[joecnc2006]

I just recieved a set of router mounts for my porter cable 7518 from Joe and they fit perfect nice job Joe!

Thanks, glad they fit good, with the measurement of the router in MM that you gave me i was able to convert to imperial dec. inches and cut the parts, I always measure in MM then draw and cut in Imperial dec. inches.

Joe

[mike hide]

I think there is a vast difference between building and operating a machine as a hobby or a business. If the machine is to provide a living then one can afford to build a better quality machine that produces faster and perhaps more accuratley.

I have been in the custom woodworking business for over 30 years now I generally charge $45 to $55 an hour [less than you get charged for the local mechanic around here ] and that is for ANY time I spend working on the project,that includes getting the required materials . That has to include wear and tear on equipment facility costs taxes work related utilities and including building the codes and any tweaking of the software.

Joe has [from what I have read in this thread ] developed an incredable machine made from off the shelf materials and operating at very low tolerances ,well within the most demanding woodworking requirements .The same equipment from a major machine tool company would probably cost thousands.

Certainly those with this equipment producing in quantity will be able to undercut Joe on a production basis ,but on a custom basis I think not with high overheads retooling and reprogramming costs for short run items it is not feasible for the major manufacturer .


Making Kits for those who want to build Joe's machine is a good start but the numbers are limited . I have found a nitch producing stuff for a limited clientel taht keeps coming back for more . Believe it or not there are a group of people who cannot get what they want regardless of cost

The april issue of "Woodshop News" has a write up of thrree cabinet shops who have bought CNC machines of late . The costs....$150K, $85K,$350K and $425K. Of course that includes software and the machines are bigger and better than Joe's but his machine still performs most of what these pricy versions do ....mjh

[Surgical]

Joe, check your PM's....... I can host your video for you and I had a couple other questions

[AMorgan]

Rockler has the 2 1/4 hp Fixed Base Hitachi router on sale for $94.99.
Here is a link:

http://www.rockler.com search for hitachi router

I bought one yesterday.

Steve

[scott wiggins]

I don't think that is variable speed.

[Surgical]

***Edited for correctness

[Madclicker]

The one on sale for $95 is fixed speed.

[joecnc2006]

I don't think that is variable speed.

The M12VC is variable 8,000-24,000 rpm
the M12Sc is single speed 24,000 rpm

[Surgical]

I should have read the note more carefully, sorry for the mis-info. The manual also states right above what I quoted "for the M12VC only"
I'll edit my post....

[joecnc2006]

Out of curiousity (and people have asked me) How Many people are looking at building the CNC Model 2006.

maybe list the stage you are at, your building schedule, are you cutting it on cnc or by hand, maybe some slight improvements or additions you have thought about and implimenting.

Also those planning but not started yet. I'm kinda looking forward to seeing some (Joe's CNC Model 2006) poping up...... LOL

Also some people have asked if i could cut templets for them and they use a flush router to make the rest (those with wood working skills).

Thanks, Joe

[jmytyk]

In Progress. With some minor changes, dual x-screws, long travel x/y. Different rail mounting method, etc... I have a build log with pics...
_Jon

[mike hide]

Thinking about it .I have read every post in this thread several times .I have no electronics skills at all so that end is an uphill battle [I must say the electronic club has been a great help in this respect] .I do have a reasonably well equipped woodworking shop and am pretty confident I could build the machine .I do like the machining qualities of MDF although the strength characteristcs leave a lot to be desired. Rather than attempt threading it and screwing into the edges often results in separation [evident in several pictures ] I will drill through holes and use nuts and bolts wherever possible . One question you seem to use quite a bit of HDPE [I am assuming that stands for high density poly ethylene] what is the source for that material ?
Again I have given quite a bit of thought to using a single pipe with the bearings spring loaded with bellville washers . The torque generated in the X axis by the cutters resistance to acme nut drive force which in turn tries to tilt the gantry is taken out by differential forces applied to the pipes by the bearings. This movement is minimized with any increase in the distance between the fore and aft bearings, however for any given lenght of machine the greater this is the smaller the working area .

