Thread: Alpha Zoot ... new aussie machine on the way!

Some further developments in the planning for your consideration and comment. I still have to work out how to fine tune the R&P for the X axis, but conceptually it should work ... I will look at the Greolt build log again, with magnifying glass! Greg, how did you do the bottom of the ballscrew on the Z axis ... it looks like a small block screwed to the plate but it must have a bearing in it somewhere!
I have ordered my Xylotex 4 axis driver and 4 269oz steppers, but need to finalise the overall geometry so I can order the rails and ballscrews etc.

Thanks for your earlier comments, I had a nice Father's Day escaping to the computer when I could.

Cheers,

Alan

Hi Alan,
I see you have got the Z axis closer to the Y axis. This is what I was trying to explain in part but if you move the bottom rail to the back in the same position as the ballscrew - but at the bottom you can shorten your gantry sides even more. It will also place the bottom rail out of the firing line of the router.
Other than that suggestion I cannot fault your design. \

Hi Alan

Hope you dont mind but i have printed out copies of your table for future reference...

Just a suggestion ...I would make a couple of the 50mm angle cross beams? longer and have it protruding out the back of the machine and use these to mount c channel alley onto ..this would be used to guide the cat track / cable chain or whatever you guys call it .
Frank

Alan

You did ask for comment.........

The spindle mounting plate meets the channel and is the limit of Y axis travel so increase the width of the Y to Z connecting plate to almost meet the Gantry side plate. This will spread the Y axis bearings a little with no loss of travel.

Extend the gantry side plate down to near the top of channel. Have the X axis drive swivel pin as close to the line of the rack as is practical.

What I would do is take that one step further and position the X axis bearings so the the gantry side plates could extend down past the channel. This will bring the opportunity to have the swivel pin in line with the rack.

On the reduction drive units you will need to provide more support for the pinion shaft. I realise you have not got to that part yet.

Greg

Rod,
Is this the sort of thing you had in mind?

Cheers,

Alan

Hi Alan,
Now we are on the same page. It is a bit of extra work but I like the rails protected from dust/swarf.
Are you using the 120x40 Item aluminium profile for the gatry cross piece?
I am looking at their profiles now trying to decide which one to use for my machine.

Originally Posted by rodm

Hi Alan,
Now we are on the same page. It is a bit of extra work but I like the rails protected from dust/swarf.
Are you using the 120x40 Item aluminium profile for the gatry cross piece?
I am looking at their profiles now trying to decide which one to use for my machine.

Thanks Rod.
Yes I was proposing to use the 120 x 40 Item aluminium.
Cheers,
Alan

Alan

What drawing software are you using?

Greg

Greg,
What size did you use on your machine?
They do not have a catalogue on line and I am trying to work out what is the best (read strongest) I should go for. About 1100 long and I will hang a 1.5kw spindle on it.
Thanks,
Rod

Alan,
Sorry to butt in on your thread but it seems pointless to start a new thread for this.

Originally Posted by Greolt

Alan

What drawing software are you using?

Greg

Greg,
I am using a program called Vectorworks on a Mac computer. I have had it for years and is an old version and a number of things don't work, but I can't justify the $1.5K to buy the latest version. It is a 3D program, but I have never worked out how to use that, so I just bubble along and use the 2D capabilities and pretend I am back on a drawing board, which i did in my early 20's!!
Cheers,
Alan

Originally Posted by rodm

Greg,
What size did you use on your machine?

I used "ITEM" brand from Linear Bearings,

http://www.linearbearings.com.au/Pro...3/Default.aspx

"120 x 80 heavy"

Expensive but I saw this as one of the critical components around which my design revolved.

Greg

Alan

One thing occurred to me. I am a bit slow and dull sometimes.

Fixing method for the supported rails to the tee slot material.??

Linear rails have one row of bolts down the centre so work well with the slot.

How does it work with the supported rails?

If not using the slot then perhaps cheaper options come into play. RHS maybe.

Greg

Thanks Greg,
I agree about rigidity and will follow your example. If smaller section fails then it is a big job to upsize once it is installed. I'll go and order some tomorrow.

Alan,
Greg does have a good point about matching the rail mountings to the ally section.

If you are settled on the 8020 you can always work a connection to the slots - adapter plate between rail support and slots. Perhaps you might be able to pick up two of the slots in the 8020 section using this method.

Greg,
Following your thinking on the gantry rail, you are correct that I am not really using the t-slots at all except for the end fixing by tapping into the centre holes (I think that is how you did Crocky's rail).
I have done a blow up of how the round rails would fix to the gantry rails ... the holes in the rail support are 30 apart and 150 centres. The holes are 5.5, so assume intended for M5 machine screws. Just looking at it, there seems to be sufficient meat in the extrusion to allow it to be drilled and tapped.
If I went with a plain aluminium RHS, I would have to fix it to the gantry ends with angles on each side, which whilst possible may not look as neat!! Am I being pedantic?

Thanks for your feedback.
Alan