CNC

You are not logged in. [ Login ] Why log in
(NOTE: Login is not required to post)

Small parts moving

11/25/16       
Dan cook

We are new to nesting and are having some problems with small parts moving while being cut through. What can you suggest to stop this from happening. We already have 2 vacuum pumps on the machine and it is still happening.

11/26/16       #2: Small parts moving ...
james e mcgrew Member

Website: mcgrewwoodwork.com

Vac has a lot of variables, the first and probably most common fix for small parts it to cut them first, (Vac is max) and use an onion skin procedure,

all vac loss counts so check for leaks at edges of spoil board and make sure it is clean and not deep ridged from previous cuts.

11/26/16       #3: Small parts moving ...
David Egnoski  Member

Website: http://www.richmondcabinet.com

I cut small parts first and use tabs as required. Very seldom have an issue with this approach.

11/26/16       #4: Small parts moving ...
Dan cook

We do use onion skinning approach but when it is making the final through cuts, that's when the parts start moving and of course the ones that move get ruined. What do you mean by tabs?

11/26/16       #5: Small parts moving ...
Wood Dust

This is just a picture I found online , I don't have any of my own work using tabs . But you'll see the parts are still connected to either each other or the nested sheet with tabs. These can be like 1/8"thick and 1 1/4" long that you can just knife off after . What program are you using ?

11/26/16       #6: Small parts moving ...
Wood Dust

This is the picture


View higher quality, full size image (1024 X 815)

11/26/16       #7: Small parts moving ...
David Egnoski  Member

Website: http://www.richmondcabinet.com

Tabs are little bridges between parts or between parts and waste areas.


View higher quality, full size image (915 X 842)

11/26/16       #8: Small parts moving ...
David Egnoski  Member

Website: http://www.richmondcabinet.com

The picture is from Vcarve Pro. My Thermwood router does this in the nesting software also.

11/26/16       #9: Small parts moving ...
Maurice Phelps

Question, since you are doing a onion skin ...are you cutting your parts on the first pass, leaving the onion and then going back and removing the onion skin, after you having left all your parts with a onion skin or are you cutting the part and the onion skin in the same pass.

Also are you ramping into your cut or plunging, a ramp will apply less force on the part.

11/27/16       #10: Small parts moving ...
B

Lots of factors involved here. We hold parts as small as 3x7" with onion skin (25hp regen blower) Sheets must be fairly flat. If small parts start to bow up as they are cut they can move. If you're cutting nasty sheeting this is more likely to happen.

The thinner the skin, the better. I leave a .03" skin and reduce the final cutout speed by 50%. They are cutout at 250ipm. Small parts are always cut first so they have maximum vacuum. Most software can do this.

Make sure your spoilboard is gasketed well if using a grid table. Make sure you fly cut often if cutting lots of small parts. We only cut about 15-20 sheets between fly cutting.

Also, blow off the spoilboard really well between sheets. Dust on the board acts like little ball bearings and will increase the chance for part movement.

11/27/16       #11: Small parts moving ...
Dropout Member

Haven't tried this yet but how about using a 1/8 bit for the final pass after onion skinning? Less side pressure than a 3/8.

11/28/16       #12: Small parts moving ...
Matt Krig

Check with your supplier and see if they have a more dense MDF, we are limited to one supplier who stocks what works for us in the size we use.
Seal the edges with edge-banding or Latex primer/paint
Fly-cut BOTH sides of spoil boards before starting to break the skin.
Run fresh sharp tooling
As mentioned- gasketing from All Star gasket for a grid table is a 100% must have.
Check your vacuum pump filters, they can be working hard, making tons of noise and producing less than optimal vacuum.
Tabs and multi-pass cuts if all else fails
Use sacrificial melamine cover sheets if you are regularly cutting say 4x8 on a 5x10 bed

11/28/16       #13: Small parts moving ...
Jim

We have cabinet vision which allows us to set up onion skin parameters on all parts 4" x 6" in size. It will cut these parts first then the balance of the sheet. Running a 10hp becker with 4 x 8 table. Do check the filters because dust always finds its way into them. We also use a dense mdf and band the edges.

11/29/16       #14: Small parts moving ...
B.H. Davis Member

It all depends upon your definition of "small parts". Some items are so small there is no holding them without bridges/taps.

