Originally Posted by mikeschn I'm not seeing the enthusiasm for a mid level machine like I am for the hardware store design.
I thought a mid level machine would be built from igus rails and bearings, or supported precision ground shafting and split bearings... but the interest doesn't appear to be there.
Is it the cost, or is the the precision required? A mid level machine is probably a skill level "mill 1", i.e. requires you to already have a mill to machine parts with.
What do you think?
Mike... |
well after all the chatter there about what bits are available from local hardware stores , and then listing tools required to complete the design
ok heres my 2 halfpence worth
i need a cnc , so set about building one , i looked at some of the construction methods used on a number of machines , and took into consideration the tools and equipment needed to build it , then i spent some time sourcing parts ,
it needs mdf for the main structure ( available form local hardware store or wood shop) i have to add here that a lot of hardware /wood shops offer a wood cutting service as long as the cuts are at 90 deg so square /oblong pieces end up accurate , although on this design i have still a lot of cutting out to do to shape some of the pieces but you get what you put in
some effort with a hand saw makes it worth it in the end
i decided to use steel angle iron for suports and bearing holders , these reqire drilling and fileing , no milling
the pricision rails well i originaly designed the machine to use 30mm dia 1.5mm thick tubeing , so something like curtain rods may be used although by using this method anything from 20mm to 30mm bar or tube could be used if it has a good surface , i opted to take an expencive route of using 20mm stainless steel bar for these , as i want to be able to machine aluminium
the size is scailable , and there is a +200mm axis requirement for the lenth of the carrage
i do not have a mill , and only hand tools to make the machine from the only singal part that is going to be a problem to make is the coupler to mount the threaded bar to the stepper motor , this is going to need a pillar drill i think
it could be built using a hardware store only , the steel parts could be made from aluminium angle if , but not shure if it would offer the strenth so opted to use steel
from the sounds of it hardware stores in the uk do not offer the same as in the us , but there is a good base of steel stock ,bearing suppliers here in the uk that makes all the parts available reasonably localy or online so do not see the problem there
but there draw slide version seems a good idea, but would say that the big diy/hardware stores in the uk do not seem to offer that style of slides
anyway i managed to fix the problem with my dxf export for the files
and uploaded them to my website
http://www.whipy.demon.co.uk
cost well you get what you pay for , if i used 9mm mdf instead of 18mm and used tube instead of bar for the rails and aluminium angle instead of steel then it could be built cheaper , but would be more suitable to a dremill than a 500w router for the cutter , and would limit the materials that could be cut , then almost all the parts would be available from the local B&Q or Homebase here in the uk , the exception being the threaded bar but CEF a trade supplier also throughout the uk stocks this and offer cash over counter for it , and bearings well google for a local supplier theres quite a few
anyway i'm going ahead with this design so feel free to comment on it ,
or come up with something copleatly diferent ,i guess once i get it built there will be problems that need iroing out , i just descovered that the router mounitng will also accept my drill so gives me more tooling options
Dave