PDA

View Full Version : Backlash with CNC kit



Richards
10-21-2006, 01:47 AM
I'm still running my IH in manual mode but I'm wondering what kind of backlash to expect when I upgrade to Aaron's CNC kit.

The reason that I'm asking, is that after I installed some digital scales on my IH (similar to the ones that Robert Warfield shows on his excellent web site), I noticed about 0.010 'slop' in my Y-axis when cutting with the rotary table. I marked the dial indicator on the Y-axis and verified that it wasn't moving before I finally realized that the cause of the 'slop' was probably the backlash inherent in the manual machine. It seems reasonable that if there is about 0.010 backlash because of the factory screw and nut, that, given sufficient force (heavy cuts with the rotary table), that the axis would be free to move the same amount as the backlash. I tried tightening the jib screws, but they're a little small to really crank down tight.

Using the rational that the backlash is the culprit, it seems that if I installed the CNC kit with virtually zero backlash, and if the servo motors has sufficient torque to not slip, that there should be virtually no unwanted axis movement.

Is there anyone who has already installed the CNC kit who can validate my assumptions?

philbur
10-21-2006, 06:58 AM
CNCing a machine is an expensive way of curing backlash. I don't know about the IH but most mills have some form of anti-backlash nut that can be adjusted. If not it's easy enough to make them.

Backlash on a well setup set of ballscrews should get you down to 0.001" or less. But then using it to cut manually could be a problem.

Regards
Phil

.
I'm still running my IH in manual mode but I'm wondering what kind of backlash to expect when I upgrade to Aaron's CNC kit.

The reason that I'm asking, is that after I installed some digital scales on my IH (similar to the ones that Robert Warfield shows on his excellent web site), I noticed about 0.010 'slop' in my Y-axis when cutting with the rotary table. I marked the dial indicator on the Y-axis and verified that it wasn't moving before I finally realized that the cause of the 'slop' was probably the backlash inherent in the manual machine. It seems reasonable that if there is about 0.010 backlash because of the factory screw and nut, that, given sufficient force (heavy cuts with the rotary table), that the axis would be free to move the same amount as the backlash. I tried tightening the jib screws, but they're a little small to really crank down tight.

Using the rational that the backlash is the culprit, it seems that if I installed the CNC kit with virtually zero backlash, and if the servo motors has sufficient torque to not slip, that there should be virtually no unwanted axis movement.

Is there anyone who has already installed the CNC kit who can validate my assumptions?

kimoyo
10-21-2006, 09:43 AM
Hey Richard,

I was just thinking about this yesterday, maybe you could ask Aaron about it. He uses Rockford rolled ballscrews and nuts in his kits. You have the option of preloaded or double ballnuts (without a spring) but I'm not sure of the pros and cons of each (question for Aaron). I think the preloaded have less backlash but doubles (< 0.002 backlash from website) are stronger?? Because he recommends the preloaded for x and y but double for the z axis. He doesn't say on the website what the LI uses.

I read that ground is supposed to be better than rolled but been told it depends on where its made. Adobe said he tested his Rockford's and

I just ran a test on Rockford rolled ball screws and their double nuts, using my DRO over 28 inches on the Z axis of my lathe that is being converted to CNC. Just for fun we loaded a 19 inch chuck and a 8 inch kurt vise in the cross slide to possibly duplicate weight and some cutting pressure.Using a simple Z program, back and forth at 51 ipm 22 times, then to home and back to 28 inches, a recorded error ( maxium) of .00087 was noted. It always returned to home at .ooo,(?), the biggest error at the 28 inch stop.The ways and ball screw were well lubricated.Unless you are making a commercial machine that must repeat at .0001- 24 hrs a day, I would say that a well set up system,using rolled ball screws and double nuts, would be fine for your application.Most errors occure due to poor bearing mounts, to include every thing that NC cams has pointed out many times concerning the correct way to engineer the mounts and pre-load.You could spend thousands on ground ball screws, but have horrible errors with out the correct bearing set up.

