fresh start 8x4 build

[reefy86]

you have me thinking now lol. are those bearing blocks not designed to screw from plate into the blocks? thats how the design is by bolting from underneath into the blocks.

[JAZZCNC]

you have me thinking now lol. are those bearing blocks not designed to screw from plate into the blocks? thats how the design is by bolting from underneath into the blocks.

The bearing blocks are threaded and you bolt dowm into them. Your design cannot access them without removing the gantry profile first which makes setting the gantry square very difficult. You'll want to access them and leave lose fit while tweaking gantry square then tighten them.

[reefy86]

dont know if im being stupid but what i had in mind was to only bolt the top alu profile untill its square then had the bottom.

[Lee Roberts]

dont know if im being stupid but what i had in mind was to only bolt the top alu profile untill its square then had the bottom.

Sounds like a plan to me , use the top one like you say, then add the bottom beam once your happy with everything else.

If the machine turns out like what you have in CAD (post 1), it will be a very nice machine indeed, I look forward to watching this one unfold and you seem to be in good hands.

Will you be doing all the work yourself Reefy?

.Me

[reefy86]

thanks lee, im a newbie on all this so the only credit ill take is actually listening to good advice. ill be getting the frame welded by an experienced welder and then have a friend help with the heavy lifting ect and then everything else is on my own.

Ash

[Clive S]

dont know if im being stupid but what i had in mind was to only bolt the top alu profile untill its square then had the bottom.

The way I see it is if you tighten the top one how will you get the bottom one in position. As Rob suggested you could rack the end plates back then you could access the bearing blocks and move the spindle back between them.

[JAZZCNC]

dont know if im being stupid but what i had in mind was to only bolt the top alu profile untill its square then had the bottom.

Sounds great in theory and will work treat in Cad but can tell you in practise it will be pain in the arse and you'll struggle to get linear rails to align and be parallel.
Fraction of degree error on wide machine shows massively at other end and you'll want easy way to adjust without affecting other areas of machine.

Then you have the fact that really you want to be bolting the bearing plates to the lower profile to stiffen the gantry.

Would be lot easier and stronger if you made the bearing plates longer and bolted to gantry. Also like whats been suggested you also want to move the gantry back to better balance the gantry on the bearings. Plus will bring the cutting area more into the machine foot print.

[reefy86]

i just roughed this out but is this what you suggest on the bearing plates? made the plate longer so can access bearing blocks and the aluminium profile is bolted to center of plate.

Ash

[JAZZCNC]

Ash easiest way is to have two plates. One bolts to the bearings and other is bolted to and part of the gantry. These then bolt together with the lower plate being threaded for bolts passing thru the upper plate and in location that is easy accessed. This way you can place gantry on bearing plate then lock into position when square. Then drill ream fit dowel pins to lock in place if wanted or just have tight fit.
Tight fit works well when first setting up and learning becuase if you bend the machine out shape can easily get back square by lossening bolts starting again.

[reefy86]

slap in the face lol. thanks dean :)