Variable pitch feed screw

[kmartin]

Update: I've been real busy but still have plans make a Var. pitch screw it just might be another week or two.

That is fine, I get paid by the hour 

[gletha]

I don’t get paid by the hour that means by the end of the week I’m almost working for free. My boss (wife) canceled my plans to get another router instead she had me buy another closed loop CNC mill that will arrive this Tuesday. Wait a second, Wife = Boss I am working for free.

[kmartin]

Well, it sounds like you have a good working relationship with your "boss" 

[kmartin]

A little quite over here. Have you gotten any further with the feedscrew setup gletha?

[gletha]

I have been working hard trying to burn up all the CapX project money before years end. I'm now going to take the rest of the year off. I need to do more work on the program to speed up the milling process. I hope I get time next week to clean up the code. My wife is making me take time off so I'll get board and cleaning up the will give me something to do.

[kmartin]

Any progress on the feddscrew machining. Just curious. You have been a bit quiet here on the forum.

[gletha]

Yes I have been busy. I'm expanding the plant. tied up with contractors and trying to make soure everything stays on track which is not. I'm a month behind on the baghouse project. I also need to try to get the plant safer ine the last few months whe had three employees to lose fingers one lost all of them on one hand. With all that said the program works. I never got aroung to cleaning up the code but if you want the code I can send it to you and you could give it a try. It might be months befoer I get around to cleaning up the code myself. The depth pass needs to be added to the code. right now it cuts everthing in one pass. The work around is to run the program with the Z axis high.Each time you restart the program lower the z axis until you get to the depth you want.

[kmartin]

Sounds good. I am in no hurry. I can wait for the finished product. Sorry to hear about the accidents at your plant.

[gletha]

I'm ready to get back to this project. I almost have the plant expandtion complete. $100,000 plus over budget  . Lesson learned. Don't buy used unless you have a lot of time to do your homework. It can end up costing as much as new. Hope to have some screw picture posted early next week.

[kmartin]

I'm ready to get back to this project. I almost have the plant expandtion complete. $100,000 plus over budget  . Lesson learned. Don't buy used unless you have a lot of time to do your homework. It can end up costing as much as new. Hope to have some screw picture posted early next week.

Sounds great. Your statement about the used machinery vs new is spot on.

[petergough]

Hi,
sorry to but in on old thread,
I often make variable pitch bottle screws/worms/scrolls.
I generate program in excel then save as *.txt file and load into Mach 3 and cut on 4th axis stepper motor fixed to gearbox with chuck on it.

Works well, but program is a little time consuming to generate(30 mins or so)and tweak.

Time to cut each worm if shape is awkward can be up to 6 hours 120mm dia x 600 long.

regards
Peter

[kmartin]

butt in all you want. we are all friends here. This thread kinda died. My company bought me some 3D CAM software & I have been using it. I have not built a feedscrew yet, but I have simulated many. All I am waiting on now are the parts to build my rotary axis. They have started trickling in though. I will be using a Dunham lathe headstock with a NEMA34 stepper motor. I posted some renders here http://forums.turbocad.com/index.php/topic,8625.0.html

The reduction between the motor & spindle is 1: 4 & I may change that to 1: 6. I went with this headstock because I wanted 5C veratility plus the spindle nose will accept a Hardinge taper chuck.