Adobe Machine ( old as dirt)
N4NV got a set of ground ballscrews and nuts from Hiwin for under $1K. He was having backlash problems and they told him that

I talked with Bobby at Hiwin today about my backlash. He said the max the ballnuts have is .0008 on the X and .0006 on the Y.
From what I was told ground would cost more than the IH machine but Hiwin has them for under $1K. I'm not sure if they are made in china but I thought ground was supposed to have no backlash?? From what they told N4NV and what adobe measured the performance seems similar.

I was going to ask Aaron (and Adobe) about this but haven't spoken with him yet but there's probably a reason he's going with Rockford rolled instead of Hiwin's ground (for example).

kimoyo
10-21-2006, 09:44 AM
BTW Richards, do you have the lastest version of the IH mill?

Richards
10-21-2006, 10:00 AM
I probably wrote a murky post that was not clearly understandable. Sooner or later (probably sooner), I'll be adding the CNC kit to the IH so that I don't have to spend my entire day turning cranks. I have no intention of running the mill manually once the ball screws are installed. My whole objective in running the mill manually, before converting it to CNC operation, is to thoroughly learn and practice the basics of machining. After I know what to expect, I won't be writing code that violates standard practices.

On the parts that I machine, 0.010" is much tighter than I need for anything except a few bearing pockets. In fact most cuts can be +/- 0.025 and still be tighter than necessary. However, I'd really like the pockets to be between -0.0000 and +0.002 so that the bearings fit properly. (The motor mounts that I make are not high precision :)) To get around the little bit of slop that I'm seeing on the digital scales, I mill the pockets to -0.025" and then use a boring head to tweak the pocket to get the final size. That method works fine.

From what I've read, I believe that the IH with CNC controls, properly installed and properly used, will get me to the 0.000 to +0.002 tolerance level, as long as I follow standard practices and use common sense. (Rough milling to +0.020 and then a finish pass to size. Properly calibrated and setup Mach 3, etc.)

Richards
10-21-2006, 10:15 AM
Thanks for the information about the Rockford screws. From what I read before buying the IH, I was fairly certain that some good quality rolled screws would be better than what I really needed. (And I totally agree that 'quality' in ball screws depends more on the manufacturer than it does on the advertising department of the vendor ;)

Now that we know what 'can' be expected, is there anyone willing to go an record and say what accuracy they're 'getting' with their IH milled CNCed with Aarons kit?

(My mill is the latest one offered by IH. It has the ground ways and other enhancements that are listed on the IH web site. In all reality, it is a very impressive machine.)

Randall
10-21-2006, 11:52 AM
There is a backlash adjustment on the maual Mill. It helps a little.
I aslo put some brass shim stock behind the mount on the end of the table X axis and that toke some out. I had some extra play that I may have induced when I took my mill apart.
On another note I have won some tapping heads on ebay and what a worthwile investment. Tapping is fun now.

Adobe Machine
10-21-2006, 12:25 PM
Kimoyo:Check my thread on converting a Manual Lathe to CNC...I spent the money on the Bearings ( Barden) and the bearing mounts.So far there is no backlash in either the Z or X axis, but there have been no cutting forces applied yet,and I have only used 12 volts to the servos in a battery borrowed from my Hot Rod, instead of 78 volts which is the power supply.
If the conversion were going to be a production lathe, seeing many hours a day in use, I may have reconsidered using rolled vs ground.With the ability to use a double ball nut, good lubrication, excellent bearing support and protection of the ball screws from swarf, dust and chips, the lathe should hold .0005 or better under normal cutting conditions, as my retro Tree mill does.
There are just so many other factors in conversions to CNC , which include the ability to adjust the ways and gibbs, constant, correct lubercation of the ways, gibbs and ball screws (by correct I mean using "way lube" to avoid stick-unstick of the axis..too many arguments on this subject, but you can change the accuracy of a machine by using the wrong lubercants on the ways..really) protection of the ball screws and the sliding surfaces, spindle condition and runout, the servo (or stepper) physical connections to the ballscrews, having servos that are correct for the load and friction, and one of the biggies: Using the correct tooling and cutters ! I purchased a turning center in the mid 90's, and thought I could use the same type of tooling we used on the manual machine..WRONG..it took three months to change my stubborn mind ( logic; a cutter is a cutter ect) and get the correct tooling. As soon as you REDUCE CUTTING FORCES with good tooling, the accuracy increases 10 fold. We ( Son and I) are rebuilding a 1929 Vintage Bi Plane, and he has a small HF type lathe, was trying to turn and thread some alloy steel shafts with no luck using regular carbide insert tooling. I sent him one of my toolholders ( modified to fit the smaller tool holder ) with some positive rake diamond shaped inserts, and what a differance. Using dial indicators on the x axis and taking .005 to .009 IPR ( inch per revolution ) he was able to hold tenths and a very excellent surface finish. He used my threading kit to cut the threads and had good results.Hu flung dung ( Hu) demonstrated in one of his theards how to grind a positive rake on a used triangle carbide insert, with excellent results.
Use good, known procedures and products to build your conversion, and it will be a usefull, fun tool..leave out any of the steps and it becomes a boat anchor in the Hobby Shop. Most of all, have fun doing it !

