New Build - Bolt Together CNC

Page 1 of 2 12 LastLast
Results 1 to 20 of 26

Thread: New Build - Bolt Together CNC

  1. #1
    Member
    Join Date
    Jan 2016
    Posts
    100
    Downloads
    0
    Uploads
    0

    Default New Build - Bolt Together CNC

    Started building a new machine recently. I'd like a machine capable of 4 cuin/min MRR in Al. But I also want it to be able to have a work area of about 30x18x6. May be a bit ambitious, but we'll see. Final difficulty is that I need to be able to disassemble and move it, so its all going to bolted together. It will mostly be constructed of 3x4x1/4" steel tube, likely filled with lead/sand/gravel for vibration damping. Total height is just under 34", length is 60", width is 34"

    Here's a rendering:
    New Build - Bolt Together CNC-img_0532-jpg

    I've got it rendered with a Clearpath servo. Not sure thats what I'll go with, still kicking around ideas. I'll probably start it with some steppers pulled from my last build. Also rendered with a dewalt trim router for a spindle. Plan is to upgrade that to a Spinogy X22 in the near future.


    Obligatorily FEA shot:
    New Build - Bolt Together CNC-3x4-png

    I've done quite a bit of modeling trying to determine where to best put material, that was just one run I happen to have a screen shot of.

    Also did some topology optimization runs with Tosca which wasn't overly useful beyond indicating I was on the right track (which has been my general experieence with generative design/optimization software). It produced this beauty:
    New Build - Bolt Together CNC-opti-png


    The eventual plan is to add an ATC, as well as a full enclosure so I can run flood coolant. Currently struggling with servo choice, as well as the design of the way covers.

    Similar Threads:
    Attached Thumbnails Attached Thumbnails New Build - Bolt Together CNC-opti-png   New Build - Bolt Together CNC-3x4-png   New Build - Bolt Together CNC-img_0532-jpg  


  2. #2

    Default Re: New Build - Bolt Together CNC

    you can use oil mixed with sand for damping and you can empty the tubes when moving.



  3. #3
    Member
    Join Date
    Nov 2013
    Posts
    4666
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Hi,
    filling the tubes is pointless.

    In order to damp vibration you require that the material dissipates energy when it is flexed, but you've gone and put inside a steel tube which by definition and design does
    not flex much at all. In order for that (little) flexure to be transmitted to the filling material requires the material adhere to the inside of the tube perfectly, a hit and miss occurrence
    at best. Were the dissapattive material on the outside of the tube that would be better.

    I would recommend you go for much thicker walls, as thick as you can find. Stiffness beats vibration damping every time, and the thicker you make the walls the stiffer it will be.
    If the machine is stiff enough it will not vibrate....or rather the vibrational frequency gets higher and higher as the machine gets stiffer and stiffer. The natural damping of engineering materials,
    even steel, increases with frequency. Bottom line is if the machine is stiff enough you won't have to worry about vibration.

    Overall it would be cheaper to use thicker steel than it would be to fill the void.

    Try getting some 100x100x9 or 100x100x12 or even 100 x100x16. The former two are reasonably common in building construction, while the later one is less common. If have not found any
    100x100x16 in New Zealand for instance, but can get modest lengths of 100x100x9 and 100x100x12 from welding companies specialising in building construction.

    Clearpath servos are easy to use, they have taken a great deal of effort to attract new buyers, but they are expensive for what you get. I'd recommend Delta (Taiwanese made in China)
    or DMM (Canadian made in China). They are good quality, good documentation, good support and most importantly free setup and tuning software at fair prices. Twice the power of a Clearpath
    for the same money. If you've got swags of money get Yaskawa's.

    There are lots of cheap Chinese brands, and to be fair to them they work, but have poor documentation, poor support and no setup and tuning software. I know you'll be tempted by the prices
    but you'll regret the day you bought them when you go to set them up. Avoid them like the plague.

