Hello,

We've been a member of this site for awhile now. We are a full machine/fabrication shop equipped with all CNC equipment. (brake, shear, mill, plasma, lathe) After some extensive research on this site, we've combined several of the great ideas here into our own version of a CNC router table.

In the following weeks, I will be adding to this thread as our new toy progresses. Currently we have the base of the table complete and we are waiting for our driver motors and our cp system (Mach 3) to arrive. I've been told that will be in the next 2-3 weeks.

Here are some pics of the table base. It is made out of 4x4 .187 tubing for the legs and 2.75x4 .250 flange I-beam. We may have overkilled the design of our table, but bigger is always better isn't it?

Really nice looking start. Can't wait to see it progress.
What is the cutting size?:rainfro:

that is one beefy router table

Thanks,

It's 4x8. We're planning on running this machine 6-8 hrs aday. 95% of the work will be alum. .015-1" thick hopefully.

Mike

Here's an update on our progress. We have the gear track assembled and installed. We used the 80/20 alum. extrusion to locate and mount our gear track on. By using this material in combo with the I-beam, we have almost hidden the gear track from any chips that could cause some problems down the road.

We have also started on our monitor mount. We are using 2x2x.187 tubing for the main frame, and the fancy gusset is made out of .25 HR plate. We cut the logo with our TM 3, hyperthem 1000. I am now in the process of designing some corner covers to take care of the gaps. Should make the wiring phase go easier.

Mike

Here's an update on our progress. We've recieved the motors and are in the process of installing them. We cut out the motor mounts for the X and Y out of .250 A-36 on our plasma. We have the gantry together and are really happy with the dual linears. Should give us a very sturdy machine.

Mike

Machine looks real good, very nice construction.

Just a couple of questions. Are you going to have some compensation got the rack and pinion for wear or backlash? I know allot of machine have a heavy duty spring with the motor mount on a pivot to keep pressure on the pinion to the rack.

Are you going to switch to a larger router?

Joe

The boss and I have been throwing that idea around since the beginning. Do we really need the spring tension? We looked at EZ router with the pivot and spring system, and another table that had 2 mounting bolts side by side (like ours) but they also had a spring attached. After we assembled the gantry with the motors installed (no belts attached) we ran the gantry back and forth, I think we'll need to cut a new set with a pivot and spring set-up.

Which would be the best system?

Thanks,
Mike

Yep, eventually we'll upgrade to a bigger router. Probably use the old one to work all the bugs out. Then get a big one.

I know this is crude, and fast paint markup. but use the same type of bracket, on the rt red circle for bolt hole, top left is a slot radius of the bolt hole, and blue represents spring.

Joe

Thanks Joe,

That looks like the solution. I'll redraw them tonite for cutting on Monday. I'll post some pics when their done.

Mike

cool, look forward to seeing them, its an easy mod.

Hello,

Here is another update of our progress to date. After talking with Joe last weekend, we have re-designed and cut the x-axis motor mounts. This looks like it will definately work. Thanks Joe, we appreciate the help. Maybe someday we'll be able to repay the favor.

We're getting close to paint! We're going to use blue powdercoat, so it matches some of our other equipment.

Mike

looking real good now, looking forward to seeing what it looks like painted.

Joe

Mike,
Nice looking machine, and lots of steel. Thanks for posting such good descriptive pictures.
I have never had any dealings with this type drive but was wondering if the drive gear should be centered between the axis bearings?

That is an option we were thinking about. Do you think it would greatly affect the performance of the machine? We have shipped everything out to the powdercoater, but it's easy enough to recut the drive brackets if we need to.

We actually have customers waiting for the machine to be finished, if everything works out we should have the machine paid for in teh first month or two.

Mike

Funny how it costs less to build your own than buy one new. :rolleyes: (or does it)
Very nice machine and very well welded.

Thanks swisher,

We still have a few details to take care of, but we are roughly 1/3-1/2 the price of buying a new complete machine.