Adobe (old as dirt )

Cruiser
10-22-2006, 12:24 AM
Richards, I have a IH mill that is full cnc. Mach will allow you to counteract for any backlash and set a couple of parameters so it will be fluid. I tried both manual/incremental and MDI and very quickly found that MDI moves of .1 or 1 inch were able to show the backlash comp much better than manual. As for accuracy before i was done with all the set-up, i just had to make some chips and cut a 1.5" circle and measured it to within .oo1" of being round. with some runin and squeeking it in it'll improve. Right now i'm trying to get the vfd on line and it be giving me fits ! I'm tired now ... good nite all ....

Loadedagain
10-22-2006, 12:29 AM
totally ignore the mid posts and answer the question from post 1. ballscrews with preloaded nuts (as ih suppies with their conversion kit) elimenate backlash. if you find the minimum preload does not get enough of the "slop" out... increase it!

ps: i'm a happy owner of an industrial hobbies (old style) mill with their cnc conversion... installed by me.

BobWarfield
10-25-2006, 07:11 PM
Z axis has an additional problem. It loses position towards the table on every up or down move and has done this since day one. Move 1 inch up and 1 inch down, it is now about .002 closer to the table than it was before. Move 10 inches up and 10 inches down, its now out of whack .020. I can typically only run 2-3 machining operations before I have to reset Z to the part. When I try to run several operations I'll be buried into my fixture plate .050 deep.

Interesting. Are you running servos or steppers? Sounds like lost steps. Did you lap the machine?

Seems like the performance of the gibs and slideways on these machines has been pretty variable in the past. Some people, like myself, have had no trouble whatsoever. Others report problems like this, but it has usually been on machines purchased some time ago. They've undergone a pretty major update with the ground ways in the latest version. Not sure what I'd do if I had an oldie as temperamental as this sounds though. Keep trying to tweak it in, I guess.

Best,

BW

BobWarfield
10-25-2006, 10:09 PM
That's a pity you've had so many difficulties.

I still think your Z problem sounds like losing steps to me. The motor just doesn't seem to be powerful enough, even with your counterweight. I can't picture why else your loss would be proportional to distance moved. I know you've got Mach 3 dialed in to the right motion per step by now, so what else can it be?

As to what to do about it, a more powerful motor, preferably a servo, seems like the only recourse. OTOH, if you're tired of it, you're tired of it.

What's the next mill gonna be?

Best,

BW

philbur
10-26-2006, 03:08 AM
If your error is proportional to distance travelled and the same in both directions why not adjusted the steps per unit in Mach to compensate.

Just a thought

Regards
Phil


The significant clue is that it loses position towards the table on both the up and down move. This is true with the gib adjusted normally, slightly tighter than normal, loose, very loose, with the gib removed, and all the above with a 180 pound counterweight added.

Richards
10-26-2006, 10:03 AM
Although I have emphathy when I read something like this: "Yep I have written this thing off, I probably have $8k to $9k into this pile of iron, no more!", I sometimes just have to scratch my head and wonder what the real problem is.

