new white nut.

[TravisR100]

http://www.travisreese.net/dyna/P1000900.jpg
Here's the scrap heap of electronics that I removed.

[TravisR100]

http://www.travisreese.net/dyna/P1000913.jpg
This is the end of the Y axis with the stock stepper removed. The stock stepper had a small gear that turned the larger gear you see here.

[TravisR100]

This is the end of the x or y axis lead screw. This is also where I discovered the first big problem I was going to have. If you look at the post above you can just see the threaded end of the screw poking out of the gear assembly. Well, the gear assembly is threaded and screwing it down tight is what gives the preload on the thrust bearing behind it. The problem is that there is nowhere to grip the screw when doing a retrofit. If you take the gear assembly off you're left with the thread and most of the small shoulder shown in the picture directly above. So, you have to figure out someway to tighten down on the thrust bearings yet also have something for a motor coupler to couple to. I'll come back to my solution for this problem in a bit. On to the motor mounting plates.

[TravisR100]

I used Alex Cole's basic design for the motor mounting plates. Obviously the hole spacing is slightly different as his mounting holes that mate to the machine were different than mine. Here are some pics of the process.


Raw stock.


First one with layout marks.

[TravisR100]

Alex made these nice round standoffs to go between the plates. I blindly copied his design. After I started making them I quickly wished I'd just used a plate as a standoff. I wouldn't have to worry about making 6 posts the same exact height, just two plates. And tapping would have been a lot easier as well. But here they are.


Raw stock cut to approximate length.


All done except threads.


All 18 finished.

[TravisR100]

Here are a couple of shots of the completed mount on one of the axes. All stainless fasteners.

[TravisR100]

Back to that problem with not having any way to tighten down on the thrust bearing yet maintain something for the motor coupler to attach to. Below is the solution I came up with.



The think end of these devices is bored out to 8mm to match the shoulder on the lead screw. The bore goes almost, but not all the way, to the skinny end. The skinny end is then threaded with an M6x? thread. So the thick end slips over the 8mm shoulder and is screwed down to bear on the thrust bearing. It's slotted and has some clamp screws so it's clamped around the 8mm shoulder after it's screwed down. The skinny end with the M6 internal thread has a 3/8" outside diameter which the motor coupler can clamp onto.