Originally Posted by
mlind
Hello,
I didn't call anyone a moron and that was not my intent. I have my machine working reliably and on my machine all the problems I had were setup issues. I'm not sure what your problems were as far as the machine was concerned.
The funny thing is at work I am always called when engineers and techs have problems getting a machine to work. They always blame issues on the machine design or a miriad of other excuses for problems they cannot fix. Nope...... 90% of the time it is something simple. By using a logical step by step trouble shooting approach most problems are easily resolved. If the machine works for one person it will obviously work for another. If it worked at one time it can obviously work again...... Reminds of a quote "what one man can do another can do".
What I also said was that if anyone needs help they can contact me and I might be able to help get their machine running. I'll even go so far as to say if you are in Houston I might even invite you over (if you ask nice and if I have time as I'm always buried with orders or at my real job working on equipment) to see Thoms machine in action and possibly help you trouble shoot your machine if you have problems. I support Thom Carr as he has supported me "WHENEVER" I needed help. He has gone above and beyond to help me when I needed it.
OK I'll try and help those here who are having problems with Thoms machine.... Don't give up and don't let it get to you. Work the problem if you are frustrated take a break. The machine works for me and it will work well for you too....
If you follow my troubleshooting procedures below I'll bet you can get your machine working as reliably as mine. Don't pay attention to those who say no or it won't work or those who say it is a bad design. Trust me it isn't because if it was why would my machine be working? and working Well..... No BS here. I'm not saying Thoms machine is perfect as I have never met the perfect machine... some are just tempermental.
Here are some but not all of the things I learned about this machine and how to set it up to make it run well. Although Thom knows his machine a lot better than I do and you should call Thom when you have problems....He supports his product irregardless of what you might see here. Call the man and talk to him even if you are mad or disappointed he will help you work out your machine problems. Thom is pretty sharp when it comes to CNC..... A lot smarter than most here on cnczone including me. But you'll figure that out when you talk to him in person.
Yes, I had setup problems that I had to work through but I'm glad I did. Its a good machine at a fantastic price. But you gotta work through the setup issues. Every problem listed below I had; and every problem below was a setup problem... Not cutting clean circles was a setup problem. Losing position was a setup problem. Mach 3 is a good controller but I prefer Kcam as it is more user friendly with faster setup times between jobs. So I can't comment on the Mach 3 problems as I changed to Kcam when I got the machine. Thom helped me over the phone set it up using MACH3. We set it up using Mach 3 but the next day I switched to Kcam. Once I had the parrallel port pin addresses and settings it was simple to convert from Mach 3 to Kcam.
The rack and pinion design of this machine makes it a bit tempermental on intial setup but you are getting a BIGGER cnc router as well as a cnc lathe for a cheaper price than just a cnc router as offered elsewhere. Look at it like this if you have one and it isn't working now you have nothing to lose by working on it right!! It's amazing what a 1/16 of a turn on the set screws will do for the accuracy andreliability of this particular rack and pinion gear train as well as the machine over all.
I do agree the screws should be counter sunk on the rails and I think a metal rack and pinion grear train would be better with perhaps different gear pitch but it works for me as is. I haven't had any problems with the screws hitting the carriage but counter sinking them would be a nice touch. I should have thought of that........ I suspect if the screws are tight your problem is related to bearing and or carriage adjustments. I also removed the screws from my machine when I reworked the rack and pinion system and I used Red Locktite when I replaced them just to prevent that from happening. I also added more screws to mine as a precaution, every 6 inches on both the X and Y axis now has a screw that is locktited in place. I also re-leveled the entire gear train as it was damaged by our favorite shipping company. I used small 1.25 inch sheet metal screws so they probably didn't need the locktite but hey I was there and I always use loctite from force of habit.
SETUP TIPS....
We will start with the basics. Make sure your motors work as they should. Left and right up and down forward and backwards using the manual controls. If that is all good then here we go.
Make sure the set screws that hold the motor shaft couplers to the gear drives and gears are tight and in the right position which is the " flat spot " on the motor shaft as well as the motor drive bar. Those pesky little set screws can cause all kinds of problems if they aren't set right and tight but don't over-tighten them because if you strip one out then you have a big job in front of you. ( Nuther words dont be lazy and use a ball driver..... use a good old fashioned flat bottomed allen wrench as there is less chance of stripping the set screw or breaking the ball end off of the ball driver inside the set screw hen trying to get it out...... ) Thats another free tip......
Also Make sure your drive gears are centered on the gear track. Very important.....
Make sure the X gantry is square to the machine frame........ Very Important use the end of the machine vertical supports to gauge this..... OR a large framing square will work too.....
ALL good to go with the above...Great lets get your machine running....
First step : Level the table to the gantry. It should be the same height in all 4 corners of the machine as well as in the middle of your work table. Take your time as once it is done you won't have to mess with it unless you use another table for other work like I do. I have 2 tables one which is lower that I use to plane round log slabs that won't fit into the planer or bandsaw. They are interchangeable but it takes a little time to change them out...Depending on what I'm doing. Also make sure the bolts holding the X-axis gantry are TIGHT!!. They have lock nuts on each bolt but check them anyway. The X gantry shouldn't move up and down at all. If it does your bolts are not tight. Remember your machine was at the mercy of a shipping company..... Shipping companies are known for gently handling crates......LOL.
