View Full Version : Mounting 4th axis rotating indexers or lathes under the gantry

Thu 11 January 2007, 23:36
There is often an interest in mounting rotating indexers or lathes under the gantry of a CNC router. Stephen Hull touched on the issue here (http://www.mechmate.com/Forum/messages/2/2634.html) and Art Ransom mentioned it here (http://www.mechmate.com/Forum/messages/329/2626.html). This thread has been started as a place to throw around ideas on this topic. I personally don't want to get too deeply involved in it yet, but just drop in some observations....

I believe that an indexer/lathe's center height must be adjustable in relation to the height of the gantry. As shown on Stephen's thread, a gantry router ideally cuts things in the range of 125 - 200mm [5" to 8"] below the gantry, therefore:

- a 24" diameter column center should be 17 to 20" below the gantry (9 to 12" below the MechMate table top)

- a 2" diameter table leg center should be 6 to 9" below the gantry (between 2" above table to 1" below table)

Clearly two very different locations and applications.

Edit: This thread started way back in the old forum. These pictures from there are interesting:

http://www.mechmate.com/Forum/messages/2/114.jpg http://www.mechmate.com/Forum/messages/2/115.jpg



Stephen Hull
Fri 12 January 2007, 00:32
Gerald, thanks for the answer and information. This is much of what I have been looking for. I appreciate you venturing into this area.

Arthur Ransom
Fri 12 January 2007, 06:19
Since I am new to CNC I often end up it the award position that in latin is called "craius in rectus". My first attempt I had 14" of travel on the Z. There was way too much flex in the gantry and Z. I redesigned using ajustable ways. In the top position I have 8" to the center of the A axis. This should let me turn up to 10". Also the ways can be used to mount a table so I can do routing. There will be stops every 2" increasing the allowable diameter by 4". The A axis asembly bolts to the machine legs in each position. This is a brief overview and I will try and get my site updated this weekend with pictures and details.

Fri 12 January 2007, 06:54

....there is no law which says that the cutting tool shall spin around a vertical axis while doing "indexing" work - the router/spindle can lie on its side and the plunging action can be horizontal....

...bolt a horizontal router/spindle directly to the Y-car...

....indexer/lathe center height can then be fixed (non-adjustable)...

....indexer can be on wheeled trolley parked/bolted against side of MechMate.....

....the inspiration is the last pic in this thread (http://www.mechmate.com/Forum/messages/2/60.html) http://www.mechmate.com/Forum/clipart/happy.gif

Arthur Ransom
Fri 12 January 2007, 16:53
Posted update to my A axis assembly.

Wayne Painter
Thu 18 January 2007, 18:03
Hey Folks,
I have a SB Alpha with Indexer mounted to the side (C-Channels) with a 12" Z-Axis. I am planning to remove it from the side and mount it along the X-Axis upright on the bed angle iron cross-braces. I would like to use a 10' piece of T-Slot to mount the headstock and tailstock. SB Indexer came with short 24"x4"x1" T-Slot machined out of aluminum. Anyone have any suggestions as to what to use for the T-Slot? Like where to buy it at reasonable price? Having it machined at a commercial shop is cost prohibitive. I am not brave enough to attempt to machine it myself. I have thought of using some kind of hardwood, then cut a T-Slot in it, but not sure it would stay stable (stay flat). Also have thought of cutting 2 pieces of aluminum with table saw for T-Slot, then fastening together. But, not sure this would be satisfactory either.

Hoping you all might have some very clever ideas...



Thu 18 January 2007, 23:06
There is no need to have real precision in the rail. A piece of steel square tube with a slot cut in the one side will work. An angle-grinder is okay for making the slot.

Sat 17 February 2007, 18:00
Gerald, I am very much interested in mounting a 4th axis on to the mechmate that I have built. I also do have one spare stepper and a driver. Can you please advice me on this issue.

Sun 18 February 2007, 20:18
I do have one spare stepper and a Gecko driver which i bought as spares for the mechmate Can some guy give me some details on how to fix the stepper onto the Head Stock.