When I was just a young guy, I was complaining one day to my dad about how a new tool just wasn't performing. He just grinned and said, "A poor carpenter always blames his tools."

This CNC stuff is not rocket science. It involves ball screws, ball nuts, ground or lapped ways, and motors. If a stepper or servo motor is being driven properly, it is going to move a certain number of steps every time - no more and no less. If a ball screw is being turned by a properly driven motor, it is going to rotate a precise amount - no more and no less. If a ball nut is being driven by a ball screw that is being turned by a properly driven motor, it is going to move a load a precise distance - no more and no less. If the ways are ground or lapped properly and lubricated properly, they're going to allow the load to be moved a precise distance - no more and no less.

When a simple machine doesn't do what it is commanded to do, it needs some kind loving attention. After all, a dumb hunk of metal is only going to do what it is told to do - and allowed to do by an operator who is totally responsible to see that the machine is properly adjusted and that all parts and pieces are working to spec.

MAX711
10-26-2006, 11:51 AM
Please don't take this the wrong way, but why would someone who is willing to drop $36k+ on a Hurco mill even look at a chinese bench mill in the first place? Your Z axis problem is very puzzling. I had a similar problem with mine, I would command it 0.1" and it would go 0.09", reverse direction, same thing, slowly getting more and more out of whack. Turned out to be the breakout board was not providing enough current to trigger the Gecko's all the time, so it was missing a few steps. What made it really hard to find was that it allways missed the same number of steps so the problem looked like a setup/mechanical issue. You would assume that faulty electronics would give you a random movement problem, but it was allways the same amount! Anyway I got a new breakout board and no problems since.

krymis
10-26-2006, 12:00 PM
first off Aaron has done nothing but help especially in your case IIRC. The mill is not one of his mills. you simply bought the conversion. The conversion has come a long way since your purchase. I am sure he would give you a great price on the servo z axis. You may not want to buy it but it makes a world of difference. If you have a stepper then you didn't pay more than 3500.00 and that is genoreous. You need to get back to Aaron with measurements also. One can not diagnose a problem without seeing and knowing. Remember your ground loop situation. It seemed like you had it all wired right but still developed a loop somewhere. It may be that simple to fix.

I am not trying to bash you but as a fellow fabricator and designer, and user of an IH cnc conversion I can see both sides of the story. But like someone else mentioned: My grandfather told me its the craftsman more so than the tool.

I will try to help you the best that i can.

Richards
10-26-2006, 12:51 PM
When you posted: "I don't use a breakout board, I configured it as per IH recommendation at the time via a parallel printer port card. I'm pretty sure this is what killed two computers.", I think that you've found the root of the problem. The last time I read the Gecko literature, it states that you must supply 16ma to the step and direction signals in order for the drive to work reliably. None of the parallel ports that I have can furnish that kind of current. (My real job is designing/building/programming process control computers for the photo industry, something that I've been doing for more than thirty-years. During that time, I've installed several hundred garden variety PCs. To my knowledge, none have/had parallel ports that could sink 16ma.)

If you're still set on buying something else, then it's your money; however, if I were you, I'd order a breakout board today, not only to get proper sink current capability, but also to isolate your CNC stuff from the PC. It will be the cheapest $100 insurance policy that you've ever spent. (Any it will keep you from replacing perfectly good computers that keep on blowing up because they're not optically isolated from your CNC stuff.)

krymis
10-26-2006, 01:32 PM
i tell you what, you figure out what you would like for the setup and pm me I may be interested in helping take it off your hands. Be fair and realize you stated that it just doesn't perform as advertised.

philbur
10-26-2006, 04:25 PM
Clearly a phase coined by somebody that had never had a fight with a Chinese mill/drill.

Example: after the third error using the fine downfeed on my RF 40 clone I stuck a DTI in the chuck to check. The feed was graduated for 3mm per rev. The reality was 2.5mm per rev.!

A more appropriate phrase today might be "Even a good carpenter sometimes buys a pig in a poke"

Regards
Phil




When I was just a young guy, I was complaining one day to my dad about how a new tool just wasn't performing. He just grinned and said, "A poor carpenter always blames his tools."