Mike

dose size make a big deferents in price i want a cnc table but for the size i want the price is so much higher but its only more steel and steel is cheap

That is an option we were thinking about. Do you think it would greatly affect the performance of the machine?
Mike

I really don't know, but under loads from various directions it kinda seems lick it should be in the center. But for sure it will work like it is.

I was kind of being the Devils advocate, hoping that one of the talented people on this type of machine would jump in if they saw the question raised. Thay still may.

Just wondering but what is stopping the head (gantry?) from tilting when that thing gets to halln ?
I don’t see any supports going down the sides.. to the bottom side of your existing track?
Maybe another track on both sides.. on the bottom side of your existing track for down force?
( Example: in cnc.. a tool carousel )
Maybe you could set me straight on this? :confused:

Not sure what you're askin me swisher, please clarify.

Mike

I think he is wondering what prevents uplifting of the gantry then machine is running or tooling.

joe

Sorry not an artist : )
Let me know if you get anything out of this :confused:

I think I understand what you're talking about.

The dual linear rails are very solid, with one on top and one on the bottom of the z axis mounting plate. As far as the gantry lifting up, it may happen. If that occurs, We were thinking about adding weight to the gantry somehow. With the gantry being made out of 30/60 extrusion that should be an easy fix (bolt a chunk of .50 plate to the backside). We will not be pushing the machine to fast, shouldn't ever cut faster than 100-125 ipm. The work we do is more quality orientated than quanity, so we can slow the feedrate down.

Mike

Here's an update. We have recieved the first batch of painted parts! We can start putting the gantry back together. I've been told that our table will be ready to pick-up tomorrow, should be a fun weekend!

Mike

Thoes are class looking parts.

Keep the good pictures coming

Thanks Mr. Chips,

It's always fun to apply our skills and machines to "other projects", from time to time. With the help we've recieved on this site, and our abilities we should have one hell of a good machine.

Our "daytime job" is desgining and building air ambulance equipment for aircraft, keeps us busy but we always have time for another project.

Mike

Good morning,

Here's another update. I drove into town yesterday and picked up our parts from the powdercoater. The owner spent a few hours last night putting thigns together. Hopefully, Mach comes through with the delivery by weeks end. If we had our cp, it would be cutting before friday. Waiting sucks. Here's a few more pics.

Keep the pics coming and maybe a video of that running :) ?

Good morning,

The wait is over! Mach came through, our new cp showed up yesterday afternoon. With any luck we'll be cutting by the weekend.

One small problem we've run into is the wiring of the stepper motors. We bought them from a company that builds CNC router tables, I won't mention names at this point. They have become difficult to deal with. After they shipped us the motors we realized a couple of things: 1. They didn't include the matching plug, and they won't provide it. (we've already solved this prob). 2. The wire colors they used do not match the schematic. How does one figure out which wire does what?

Mike

Thanks swisher,

I don't have a web cam yet. Sounds like a great excuse to go and get one.

Mike

Good morning,

The wait is over! Mach came through, our new cp showed up yesterday afternoon.
The wire colors they used do not match the schematic. How does one figure out which wire does what?

Mike

Be absolutely sure with the wiring BEFORE yopu power up. I smoked 3 Xylotex boards by having them wired improperly. But thoes boards at that time 5 years ago did not have short or open protection they might now.

Good luck.

I'm really quite surprised noone uses poly switches (or at least not that often). They're relatively cheap, and when they get too much current running through them they open up. Once they cool down enough they close again like nothing ever happened. We use them on all the rocket power systems after a shorting incident about 15-20 years ago. You can get anything from a few milliamps to several tens of amps.

Hi - I am studying rack and pinion based systems for my own DIY build. The rack you used on the X looks pretty long - is it one piece, or did you splice it together ? Could you please share the specs / supplier on it ?

Thanks

Hi harryn,

Our's is one pc, 12 ft long, bought from Moore Gear and Manufacturing in Missouri. The telephone # is (573) 486-5415 ask for Diane, that's who we dealt with.