Sun 18 February 2007, 23:04
Quite frankly, I think a "board-cutter" and an "indexer" are two totally different machines. A combination machine will have to make big compromises.

If I had to build an indexer tomorrow, I would:
- decide on the length and diameter of the workpieces.
- build a MechMate gantry where Y=half diameter. Yes, a very short gantry. (One x-motor may be sufficient on one side only)
- build a very narrow table where X=length and Y=dimension above. The table cross-members will be fewer, lower and height adjustable.

The "headstock" will have interchangeable gearwheels for different diameters of work to be turned. The gearwheel diameter will be approx the same as the workpiece diameter. The standard MechMate spring-loaded motor mount, and motor with standard 20 tooth pinion will ride on the gearwheels.

Mon 19 February 2007, 08:35
Your point is well taken. But Gerald, as I would have pointed out to you earlier, in Countries like Sri Lanka where people are new to CNC machines they do not they do not understand and realise as to what could be done with a CNC machine. So due to this we have to initially make samples and show people as to what could be done. Once business starts to grow you could think of having dedicated machines for each type of job.

Mon 19 February 2007, 09:08
How about starting from a regular wood lathe and fit the unit on your machine then figure a way to drive the lathe with your stepper? It's an easy way to get started that lots have chosen. You get pretty much all you need; head stock with accessories, tail stock and you can even consider to use the lathe conventionally.

From that point, you got two challenge; connecting your stepper and mounting the lathe on your tool.

Before I (and other) go on with suggestions and ideas... is that what you're looking for to do?

Mon 19 February 2007, 09:58
If you only want to make a few samples, then do it like the first couple of pics in this thread (http://www.mechmate.com/Forum/messages/2/60.html) that I have linked to before. (across the end of the table).

That thread very much covers the options of mounting locations on a board-cutting table. You can move the Z-axis inside your y-car to reach further over the end of the table if necessary.

Tue 20 February 2007, 05:47
Art, What should be the lowest and the highest RPM's that you shoud consider for a indexer (including sanding/finishing work).

Arthur Ransom
Tue 20 February 2007, 08:09
Yesterday I finally got all the pieces together and was able to round and flute a 6" by 6" by 96" column. My axis is a 1200 oz. stepper with a 4.5:1 ratio. This ratio needs to be higher probably 50:1 range. Open to suggestions on how to accomplish this. I need a lot more torque to prevent stalling with heavier pieces.
I did the rounding using a straight 2-edge bit and cutting on the side of the piece (Y-axis).
Here is the program
G0 Y0 Z0 X1
M3 F80
G0 x0
M98 P123 L1


G91 x.01
G90 A2200 Y70
G91 x.01
G90 A0 Y0

M3 picks the solid state relay that turns on the router and dust collector and M30 turns them off.
Surface is X0 but G0 Y0 Z0 X-1 places the cutter 1" from the stock so the bit doesn't grab at router start and then it is mover into cutting position at x0
G91 x.01 moves to a cutting depth of .01? deeper cut used for roughing.
G90 A2200 Y70 A rotates 2200 times while Y moves 70?
M98 P123 L1 subroutine runs L number of times.

Values of L, A, Y, and X are changed as needed.
The A axis rotation was 67 RPM and I need to work with motor tuning to see if I can?t get it faster without stalling during positional moves when fluting.
Here is the fluting program
G90 X0 Y0 Z.25 A0 F80
M98 P100 L10


G90 Z-.02
G91 Y4
G90 Z-.02
G90 Y0
G91 Z1
G91 A.1

Cutting is done top center of the piece and this does 10 flutes.
L, Z,Y and A are changed as needed.

These are crude but I am just learning G code so suggestions welcomed


How do I home A only?
How do enter comments into program?

Tue 20 February 2007, 12:16
The following two statements are mutually exclusive (contradictory)

"This ratio needs to be higher probably 50:1 range."