Runner4404spd
10-26-2006, 05:05 PM
CNCPlastics,

if your still having such a terrible time with this mill and setup, let me know. i might be willing to give it a crack if the price was right. you can email me at jczub@hotmail.com.

Richards
10-26-2006, 05:24 PM
Phil,

I still have to stand by my statement. Whether the tool is as advertised or not, a 'good carpenter' knows his tools and how to use them. Compared to the fine tools that we have available today, those used by my father and grandfather were 'out' a lot more than 1/2-mm, and yet they produced parts and pieces that I can hardly match with today's more refined tools. Simply stated, they knew how to work around the 'gotchas' of their tools.

Take for example, the suggestion that a break-out board was/is not needed. That's one person's opinion - even if that person is the supplier of the equipment. There is no shortage of horror stories on this forum, on the Gecko forum, on the Mach forum, and on the CAD_CAM_EDM_DRO forums that point fingers at problems caused by NOT using a breakout board. Since, by definition, the IH CNC package is a do-it-yourself job, a 'good carpenter' would study his tool until he knew more than the manufacturer. And, he would know how to 'adjust' his tool until it worked to suit his needs.

Now, I know that a lot of people just want to buy a 'turn-key' tool. However, if that's the case, why would he/she buy a do-it-yourself kit and then expect it to work without experimentation and adjustment?

philbur
10-26-2006, 07:43 PM
But then again you can't make a silk purse out of a sows ear. Quoting old worn-out ambiguous clichés adds nothing to the discussion. I’m sure even a good carpenter has, on occasion, binned a tool because it was not capable of doing the job he required. Possibly part of his skill is in recognising the difference. The fact that you can hardly match your ancestors’ ability with your more refined tools could be interpreted in more than one way.

Regards
Phil


Phil,

I still have to stand by my statement. Whether the tool is as advertised or not, a 'good carpenter' knows his tools and how to use them. Compared to the fine tools that we have available today, those used by my father and grandfather were 'out' a lot more than 1/2-mm, and yet they produced parts and pieces that I can hardly match with today's more refined tools. Simply stated, they knew how to work around the 'gotchas' of their tools.

Take for example, the suggestion that a break-out board was/is not needed. That's one person's opinion - even if that person is the supplier of the equipment. There is no shortage of horror stories on this forum, on the Gecko forum, on the Mach forum, and on the CAD_CAM_EDM_DRO forums that point fingers at problems caused by NOT using a breakout board. Since, by definition, the IH CNC package is a do-it-yourself job, a 'good carpenter' would study his tool until he knew more than the manufacturer. And, he would know how to 'adjust' his tool until it worked to suit his needs.

Now, I know that a lot of people just want to buy a 'turn-key' tool. However, if that's the case, why would he/she buy a do-it-yourself kit and then expect it to work without experimentation and adjustment?

BobWarfield
10-26-2006, 08:45 PM
If you give up, you give up, no harm in that. Kits are not for everyone, whether as a function of skills, interests, or just too busy trying to run a business.

I will say that everything you've mentioned seems like stuff these forums would have diagnosed very quickly. In particular, failure to use an isolated breakout board would have raised a ton of eyebrows two years ago just as it does now. It sure sounds like it almost certainly had a lot to do with your loss of computers as well as potentially losing steps to the Geckos because the parallel port couldn't provide enough current. Ironically, a proper breakout board is not even a very expensive thing, nor is it something that is part of Aaron's kit.

The other thing we have to keep in mind is there are two sides to every story and only one is being heard at this point. That's fine, no harm, no foul, and certainly no accusations, but one does have to keep a perspective.

Best of luck to you, CNCPlastics. The Hurco looks like a fabulous mill. Keep some budget available for its maintenance. Since you didn't build it, you won't be able to work on it, and it does require maintenance. Things will break, etc. etc. If you have any doubts, spend time on the CNC forums over on Practical Machinist. They all scoff at things like IH Mills, but they also spend thousands in annual tuneups and other costs to keep their pro mills humming along.

There are no free lunches in this world!