    Craig

    Attached Thumbnails Attached Thumbnails New Build - Bolt Together CNC-newmill3-jpg  


  4. #4

    Default Re: New Build - Bolt Together CNC

    looks like it works just fine





  5. #5
    Member
    Join Date
    Jan 2016
    Posts
    100
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Quote Originally Posted by ardenum2 View Post
    you can use oil mixed with sand for damping and you can empty the tubes when moving.
    That's an interesting idea, I might try that. I'm not sure I'll be able to keep the tubes completely sealed though.


    Quote Originally Posted by joeavaerage View Post
    Hi,
    filling the tubes is pointless.

    In order to damp vibration you require that the material dissipates energy when it is flexed, but you've gone and put inside a steel tube which by definition and design does
    not flex much at all. In order for that (little) flexure to be transmitted to the filling material requires the material adhere to the inside of the tube perfectly, a hit and miss occurrence
    at best. Were the dissapattive material on the outside of the tube that would be better.

    I would recommend you go for much thicker walls, as thick as you can find. Stiffness beats vibration damping every time, and the thicker you make the walls the stiffer it will be.
    If the machine is stiff enough it will not vibrate....or rather the vibrational frequency gets higher and higher as the machine gets stiffer and stiffer. The natural damping of engineering materials,
    even steel, increases with frequency. Bottom line is if the machine is stiff enough you won't have to worry about vibration.

    Overall it would be cheaper to use thicker steel than it would be to fill the void.

    Try getting some 100x100x9 or 100x100x12 or even 100 x100x16. The former two are reasonably common in building construction, while the later one is less common. If have not found any
    100x100x16 in New Zealand for instance, but can get modest lengths of 100x100x9 and 100x100x12 from welding companies specialising in building construction.

    Clearpath servos are easy to use, they have taken a great deal of effort to attract new buyers, but they are expensive for what you get. I'd recommend Delta (Taiwanese made in China)
    or DMM (Canadian made in China). They are good quality, good documentation, good support and most importantly free setup and tuning software at fair prices. Twice the power of a Clearpath
    for the same money. If you've got swags of money get Yaskawa's.

    There are lots of cheap Chinese brands, and to be fair to them they work, but have poor documentation, poor support and no setup and tuning software. I know you'll be tempted by the prices
    but you'll regret the day you bought them when you go to set them up. Avoid them like the plague.

    Craig
    Of course the steel tubes flex, if they didn't flex they wouldn't be vibrating. I am not convinced that I will need additional damping, nor am I convinced as to how effective filling the tubes would be. However filling the tubes is basically free, not sure why you think it would be cheaper to use thicker steel.

    Your dislike of clearpath servos is well documented. I like their packaging, documentation, and support though. A quick look at a DMM and the price appears to be similar to clearpath for a ~400watt servo+drive ($687 vs $622), Delta looks even more expensive with just a 400W ASDA-A2 drive costing $712. Is there a cheaper Delta drive that would be suitable?



  6. #6
    Member
    Join Date
    Nov 2013
    Posts
    4666
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Hi,
    wasting your time and money, build with thicker walls so the machine is more rigid and you need not bother with damping.

    Craig



  7. #7
    Member
    Join Date
    Nov 2013
    Posts
    4666
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Hi,

    Your dislike of clearpath servos is well documented. I like their packaging, documentation, and support though. A quick look at a DMM and the price appears to be similar to clearpath for a ~400watt servo+drive ($687 vs $622), Delta looks even more expensive with just a 400W ASDA-A2 drive costing $712. Is there a cheaper Delta drive that would be suitable?
    I don't know where you are buying from but they must have seen you coming.

    https://www.fasttobuy.com/flange-80m...er_p28084.html

    $438USD for a 750W servo kit. I have bought three from this company this year alone, at the same price. About $150USD shipping to New Zealand 3 day DHL or 3 day Fedex.

    https://www.fasttobuy.com/220v-127nm...ol_p28069.html

    $398USD for a 400W servo kit, I have bought two of these this year. Fine if you have restricted size or really only need a small servo because for $40USD more you can get a 750W model. This is where my assertion that 'I can get
    double the power from a Delta servo than Clearpath for less money.' comes from.

