newbie from bristol soon to be up and running

[uppy121]

hi everyone

i am new to cnc. i live in bristol started to build my own machine in jan 13 just a few more bits to get and i will be up and running. if i can i will post some pics

[Jonathan]

What are you planning on cutting with it and what bearings have you used on the ballscrews?

[Ricardoco]

hi everyone
i am new to cnc. i live in bristol started to build my own machine in jan 13 just a few more bits to get and i will be up and running. if i can i will post some pic s

Well welcome to the forum and you get a thumbs up from me because its in your house!! looks like your almost there, i look forward to seeing your pictures and your progress, And again welcome.

Rick

[uppy121]

i will be cutting ply ,mdf, softwood, and yes it is in my front room good job i live on my own

[Jonathan]

i will be cutting ply ,mdf, softwood

That's good, since the machine will just be able to cut those, but nothing harder. I asked because there are a couple concerning things about your current design:

The unsupported rails on two of the axes will significantly reduce the rigidity of the machine, see here for a detailed explanation as to why. To start with you might as well try the machine with them, but I'll be surprised if you don't swap them for supported rails in a few months.

It looks like you haven't put any angular contact bearings on one end of the leadscrew and that you're possibly using the motors to resist axial forces on the screw? If so you need to change this before running on the machine, as standard 'deep groove' bearings are not designed to work with axial forces, so they will quickly fail in addition to adding end-float to the screw. If you use a pair of angular contact bearings that wont be a problem. Look up the standard end-machining for ballscrews and it should be fairly obvious how to proceed.

What pitch screws have you used on the longest axis and how long are they? The critical speed/whipping might be a problem.

[blackburn mark]

Splendid stuff :)
nice and warm inside

looking at you Y axis, the rails look unsupported which may lead to some problems over such a large distance
they will be like guitar strings when you get going (maybe bass guitar strings )
If it turns into a problem it looks like a supported rails would fit right in there without to much heart ache

EDIT: oops, Jonathan beat me to it

[Swarfing]

Welcome local chap...

shooting him down in flames already? Don't listen to them, you got this far without em. It would cost you thousands in training to learn what you have so far. Just get on and enjoy what your doing and keep on learning

[GEOFFREY]

Hi, wellcome. Built in your living room - thats great. At least you wont have any rust problems. Reminds me a bit of a WI competition that my wife entered a few years ago. In answer to the question "what is the most useful item in your kitchen" she put " my husbands bandsaw". I had a machine for several years, unsupported rails, rack and pinion drive etc., but it worked well for me as I only cut mdf and ply. As Swarfing said just enjoy it. G.

[uppy121]

thank you i will be building a second machine and i will take in your advice on the bars so all advice welcome all i have to do is sell a few woodworking machines and i will start buying some more parts thank you all very much

[kingcreaky]

shooting him down in flames already? Don't listen to them

Excellant work uppy. You'll have great fun learning, much the same as I am at the moment. Make sure you keep us posted with your build photos!