"The A axis rotation was 67 RPM and I need to work with motor tuning to see if I can?t get it faster without stalling during positional moves when fluting."

Higher gearing will make the moves slower, and vice versa.

An indexer ideally needs gearing optimised for each job diameter - a one-size-fits-all approach can't work.......unless we can get those PC's and control cards that can spit out very high frequency step pulses.....

Arthur Ransom
Tue 20 February 2007, 12:34
With a higher ratio I can go into motor tuning and raise the motor RPM and steps without boging the motor.

Tue 20 February 2007, 12:45
Mach, when stretched, gives pulses at 45000 per sec, but more reliably at 25000 per sec. To turn a motor a full turn needs 2000 pulses. To turn a 50:1 gearbox a full turn needs 100 000 pulses. At 25kHz, it will take 4 secs to make one rotation at 50:1. If that is fast enough for you, then you are golden. But watch the backlash in a gearbox of that high ratio.

Tue 20 February 2007, 21:31
gerald, Art, Initially I intend to use the mechmate for indexing work. I will be mounting the indexer parallel to the Y axis in the machine. Later on if required I would love to have a dedicated machine for turning jobs. The stepper that I initially use with mechmate should be able drive the load of the final dedicated machine as well. Will a 1200 Oz stepper be ok for my purpose.

Tue 20 February 2007, 22:41
Fabrica, what are your gearing plans for that 1200 Oz stepper?

Arthur Ransom
Wed 21 February 2007, 01:09
Mach seems rock solid with 45000 selected. Getting cycles constant in the 43.5 K range. Running 7568Mg Ram on a 2.2 Mhz $149 new PC from Fry. Came with 1 parallel port, 8 USB ports. CDR, 10/100 NIC, flopppy drive,sound,serial port 40 Mg HD.mouse, speakers, keyboard and 128K of RAM. I added 256Mg of RAM for $49.
The indexer needs more than 1200 steppper at 4.5:1. Not familiar working in oz/in mode but based on my Powermatic 3520A wood lathe which has a 2HPp variable speed motor. The motor has a max RPM of 1750 and on the low pulley setting it's max RPM is 1500. Does that make the gear ratio approx .9:1? My present configuration maxs out at 67 RPM but a 1" bit with a .25" deep cut can move the work. Seem to rember seeing somewhere that 1 HP is 30,000 oz/in. Need recomendation on size of stepper or servo to get for indexer.

Wed 21 February 2007, 01:21
Gerald, I am clueless about it. Maybe a stepper with 7.2 gearing ratio connected to the indexer through a tooth belt drive.

Arthur Ransom
Wed 21 February 2007, 02:07
Here is a pic of 40 flutes on a 4" column.

Wed 21 February 2007, 04:03
If we have a 600oz/in stepper doing a good job for the linear table, then we don't need a bigger motor for an indexer . . . . . provided that the gearing is correct. The magic is all in the right gearing.

If the recommended Oriental Motor with its 3.6:1 or 7.2:1 gearbox is doing a good job of linear cutting then it will do as well when it turns a small workpiece directly as an indexer. Strictly speaking, a small workpiece with a diameter equal to the pinion diameter (only around 25mm [1"])will give the same surface speeds and loads.

If you want to index a 6" workpiece, then you would theoretically want 6 times more gear ratio. Instead of 3.6 or 7.2 to one, you want to look at 22 or 44 to 1.

Fabrica, your idea of a 7.2:1 box with a further tooth belt drive is good. But I would experiment with cheap bicycle sprockets and chains first......

However, the main point I want to make is that I don't see a need for bigger stepper motors - only for more gearing.

Normand Blais
Wed 21 February 2007, 13:19
If you turn even circular object, but if you start carving, the center of gravity change. By how much ? depend on the design. you may need stronger motor?

Wed 21 February 2007, 13:28
Yikes, I didn't think of that factor. Valid point.

Thu 22 February 2007, 07:55
So finally what do you guys suggest.