Mike

Hi harryn,

Our's is one pc, 12 ft long, bought from Moore Gear and Manufacturing in Missouri. The telephone # is (573) 486-5415 ask for Diane, that's who we dealt with.

Mike

its it impolite to ask how much you paid?

No prob, the owner has that info I'll see if I can get it out of him.

Here's is another update on our machine.

We've finished wiring just about everything in, had a few issues with bad connector pins. Threw those away and used some in-house avaition-grade stuff; necessity is the mother after all. We still have to wire in an additional e-stop and some limit switches, but it's running!

Here's a few pics

Mike

OK now we need VIDEO!!

A really professional looking dream machine.

Hello,

We've been putting in alot of hours lately. We probably should've built 2 of these machines! The backlog of jobs is unbelievable, this was definately the way to go. Thanks for all the help everyone.

Other than some clamping issues, and the lack of a dust collector I have no complaints. This machine can hold +/- .005 all day. We're not cutting faster than 15-20 ipm on alum., but with our type of work, quality is what brings the customer back. They are also normally willing to wait the extra time to get it right the first time.

I haven't had a chance to pick up a web cam yet, but here's a few pictures of what we've been up to the past few weeks.


Mike

one more thing,

We also installed a cool shot system. It takes compressed air, chills it 80-100 deg. It has been working great. Keeps the bit nice and cool and also the material, just enough air pressure to keep the tool path clean too.

i was going to include some pictures of this also, but the camera went dead since the last post. We have also upgraded the router to a 3 1/4 hp porter cable variable spd. router (10,000-21,000 rpm). Works great, but we may need to design a dust collector for the special projects we always seem to run across. I cut up some .50 structural fiberglas llast weekend, covered everything in the shop with fine powder. Spent a few hours cleaning, and I'm sure it wasn't great for my lungs, but the job is done and the customer is very happy with his parts. That is the most important part.

Mike

do you have a details showing your y axis gear reduction on the gantry and how your keep it in tension is it the same set as the x axis?
What ratio did u end up using?





No prob, the owner has that info I'll see if I c



an get it out of him.

Here's is another update on our machine.

We've finished wiring just about everything in, had a few issues with bad connector pins. Threw those away and used some in-house avaition-grade stuff; necessity is the mother after all. We still have to wire in an additional e-stop and some limit switches, but it's running!

Here's a few pics

Mike

Very nice work, not only the machine but the shop always looks nice and clean as well.

Good morning Markus,

Here are a few pics of our Y-axis and gantry. Unfortunately, I don't have much time this morning, the customers are screaming for their parts. I'll have to get back to you on the ratios.

You'll have to cut me some slack on the coolant mount, it was a quick fix to keep the machine running. Eventually, we'll catch up with the work load and make a better one.

Thanks for the compliment Jhop, we run a pretty tight ship. Keeping things clean and in their place helps with everything from impressing the customer, getting things accomplished faster, and it's safer.

Mike

Wow, great machine!! Quick question if you have the time - do you get much / any noticeable deflection in your top 80/20 gantry beam? (the 3060 piece) If it holds up to that big a machine with a span like that, I think it'll more than cover mine. :) Also I'd thought of using one of those cool air units for cooling, looks like it was a good thought after all! Nicely done!

Thanks riceburner,

We haven't had any deflection issues yet. I've been cutting fiberglas, ploycarbonate, lexan, wood, copper, brass, and a bunch of alum. 6061 and 5052. Been able to hold +/- .005 without to much of a hassle.

The one thing that puzzles me is our feedrate, I constantly hear about guys pushing their machines 200-600 in/min. On alum. anything above 25-30 in/min doesn't get me the edge quality we need. On the plastics I can get around 50-60 in/min before edge quality gets bad. We're using brand new end mill bits, by the way. Any thoughts?

Mike

I personally only use a small Taig CNC mill right now, but never really go over 15 or so on aluminum.. How deep are you cutting the AL? The pictures of your parts are quite impressive! Trying to convince my buddy with a cabiniet / interiors business that he needs me to build him a machine like yours. :)

You might want to try some aluminum cutting router bits from www.onsrud.com but I think you may need a "real" spindle to get better cut quality.