    In recent times I have noted a number of Chinese companies have started to heavily discount Delta servos as they struggle with a China wide slow down in business. I saw yesterday a 1.5kW Delta B2 series kit for $324USD.
    I have made repeated purchases from Fast-to-Buy, and despite being able to maybe save a few dollars by shopping around, I prefer dealing with a company I trust.

    https://dmm-store-shopify.myshopify....nt=20982430342
    https://dmm-store-shopify.myshopify....ac-servo-motor

    $247USD and $270USD plus cables for a 750W DMM servo, is somewhat pricier than Delta, remembering Delta include 3m cables whereas DMM do not.

    If you think $687USD (or $622USD, its not clear which price applies) is good value for a 400W Clearpath then have at it. Note with a Clearpath you will require a DC power supply in addition to the servo.
    The Delta an DMM models I have linked to do not require a power supply as they are direct off-line ie 230VAC input.

    Craig



  8. #8
    Member
    Join Date
    Nov 2013
    Posts
    4666
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Hi,
    just rereading your post and I see you have quoted a price on a Delta A2 servo......and well yes, they are more expensive, being a later and very much more sophisticated model.

    The Delta B2 series I have linked to and recommend are in effect Delta's entry level model. They have a 160,000 count per rev encoder. The A2 series has much higher resolution again,
    1,280,000 count per rev encoder but has a secondary encoder input in addition. It's the secondary encoder that adds some tantalizing possibilities.

    The normal rotary encoder is required for the servo to operate the FOC (Field Oriented Control) algorithm, but with the A2 series the position loop can be closed by the secondary encoder.
    The secondary encoder could be a linear scale or an interferometer of LVDT or whatever. This allows what most hobbyists call 'full closed loop', although I think the terminology poor or misleading,
    it does mean that you can use a linear scale to accommodate a less than perfect ballscrew or rack and pinion.

    The A2 series servos have traditionally attracted an extra $150USDS per kit. I have had no need for that extra sophistication, the B2 series having in every respect satisfied every performance demand
    I have....so why spend the extra?

    The latest model from Delta is the B3 series, and is comparable in price to the B2 series, although I do not know whether is has the secondary encoder feature.

    Craig.



  9. #9
    Member
    Join Date
    Jan 2016
    Posts
    100
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Quote Originally Posted by joeavaerage View Post
    I don't know where you are buying from but they must have seen you coming.

    https://www.fasttobuy.com/flange-80m...er_p28084.html

    $438USD for a 750W servo kit. I have bought three from this company this year alone, at the same price. About $150USD shipping to New Zealand 3 day DHL or 3 day Fedex.
    Those were prices from Digikey.

    I spoke with Delta and they said that Fasttobuy is not a distributor and in fact they had never heard of them and they implied they would honor a warranty on servos bought from them. Looking around it seems that nobody else besides for you has used them, and you post about them incessantly. Ohh and their cert is expired now. Delta recommended using a local distributor, G&G Technical, their prices were actually a littler higher than Digikey's.

    I noticed that StepperOnline has some servo's now that are so cheap I might grab one just to try.



  10. #10
    Member
    Join Date
    Jan 2016
    Posts
    100
    Downloads
    0
    Uploads
    0

    Default

    Started making up the frame, making good progress so far. Next challenge is going to be mounting the linear rails. Debating if I should pour some SC-15P epoxy for them to mount to or just use shims and indicate them in. The epoxy would certainly be easier, but more expensive.

    Attached Thumbnails Attached Thumbnails New Build - Bolt Together CNC-img_9986-jpg  


  11. #11
    Member
    Join Date
    Nov 2013
    Posts
    4666
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Hi,

    spoke with Delta and they said that Fasttobuy is not a distributor and in fact they had never heard of them and they implied they would honor a warranty on servos bought from them.
    BS. I've been buying off Fast-to-Buy for four years. When I wanted a braked version on a servo they did not have in stock, they got one in direct from Delta within two days. Additionally every once in a while
    Fast-to-Buy email me with discount information that comes from Delta.