Thu 22 February 2007, 07:58
Still say that you should get exactly the same motor/gearbox as for the rest of the Mechmate, but then to add further gearing/belting/.... to that motor.

Thu 22 February 2007, 08:03
Can we think of a tooth belt driven pulley.

Thu 22 February 2007, 21:05
Can some guy recommend to me a good source from which I could buy a good set of head stock and tail stock.

I also need to know weather I could do them in my workshop itself.

Arthur Ransom
Thu 22 February 2007, 22:24
On my site at http://turningaround.org/4_axis_mill.htm near the bottom is my head stock and tail stock are shown. All off the shelf iteams except for the #2 Morse tapper in the end of the tail stock quill.

Arthur Ransom
Thu 22 February 2007, 22:37
Today I worked on doing motor tuning on the indexer axis and it is running great at 300 RPM. Got too involved and didn’t try faster speeds. At this time I don’t see any need for speeds over 100 RPM except when rounding rough stock. At this speed it takes 11 minutes to make 1 pass of 96”. Also I have order a set of laser cut parts and will replace my crappy gantry with the MechMate one.

Thu 22 February 2007, 22:45
Art, What were the prices that you paid for these items and what was the source of that you bought them from.

Arthur Ransom
Fri 23 February 2007, 07:56
1.25" allthread Macmaster Carr $40 ?
Nuts $20 ?
4 jaw chuck Harbor Freight $16
Live center $95 Oneway lathe
pillow blocks $10?
Machining #2 moris taper $20
I used the Oneway line center because I have a backup one, the Harbor Freight chucks screw on,and the bearings are replacable.http://www.mechmate.com/Forum/messages/19563/3511.jpg

Sat 24 February 2007, 23:50
Gerald, If I am to go by your suggested configuration where the gearing ratio changes depending on the diameter of the stock.

I need to work with stocks having diameters ranging from 1" to 12". The RPM's I would like to work with would range from 1-200. Assume that I will have a 3.2 gearing ratio on the motor. How many sets of pulleys and belts will I need.

Sat 24 February 2007, 23:54
Sorry, reference to the earlier post my motor gearing ratio is 3.6:1.

Sun 25 February 2007, 00:40
Gerald, I did some quick calculations on a worksheet I got done to do RPM calcualtions for the indexer.

If I use a 3.6 geared motor and set the pulsing speed to 45,000 RPM and also if i set the pulley ratio to 1:1.8 (1" pulley on motor shaft and 1.8" pulley on head stock shaft). I would get a indxer RPM of 200 (This i feel should be the minimum for rounding up work on rough stocks).

AS per your theory which says that the pulley diameter should be equal to to the diameter that you are working on then the max diameter of the stock that I can work with would be 1.8" in diamater.

If I need to work on 12" stock (with 12" pulley mounted on Headstock shaft)I can only operate at a max RPM of 30 RPM.

The other option available to me is to do the rounding of the square stocks on a basic turner with no stepper involvement and then transfer the workpiece on to the machine we propose to build.

Sun 25 February 2007, 00:55
Fabrica, you are starting to realise to difference between an "indexer" and a "turner"(lathe)...
- indexer turns the work at low speed while a fast spinning cutter (router) takes deep cuts.
- lathe turns the work at high speed, while a static cutter takes shallow cuts.

They are completely different machines. You seem to want an indexer that has the speed of a lathe? With a router driven cutter, the speed of the workpiece can be much slower.

Rough turning in a lathe is good. Sandpapering in a lathe is also very good. Sandpapering on an an indexer is hard work.

I would pick 2 gear ratios max. Probably 3:1 and 9:1. The idea is that you can have:
- direct drive
- 3x slower than direct drive
- and 3x slower again (9x)

Don't pick the middle ratio in the "middle". If your top ratio is 10:1 the middle appears to be 5:1 but that is actually 5X from the bottom and 2x from the top.