Second Step ........Set the gantry bearings correctly, make sure "ALL" bearings are engaging on all 4 sides of the rails for the Y axis as well as the X axis. Most of your problems will ocurr on the Y AXIS. If the bearings aren't engaging accurecy will be compromised and you will see bobbles when cutting. There are hidden set screws to adjust the bearings...... although I removed them and used bolts where I could to make setting them a little faster and more user friendly. Plus, I can never find a allen wrench when I need one...hahahahaha SOme day I will clean the shop LOL.... Anyway back to it. All the bearings should be moving when the gantry or carriage is moving. There should be no binding when you move the gantry and carriage slow and steady. If there is it isn't adjusted correctly. Again take your time setting it up because once you set the bearing depths you won't have to mess with them again.......Ever........ unless a bearing goes bad on you.
Third Step ..... If one over-torques or under-torque the set screws that adjust the up/down position of the drive gear you will have nothing but problems..... Don't over-tighten the set screws, be gentle with them and set it up in each of the 4 corners of the work table by turning off the motors and moving the gantry by hand. You shouldn't hear or feel any gears jumping or not meshing. If you do adjust the set screws until the gears mesh smoothly. (Don't over tighten the set screws) slightly loose is better than too tight!!!. There has to be a little bit of play for the gears to mesh smoothly but not so much that the gantiy is loose when you apply hand pressure to them with the motors turned on. That is the purpose of the springs to allow the gears to mesh firmly while allowing for just a little play in the gear train. If you have adjusted and left the springs compressed (too tight) you might have to pull them out and "stretch them back out a little bit ". Compressed springs are not good on this machine. Been there done that.
ALSO make sure your controller is using ramping speed control on your machine. I start at 20ipm for setup.
4th Step........... After setting the gantry 4 corners ( A Tad on the loose side ) Start with cutting a big Square (SLOW CUT!!!) about 8-10ipm shallow cut about 1/8 depth with a good new sharp 1/8 end mill or router bit with the router set to max speed cutting slow like 8-10 ipm. Don't use a big bit and don't cut deep or fast..... Remember you are setting up the machine to run reliably not starting your own sawmill as that will come later.
When the gantries are semi-tight watch for bobbles in the toolpath. If there is a bobble in the square in one spot stop the cnc and turn off the motors and manually move the gantry to the position of the bobble and turn on the motors and manually try to move(wiggle) the gantry by hand, If it moves at all you have to adjust the corresponding gantry gear set screw('s) to eliminate the bobble. Keep working on it until you cut a perfect square with no Bobbles in it.
Once it is cutting a perfect 3 foot Square with no bobbles you are done.
5th step .........Now use the same procedure to cut a large circle and work through any bobbles you might encounter using the same procedure above....If it bobbles turn off the motors and move the gantry by hand to where it bobbles turn on the motors and (wiggle the gantry) if it moves at all adjust the corresponding drive gear set screws (With the motors on) until there isn't any bobbling in the axis that is causing the problem...... If no bobbles then the machine is dialed in and you won't need to adjust it for a long time. It will cut nice smooth circles.
6th step............. Cut both another larger circle and a larger square as well as a couple smaller circles and squares making sure there are no bobbles in the toolpath. If there is a bobble in the toolpath work it out using the spring set screws. It seems like it is quite a bit to set up the machine but after doing it a couple times and getting the feel for the machine and this procedure you will get to the point where you just know how to adjust the machine if needed.
The reason you start with a square is so you know which axis is causing the problem. Its pretty simple to figure out if it is the X or Y axis when cutting a square. When cutting a circle it can be a little tricky figuring out which axis is giving the problem....
Another tip once you have been cutting for a while.......On the Z axis a touch of WD40 lightly applied "LIGHTLY" to the linear rails with your (FINGER TIP) every week or so to help prevent rust and will eliminate any bearing to rail chatter that is generated on the Z-axis when sawdust gets into the linear bearings. The grease used on the bearings has a tendency to attract and hold sawdust.... WD40 won't get rid of it but it will smooth the Z-Axis if it starts chattering as it will. Sawdust is a nuisance.
Another TIP .........Also on the table I installed adjustable bolts to adjust the height of the table as it is easier (for me) to level the table height to match the gantry than it is to level the gantry to meet the table. If you level the gantry to the table you might have to do the alignment procedures I listed above. But I have done it both ways but for me it is easier to level the table to the gantry as I don't have to go through the "time consuming" bobble steps above..... I figure on a first attempt at debugging this machine it will take about 6 hours to make it work depending but once dialed in it you will make more sawdust than you can possibly imagine.
I'll also go as far as saying that I'll stack my machine up against any machine in the same price range and I'll betcha Thoms machine will run as good if not better. But you gotta find a commercailly available 48x48 machine for less than 3.5K unless the price has gone up on Thoms machines...plus can you find a machine in this price range that includes a cnc lathe? (Smile) Yeah I know the 4th "axis" is slow in coming but It will get there. Call Thom and tell him you need it and I'll bet he gets it to you.
As for support from Thom call him and ask questions. Yes I mean just that, call him and he will get back to you HIS WORD IS GOOD..... When I call he always calls or emails me back. So give him a holler. To bad he isn't a member here on CNCzone but he is a fixer and designer rather than a chatter.
Good luck hope this helps someone out there.