CNC Workbench Top

[Mike Goetzke]

I'm putting together a new work table. I've decided to have three MFT type slabs from one sheet of MDF that have a grid of 3/4" or 20mm holes drilled (most likely give in to 20mm). I have a few questions:

-For the design I hear others get a DXF file and give it to the CNC routing guy to save $. I have a simple 2-D CAD program that can produce a DXF file but one guy I sent the file to said he still need $100 for programming. Should it be easy to mill my slabs with just a DXF file?

-I'm in the Chicago area - any suggestions where I can get this CNC work done?


Thanks,

Mike

[Martin Wasner]

I can't take a dxf straight to post.

$100 doesn't seem that out of line to me. Drawing it wouldn't take long, I'm a hack and I could probably have a program ready in 5-10 minutes, that's if you don't change your mind on what you want.

What you're paying for is him pulling away from the things that keep his doors open. The risk of something going wrong and creating other problems

[Brad Shipton]

The .dxf file only has the vector coordinates of the circles. They still need to create the toolpath file that actually tells the machine what to do. That said, most have a automatic recognition routine for holes that takes seconds to run. The $100 cost sounds like a price from a shop with minimums. They likely do not like this type of work much. You could look at the $100k garages site, or post a request on the camheads site.

[Mark Bolton]

I'd agree with the other responses. Think of what you earn. Add to that what your employer pays over and above your salary, and then add the cost of the building and infrastructure that also goes to support your salary.

Virtually anything anyone walks into my shop and asks me to do no matter how big or small is going to cost me an hour minimum. Asking g me for a price is the first several minutes.. opening the email, looking at, and toolpathing the file you send me (provided it's something I can work with ditectly) is several more minutes. Meeting you to drop off material and associated jibber jabber is several more minutes. Then I run the job, and repeat the steps of material drop off mentioned before.

I will be lucky to get out of that transaction for a couple hours all told.

Dont mean to sound touchy at all and for a local I'd usually run it for peanuts or free and the shut the door behind the local and proceed to rant about someone being unwilling to pay me at the same rate they earn.

I wouldn't expect to occupy an hour or two of any business time for less than a couple hundred bucks minimum.

[Jim Becker]

I would be charging at least that to take a vector drawing and design the toolpaths to cut the job. As others have mentioned, the DXF file is just the starting point. It's the design. But that design has to be translated into instructions that the CNC machine can execute to reproduce that. $100 is a typical hourly rate for this kind of work.

[bobby milam]

I'd just pay the $100 and be done but if you want to look for it cheaper, try the shopbot or camaster forum or even your local high school. It sounds like what you are wanting is pretty simple and you can probably find someone who is just a hobbyist or student to do it at a fraction of the price because they don't have doors to keep open.

[Gerry Grzadzinski]

If I received the .dxf, I'd redraw it to make sure it's right, as 20 years have taught me not to trust other people's CAD work.
And even if it only took 5 minutes (Which is all it would likely take), I'd charge $100 as well.

[Mike Goetzke]

Thanks to all for responding.

I just happened to call a millwork shop near my work and they gave me the phone number of the guy they use for CNC. They said the guy works out of his garage. He told me he would like to machine the 4x8 sheet then cut it in three afterwords - makes sense. He quoted $50-$60 for each slab including material so $150 to $180 plus $100 programming (or $83 to $93 per slab). Starting to sound like that's not to bad. He did ask how the holes needed to be cut because the CAD drawing I got online had them at 20.2mm. He could use a 1/2" router and trace them or he said he could buy a 20mm drill bit and drill them. I have heard some say that 20.2mm is a bit sloppy. The videos of the tops being made that I have found show the router method.

Thanks

Mike

[Gerry Grzadzinski]

A 20mm boring bit is the best way to do it, if you need 20mm holes.

[Jim Becker]

For doing an MFT type top manually, I used a 20mm bit and the fit for 20mm accessories was just fine...they already compensated for the hole size. On my CNC, I wouldn't use the 20mm cutter, however...I'd pocket the holes out with a smaller cutter, such as a .25" or .375" spiral.

[Jerome Stanek]

I get these type of files all the time. they send me a DXF and I convert it to a cut file in less then 5 minutes not at all hard to do. If it is a new customer I don't let them know how much work is required Even the company that I worked for that had 2 cnc machines that they had a programer for. I cut a lot of 1 offs for them as it was cheaper to have me do it then to do it in house.

[Martin Wasner]

A 20mm boring bit is the best way to do it, if you need 20mm holes.

For one sheet though? I agree, but not worth buying a tool that may never get used again unless the OP is willing to pay for it.

[Jim Becker]

Jerome, you're correct that quite often, the tool path work doesn't take a huge amount of time if the vector graphic doesn't have problems after import. Minimums for setup account for the "disruption" and use of the human resource to get things ready for cutting. As a startup, I've done a few simple things and only charged for a quarter hour, but ultimately, I'd probably still charge for an hour of time minimum because of the various other little things that go into getting ready to tell the machine what to do.

[Mark Bolton]

For one sheet though? I agree, but not worth buying a tool that may never get used again unless the OP is willing to pay for it.

I'm in this camp. I'd never buy a specific tool at these prices. Itd be whatever cutter is in the rack that's smaller than 20 mm and an inside profile and done.

In agree with the replies that say creating this toolpath file from a scratch drawing or the customers dxf is a task that will take single digit minutes. But you will be lucky to get out of the entire transaction, including the phone and physical conversations, and disruptions to your other work, for an hour sum total

[Brad Shipton]

I bored them with this bit https://www.vortextool.com/320057.html for my table. If using a machine of Martin's class, I would not be bothered with a pocket tool path, but I would be less inclined to accept that from someone with an entry level machine for fear of oblong holes. The festool dogs are around 19.5mm - 19.8mm if I recall correctly when I was measuring them. Sloppy holes to save $30 would annoy me.