Sun 25 February 2007, 01:00
It is easy to do this theoretically, but you need to find practical pulleys or gears....

Sun 25 February 2007, 05:47
What you mean is that a diference between a indexer and lathe is that the same job that is done on a lathe at high RPM's could be done on Indexers at a low RPM. But for sand papering and rough cutting lathe is a better option.

OK assuming that If I take the indexer path, I already have a stepper with a 3.6 gearing. If I drive it direct the max RPM would be 375, With 3:1 gearing 125 RPM and with 9:1 gearing 42 RPM.

Your suggestion is to do trials with chains and sprockets.

Sun 25 February 2007, 07:06
Here (http://www.hardwoodcolumns.com/custom-wood-columns.htm) is an example of true indexer work. As you will appreciate, the RPM is not a factor when cutting these shapes. And you cannot do them on a normal lathe. To sand them, they must stand still.

This (http://images.google.com/images?q=turned+wood+spindle&svnum=10&hl=en&safe=off&rls=GGLD%2CGGLD:2005-07%2CGGLD:en&start=20&sa=N&ndsp=20) stuff can be done on indexers or lathes. People want to sandpaper them while they spin. Here speed is an important factor.

Sun 25 February 2007, 08:34
What I am interested in at the moment would be the second type of machine. Architectural wood coluns does not interest me at least for the moment.

It will mainly be candle stands, stairways, walking sticks etc not exceeding a lenth of 48".

Arthur Ransom
Sun 25 February 2007, 09:09
Gerald now I begin to understand. What I have built is an indexer. What is the difference between a 4-axis mill and an indexer? Using 2" stock at 100 RPM it equates to 600 IPM. This would be too fast if I was Cutting with the point of the cutter but it has been my experience that I get a cleaner cut if cutting with the side of the cutter with the cutting edge coming down into the wood (climbing cut?). It is my interpretation that if I use the point of the cutter then for a 2” piece the max rotation will probably be 50 RPM and a 24” piece will be 6 RPM. Side cutting will probably be limited to 12” and less. What IPM range would you consider the max for side cutting? The only time higher RPM's are desirable are when roughing a multi sided piece to round. This is the code I am using, G0 Y96 A1000, for roughing and G0 Y966 A2000 for finish cut and I am side cutting. Is there a better way? On pieces where you can’t reach horizontal centerline to cut the cutting would be done as close to centerline as the tool will reach. This way the tool is still cutting with the side.
The RPM speeds I have used in other posting are in doubt. If I set F200 then Mach posts feed rate at 200 but posts units/minute of 167. What is my actual RPM?
Sanding solution.
Sanding manually is a PIA. A better solution is a flap sander. Here is a version used on the Legacy that could be modified to MechMate. I see it as mounting on the side of Y car with manual Z and XY plane adjustment.

Sun 25 February 2007, 09:16
Art, What does PIA stand for. I hope and pray that you meant "Pakistan International Airlines". Most of the Pakistani test Cricketers still work for this institution (Just having some fun on your account).

Sun 25 February 2007, 10:04
Art, As I understand The main difference between a indexer and a wood turner is this.

In a wood turning lathe the force to cut the wood is provided by the RPM and the weight of the stock. You need a powerful motor to provide this circular to motion to the stock. This is why you talk about this 1 Hp motor.

In a indexer the cutting force is mainly provided by the router and not by the RPM of the stock. Due to this the machine has the luxury of turning at a lower RPM.

Sun 25 February 2007, 11:13
An indexer is a device which can control the exact rotational position of a workpiece. They can stop and hold with minimal backlash.

Fabrica, you say you want to do the "second" type of work (candle stands, stairways, walking sticks etc.). For that you do not need a stepper motor (or MAch3 or gecko) to turn the wood because you do not need a precise stopping position to cut detail. Therefore you don't need an indexer.

The right production machine for candle stands, stairways, walking sticks etc. is a copy lathe, and the MechMate will be perfect to cut the templates (or masters) to use on the copy lathe.

