How many sheets of MDF in a day ?

[tomasz]

Hello,
On a new Alpha PRS,
How many sheets of 3/4 MDF would I be able to cut in 1 day not breaking a sweat? 24" circles (8) from 1 sheet or how long from a 1 1/2" mdf (2) 3/4 glued together, same 24" circles if this would be faster. Thanks in advance !

Tomasz

[fleinbach]

At 5ips with a 1/4 bit making 3 passes would take around 25 minutes on the 3/4 inch sheet. If you up the speed to 10ips and make a single pass you could cut them in about 12 minutes.

Why would you want to glue 2 sheets together? You can purchase MDF all the way up to 2" thick.

[joelschuman]

"not breaking a sweat" is the hard part. You don't say how large the sheets are or how long your day lasts. If you don't have a vacuum lift arm and have to hump the sheets yourself, I'd say add 15 minutes per sheet to cut time for load/unload. 24" circles from a 49"x97" sheet requires semi accurate positioning - you can't just flop it down anywhere, even if you use stops. Unloading the circles and skels and cleaning the table takes a few minutes. Laminating two sheets makes a backbreaking heavy workpiece and ultralight is usually 48x96, so that's not an option.

[jhicks]

As usual a lot of helpful advice and experience here. My comment would be, why do you ask? Because you want to estimate for a bid/proposal?
If thats true, I would strongly suggest a dry run. The simple stuff is always what gets in the way.
How will you fixture it or hold it down?
How long does it really take to remove, clear dust, reload, re square, re Zero?
The real time is often not the cut file but the remove, sort, sand if necessary, reload, re run and start over so time yourself with real cuts on real material and clock in from start of 1st sheet to end of 3rd sheet and you will have a pretty good idea of all the varialbles, edge quality, out of rounds, depths of cut, speed, bits, sheet stock storage and staging, part stacking and inspecting, boxing, etc, etc.
Good luck and don't get hung up or burned on a virtual cutting time estimate then find out there's a bit more to consider.Usually more time there than cutting anyway.
Thats advice based on experience so hope it helps.

[tomasz]

Jerry,
I ask because I don't have a bot YET and I'm trying to get an idea of how much time I would save with my current project. I was asked to make some 24" tables mah. veneer on MDF 1.5 " thick. The cost of 1"or 2"mdf is double so i'd rather glue them together.So from what I gather I could easily cut out 16-20 circles in one hour times 8hr day = up to 160 single or 80 with 1.5" thickness. I was also trying to figure out how many passes ? I was doing fine with hand held router with only two passes and 1/4" down cut spiral. Thanks for all your input.

[myxpykalix]

I would be considered a newbie so i tend to go slower than so of the more experienced but i don't think regardless of any material i have cut so far i have taken more than a 1/4" deep cut at any one time. With my limited experience, if you need 1 1/2" thick material you would be better off cutting 3/4 material then gluing together. That way you can use a 1/4" bit which cuts less material, less stress on the bit and router and less dust. To cut 1 1/2" you're going to have to use a 1/2" shank bit as i've not seen a long 1/4" shank bit to cut 1 1/2".

As far as speeds are concerned I usually start out slow and manually run the speed up as it goes along so i can gauge how fast i can go without setting it too high right off and having it mess up material. Thats my 2c

[fleinbach]

When it comes to speed I have cut 1" MDF at 10ips with a 1/4" bit many times.
Tomasz,

I haven't bought any 1 1/2 MDF for about 9 months so I don't know what the going price is right now but when I did it was only about 15% higher then glueing 2 sheets of 3/4" material together.

Jack,

I have done some cutting in 2" material using a 1/2 X 4" bit with 2" cutting surface. The bar in my last theater room was made out of 2" poplar and instead of running the board through my joiner I ran the bit down each edge and it made a beautiful joint.

[knight_toolworks]

remember it would take a couple months maybe to get the machine and get it up and running.

[jhicks]

Also, don't forget that MDF Chews up bits rapidly.
Maybe I'm missing something but given the choice i wouldnt cut and glue over cut 1,1/2" and see no benefit in doing so. Time to cut double the parts, then glue, clamp, match edges, sand, and so forth would outweigh simply cutting 1,1/2" and be done.
You can always get 3/8" bits or other sizes so go as big, as fast, and as deep as you can. Now going with Trupan in 3/4" or 1,1/2" if you can find it is a nice idea, cuts easier, faster, and way less dust.
a bit more costly but worth it.

[dray]

you can cut 3/4 MDF in a single pass at 500 inches per minute with a 1/4" bit

I would say 50 sheets a day working hard loading and unloading etc

30 taking it kinda easy.. thats 256 circles cruising without pushing it

[gene]

Thomaz .
Where are you located ? (why dont people fill out their profile completly?)
I would like to cut for you or at least show you what the bot can do. I have an alpha with a spindle and roots vac holddown. Gene

[tomasz]

Gene,
Just added my info so You see where I'm at.Thanks for all your input I try to keep myself from buying a Bot and just have it sit there but it looks like a whole new door that can open many possibilities and opportunities with it.Thanks again.

[dray]

You cant stop yourself from buying a bot....

You now have an illness known only as "bot whammy"
and there is no way to cure it except buying a bot and sharing your experiences!

You are cursed!