Very nice machine. I'm running a Porter Cable 3.5hp. We cut alluminum at 45 ipm and woods up to 80 to 120 any more and the machine isn't happy. So I think its spindle time. I still don't know what size to get ,I'd be interested in what your going to upgrade to after all time is money. Have you mounted a plasma torch to your machine yet?
Keep up the good pics,
Tim

Very nice job

How thick al are you cutting homemade? We also run a 4 x 8 torchmate with a 1000 hypertherm. Here's a picture of it shortly after we moved it into the new addition

Thanks manroe

Mike

Thanks riceburner,

We haven't had any deflection issues yet. I've been cutting fiberglas, ploycarbonate, lexan, wood, copper, brass, and a bunch of alum. 6061 and 5052. Been able to hold +/- .005 without to much of a hassle.

The one thing that puzzles me is our feedrate, I constantly hear about guys pushing their machines 200-600 in/min. On alum. anything above 25-30 in/min doesn't get me the edge quality we need. On the plastics I can get around 50-60 in/min before edge quality gets bad. We're using brand new end mill bits, by the way. Any thoughts?

Mike

Mike,

The best advice I can offer you is to get the chipload correct and also make sure your Max RPM on your router is not greater than it should be for the given material. Lets do an example for cutting Aluminum:

First, We determine the max RPM to turn the cutter. I looked in my Machinery's Handbook and the machining rate for Carbide in Al is around 600 SFM (Surface Feet Per Minute). Convert it to surface inches per min and we have 7200 ipm. Next, we need to select a cutter. Let's go with a 1/2" 4 flute cutter. Now, apply the formula RPM = machining rate / cutter circumference to get the max RPM. In this case the Max RPM to turn the cutter is 4854.

Next, we need to determine how fast to push the cutter through the work. We will use a conservative chipload of .003" per tooth on the cutter. Let's assume that our router is turning at 4000 RPM. This means that 16000 teeth per minute are moving through the work. With a .003" chipload, we need to push the router through at 48 inches per minute (16000 tpm * .003").

These formulas are simple math that anyone should be able to do. If you run in the correct chipload range you will maximize your cutter life.

Hope this helps.

Nate

Nice explanation! I've been doing trial and error cutting, mostly because my small machine can't do 48ipm.. Out of curiosity, what effect does depth of cut have? Do the same calculations apply, as long as tool flex and spindle horsepower can keep up? You wouldn't see much flex with a 1/2" cutter, but down to 1/8", 1/16" or 1/32", it would matter a lot more. I was using a 1/32" on AL the other day, and had to take a .002" depth of cut, took quite a few passes. Applying the formula, I probably should have been doing 60k rpm to get a decent cut at a good depth. :(

Nice explanation! I've been doing trial and error cutting, mostly because my small machine can't do 48ipm.. Out of curiosity, what effect does depth of cut have? Do the same calculations apply, as long as tool flex and spindle horsepower can keep up? You wouldn't see much flex with a 1/2" cutter, but down to 1/8", 1/16" or 1/32", it would matter a lot more. I was using a 1/32" on AL the other day, and had to take a .002" depth of cut, took quite a few passes. Applying the formula, I probably should have been doing 60k rpm to get a decent cut at a good depth. :(

Very good question Riceburner. I probably should have addressed it in the first post but was only thinking of chipload at the time. The rule of thumb I use for plain high-speed steel endmills is the max ever depth of cut to use is 1/2 the diameter of the cutter. However, the max depth of cut you may be able to do on your machine will probably be less.