Sun 25 February 2007, 11:21
Copy lathe:


Sun 25 February 2007, 18:22
It might still be interesting to use the CNC as the copy device...

Check those out:

link 1 (http://s98.photobucket.com/albums/l249/brianharnett/Modified%20and%20Made%20Machines/?action=view&current=homeadeshopbotlathe.flv)

link 2 (http://s98.photobucket.com/albums/l249/brianharnett/Modified%20and%20Made%20Machines/?action=view&current=homeadeshopbotlathe3.flv)

link 3 (http://s98.photobucket.com/albums/l249/brianharnett/Modified%20and%20Made%20Machines/?action=view&current=homeadeshpbotlathe2.flv)

Sun 25 February 2007, 20:16
Gerald, How am I to do the flutes on the stock. Paco Thanks for your info. I think the machine that you suggest is what I have in mind. How can I get more info on it. I need to mount this on to the mechmate.

Sun 25 February 2007, 22:03

you though about it, I did and so some other did too, but the links I shared are from a talent fellow Botter that share his trial recently. (http://www.talkshopbot.com/forum/show.cgi?tpc=312&post=46940#POST46940) I suggest you do a search on this forum and maybe post your questions directly to Brian. In fact, he might just be reading this thread HERE too...?!

The concept is quite simple; it's pretty much what Gerald post above but the cutter is driven with the CNC X (or Y) and Z axis. You may want to chuck in a 60 deg. V tool bit for final sharp inside corner detailing...

Sun 25 February 2007, 23:04
Thanks Paco for your valuble info. I will get in touch with Brian.

Sun 25 February 2007, 23:29
The main reason I mention a copy lathe, is for production. In a country where labour is relatively cheap, a copy lathe will very easily beat a CNC indexer for speed, price and ease of sandpapering.

Of course, a copy lathe can be equipped with CNC motors, but then I will put the "gantry" under, or behind, the workpiece so that the operator has maximum access for sandpapering.

Mon 26 February 2007, 03:55
No Gerald What I plan to do is to have this thing mounted on the Mechmate parallel to Y axis.

Mon 26 February 2007, 04:08
You already said you would do that for making small quantities of samples, and I am not arguing with you. I am simply pointing out some options for mass production.

Thomas M. Rybczyk
Mon 26 February 2007, 06:45

Here are a couple more pictures of another Shopboters lathe\indexer.



I also will be doing this to my machine at some point.

Good Luck,

Mon 26 February 2007, 19:50
Thanks Tom for your info.

reza forushani
Tue 27 February 2007, 02:41
Where are you with your laser deal?

Tue 27 February 2007, 18:45
I have received the optics the gun is on the way.

Sun 25 January 2009, 21:55
Here is a 18" pedistal that I am roughing out. I have to rough it up between each layer glued up because I only have 20" between the rails and not enough Z depth. I am rebuilding the Z with 10" of travel and using a lead screw because of the laterial impact forces involved.

Gerald D
Sun 25 January 2009, 23:14
Art, do you use much y-travel when you rough out? Could you do the roughing with the y-car nearly fixed in one position? (say 6" or 4" off TDC). I have an idea for a simple "stabiliser" for roughing out . . . . . .

Tue 27 January 2009, 07:40
Normally I cut about 1" off top dead center. This one is being cut so far off TDC because I don't have enough Z travel to get higher.

Gerald D
Tue 27 January 2009, 09:29
Then this stabiliser rod should work:


The idea is to disconnect the y-motor so that the y-car can ride a little, as controlled by the swing arc of the stabiliser and the plunging of the Z.

For the ends of the stabiliser, use ball joint rod ends, suggest McMaster 6072K185, and put all thread between them with locknuts. Arrange it so that the rod is being pulled (tension) to resist the cutter force.

Attach one end to the z-slide, or even the router bracket. The nearer to the cutter the better.

Attach the other end to the gantry (10 20 450) between the v-wheels, in line with the cutter, as low on the x-rail as you can go.

