How fast can you cut?

[Blacknbart]

I am trying to understand how fast a Shopbot machine with a router or spindle attached will cut these simple requests.

How long would it take to cut six 24’’circles out of a:
I know the circle might be sized a little less to accommodate the board in the width and length.

4’ x 8’ sheet of ½ MDO plywood.

4’ x 8’ sheet of 3/4 MDF plywood.

4’ x 8’ sheet of ¼ Acrylic.

4’ x 8’ sheet of 13mm Sintra




How long does it usually take to carve out some text and simple detail artwork out of HDU sign foam. Sizes are sizes:

2’ x 4’

4’ x 8’


Thanks for the help!!

Bart

[srwtlc]

Bart, by the looks of your profile picture, maybe you outta lay off the coffee and slow down a bit.

Sorry, couldn't resist. ;)

[knight_toolworks]

the plywood can be cut 3ips though I usually do a cleanup pass so figure about 5 minutes or so.
plastic is a fair amount slower only 1.ips or so. the sintra two passes and say 2ips.

[srwtlc]

Depending on the tool size, veneered MDF can be cut fairly fast. I will often cut at 6"/sec with a 3/8" compression and 5"/sec with a 5mm compression at 0.375"/per pass. Lots of dust!

[Blacknbart]

Thanks for the helpful information it's a little clearer how fast a router can cut these materials. Providing the machine is set at the correct settings and I'm using the correct bit and compression. So I can I assume if I had a 2' x 4' HDU Sign to carve out it would take no less the 10 minutes to route and carve any letters and or shapes given.

[curtiss]

take good care of that good eye... :cool:


Depending on how you hold things down, more time can be spent with hold down procedures compared to cutting procedures.

[wberminio]

Bart

You can't give accurate times.It all depends on many variables.
Material/How complex the design and /or letters......

No matter how long it takes,It will be more accurate and faster in the long run then any other method

[jerry_stanek]

I cut Sintra and Acrylic all the time. Sintra I cut at 4.5 IPS .26 deepapass and acrylic at 3 IPS

[dlcw]

Bart,

I cut 1/2", 5/8" and 3/4" plywood at about 6 inches per second and always make two passes. First pass (climb cut) leaves a 1/32" skin and the second pass (conventional cut) trims to exact size and cuts 1/64" thru the ply into the spoil board. I can turn a sheet of 3/4" plywood into cabinet parts, ready to assemble, in about 10-20 minutes. All depends on the number of parts that are being cut.

I cut 1/4" and 1/2" MDF at 3-4 inches per second as well and cut hundreds of parts for a local sports plaque company. Everything from 4" circles to 25" circles as well as football shapes. The 1/4" takes awhile because I'm cutting 230 circles with a .1875" downcut spiral bit at 3ips. The 1/2" MDF I cut with a 1/4" downcut spiral at 4ips.

Carving something takes longer depending on the amount of detail you want to end up with. Most carving I do with a 1/8" ballnose using a 6% stepover rate. This makes for a very detailed carving with little sanding left to do. Most carving is a 2 step approach where the roughing is done with a larger bit and the a second pass is done with a smaller bit. The attached business sign I use at shows plaque took about 4.5 hours to carve to give you an idea of timing.

[chiloquinruss]

Don, I love that border on your sample sign, how was it accomplished? Russ

[Blacknbart]

Excellent information guys! Thanks for your help and guidance! Please keep your eyes peeled for my wild questions from a Fresh Cut!

Bart

[gc3]

...she'll cut 'till she drops :eek: a vintage pr machine...learn what she likes...and she will treat you like gold...be kind to your ass for it bears you

can cut as fast as she'll go or as slow as she'll go

as others have said, depends on the project.

[joe]

I'm with you Gene on the advantages of the old PR machine setup. The basic concept was an excellent design and could be maintained with ease. To make this old equipment come alive was the upgrade control box.

Perhaps you could tell us what updated you've made and any suggestions with to that reguard.

Joe

[gc3]

Joe,

I capped the unistrut rails with .125 angle iron which helped keep the carriage where it belongs...that works very well. I shortened all the motor cables, no splices, can't tell if it made a difference...put on cable carrier instead of the hoop, again, can't tell a difference but I like the way it looks! I think the biggest improvement was getting a computer with 4gb ram....I can run it as fast as v3.4.27 will do 6ips x,y 3ips z, since changing computers I have had no comms errors and on large files there is almost zero pause when loading lines over 100K. I also switched to 25 tooth pinions, gave me a little more speed but tight radius cuts are quite choppy a trade off I can live with.

I was going to do a prt parts upgrade(sorry Dave for flaking on buying those) but I have decided to do a sort of hybrid machine using the table plans from Mechmate and using pr parts where I can...still unsure if I want't the 4g board or build a controller and use mach. My pk296a1a sg3.6 motors are 6 wire so I think I could squeeze out a little more speed wiring them as per suggestions of Mike Richards...not sure if that configuration would work with the 4g board. All in all I am very impressed at how well this little pr works, we named her Betty and she does us proud!

[bleeth]

Don't worry about it Gene-dreamed plans are always subject to change!!
Before I decided on going with the gantry upgrade I did I had a set of the MM gantry parts that needed to be precision cut and bent done and shipped and at this point they have company!

[MogulTx]

Minor Thread Hijack

Gene,

The bearded man you are carving (Neptune / Poseidon?)... do you have a finished picture? I am really enamored with your work- and would love to see the finished carving. I am workign up to doing 3D... not there yet.

Thanks

[Blacknbart]

Gene,

So how long did it take to carve out this piece?

[gc3]

Gene,

So how long did it take to carve out this piece?

rough pass 4 hrs .5 ballnose 65% 4ips xy 3 ips z. finish pass 6:44 hrs .25 ballnose 10% 4.5ips xy 3ips z.

size 32"x23"x2"

[MogulTx]

THAT IS GREAT! I love it!

[Blacknbart]

Thanks for the information it gives me a better idea how long it take to do this kind of work. Thank you for sharing.

Bart

[Blacknbart]

When pricing a large carving project like Gene's what is the standard method to get a Win/Win situation for both Customer( feeling received a standard fair price) and yourself (Profit, fixed and variable cost coverage). I'm driven more toward Price per sq foot rather than per hour cost. What do you think?