This past weekend I was cutting some 3/4" thick hard maple parts that were about 1" wide x 4" to 6" long. Given the shape of the parts bridges would have been difficult to clean up after removing the parts. The solution was to start with thicker material and not cut all the way through. Then I planed away most of the extra bottom thickness and finally removed the rest to free up the parts in the wide belt sander.

BH Davis

11/29/16       #15: Small parts moving ...
Puzzleman Member

I cut many small parts every day using a system like onion skinning. What I do is apply 2 lines of 24" wide tape from a sign store to the back of the sheet. Then vacuum the sheet to the table down to the table. Then cut through the piece leaving the tape intact.

There are different levels of tape tack, so you can select the right option for you.

I primarily cut appleply sheet goods 1" thick with a prefinished surface.
Pieces measure in size from 1" x 2.5" to 4" x 6.5".

12/3/16       #16: Small parts moving ...
Stewart Member

Dropout,

I really like your idea of using an 1/8" bit on the final pass through the onionskin and have tried to set that up in CV but to no avail. How would you do this?

12/3/16       #17: Small parts moving ...
Dropout Member

Not sure how you do it in CV but in the software that I use it's possible to to assign different cuts with different tools to the same layer of the CAD file.

12/23/16       #18: Small parts moving ...
Scott

The best solution I found is you onion skin or use bridges, when you remove the pieces you keep a laminate trimmer close by and flip the piece and clean it up. If you go back and try cut out the onion skin it will move on you. To use a 1/8 bit you have to do a tool change and then it still might move? Who has time for that?
We always vacuum our spoil board, I read about the idea on this website few years back, it is way better than forced air, also keeps the shop a lot cleaner.

1/4/17       #19: Small parts moving ...
George

Website: https://plus.google.com/u/0/+TheCNCFixtureFactory

How big are the parts you are trying to cut? Maybe you could post a picture? Is this a job that will be returning to your shop?


Post a Response
  • Notify me of responses to this thread
  • Subscribe to email updates on this Forum
  • To receive email notification of additions to this forum thread,
    enter your name and email address, and then click the
    "Keep Me Posted" button below.

    Please Note: If you have posted a message or response,
    do not submit this request ... you are already signed up
    to receive notification!

    Your Name:
    E-Mail Address:
    Enter the correct numbers into the field below:
     

    Date of your Birth:



    Return to top of page

    Buy & Sell Exchanges | Forums | Galleries | Site Map

    FORUM GUIDELINES: Please review the guidelines below before posting at WOODWEB's Interactive Message Boards (return to top)

  • WOODWEB is a professional industrial woodworking site. Hobbyist and homeowner woodworking questions are inappropriate.
  • Messages should be kept reasonably short and on topic, relating to the focus of the forum. Responses should relate to the original question.
  • A valid email return address must be included with each message.
  • Advertising is inappropriate. The only exceptions are the Classified Ads Exchange, Machinery Exchange, Lumber Exchange, and Job Opportunities and Services Exchange. When posting listings in these areas, review the posting instructions carefully.
  • Subject lines may be edited for length and clarity.
  • "Cross posting" is not permitted. Choose the best forum for your question, and post your question at one forum only.
  • Messages requesting private responses will be removed - Forums are designed to provide information and assistance for all of our visitors. Private response requests are appropriate at WOODWEB's Exchanges and Job Opportunities and Services.
  • Messages that accuse businesses or individuals of alleged negative actions or behavior are inappropriate since WOODWEB is unable to verify or substantiate the claims.
  • Posts with the intent of soliciting answers to surveys are not appropriate. Contact WOODWEB for more information on initiating a survey.
  • Excessive forum participation by an individual upsets the balance of a healthy forum atmosphere. Individuals who excessively post responses containing marginal content will be considered repeat forum abusers.
  • Responses that initiate or support inappropriate and off-topic discussion of general politics detract from the professional woodworking focus of WOODWEB, and will be removed.
  • Participants are encouraged to use their real name when posting. Intentionally using another persons name is prohibited, and posts of this nature will be removed at WOODWEB's discretion.
  • Comments, questions, or criticisms regarding Forum policies should be directed to WOODWEB's Systems Administrator
    (return to top).

    Carefully review your message before clicking on the "Send Message" button - you will not be able to revise the message once it has been sent.

    You will be notified of responses to the message(s) you posted via email. Be sure to enter your email address correctly.

