Initial Design Check Please

[irving2008]

You need some diagonal bracing on the base. How are you going to ensure the rails are on the same plane? There doesn't seem to be any adjustability in there.

[JAZZCNC]

How are you going to ensure the rails are on the same plane? There doesn't seem to be any adjustability in there.

He can shim the Profile between the box section. This will work well and be easy enough to get on same plane with careful setup.

Trev. Design looks ok but I'd build the frame differant regards how section is arranged.? Make the the legs extend down to the floor this will make the welding easier and give more support to the uprights. See pic knocked up to show what mean.

[Gotty101]

Thanks for the replies. My dads got the lower frame priced up built from a company who does work at his company. They gave the choice of carbon steal or aluminium in 50x50x3mm. I will see if i can have the design tweeked. I know they will do a first rate job as they do all sorts of precision work.

Ive just been working through the costs, to see if im in the right ball park. Do these seem right so far or does anyone know where i could get items for a better cost?



Hiwin 20 Rails 4x (off cut of two will build z axis) £155.15 http://www.aliexpress.com/item/750mm...832489900.html
Hiwin 20 Bearing blocks 12x £222.42 http://www.aliexpress.com/item/1PC-E...048643961.html
Gantry Profile £72.02 http://www.metallin.co.uk/
ball screws £250
spindle £183 http://www.ebay.co.uk/itm/2-2KW-WATE...item3f0a793189
steppers
drivers
controller
aluminium


Thanks again

Trev

[JAZZCNC]

Try these for profile they are cheap and quick delivery despite being in Germany. I buy my profile here and they are very good with accurate cutting.
http://www.motedis.co.uk/shop/Slot-p...91_999993.html

Tip with the gantry profile if you use Bosch rexroth BR type profile 90 x 45 then the BK/BF12 bearing holes match the slots. With Item 8 series type they don't and you'll need to make plates for mounting. I Make machines that use L shape arrangement with 90x45 and they are more than strong enough so don't worrie about using shorter widths.

[EddyCurrent]

Thanks for the replies. My dads got the lower frame priced up built from a company who does work at his company. They gave the choice of carbon steal or aluminium in 50x50x3mm. I will see if i can have the design tweeked.

I think you will find mild steel is sufficient for the frame and will be much cheaper than aluminium, also the extra weight will be a benefit when the machine is working.

[JAZZCNC]

I think you will find mild steel is sufficient for the frame and will be much cheaper than aluminium, also the extra weight will be a benefit when the machine is working.

Agree with Eddy and aluminium tends to crack around welds from vibration over time so wouldn't use it for the frame. I weld aluminium often and wouldn't build the frame from it unless weight was critical and even then I'd use much thicker aluminium than I would steel.

[Gotty101]

thanks for the replies guys.

With regards to the HGH20CA blocks ive found some at a great price but the spec is HGH20CAZOC Very light preload. Or should i go for Z1?
Ive had a look around and this thread said z0 (http://www.mycncuk.com/threads/3711-Hiwin-linear-blocks-HGW-20-CC-what-preload-to-spec)

Thanks again.

Trev

[JAZZCNC]

Stick with Z0 don't need higher preload than this. The HGH20CAZOC are normal grade bearings and will be fine.