NEWBIE ADVICE Another CNC desktop


Results 1 to 8 of 8

Thread: NEWBIE ADVICE Another CNC desktop

  1. #1
    *Registered User* djolemag's Avatar
    Join Date
    Jan 2019
    Posts
    6
    Downloads
    0
    Uploads
    0

    Default NEWBIE ADVICE Another CNC desktop

    Hi guys,
    I’m following this forum silently for a long time but I registered few days ago.
    Let me explain few my reasons:
    I’m IT consultant for last 20 years and that is what I do for living. However, I’m also hobbyist for many many years, doing various crafts. Seems like my interests are combined in weird way: electronics and high IT stuff at one side and ancient crafts like watchmaking at the other side. Hence, 20+ years ago I’ve been watchmaker’s apprentice for some time but life took me on other side. Now, I have a time and resources to get back to my “first love” – watchmaking.
    So I’m doing it for last 5 years at purely hobby level, but dived pretty deep into… Now we come to the point.
    Three years ago I started my build of DIY CNC router. Idea was to have a small device, fixed gantry type, approx. table dimensions about 40x40 cm, height of upsides to bridge about 550 mm (Yes pretty high). It had to be made of double layer 6mm thick steel plates (so total 12 mm per side) made with laser cut, very well fixed with some slot fixtures and screws. I will take some pictures during the day and post them here. In the meantime, I found some old CAD drawing for laser cutting so I’m posting image of one side plate just to get idea…
    In lack of info, not enough reading and wrong estimations, I designed it with round shafts and linear bearings, so x and y axis with 16 mm shafts and z axis with 12 mm…
    Hence, now I’m having more and more demands to accomplish some job like making new part of custom engraving, so I definitely need sort of CNC router or mill… I have small lathe to accomplish some turnings, but I need milling from time to time too.. Mill would be overkill option according to my demands, so router is ideal for now.
    Since it needs to be small and I need to produce small parts, ideal table dimensions are not more than 20x30 cm, with height travel about 50-70 mm max.
    I need to mill mostly light materials for modeling, but also need to work with copper/brass/bronze and sometimes to make small parts of thin steel plates , like 0.4 to 0.8 mm thick.
    Therefore it needs to be sturdy and rigid.
    I saw one my “colleague” took Chinese 3040T 4-axis with 24,000 RPM spindle and he says he is super satisfied, milled metal plates and similar with no trouble )will post link here later). I read many pages about that machine here but it doesn’t looks like appropriate to me.
    My doubt is:
    1. Buy 3040 or 2030 hardware kit and improve it with Gecko, proper Nema23 motors and appropriate spindle
    or
    2. Continue my work on rigid frame I still have in my cellar?
    I intend to finish this frame with proper base, adjust design to use linear supported rails (beams or slotted, like Hiwin ?), use ballscrews 1605 for all axis, Nema 23 motors and some spindle. Worktable is made of 2 layers of Aluminium, 6 mm each, so 12mm total thickness, dimensions about 40x40 cm.
    What do you think about it at all? I have spent some time and bucks on frame, I think I can improve it to be pretty useful, compared to 3040 hardware kit made of aluminum extrusion.
    1. Should I use supported rails or slotted one? Is 20 or 25 mm enough for x and y axis? If slotted, which dimension is fine?
    2. What size for z axis? How much travel would be enough?
    3. Ballscrew 1605 is good enough?
    4. Motors?
    5. Spindle, really pain… Some says 800 W is enough, some 1.5 kW… AC or DC? Water or air cooled? I’m pretty confused. Please bear in mind that ER11 collet is enough for all my work, time is not an issue in a means of speed… So, must focus on precision.
    Any input highly appreciated. Sorry for long post. Will add some pictures tonight.

    Similar Threads:
    Attached Thumbnails Attached Thumbnails NEWBIE ADVICE Another CNC desktop-cnc-router-upstream-jpg  


  2. #2
    *Registered User* djolemag's Avatar
    Join Date
    Jan 2019
    Posts
    6
    Downloads
    0
    Uploads
    0

    Default Re: NEWBIE ADVICE Another CNC desktop

    Here are some pics
    Also I mentioned a watchmaker using CNC for making parts, here is a link https://watchguy.co.uk/a-new-era/

    Attached Thumbnails Attached Thumbnails NEWBIE ADVICE Another CNC desktop-20190116_212551_hdr-jpg   NEWBIE ADVICE Another CNC desktop-20190116_212618_hdr-jpg   NEWBIE ADVICE Another CNC desktop-20190116_212644_hdr-jpg   NEWBIE ADVICE Another CNC desktop-20190116_212724_hdr-jpg  