    WOODWEB's forums are a highly regarded resource for professional woodworkers. Messages and responses that are crafted in a professional and civil manner strengthen this resource. Messages that do not reflect a professional tone reduce the value of our forums.

    Messages are inappropriate when their content: is deemed libelous in nature or is based on rumor, fails to meet basic standards of decorum, contains blatant advertising or inappropriate emphasis on self promotion (return to top).

    Libel:   Posts which defame an individual or organization, or employ a tone which can be viewed as malicious in nature. Words, pictures, or cartoons which expose a person or organization to public hatred, shame, disgrace, or ridicule, or induce an ill opinion of a person or organization, are libelous.

    Improper Decorum:   Posts which are profane, inciting, disrespectful or uncivil in tone, or maliciously worded. This also includes the venting of unsubstantiated opinions. Such messages do little to illuminate a given topic, and often have the opposite effect. Constructive criticism is acceptable (return to top).

    Advertising:   The purpose of WOODWEB Forums is to provide answers, not an advertising venue. Companies participating in a Forum discussion should provide specific answers to posted questions. WOODWEB suggests that businesses include an appropriately crafted signature in order to identify their company. A well meaning post that seems to be on-topic but contains a product reference may do your business more harm than good in the Forum environment. Forum users may perceive your references to specific products as unsolicited advertising (spam) and consciously avoid your web site or services. A well-crafted signature is an appropriate way to advertise your services that will not offend potential customers. Signatures should be limited to 4-6 lines, and may contain information that identifies the type of business you're in, your URL and email address (return to top).

    Repeated Forum Abuse: Forum participants who repeatedly fail to follow WOODWEB's Forum Guidelines may encounter difficulty when attempting to post messages.

    There are often situations when the original message asks for opinions: "What is the best widget for my type of shop?". To a certain extent, the person posting the message is responsible for including specific questions within the message. An open ended question (like the one above) invites responses that may read as sales pitches. WOODWEB suggests that companies responding to such a question provide detailed and substantive replies rather than responses that read as a one-sided product promotion. It has been WOODWEB's experience that substantive responses are held in higher regard by our readers (return to top).

    The staff of WOODWEB assume no responsibility for the accuracy, content, or outcome of any posting transmitted at WOODWEB's Message Boards. Participants should undertake the use of machinery, materials and methods discussed at WOODWEB's Message Boards after considerate evaluation, and at their own risk. WOODWEB reserves the right to delete any messages it deems inappropriate. (return to top)


  • Forum Posting Help
    Your Name The name you enter in this field will be the name that appears with your post or response (return to form).
    Your Website Personal or business website links must point to the author's website. Inappropriate links will be removed without notice, and at WOODWEB's sole discretion. WOODWEB reserves the right to delete any messages with links it deems inappropriate. (return to form)
    E-Mail Address Your e-mail address will not be publicly viewable. Forum participants will be able to contact you using a contact link (included with your post) that is substituted for your actual address. You must include a valid email address in this field. (return to form)
    Subject Subject may be edited for length and clarity. Subject lines should provide an indication of the content of your post. (return to form)
    Thread Related Link and Image Guidelines Thread Related Links posted at WOODWEB's Forums and Exchanges should point to locations that provide supporting information for the topic being discussed in the current message thread. The purpose of WOODWEB Forums is to provide answers, not to serve as an advertising venue. A Thread Related Link that directs visitors to an area with inappropriate content will be removed. WOODWEB reserves the right to delete any messages with links or images it deems inappropriate. (return to form)
    Thread Related File Uploads Thread Related Files posted at WOODWEB's Forums and Exchanges should provide supporting information for the topic being discussed in the current message thread. Video Files: acceptable video formats are: .MOV .AVI .WMV .MPEG .MPG .MP4 (Image Upload Tips)   If you encounter any difficulty when uploading video files, E-mail WOODWEB for assistance. The purpose of WOODWEB Forums is to provide answers, not to serve as an advertising venue. A Thread Related File that contains inappropriate content will be removed, and uploaded files that are not directly related to the message thread will be removed. WOODWEB reserves the right to delete any messages with links, files, or images it deems inappropriate. (return to form)
    Suction Cups, Vacuum Lifters, Vacuum Pumps from Anver Corporation ecabinet systems.com Thermwood Limtech Industries, Inc.