In my mind the best way to minimize this torque is to attempt to get the acme drive nut on or about the same X,Y, plane as the cutter . As different Z axis settings are always a possibility moving the X axis drive up from the bottom of the base table to at least the top of the table or slightly above that would minimize the moment and essentially end up with an axial nut load. As with everything it is a trade off, the suggested arrangement wpold result in two leadscrews driving the gantry sides . The question in my mind is can both screws be driven by a single motor [through a belt drive or the like] or would it be necessary to use two motors ,one slaved to the other [hopefully with zero lag ]

one other question if I may, what is the bed depth ?

Many thanks Joe for your efforts ,,,mjh

[mike hide]

Some further thought I might be an idea to check the static CG position of the gantry .ideally it should be be centered between the track fore and aft bearing pairs. The gantry " torsion box" has undergone modifications and so presumably has the CG as a result. It would seem to me advantageous to have a unidirectional distributed load on the tracks and bearings to ensure smooth operation and optimum wear ...mjh

[ger21]

Cutting forces are probably more important than the CG, and they would apply to the pivot point where the bearings are mounted. Cutting forces are amplified because the Z-axis acts like a lever. On our large commercial machine at work, I've seen the entire 500 lb head that the spindle is atached to actually lift up when plunging with a 1/2" diameter bit.

[wallyh]

I am in the planning stage, have studied all your great drawings. I would be interested in the templates, if available.
Wally

[joecnc2006]

In Progress. With some minor changes, dual x-screws, long travel x/y. Different rail mounting method, etc... I have a build log with pics...
_Jon

Looked at your plog, with a larger motor and pully system it looks like it should work well with the double leadscrew for the long axis, Also looks like you changed to the double rail pipe system I have running now, You will be happy with it I'm sure. It just makes the gantry much more solid.

Joe

[joecnc2006]

mike hide,

I get the HDPE locally here in town. Most Plastic deistributors will carry it, I
Would also be very Hesitant about using the bellville washers, because you want the gantry to be locked into the bearing slides and this might lead to shifting of the gantry while in motion and cutting.the whole reason of the double rail system is to prevent gantry movement and help stabilize it.


Whallyh,

I can help you with what ever you feel you need.



joe

[mike hide]

Cutting forces are probably more important than the CG, and they would apply to the pivot point where the bearings are mounted. Cutting forces are amplified because the Z-axis acts like a lever. On our large commercial machine at work, I've seen the entire 500 lb head that the spindle is atached to actually lift up when plunging with a 1/2" diameter bit.

With some knowledge of loads what you describe [some what scary] this condition will occur whan plunging too quickly or using a bit that is not designed to plunge .

As I see it the moment is generated [in normal operation] by the cutting forces at the cutting tool which will vary with material, depth of cut and feed rate times the distance from the cutting tool and the acme drive nut .

This torque is counteracted by the bearings on the truck running on the black pipe, one end with a downward force the other with an upward force . According to the direction of the cutting action this moment direction will vary. What I had in mind was in effect to reduce the lever arm [cutter to acme nut distance ] and in turn the magnitude of the moment . To do this I anticipated moving the nut axis as close to the cutter axis as I could within reason,basically moving the nut drive from the bottom of the bed to the top .

As you mentioned probably the cutting forces have more influence than the CG situation, however it would still be nice in my estimation to have it within the fore and aft bearings rather than having one set have a harder life than the other ...mjh

[glnth]

I would be interested in the templates also. Joe what would you estimate the tolerance you can hold? Within .015 or + or - .015 is my guess.

[joecnc2006]

I would say there abouts maybe a little better.

Joe

I would be interested in the templates also. Joe what would you estimate the tolerance you can hold? Within .015 or + or - .015 is my guess.