First, let me start off by saying that chipload isn't really related to cutting depth. If you look at the picture (courtesy of Wikipedia) the measurement "cutting depth" is the chipload. No matter what the depth of cut is your chipload will always be the same. You want to strive to keep the chipload in the acceptable range while maximizing depth of cut.

http://upload.wikimedia.org/wikipedia/commons/thumb/8/83/Climb_Milling_01.png/300px-Climb_Milling_01.png


Depth of cut is influenced by several factors. The Rigidity of your machine is perhaps the largest. When you try and take to much of a depth of cut, your machine will chatter and try to vibrate itself apart. The cutter you use, the feedrate, and the material you are cutting all are factors as well.

Now down to the practical stuff. I don't have a nice neat formula for you to use. First, leave the RPM of the spindle in the calculated range. Then, I normally calculate a target range of feedrates based on the chipload range I look up. Choose a feedrate in the middle of the range and maximize the depth of cut off of that first. To maximize it further, slow the feedrate down. If the feedrate needs to drop below an acceptable chip load, decrease the depth of cut instead. Cutting material at too low of a chipload (slower feedrate) will prematurely dull the endmill. Fewer teeth on the milling cutters will also allow you to increase the depth of cut. Fewer teeth will allow for larger teeth on the tool and therefore more chip clearance.

Thanks solodex,

It sounds like i'm turning way to fast. Our variable spd router runs from 10,000-21,000 rpm's (3.5 hp porter cable). I suppose our best option would be to upgrade to an industrial spindle that could give me adjustment from 0-5,000 rpms.

Mike

Thanks solodex,

It sounds like i'm turning way to fast. Our variable spd router runs from 10,000-21,000 rpm's (3.5 hp porter cable). I suppose our best option would be to upgrade to an industrial spindle that could give me adjustment from 0-5,000 rpms.

Mike

Mike,

I would see about getting a headstock assembly for the Taig Mills and using that in place of the router for Aluminum. I know some people here on the forum that have had good luck with that setup. That should get you the speeds you need at price that won't break the bank.

If you use a 1/4" bit, the max RPM goes up to 9100 or so. The Hitachi routers go down to 8000 RPMs and with a 2 flute cutter the feedrate is still 48 ipm. On the other hand if you go with a 4 flute cutter your feedrate will double. With a 1/4" bit I would advise against a 4 flute bit though because your depth of cut is going to really suffer.

There is nothing stopping you from continuing to use the PC router, but I would be willing to bet you start to see your endmills wear out quicker.

Nate

You could also try buying router bits designed to cut aluminum at higher spindle speeds and feedrates.

https://www.onsrud.com/xdoc/ChipAluminum

Things have been going great, until 2 weeks ago. We've been having a problem with our gecko drives. It seems to only effect the x axis and the a axis (slaved) drives. Steppers are running great, they aren't making any weird noises. The 5 amp 250 volt fuse blows and toasts our drives.......not sure what's going on, but I'm in dire need of a solution. Customers still need their parts, and we can't afford to be replacing geckos every week.

Mike

Hi Med Pac

Im thinking about building a router similair to the one you guys built, your one looks awesome.
What ratio did you gear the stepper motors down to for the rack and pinion drive, also what size stepper motors are you using

What are the particulars on the racks you are using?? Pressure angle, pitch, width, height, etc??

What motors (specs) are you driving them with and gear reduction??

What resolution do you expect?? Pulses per rev??

How fast do you plan fo it to move (ipm)

Thanks for any info. I am in the process of building a 4'x4' table and am nearing the point to order the racks / etc. and want to make sure I get the right stuff the first time around.

Kirk

We're using 6amp, 960 ounce steppers from San Motion. They are actually the same motors that EZ router uses. The owner was able to buy them directly from EZ router.

I'm not sure what the angle pitch of the gear rack is, I'll look into it. We're extremely busy though, don't have much time for the computer this week. Holiday was nice, but now I'm even farther behind.

We have been running our machine around 5-25 ipm on alum., 30-50 ipm on plastics. Our fast travel is at 150 ipm's. I know the motors are capable of much higher travel rates, but we don't need to go that fast. Plus, you get a better finish, better tolerances, and our machine will last longer with fewer break downs than the guys that are running at 200 ipm's or faster.

Mike