Cutting out parts side by side

[GrandpaB]

Gentlemen,

I'm new to this entire process, so I've got some newbie questions. I am considering a job that cuts out 20 identical parts on a pine board. One side of the part is a straight line. To save material and milling time I'd like to position two of the parts so that their flat surfaces face each other and position them so that with one pass the router would cut both flat surfaces. I'd also like to leave a tab so that the parts are connected. This seems to me to be more efficient than having the router go around each part. Is this possible?

[Loudspeakerboy]

It's possible. Have a look at the "Nesting" tutorial. It will give you the info you need as far as offsets etc..

[tmerrill]

Combining this with your other post I picture you trying to do something like shown in the attached picture. If so, you would want to create one matched pair, then join them into a single vector shape. This shape will be cut with a single outside profile toolpath. Then you would divide the two pieces with a single line in the middle that will cut using a profile-on toolpath. Once you have one set drawn you would use the Array Copy tool to generate the duplicate shapes. All of this would be straight forward using the tools in V-Carve Pro or Aspire.

Here are a couple of thoughts.

The single line vector between the shapes will be cut by multiple passes, but only in one cut direction. Between each pass the bit will retract, return to the beginning, plunge and start the next pass. This will most likely eliminate any time savings over just profile cutting each part with a ramp set.

A second thought will be the time required to cut all the tabs and sand flush. It sounds like you are starting with 2X dimensional lumber which you said would be planed to 1.4". Instead, plane to 1.43" or so and set the cut depths to 1.4" leaving an onion skin. This would eliminate the need for tabs, but then you would need a means to remove the onion skin and I would suggest a drum sander for this. Because of the size of the parts, you would not want to pass them through a planer again. Just a thought and if you don't have a drum sander, it may be something to consider if you are going to do a lot of these. There are some smaller ones that won't break the bank.

Tim

[Eagle55]

I haven't fully read the previous post but was impressed with the results... these guys are good! The only thing I might suggest is that instead of connecting the two parts in the middle with a tab, that you consider putting the tabs on the sides of the pieces so that all you have to do is run the whole assembly through a table saw twice to free all 20 pieces. I have better luck sanding out a tab on a straight edge rather than on a curved surface. A lot of it comes down to how it works best for you, biased on material thickness and strength of course. (And be sure to cut it slower.... I slow everything down.)

Roger

[Bob]

If parts are big enough, I use a piloted trim router to remove tabs after the piece has been removed from the base material.
Bob

[BobA]

Thanks Bob,

Another great idea. I have been using a band saw and then sanding the edges on a belt sander.

Thanks,

Bob

[GrandpaB]

Thanks to you all!!!

The picture that Tim attached is exactly the effect I was trying to achieve. The project is for Toys for God's Kids, a non-profit, that was founded in 2000 and builds small toy cars for under privileged children around the world. To date they have distributed more than 450,000 cars through missionaries and our overseas troops. For many children this is their first toy.

The cars have been built by woodworkers in their basements. I’d like to include residents of retirement communities, and mentally challenged adults who are clients in workshops. I envision the CNC project for the retirement communities and workshops. I would provide them with boards containing car bodies attached with tabs. The volunteers can cut out and sand the car bodies using hand tools.

I would also provide them with wheels and axels so that they could then assemble the cars. The cars are finished by wood burning USA on the back as a license plate, dipped in a mixture of mineral spirits and linseed oil, and finally stamped on the bottom with a “Toys for God’s Kids” logo that also identifies the retirement community or workshop where they were assembled.

The people distributing the cars are asked to send pictures of the kids playing with the cars to the people who assembled them. This creates smiles in children who receive the toys and the volunteers who build them.

I also need to manufacture wheels; I’m just beginning to think through that process. The wheels are oak and are 1” in diameter and 3/8” thick. They have a ¼” blind hole on the middle which is ¼” deep. I could envision using a ¼” router bit for this job, but I haven’t figured out how to lay it out to get the maximum number of wheels from a board. With the wheels I could possibly start with a board 7/8” thick, cut wheels on both sides and then use a band saw to cut the wheels out of the board.

You are a bunch of creative guys and I know that you’d again be able to provide some valuable suggestions. I’m trying to have the volunteers do as much of the work as they can without the use of power tools. The more skin they have in the game the greater their sense of satisfaction will be. If you want to view a finished car you can go the website: http://toysforgodskids.com. Thanks again.

[tmerrill]

Very noble effort, you and your organization should be commended!

Keep us informed, there are many here willing to help you.

As for laying out the wheels that would be easy. Create one and use the Array Copy tool to make the copies over your available material size. You could pocket the axle hole with the 1/4" bit and then cut the wheels out with the same bit. The two sided approach is a good one, both for effective use of material and you would not need to use any tabs to hold the wheels in place.

Tim

[GrandpaB]

Tim,

Thanks, for the wheel ideas. I'm really trying to think of how to partially produce the wheels so that the people doing the finishing work have something to do. Cutting the wheels off the board with a band saw is too dangerous for the people I see assembling the cars.