Ready Steady Eddy

[JAZZCNC]

Yep that's getting better.!. . . couple of things worth a mention.?

The way you have ballscrews fixed into gantry ends using FF/FK blocks will cause you problems with alignment and getting in and out because it's effectively trapped.
With this design you'll be better with BK/BF blocks either sat on box section or fasten thru sides of blocks into ends.

How you going to fasten the 120x80 box to those plates which I presume are Aluminium.? You'll have to make sure those ends are cut or machined perfectly 90deg otherwise they'll be a pain and if you weld plates on ends and bolt into Aluminium the plate will need milling perfectly flat.

Fastening the ends to gantry box section will also need careful end machining and attention, Esp if bolted together. If you weld it together you'll need to pay very careful attention to it twisting. . . . Personally I'd weld it together then Epoxy level the front so both rails are on the same plane. This way doesn't matter if it twists has the epoxy will remove any so all you need to ensure is that it's square which is easy done with careful measurement.

I'd also increase those little up stand brackets, basicly make them triangles that go at least half way up the Box section height.

[EddyCurrent]

The way you have ballscrews fixed into gantry ends using FF/FK blocks will cause you problems with alignment and getting in and out because it's effectively trapped.
With this design you'll be better with BK/BF blocks either sat on box section or fasten thru sides of blocks into ends.

You're right, I was thinking the gantry sides might be bolted together thus allowing access to fit the ball screw.

How you going to fasten the 120x80 box to those plates which I presume are Aluminium.? You'll have to make sure those ends are cut or machined perfectly 90deg otherwise they'll be a pain and if you weld plates on ends and bolt into Aluminium the plate will need milling perfectly flat.

I can see the 90deg aspect will be a problem whatever method of construction is used. I was thinking of bolting a block to the aluminium that was a tight fit into the box section, then bolt the box section to the block. Welding a bottom plate as you say and milling might be a better idea.

Fastening the ends to gantry box section will also need careful end machining and attention, Esp if bolted together. If you weld it together you'll need to pay very careful attention to it twisting. . . . Personally I'd weld it together then Epoxy level the front so both rails are on the same plane. This way doesn't matter if it twists has the epoxy will remove any so all you need to ensure is that it's square which is easy done with careful measurement.

I was thinking welding would be best, I would make a jig to hold it.

I'd also increase those little up stand brackets, basicly make them triangles that go at least half way up the Box section height.

I had them like that at first, will change back.

[EddyCurrent]

Metal ordered, ball screws etc. ordered (Chai), pondering HIWIN or similar guides but Zapp is easiest to order these from and they have exact lengths I need without having to cut them. Also I (re)decided that I didn't really want a challenge building this machine, I just want it to work as planned so I can use it. With this in mind then I reverted back to the L gantry which I earlier said I didn't like but it simplifies the making of it quite a bit. It will be something like Matt's (kingcreaky) machine with a few changes.

[Jonathan]

Metal ordered, ball screws etc. ordered (Chai), pondering HIWIN or similar guides but Zapp is easiest to order these from and they have exact lengths I need without having to cut them.

Since it seems you're happy to get the rest of the linear motion parts from China, I'm surprised at your choice of supplier for the linear guides. There are quite a few sellers on aliexpress which sell them for a lot less. For example:

BST AUTOMATION - Small Orders Online Store, Hot Selling Ball screws,ballscrew,linear guide and more on Aliexpress.com

Just send them a message with the lengths you want, and make sure you get the right preload - i.e. not zero.

[EddyCurrent]

I didn't ask Chai about the rails because on ebay he seemed to be selling only round rail. I looked at Aliexpress and that's why I'm pondering, sometimes I just like it easy rather than cheapest.

[EddyCurrent]

Ball screws etc. arrived from Chai all machined exactly to my spec. with dimension F extended to 30mm for pulley.
Decided to get Hiwin rails and blocks from UK but not from supplier I was thinking about, arrived within 2 days, great !

[EddyCurrent]

This weekend got the Ethernet Smooth Stepper, BOB (DIYCNC), Spindle board (DIYCNC), 5v and 24vpower supplies.
Lashed them together and plugged into PC, it took a while to get it sorted as this is the first time I've used Mach3 and the hardware but by afternoon had everything working and the inputs set up as per my drawings. Need to get the control cabinet layout finished so I can order the right size box. Having to wait for the AM882's coming in.
Also got the main power supply transformer, 22000uF capacitor, bridge rectifier, aluminium plate to mount it.
Nearly got the bottom frame design finished and have all the metal ready to start cutting, Brother-in-law booked in with his MIG.