Thread: Steel Framed Router
Hello. I am hoping to design and make a router for hobby use just like many have done previously on this site, and I am currently putting together a concept and these are my current thoughts.
I am aiming for a working area of 1000mm x 1300mm (approx 3’x4’) and a Z of 130mm (5’’).
The main frame and gantry is currently 50x50x4 steel square hollow section with 25x25x2.5 bracing for the bed. This will be bolted together unless I find a good welder.
The linear rails are 25mm dia for the Y axis and 20mm for the X and Z, and hoping to use a 2510 ballscrew for the Y a 1610 ballscrew for the X and 1404 ballscrew for the Z. (hope I haven’t confused the X and Y).
I would appreciate your comments and constructive criticism as the design is easily changed at this stage before any serious money is spent. This is only a hobby machine and its main use will be engraving hard wood panels and cutting out the odd speaker panel.
If you are using 25mm supported rails you will need box of 60mm and over
plus two ballscrews as to stop the bed crabbing
this is just the advice I have received as I'm by no means a expert
you may want to look at Jonathan's and chips CNC machine
James and Luke
I have details of a fully supported rail that has a 21mm dimension across the base. I hope it is still available.
As for the crabbing, I was hoping by spreading the lower bearings apart as far as I did this may be avoided, but I will take the comment on board.
Ive seen the crabbing or twisting of the gantry avoided by framework being added to the opposite side of the gantry to the spindle as in the commercial machines.
These are just observations and are not supposed to imply any knowledge or special wisdom on my part.
Oh and what software did you used to produce the pictures?
RickAlways bear in mind that your own resolution to succeed is more important than any other - Abe Lincoln
I just used Google SketchUp for the drawings as its quick.
Rick, I've attached a zipped copy and hopefully it has worked.
Ok ive just done enough tinkering to give you an idea, of where bracing could do with looking at.
It may also be an idea to widen up underneath the table on the gantry just enough to stop the diagonal flex when the spindle is working at the far reaches of the gantry axis.
I built a table router very similar to this one some time ago and that is the only real problem area i had to re-think..
I would have put a double row but unless your stepper was on top it wont fit.. Good luck with the project i will be interested to follow your progress, its always nice to see projects from concept through to completion..
All the best RickAlways bear in mind that your own resolution to succeed is more important than any other - Abe Lincoln
25mm ballscrew is also not recommended for a machine this size, you've probably gone with 25mm because of the 10mm pitch not being available in 20mm.
25mm screws are large and they produce a lot more inertia which has to be stopped and accelerated this means big strong motors needed amongst over things which all make it not ideal.! . . . Bigger is not better when it comes to some things, screws being one of them.!
At the size your looking to make 16mm is getting on the edge of being whippy thou with carefull aliagnment and sensible speeds you would be ok.
You could go with 20mm 5mm pitch and gearing 1/2 this way you get the speed thou at the cost of a little torque. I can tell you from experience 6nm Nema 34's will handle 1/2 setup without any problem. There is an up side with 1/2 gearing as well to this if you find you ever need the extra resolution of 5mm pitch and higher torque it's a simple pulley change and away you go.
You could go with rotating the nut but it gets a bit more involved, thou does work well if done right.
With the steel box section frame you will also get lots of resonance which has a big affect on quality of cut esp when cutting hard materials so a big tip if you go all steel is cap the ends and fill the frame with kiln dry'd sand it makes a big difference.
Definatly go with twin screws on the X axis it makes a very accurate strong stiff machine. Either with a motor on each screw slaved together or one motor with belt between the 2 screws.
Dont be put off by the belts they work fine and more than good enough for the work you intend to do. I have a machine that use's this 5mm pitch 1/2 twin screw belt setup and I cut every thing from steel to plastic with it no problems and it's super accurate. Even cut cast iron with it last week for the first time without any trouble.!
Not a pritty thing but it gets the job done and very very reliable and super accurate.
By Wejjmeister in forum Gantry/Router Machines & BuildingReplies: 87Last Post: 02-01-2016, 11:45 PM
By Boyan Silyavski in forum Machine Frames & BedsReplies: 0Last Post: 06-11-2013, 04:58 PM
BUILD LOG: Steel Framed CNC routerBy Joe in forum DIY Router Build LogsReplies: 14Last Post: 23-06-2013, 09:45 PM
BUILD LOG: Formed steel cnc routerBy sbams in forum DIY Router Build LogsReplies: 4Last Post: 07-03-2013, 01:00 AM
BUILD LOG: My steel framed routerBy pavlo in forum DIY Router Build LogsReplies: 17Last Post: 06-03-2011, 09:08 PM