    Looking around it seems that nobody else besides for you has used them, and you post about them incessantly. Ohh and their cert is expired now.
    I'm telling you about MY EXPERIENCE, if you don't like it then do your own thing and good luck to you. I don't know why you bother asking for information or opinions you never listen to
    any of it.

    I noticed that StepperOnline has some servo's now that are so cheap I might grab one just to try.
    The price is appealing....but thats about it. If you have not set up AC servos before then you'll want a servo/drive that has set up and tuning software. Does this unit have that? Most cheap Chinese brands do not.

    Craig



  12. #12
    Member
    Join Date
    Jan 2008
    Location
    Australia
    Posts
    1551
    Downloads
    2
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    I have bought a delta servo from Fasttobuy without issues in the past.

    A lot of businesses operate on a distributor model.
    They will have distributors in each region. They will try and force you to use those distributors and not go around them. Pricing can be vastly different in different regions.



  13. #13

    Default Re: New Build - Bolt Together CNC

    stepper onlines integrated 750W and T6 series seem to have some tuning software in the downloads section

    https://www.omc-stepperonline.com/75...2-80tr-48v750a

    https://www.omc-stepperonline.com/t6...rs750h2a3-m17s

    or try lichuan A5's with 23bit encoder, 60x60 frame 600W should suffice for a light frame like this, maybe even 400W, around the same price like stepperonline. https://lichuanmotor.en.alibaba.com/ (alibaba prices are without tax)

    by the way isn't fast-to-buy a market not a seller? what's the actual seller name?

    Last edited by ardenum2; 09-05-2023 at 05:58 PM.


  14. #14
    Member
    Join Date
    Nov 2013
    Posts
    4666
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Hi Ardenum,
    those two models do indeed look to have setup software, and good for them.

    The E6 model that Jaguar36 linked to has a manual, and not too badly written at that, but I could find no setup and tuning software for it.

    I think Stepperonline rebrand other manufacturers products, certainly their prices are sharp.

    I have had good and repeated purchases from Fast-to-Buy and while I might save $50 or $100 by buying from the cheapest supplier, I stick with a
    company I trust. That's just me of course, other people will decide differently.

    Craig



  15. #15
    Member
    Join Date
    Nov 2013
    Posts
    4666
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Hi,
    there is one advantage that I enjoy about buying Delta B2 series servos and drives. When I set them up using the setup and tuning software you can record it.

    If and when you buy another servo you can clone that setup. Lets say I bought another servo for a fifth axis ( I did actually do this about three months ago) and it requires a set-up
    not dissimilar to my A axis servo I bought at the end of last year. So I just clone the setup and program the new drive. All I have to do then is change the electronic-gearing
    numerator and denominator to accommodate the different servo reducer and I'm done. Several minutes work....too easy!!

    Craig



  16. #16
    Member
    Join Date
    Jan 2016
    Posts
    100
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    The E6 servos apparently work with Servostudio. I assume the servo drives are actually made by Servotronix. The software looks pretty dated, but for the price I might roll the dice on one.

    Its a shame that used drives seem so hard to come by. There are a ton of nice used Yaskawa servos available for cheap, but the drives always cost a fortune.

    Still leaning towards using Clearpath servos.

    Gotta get the linear rails mounted first regardless. Think I'm going to pull the trigger on the SC-15P epoxy, wish there was another source though, Precision Epoxy only takes a check, and the frieght cost on the 1.5 gallon kit is like 30% of the cost of the epoxy.



