Planning Strength, speed, stability..

[ART]

Yeah, that'd be painfull. Id just load them on the Y side..

Art

[Garyv]

Sorry_for_the______s,But,keyboard_in_garage_is_broke>>
I_am_building_a_router_table_,I_have_a_4x8_sheet_of_.750_Starboard_and_I_am_Thinking_about_using_that_
for_the_build_..My_question_is_has_anyone_here_tried_using_starboard_poly_sheets_for_any_parts_on_a_router_with_any_success?
And_I_am_getting_low_cost_servos_on_ebay_so_I_can_Use_the_same_controller_that_I_use_on_my_mill..
I_am_trying_to_keep_the_cost_down_because_this_is_my_first_Homebuilt_router_so_for_this_one_I_am_using_berillium_slides_on_5/8_and_3/4_polished_rails.
Then_I_am_looking_on_ebay_for_bearing_slide_rails_for_my_next_one_in_case_This_one_works_good..
I_am_making_the_prototype_out_of_MDF_to_get-the_peices_right_then_will_use_the_starboard_IF_It_will_stay_solid_enough.
Any_Input_will_be_apreciated..
Thanks
GaryV

[Garyv]

OK-I-have-the_z-and-x-axis-built-I-decided_to_use_mostly_MDF_for_theMain_construction_it_seems_like_the_starboard_
had_a_little_flex_and_also_swelled_or_flexed_when_you_put_screws_in..
Just_a_little_info---
Gary

[Garyv]

OK ,
  I dropped the MDF idea , I did finish the router but it is just not as tight as I would like to have so I have been obtaining linear rails on ebay to get stated on an all metal
frame gantry this time..And I do have a Mig welder to set things up.
    The MDF was a good learning tool but soon found out the round rods and bronze bushings just didnt stay tight enough or they would start to bounce and flex when at the outer edges of my cutting area.
     I have the linear bearings now to start my Z and Y gantry but I am still trying to decide on the best design..
  Any suggestions would be appreciated before I re-build again..
     What would be stronger for the Y gantry a 2"x6" thick walled aluminum tube or 2 separate 2" square tubes spaced 2" appart with the linear rails on the face?
And what about linear bearing placement? I have seen all different kinds from the bearings on the face and the bearings on the top and bottom to sandwich the rails in a U channel..Also a few with a bearing on the top as well as on the face of the tubing..
    Any ideas guys.?
Thanks
Gary

[Sam]

I see you got your keyboard fixed. What is the span of the gantry?

[Garyv]

Well I'm on my computer in the house , the no space bar sucks on the CNC computer in the garage but I have ordered a smoothstepper so I can put this computer in the garage in a few weeks ,,,It is annoying to read with all the underscores....
   The span on the gantry is going to be approximately 30 inches with 24 inch travel..I have seen a lot of machines set up with the structural aluminum but I am not sure how strong they will be , I would like to be able to cut aluminum sometimes if I need to.
 I also have a Shoptaske mill ,lathe combo machine but it only has about 9" x 9" milling area.So if possible I would like to be able to cut some aluminum on the router but more than likely 99.9percent will be wood..
And the X will be about 48" to 55" inches considering which bearings I get for that axis..So I have been getting the bearings first then design the size according to which bearings I can find at a reasonable price..
Also on the X I will be going with 2 acme screws one on each gantry base to stop any skewing that might be caused by pulling one side..I did find a fairly simple picture of a router which looks like it might work OK with minimal set up...here's a picture ( if I can figure out how to post it)
Thanks for the help..

[Garyv]

OK,
 I received my Y axis bearings today , rails are 28 " with 4 bearings and the Z axis rails are 15 3/4" so I am planning about 6 inches of Z travel and 23" on the Y axis , So back to the drawing board for the gantry...
  Does anyone have anything good or bad to say about using 2 pieces of 2" square tubing with4 inches in between them  for the acme screw in the center . The picture in the last post has the leadscrew near the top , I think the center will give a more even slide.
   I am using a roto zip motor on my other router but plan on getting either the porter cable or variable speed rigid from home depot , it seems to have a nice straight column for mounting brackets and adjustments..
   I would really like input from all of you guys on here because I don't want to tear this one down a week after building like the last one.Also I did get confirmation from Warp 9 and paid for my smoothstepper to be on its way in a few days so my servos will be able to do more than the 50 IPM like it is now .........
Thanks Guys , I'm just looking for help and trying to keep this section open...
Thanks
GaryV
Also Any one else In Florida near Port Saint Lucie area o trade ideas?

[Sam]

I will give you my $0.02, since you asked. Take it with a grain of salt.

  Does anyone have anything good or bad to say about using 2 pieces of 2" square tubing with4 inches in between them  for the acme screw in the center

Good= Can be done cheaply.
Bad= Can be unstable.

I guess it all boils down to how much you want to invest, and what kind of tolerances your trying to achieve. My router http://sinistersam.com/mill/router.html is made the "cheap" way. 2X2 extruded aluminum tubing with a span of around 50". Kind of like the one in the picture. I have found out that without proper support, you will get a bit of flex when cutting forces are applied. Not a sideways or vertical flex, but rather a front/back tilt flex. Leaning back in a recliner comes to mind. Its not very much, but its enough to not build another one that way. If your using linear rod without a center support, I would guess you will get some flex anyhow. Linear ways are a better choice for a multitude of reasons, but are costly. A solid gantry like rceebuilder's http://www.machsupport.com/forum/index.php/topic,6766.0.html would be my idea of a good solid gantry. Werther or not you need one that rigid, is up to you. Even with the amount of flex I have with a 50 inch gantry, I would not hesitate to tackle any woodworking project that comes to mind. Engraving detailed patterns in aluminum is really where it rears its ugly demon head. Good luck!

[Garyv]

Thanks_Sam,
I_am_going_to_be_using_all_linear_bearings_I_am_getting_away_from_the_Unsupported_round_rods_after_my_last_build.
I_am_thinking_of_using_a_2X6"_steel_tubing_and_gussetted_plates_for_the_sides...
Thanks_for_the_info..
Gary

[rglindholm]

I would also recommend a double drive Y axis.  With the screws on the outside, It frees up the underside of the main cutting surface to be converted into a vacumn  hold down surface. 

I have used motion master table routers in the past.  One had vacumn the other didn't.  Setup on the vacumn table was much faster and preferred.
Ray