Sat 31 January 2009, 16:16
I'll have to move this over a bit more but I think it will work well here. The last bed rail will have to move too I think. Any other opinions/thoughts/ideas on this 4th axis?

Sun 09 August 2009, 15:10
Just as a way to clear this up in my head... is it mandatory to have x,y,and z axis + the a axis (rotational) or can you build an indexer with x or y and z and a? I am asking because sometimes in theatre (our machine is being built so we can build scenery and props more easily) there is a requirement for the type of things an indexer would be great for and we don't need production level speed, but I purchased the G540 which will only drive 4 motors. If I run an indexer parallel to my y axis and use one of the x motors (and disable the other) I would have enough motors for my needs. Also, do Mach3 and the vectric software packages handle indexers to anybody here's knowledge? It looks like people are modifying their gcode directly, but that seems like it would be a rough approach to something like a spiral cut spindle.

Thanks for any input, I probably won't try to set up our MechMate as an indexer for quite sometime but I'm sure that when we find out we could use it we won't have much time to implement the system.

Sun 09 August 2009, 18:14
Since you are using the G540, your options are pretty few. With the prewired configuration of the G540 you are allowed x, y, z and a. x and a will be the x axis gantry motors, y - the cross car, z - being z. Mach will slave a to x in your setup.

For you to add an indexer in the future my suggestion would be to purchase a second BOB, like the PMDX 122 and add a second parallel card to your PC and then an extra driver.

Cost for the aforementioned will be about:

-88$ for the PMDX
-20$ for the Parallel Card
-147$ for a high current Gecko Driver (you will need at least a 4.5A output to do the job well at your voltage)
-250$ stepper motor to do the job

(also, if you happen to find a indexer unit like mine on Ebay, it could be servo driven with encoder feedback to the amplifier with the same setup but purchase the appropriate Gecko DC servo amplifier card.) It's not TRUE closed loop feedback, but the servo reacts to step/direction control the same as a stepper)

Mach 3 will easily address the indexer and second parallel card. Don't be concerned about Mach 3.

The biggest challenge you will have when your ready to jump to true 4th axis cutting will be the CAM software package.
I am a recent "expert" :D on purchasing a 4th axis package and entry level is about $2500 for the most affordable and usable package from RHINO CAM or Visual Mill (Same vendor) The price quickly goes up by thousands from here.

You can do simulated 4th axis in the 300$ range and is about as accurate depending on what level of column, prop skull/statue etc. your trying to achieve. Vectric has a very good 3d carve program that does 4-face machining in the indexed mode and will cut in 90 degree rotations. Very affordable, very easy, very quick to learn.

Your welcome to give me a ring on the phone if you want to discuss in detail.


Gerald D
Sun 09 August 2009, 21:53
Brian, I think the reason that the indexer people need so many axes is because they alternate between cutting with the tip of the cutting bit (better detail?), or the side of the bit (smoother finish?). If they were only using one strategy, then there would be an idle axis.

Mon 10 August 2009, 11:50
At http://turningaround.org/MechMate/Mechmate.htm you will see my indexer. I am updating site and if you have any questions please ask and I will add to site/reply. A indexer can run with as few as 4 motors representing X, Y, Z and A. A fifth motor, B, can be added as a slave to the X. I have it on very good athority that X and B can electronicaly be slaved on the controler by Campbell shown on my site. I will be confirming this within the week and will post results. The problem is that if Mach has a slave axis on Reference All the slave will also try and go to a limit switch. I don't need a limit switch to true the gantry on the slave side so if I electronicly slave the motors Mach doesen't know that the slave exists. As to software 90% of the stuff I do can be done with the wizard listed on my site. Best $75 I have spent. I am beta testing the new version which is even better.

Tue 11 August 2009, 12:26
Also there is a write up and examples of some examples of work done with Rich'e wizard.

Tue 11 August 2009, 13:18
The writeup on the wizards looks great. Cant wait to get a machine and indexer running.