. .
Page 2 of 2 FirstFirst 12
  1. #11
    You are making the Z axis much heaveir than it needs to be with this arrangment by having the motor, ballscrew, bearings etc moving with it. All it's doing is creating more work for the motor and lowering performance and add's nothing to the strength.
    Also I would widen the bearing and rail spacing to give more stabilty, I understand your chasing space but a few CM's makes a big difference and is worth losing sometimes.

    Regards the tubes, you do realise Tube doesn't have sharp edges don't you.? At this size they will have between 8 to 12mm radius and you show the gantry ballscrew bearing at the edge and this won't work as you'll be drilling into the radius and the side wall.
    Yes, small detail I know but these make a big difference and are what catch you out. If you are going to model the design make sure you model every detail because if not then at some point you will find things that don't fit as you expect and sometimes they can be very diffcult or impossible to correct without major upevil.

    The gantry need bracing where the bearing box meets the gantry box and again I would widen the bearing spacing.
    If you are going to weld plate to the box section then only weld it in short sections 30-40mm in length spaced 100mm apart and staggered on each side, don't fully weld the edge because it will put stresses into the tube which will release when you have the tubes machined unless you have it heat treated first.

    If you don't want to go the heat treat/machined route then think about using epoxy metal putty on the surfaces and putting on a surface plate to create flat and parallel surfaces. You'll need a large surface plate but it works very well and is easy and quick. I use this method all the time and it's very accurate and strong.
    -use common sense, if you lack it, there is no software to help that.

    Email: [email protected]

    Web site: www.jazzcnc.co.uk

  2. #12
    Quote Originally Posted by iGyros View Post
    I have made plans today after all. The whole square tubes are 100 x 80 x 6.3 mm tubes. The plates on the Z axis are 25 mm flat steel. There is one thing I would like to adjust that is not in the plans yet. I will weld 10 mm of flat steel on all support surfaces and have it milled flat. These are 25 mm guides and ballscrews with 20 mm.


    This is all still very rough, but I would be happy if you can tell me if I am on a real path or if there are already huge mistakes in there.

    Attachment 29067
    Attachment 29066
    Attachment 29068
    Hello iGyros,

    Look like you could use my design to refine yours.

    I have used 120x80x4 mm and 80x80 for the bed..

    Did you already decide on 1 or 2 ballscrews on the long axis?

    The linkage on those are a weak point in my design. I have no real world problems with it yet but would rethink it when done all over again.



    Grtz Bert.




    Verstuurd vanaf mijn SM-A505FN met Tapatalk

  3. #13
    Hello guys,
    I have worked a little bit on the design again.
    I also tried a plan with a fixed portal, but it would be much more complicated.


    Here are a few important points that I have adapted.
    - The portal is 850 mm wide.
    - The travels are about 510 mm x 425 mm x 200 mm.
    - Steel profiles with the dimensions 60 x 100 x 6.3 mm are planned everywhere.
    - The profile for the portal has the dimensions 150 x 100 x 6.3 mm.
    - I plan to use 25 mm linear guides and 1605 Ballscrews.
    - Now all support surfaces are underlaid. So far I plan to use 10 mm flat steel for this.
    - I made the Z axis much more massive and moved the motor to the fixed side.
    - Where it is possible (and useful), I have added angles. These are made of 20 and 15 mm flat steel.
    - I have planned a slot table. It consists of a large 10 mm thick steel plate and single 15 mm steel plates for the slots.


    I have the following questions.
    - What do you think of the Z axis? Does the reinforcement on the "fixed" plate (not on the movable side) give me something or is it just unnecessary weight?
    - Do the angles bring me a serious advantage or is that unnecessary work?
    - The Z axis plates are 25 mm steel and the reinforcements are 15 mm steel. Is this too thick and just unnecessary weight?
    - I would like to mill the angles and the steel slotted table with the machine once it is set up. How realistic is it that I want to mill steel with the machine?
    - Which steel should I use for all the components?
    - With the size Nema 34 motors (for now) are sufficient?
    - I am practically dependent on the 16 mm ballscrews, because I would have to mill too much with the 20 mm ballscrews and I currently have no milling machine. At work a college can facemill the all mounting surfaces, but unfortunately they can't do too much for me there. Would I have a big advantage for 20 mm ballscrews?

    What do you notice about the plans? Are there any more mistakes somewhere?

    Click image for larger version. 

Name:	8.PNG 
Views:	157 
Size:	357.9 KB 
ID:	29071Click image for larger version. 

Name:	10.JPG 
Views:	182 
Size:	118.1 KB 
ID:	29072Click image for larger version. 

Name:	7.PNG 
Views:	140 
Size:	229.7 KB 
ID:	29073Click image for larger version. 

Name:	Unbenannt.JPG 
Views:	136 
Size:	75.9 KB 
ID:	29074

  4. #14
    You need to model your end mill / cutting bit and look at whether it will clear above your workpiece.

    If you are using a vice, it will use up a lot of Z travel.

    Also check how you will actually bolt the linear bearing carriages. You usually can't have them right on top of each other as you can't bolt them that way.

    Overall lots of good things in your design. Bracing is good

Page 2 of 2 FirstFirst 12

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. New CNC build gantry questions
    By Capsuna in forum Gantry/Router Machines & Building
    Replies: 8
    Last Post: 04-12-2019, 12:59 AM
  2. CNC Build - TEP milling machine conversion
    By craynerd in forum Gantry/Router Machines & Building
    Replies: 6
    Last Post: 06-07-2015, 02:09 AM
  3. Milling machine -maintenance? (oil, lubrication, specific questions)
    By diy-john in forum Milling Machines, Builds & Conversions
    Replies: 0
    Last Post: 24-02-2013, 09:03 PM
  4. A few questions before I start my build
    By eclassic in forum General Discussion
    Replies: 0
    Last Post: 11-07-2011, 10:54 PM
  5. NEW MEMBER: Hi Help to build a CNC router/milling machine
    By peterashuk in forum New Member Introductions
    Replies: 1
    Last Post: 28-08-2010, 12:22 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •