[Alex_Cole]

Rodger

It is going to depend on how yours is setup. If you look at the pictures in my post you will see one of the Z axis backlash nut. If yours is of this type then it is adjustable. I have not done a major ammount of work in getting this dialed in yet as I am still working on the z axis driver issue right now but on my X axis using my digital indicator I have been getting a consistant reposition of .0005. I tested the Z axis just the week before last and I am getting the same results with it.

These machines are built well if you have one that has the same construction as mine. Some have a little spring loaded nut that isn't really adjustable. For units with that type of nut I cannot comment about as I am unfamiluar with them. With my unit and the ones like it from what I gather they are supposed to be able to have a repeatablility of somthing crazy like .0002 in there origional configuration.

I will try to help with what I can. Just post any questions you may have and some one will most likely be able to help.

AC

[ScottC]

Hi guys, just finished the control upgrade on my dyna 2400 and am setting up mach 3. Could anyone suggest the correct proceedure for removing backlash from the x and y axis on the 2400?

Ive had the table apart to check the ways etc and noticed on the screw nut a large hex bolt, is this used to control backlash? Anyone know how much load i should put on the nuts at the end of the screws?

Scott

[woodturn]

Sorry, I have the plastic spring loaded type. So I have no idea.
dave

[Alex_Cole]

At this point I have adjusted the nuts at the end of my screws until there was no linear movement anymore but also not so tight that it created major resistance on the rotation of the screw. If you have them too tight I figure you will wear out the thrust bearings pretty quick. As for the backlash screw on the block I used my indicator and adjusted this screw until there was no backlash but again not so tight that it made it too hard to turn the screw.


HTH
AC

[kel1]

Hey Guys,

Does anyone know what the original spindle motor transformer was rated for on the 2400? Mine did not come with any electronics(just the 80vdc motor with snipped off wires) at all so we wound one from an old transformer. When testing to figure out the DC voltage to achieve 10000 rpm (at the spindle) with a Variac and a tach we came up with 55 volts AC converted to DC with a rectifier circuit gave us 10000 rpm. We built the transformer to put out about 3 amps.
I was wondering if anybody has the original specs to see if we are close or not.
Another question I had was when the spindle is under load or cutting conditions does the spindle motor rpm decrease much or does it have a circuit of some kind to keep it at a constant rpm continuously? With the transformer and rectifier circuit we made the rpms do drop somewhat under heavy loads.We also made a speed controller that works but we blew one transistor so far. It has been replaced and added a larger heatsink for the transistor but havent tried it again yet and we are not sure why it blew yet ??

Any info would be appreciated. I am just learning electronics basics from a friend so this is all new to me but very interesting.

Thanks Kel

[ScottC]

Hey Kel,

I converted my mill from 110v to 240v. One thing i did was replace the spindle control and powersupply. I puchased an all in one unit that basically plugs into the exisiting wiring loom. Its called a whisperdrive, can look up the product code on monday. It lets me input either 110 or 240v and has trim pots that let you control heaps of things like ramp in and ramp out, speed control, auxilary relay switching from the pc, spindle lock and overload protection. I also have the exisiting spindle driver board lying around

Scott

[Alex_Cole]

My spindle will bog under load. Sorry I don't have much time today guys but just wanted to let you know.

AC

[kel1]

Hey Kel,

I converted my mill from 110v to 240v. One thing i did was replace the spindle control and powersupply. I puchased an all in one unit that basically plugs into the exisiting wiring loom. Its called a whisperdrive, can look up the product code on monday. It lets me input either 110 or 240v and has trim pots that let you control heaps of things like ramp in and ramp out, speed control, auxilary relay switching from the pc, spindle lock and overload protection. I also have the exisiting spindle driver board lying around

Scott

Your "whisperdrive" sounds interesting. Do you have a link to it ? Was the original spindle driver board not adequate enough ?

[ScottC]

Kel,

http://www.kbelectronics.com/manuals/kbws.pdf

The existing spindle driver runs on 110V, I wanted to get rid of the huge 110-240v transformer that was atttached to the side of my mill since everything else is now 240v. The new spindle drive is much more compact and lets me input either 240 or 110v. There is some drawbacks inputting the higher voltage but wont be a problem for you running 110v. Ive had my spindle runnning nicely for a while now.

[kel1]

Here are a couple of pictures of my Dyna 2400.

As you can see it was pretty much stripped of all electronics when I got it. It is in excellent mechanical condition though and as others have stated these machines look like they were well built. It has good backlash adjustment and leadscrew nut adjustment for better accuracy.

I decided to go with stepper motors so I chose the Xylotex 4 Axis Kit. It should be in this week sometime. This should be an interesting project. I plan to make my motor brackets etc etc with the machine manually so I can get a feel for what kind of loads you can put on the spindle without burning up the bearings.


Kel

[ScottC]

Kel, I made engineering drawings for the motor brackets based off the old brackets to fit nema 23 motors to the exisiting gears. I made the motor mounts myself and they work very well. Its been a week since ive had my mill running cnc. Rapid speed is painfully slow using the original gear reduction in the mill. I am about to make motor blocks that will direct drive the leadscrews trhough couplers.

[Alex_Cole]

I also have cad files somewhere with my motor mounts, if you need them.

AC

[ScottC]

Hi Alex, are you direct driving the lead screws or running through the reduction gearing? Im finding rapiding my mill slower than a wet week.
I want to do something similar to this build i found searching on the net:

http://www.grifftek.com/images/dyna2400remec/

Some movies there too showing the rapid speeds, my only concern is introducing extra backlash through the coupling. Ill order a coupling set and see how it feels.

Scott

[Alex_Cole]

My servo runs with a 2.8 to 1 belt reduction. If you look in the images of the post you will see the little black boxes that the servos are mounted to. Inside there is the belt reduction. I ordered some LoveJoy couplers and used my lathe to turn them down for attaching to the lead screws. I had to bore the ID to get them to mount on the screw. You can see how they are turned down in my pictures as well. The largest reason for me turning them down was to reduce rotating mass for the servos and drive. They seem to be working well. I believe I have a cad drawing of the couplers if you need.

AC

[kel1]

Hey Guys, Any CAD files you may have would be greatly appreciated. It would give me a start on what I have to make .

I was thinking of going direct drive from the steppers to the leadscrew with a homemade coupler. I guess whatever way you decide to couple the motor to the leadscrew you just have to keep backlash into consideration. That is why I was thinking of going direct drive. I allready have the backlash on the machine adjusted to allmost nil.

Kel

[Alex_Cole]

I will try to get the files posted tomorrow when I get a chance.

AC

[kel1]

I will try to get the files posted tomorrow when I get a chance.

AC

Thanks Alex

Kel

[Alex_Cole]

what format would you like them in?

AC

[kel1]

Hi Alex, DXF or IGES files would be fine.

Kel

[kel1]

Hi Alex, DXF or IGES files would be fine.

Kel

A PDF file would be nice to have if you can convert it also.

kel