  17. #17
    Member
    Join Date
    Nov 2013
    Posts
    4666
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Hi,

    Fast-to-Buy also stock Yaskawa, for instance:

    ://www.fasttobuy.com/sgmgv13adc61sgdv120a11a-yaskawa-200v-13kw-834nm-1500rpm-ac-rotary-servomotor-drive-kit_p28145.html

    Which for a kit of servo and drive (5 series) is not too bad value, but still over $1000USD. Many of the other Yaskawa servos and drives, especially the 5 and the 7 series seem very expensive to me.
    I used one some years ago, it was branded Omron but was in fact a 200w 5 series Yaskawa. It cost $3000NZD!!!....but that's what the customer wanted so we got it for him. It was very nice, and
    Omron were excellent at supporting it with help to install and set-up.....but $3000NZD!!! I could have bought six 200W Delta's for the same money. Over that same time frame (10-12 years ago)
    I did buy Delta servos and drives and install them in various machines, mainly plasma tables, and to my knowledge they are all still working 10 years later.

    Overall I go with your opinion that Yaskawa are just overpriced.

    Cured Epoxy has a Youngs modulus of 3GPa-5GPa. Do you not think that its too 'squishy' to mount rails on? Can you not machine the rail mounts flat?

    Craig



  18. #18
    Member
    Join Date
    Jan 2016
    Posts
    100
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Quote Originally Posted by joeavaerage View Post
    Cured Epoxy has a Youngs modulus of 3GPa-5GPa. Do you not think that its too 'squishy' to mount rails on? Can you not machine the rail mounts flat?
    Ideally yeah, I'd just mount them directly to the steel tubes. But I'd need to either machine them in multiple steps on my Bridgeport (as they are too long to do in a single setup) and hope I'm able to keep a consistent enough setup that I get a good surface, or send them out to be ground. Since these are just structural steel tubes that are welded together, I would also be concerned that as you machined them they would warp and twist such that you would never be able to get a good mounting surface regardless. Plus then I would have to still indicate in the left and right rails to be co planer with each other.

    Using a self leveling epoxy designed for linear rails theoretically eliminates alot of these issues, as you can make cross channels so the epoxy can level between both rails. As for deformation, the SC-15P epoxy is steel reinforced so I would hope it is stiffer than that, although I couldn't find any published specs. Regardless, since the epoxy is a very thin layer, and the load is spread out over a large area underneath the trucks it won't have a meaningful effect on the overall deformation of the mill.

    For instance under a 50lb compression load, under my 45mm rails the deflection due to the epoxy is (50/(1.77*4))/500,000*.25 = 0.00000353in.

    Now that I think about it though I wonder what happens under a moment, as that will only load a small area under one edge of the rail. I doubt it will be an issue, but I think I will build a FEM to check.



  19. #19
    Member
    Join Date
    Jan 2016
    Posts
    100
    Downloads
    0
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    I threw together a FEM of a section of rail to study how a moment on the linear rail trucks would deform the epoxy under the rail. It's a non-linear FEM, with the fasteners modeled using solid elements and a preload applied to them. I'm assuming some clearance between the fastener and the rail, so all the load gets transferred via friction. Applying a 1000in-lb moment (which is an order of magnitude larger than its ever going to see), the deflection is only 0.000012 in difference between having a 1/4" epoxy layer vs just being on steel. I also applied the load on just the top flange, which is also conservative, as in reality one side would be mostly reacted near the bottom flange.

    New Build - Bolt Together CNC-cnc-rail-png

    Attached Thumbnails Attached Thumbnails New Build - Bolt Together CNC-cnc-rail-png  


  20. #20
    Member
    Join Date
    Jan 2008
    Location
    Australia
    Posts
    1551
    Downloads
    2
    Uploads
    0

    Default Re: New Build - Bolt Together CNC

    Epoxy creeps over time.

    I did epoxy levelling for my router. It has been disappointing. Requires about 6mm thickness to actually self level.
    The rails and ball screw mounts have created indents in the epoxy over time.

    It works fine for a wood router, but epoxy is not the perfect solution some people imply it is.

    Steel filled epoxy designed for joint replication may be different, but you have to mold / install it in the final precision. A straightedge works for one rail bed, but doing two that need to be precisely on the same plane is not easy.



Page 1 of 2 12 LastLast

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

New Build - Bolt Together CNC

New Build - Bolt Together CNC