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

Planning update ... have been laid up for a day or so with the dogs disease! With the feedback from Greg and Rod, I have made some fairly major revisions including increasing the gantry rail from 40-4012 to 40-8016, that's 80mm wide and 160 deep and should beef up that to allow a spindle at some stage down the track!
I have dropped the gantry ends down below the rail and the rack which has allowed me to drop the pivot point for the r&p motor plates. I have increased the width of the Z axis backing plate to allow the Z axis rails to be pushed further apart. I have also come up with a preliminary design for the X axis motor plates, but need to get some info from Greg in relation to the r&p configuration ... rack size/pitch, pinion size, reduction pulley size, belt size and motor pulley size... sorry lots of questions.

Cheers,

Alan

Hi Alan,
Looks good to me.

You have certainly upped the ante with that much larger tee slot section Alan.

Might be in for a shock when you find out how much it costs. Maybe something in between.

What I said about spreading the width of the plate between the Z and Y might have been misunderstood.

My idea would be to make the Z member (Router mount) as narrow as is practically reasonable. Just wide enough to fix the bearing blocks with ballscrew between.

At the full extent of Y axis travel this will come against the main side members (channel). When that happens there is still space for the Y axis plate to be a bit wider because it stays above the channel.

An increase the width of the Y plate will spread the spacing of the Y bearing blocks with no loss of Y axis travel.

I have attached a pic to illustrate what I mean. Not trying to infer you should do all exactly what I did. Just to get an idea across.

Greg

Yes Greg. I did get a shock ... $370.00 for one length 1160mm long. Am currently looking at other options.

Xylotex drives and steppers have arrived and I have ordered my rails and ballscrews from China.

Chasing up local suppliers for the metal table frame and aluminium for the gantry.

Not long now before the rubber hits the road!!

Cheers

Alan

Hi Alan,
I know what you mean. It took a week to get some over to Perth and for a 1200mm length of 120/80 heavy it cost $240 and another $56 for the T nuts. I want this machine to be mickey duck so I just grin and bear it.
I also got a 5.5 metre length of 76 by 76 by 10mm angle to mount my rails on for the X axis. Not as bad as the 120/80 but it is not cheap. Mind you steel went up an average of 25% in July so expect a few surprises there as well.
I was actually thinking about drawing it up while I was in the shed tonight but when I sat in front of the computer I lost interest. I am sitting here doing a couple of sketches on on a bit of scrap paper so does that make up for it?

Design update # ??
I seem to be getting really left behind by Rod and Twisted Fuse ... but I am making some progress!
I think I mentioned that I have ordered my rails and ballscrews from China, so just waiting for them to arrive. Have been pricing steel, r&p, pulleys and belts etc AND have modified the design to accomodate 120 x 80 t-slot for the gantry beam. I have also finalised (well, as finalised as things get here!) the swing plates for the r&p reduction gear and stepper etc.
Now, what colour should I paint it??

Anyway that's it for the time being. As soon as I get all the gear together I will start photographing the progress. I have programmed for construction to happen in October, with the first signs being produced in November. (Well we'll see!!)

My great name idea of Highlands Timber Signs was knocked back by the Dept. of Fair Trading here in NSW, but they have accepted one of my alternates ... Rural Timber Signs.

Cheers,

Alan

ps ... tried to insert JPG's, but could not get the size down ... hope you can open the pdf's.

Hi Alan,
I am probably behind you Alan as I only have a few scraps of paper with drawings and 20 brackets made. I will have to work my design on the fly which is how I usually do it. I have been busy with other things so have not had any time for machine building. I ordered pulleys and belts today so have all the bits ready to go just need to make time.

Just one suggestion with your design. Flip around the end angles on the table. This will make it easier to clamp end to end on the table. Fixing your work pieces to the table can be difficult so worth planning ahead.

The drawings are great and will provide some decent information to prospective builders.

Looking good Alan.

See if you can get the reduction drives pivot point down. The idea to hang the gantry sides down was for this purpose. Ideal is in line with the pinion shaft.

And give some thought to the pivot. The slightest slop here goes straight to backlash. It is a critical part of the R&P system.

Greg

Thanks Rod & Greg for your helpful comments. I have already turned the end angles around on the table, but am struggling with what to do with the pivot.

Greg, you will see on the sketch below, that I was trying to use the gap beside the rail for the pivot connection. You will also note from the other drawings that I have substantially reduced the height of the gantry end plates ... I did this so that I could at least mill the various holes and bearing recesses using my widgitmaster ... my only milling capability at the moment. If I dropped the pivot to the same level as the rack, I would have to increase the height of the gantry ends to a size where they wouldn't fit in the wm. Thanks for the suggestion and I do know where you are coming from. I will just scratch my head a bit more and see if I can get on the same bus as you!

Many thanks,

Alan

Hi Zoot,
Try moving the rack a bit to the left and re-position the pivot under the C section. It will mean that the swing plate will almost be sideways to the position in your current elevation and the pivot moved forward (or back). You will also have to extend the bottom of the gantry side plate. Perhaps an end elevation might make it easier to see the adjustments.

Hi Alan,
OK after reading it again I realise wm stands for widgetmaster so I have lead you down the proverbial path. Can you index the gantry plate and cut it in two positions? I would imagine that the reference between the gantry top and pivot area is not sub mm accuracy so a move might work out OK as long as both sides are the same. I make use of MDF jigs when building and maybe you could work our something for this?

Greg & Rod ... have had my thinking cap on and come up with this idea.

I hope you can read the sketch ... it is a bit like an xray with things overlaid, but the concept seems to work unless there is a problem with having the pivot close to the front of the gantry ends and not in the middle where I had it before. I only had it in the middle before, because it looked good ... no mechanical advantage as I saw it! Anyway, I think this one looks good as well with the angled dooverlackey hanging down to take the pivot. I could trim a bit more from the bottom left corner to make it easily fit the Widgitmaster.

I was going to ask you as well if there is any easy way to tap the bolt holes in both the steel and aluminium ... not having a fancy end milling machine ... or is it just a hand twisting job!

Thanks again for your helpful comments,

Cheers,

Alan

Hand twisting. Couple of hundred holes........builds character.

Smaller tapping can be done with a battery drill. Takes a bit of finesse.

Or one of these ..........

http://www.machineryhouse.com.au/Pro...tockCode=T002A

Not everything that needs tapping can be manoeuvred under a machine of course.

Greg

EDIT: Now your getting the idea with the pivot point.

Hi Alan,
Good lateral thinking on turning the gantry end plate so it fits the wm - that's WidgitMaster .
I use a cordless for tapping threads. Use lubricant (Tap Magic is good but anything is better than none) , Low speed, clutch backed off so you don't break taps, lots of forward reverse movements and make sure tap is square to hole. Only use HSS taps as carbide are brittle and have a tendancy to break. In any case 4mm taps and below are risky as they snap easy but if this happens drive the broken tap through with a drift - one of the advantages of working in aluminum..
If you are not confident a trick is to have a block of wood (steel or allly is better) with a hole drilled through it in the drill press. Use it like a dovetail guide to keep the tap vertical to start the hole. The safest way is to put on some good music, brain in neutral and hand tap.