    NEWBIE ADVICE Another CNC desktop-20190116_212758_hdr-jpg   NEWBIE ADVICE Another CNC desktop-20190116_212817_hdr-jpg   NEWBIE ADVICE Another CNC desktop-20190116_212831_hdr-jpg   NEWBIE ADVICE Another CNC desktop-20190116_212905_hdr-jpg  



  3. #3
    Registered ninefinger's Avatar
    Join Date
    Sep 2006
    Location
    Canada
    Posts
    466
    Downloads
    0
    Uploads
    0

    Default Re: NEWBIE ADVICE Another CNC desktop

    I will answer what I'm comfortable answering.
    Spindle HP - 800W is more than enough. At 24000rpm you would be able to feed at 3m/min ( ~118ipm) a 12.7mm (1/2") diameter cutter into aluminum which sounds far more aggressive than you plan to use the machine.
    1605 ballscrews will be fine (i.e. more than rigid enough).
    For Z axis - think about how you will hold your work and account for its height. i.e. will you use a vise? Ever plan on a 4th axis? you will need clearance over it.
    I won't recommend motors as that takes a bit of thought (how much weight is being moved and what acceleration and speeds do you want / need) - though realistically most people over motor their axes as the cost of larger motors / drivers is not significant for one off builds.So you could just look at someone else's build of a similar size machine and pretty safely match what they used.
    Never used rails so no idea there...

    Mike



  4. #4
    *Registered User* djolemag's Avatar
    Join Date
    Jan 2019
    Posts
    6
    Downloads
    0
    Uploads
    0

    Default Re: NEWBIE ADVICE Another CNC desktop

    Quote Originally Posted by ninefinger View Post
    I will answer what I'm comfortable answering.
    Spindle HP - 800W is more than enough. At 24000rpm you would be able to feed at 3m/min ( ~118ipm) a 12.7mm (1/2") diameter cutter into aluminum which sounds far more aggressive than you plan to use the machine.
    1605 ballscrews will be fine (i.e. more than rigid enough).
    For Z axis - think about how you will hold your work and account for its height. i.e. will you use a vise? Ever plan on a 4th axis? you will need clearance over it.
    I won't recommend motors as that takes a bit of thought (how much weight is being moved and what acceleration and speeds do you want / need) - though realistically most people over motor their axes as the cost of larger motors / drivers is not significant for one off builds.So you could just look at someone else's build of a similar size machine and pretty safely match what they used.
    Never used rails so no idea there...

    Mike
    Hi, thanx for the answer.
    Yes, I'm thinking of adding 4th axis in some future, so I will need to keep this height as shown on pictures.
    Ballscrews 1605 seems reasonable too.
    Now I'm just having two doubts:
    What size/power of Nema23 stepper motors ?If anyone has a link to good source, would be great...
    2. Linear rails like Hiwin or beam type shafts SBR or even better TBR ? There is some difference in cost for sure... Is a trade-off with cheaper beam type rails compared to slotted hiwin rails good option or not?
    Thanks again for all inputs...



  5. #5
    *Registered User* djolemag's Avatar
    Join Date
    Jan 2019
    Posts
    6
    Downloads
    0
    Uploads
    0

    Default Re: NEWBIE ADVICE Another CNC desktop

    Please share with me your thought regarding my pictures of steel frame, that is the starting point for all further decisions.



  6. #6
    Registered ninefinger's Avatar
    Join Date
    Sep 2006
    Location
    Canada
    Posts
    466
    Downloads
    0
    Uploads
    0

    Default Re: NEWBIE ADVICE Another CNC desktop

    it looks ok but could use some stiffening. The side to side loading of moving the Z axis will cause some flex even with the thickness of steel you have. I would add stiffening "ribs" to the outside of those, use either angle iron or rectangular tube to add some rigidity ~25mm to 30mm on both sides should help allot.



  7. #7
    *Registered User* djolemag's Avatar
    Join Date
    Jan 2019
    Posts
    6
    Downloads
    0
    Uploads
    0

    Default Re: NEWBIE ADVICE Another CNC desktop

    Yes, agree totally. I will draw a sketch in coming days and post a design here.
    I thought about adding one more plate on the front of gantry/bridge ( parallel with existing one) to make it more rigid and put y axis on it...

    Sent from my LG-D855 using Tapatalk



  8. #8
    *Registered User* djolemag's Avatar
    Join Date
    Jan 2019
    Posts
    6
    Downloads
    0
    Uploads
    0

    Default Re: NEWBIE ADVICE Another CNC desktop

    What do you guys think about this linear setup:
    Hiwin or similar 15mm for X and Y axis, with ballscrew 1605, while 12 or 15mm rail for Z axis and ballscrew 12mm? Or something else for Z axis, like leadscrew?



Tags for this Thread

Posting Permissions

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


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

NEWBIE ADVICE Another CNC desktop

NEWBIE ADVICE Another CNC desktop