Dman's Dually - Thanks Joe

[Dman]

Well this is the first of I'm sure many routers patterned after Joe's 2006 dual rail machine. Although I didn't get his drawings I did study every picture of his machine in detail and then started drawing my own version of the dual rail router. I should have started a log for this but have been very busy at work and was so excited about getting this thing done I spent the rest of the time building. Here are some pictures of what I have finished so far. The first pic is of my current working router that will be taken apart after the dually is done. It has served me well over the past year. Although accurate it has always had problems with flex. Dually does not show any signs of this problem.

[scott wiggins]

Any updates? What about Plans?

[txcowdog]

What a monster! How much does the gantry weigh? How large of a cutting area do you expect?

[Dman]

I now have this machine up an running. My cutting area is 23x38. Sorry I do not have a total set of plans made, I only have TuboCad Designer and it does not do 3d to model the machine. I never weighed the gantry but would say 60lbs would be close. I use a HobbyCNC card with the 200oz motors, 24v power supply, and 5/8" 6tpi acme screw. I can get rapids up to 120ipm but this is very close stalling out. I generally rapid at 100ipm and cut at 60ipm. I have cut at 80-90 ipm but start to get some chatter from the router so I leave it at 60 and it cuts great. The carriage for the z axis is what causes the chatter as it will flex at those speeds. I need to figure out how to eliminate that flex and will be much better. Although with the motors pretty much at max speed now I really don't know if I will mess with it. 60ipm cut speed is just fine with me. Some of what I have cut with it so far can be seen on the PhotoVcarve forum.

[joecnc2006]

Looks good, How did the Double Rail system work for you compaired to your other machine in 1st picture? when i thought of it it just made sence to me.
I think you are the only one so far with a complete machine and using this design, Hopefully there will be alot more. I know three people building my model 2006 machine now.

Joe

[Dman]

Joe,
The dual rails work great. There is no comparison between this and my old machine. My new machine is wonderful. Gantry flex is as good as I think it could be using MDF. My only problem is the z axis flex when cutting (it will flex when I push on it) at higher speeds. The x and y axis don't seem to flex at all. This dual rail seems to be the way to go. Do you notice the flex on the z also or is yours more rigid? I thought about looking on ebay for some THK rails for the z and see if that helps but that would take all of the fun out of making the linear motion homemade. Thanks again for a wonderful design. By the way have you been using the PhotoCarve software yet? Did you buy Vcarve Wizard also? I'm still looking for the funds for Vcarve but will be getting it soon.

[spalm]

Dman, looking good.

Can you post some updated photos with your motors and router attached?

You keep mentioning Z axis flex (like when you push on it). My last machine was a bit like yours, and I had a problem with the carriage tilting forward/backward when pressed (I could really see it with the router turned off and then driving the Z into the table). Or do you have a problem with your Z flexing left/right or forward/backward?

So, is it the carriage that holds it or the up/down Z itself?

Not to discourage, rather to help,
Steve

[joecnc2006]

I do not notice flex in my machine, I have the Z-Axis Boxed in on mine. It looks like you have the Z-Axis pipe suports and adjustment blocks cantalivered out can this be causeing the flex? (see photo attached)

I agree with Spalm if you can take some pictures and also maybe draw arrows of the flexing area and direction it would help, and we have many many people here that have great idea's on a remidy, thats what makes this place great and how I learn more every day here.

Joe

[Dman]

Steve is right about where the flex happens. It is a matter of up and down rather than side to side. Joe, I agree about the pipe being cantilevered outside the box but got greedy on the cutting size side to side (If I made the box wider I would lose cutting area) so I made it this way. Right now I'm not sure if the pipe on the cantilever is flexing or if I am getting a twist where the z carriage bearings ride. I could try to tighten up the bearings on the carriage and see if that will help. Thanks for the help guys. Like all of us here I have learned soooo much over the last year since joining and still have a long way to go. I can see this will be a never ending process. I don't know if you guys are like this or not but I am thinking about this "hobby" most of my free time. How could I do this better. Hey, I can make that. Wonder if I could make that. It never ends. I've been playing with the Photocarve software for a couple of weeks and am trying to find a good cutting/finishing method for the pictures. Steve, I will try to take more pics and post sometime soon.

[randyf1965]

Can you fix a rib in perpendicular to the top of the cantilevered gantry? This should reduce or eliminate the flex... Triangulation, if something flexes redirect the force into something that will not flex. Kinda of like chassis building.