Best,

BW

Ron111
10-26-2006, 09:03 PM
CNCPlastic,
Hate to hear about experiences like what you went through. I had bought a different cnc machine complete from the factory, which I will not name. But it was advertised to be able to hold tolences to .001 and the truth be known, there is at least .012 backlash in the single ballnut system on all three axis(and .0018 on the X and backlash comp can do only so much), and because the ballscrews are welded onto the original acme screw ends(in order to not have to make bearing blocks and reuse the factory bearings), you can not even replace the nuts. All that to say, it is disapointing when things don't work out and you are just stuck with it.

There will be arm chair quarterbacks which will say...... but the truth being some times, whether the supplier intends to or not, you will be ripped off, and in your case, it sounds like that is the case.

I feel for that your Jan07 purchase will be the right move for you and wish you the best of luck!!!

From one that knows the disappointment of receiving something that does not funtion as advertised and being stuck with a product that doesn't work.

Good luck and thanks for sharing your experience.

Ron

Richards
10-26-2006, 09:50 PM
Phil,
I think we're squabbling over semantics a little. To me, there are two parts to this debate.

1-Can the machine be made to do what it is supposed to be able to do?
2-As the owner/operator of that machine, do I have the expertise to tune it up or modify it until it does what it is supposed to do?

I cannot imagine why a simple mill cannot be made to do what it should do. There is not much in this world that is more basic in construction than a vertical mill. Good golly, you've got metal sliding on metal (the ways), a mechanism to move that metal (screws), and a mechanism to turn those screws (motors or cranks). That's just about as basic as it gets.

Since, by definition, the operator of that mill is a machinist, he/she should have the basic knowledge to tune or fix his/her basic machine. If he/she doesn't, how can he/she be expected to use that machine to make parts that might easily be much more complex than the machine used to make those parts?

If there is something wrong with the ways, lap them, have them ground or replace them with something better. If the screws are sloppy, tighten things up or replace them. If the motor or crank is at fault, fix it or replace it. A man can spend a whole lot of time either wishing he had something better or cursing the manufacturer of the blasted machine. Live with it as it is, fix it up, or get rid of it. After all, it's an object - not a family member.

That is why I keep making 'cute' generalized statements. Here's another one: A mill does not a machinist make.

CNCPlastic
10-27-2006, 12:54 AM
Please delete this post

Loadedagain
10-28-2006, 01:19 PM
And before any more "good carpenter" analogies hit the thread let me say I'm not an idiot. I worked in a machine shop running big Mori and G&L lathes with 30 inch chucks machining stainless plug screws for two years. I was too smart for that job so they moved me to the engineering dept. Auto mechanics, electrical wiring, plumbing, woodworking, home remodeling, cabinet making, electronics, I can hold my own in all of these areas. I scratch built a horizontal bandsaw with a 22 inch width of cut. By day I'm a software engineering manager making $100k plus at a global firm. Sorry if this sounds like a resume but the problems I have had with this kit were not because I'm a moron. :D

that's not a resume. that's puffing out your chest. the result is not in your favour.

aaron is a nice fellow, but believing a salesman in lieu of doing research on a product is somewhat irresponsible on a consumers part.

your mill appears to have a few issues, but like others have said there are a few rather straight forward remedies. #1 being the installation of a breakout board! $100 board vs more for a computer? not rocket science mate... and you're in for how many computers?... stepper motors have no feedback. you know that. aaron knows that. we all know that. minimizing loss of steps is in your best interest, no? the board will help.

whether you like it or not you purchased a kit. you knew that walking through the door. unfortunately you never read the fine print. with a small amount of research (now or years ago) it is easy to see not all chinese mills are the same. i personally have seen two of the same manufacturer/model with completely different y slide castings. no kit can bolt onto these mills without some "re-engineering".

comparing a haas vf1 or tool room lathe to an ih? apples to oranges.

another point of note: you make $100k+ that amounts to more than $50 an hour (depending on how aloof you are). your time to assemble the kit must have been of more value than the kit itself. that just doesn't make sense.

one final point of note: with your years of experience and above average intelligence i'm almost positive (mind you i'm not that smart) you have run into at least one problem that required some effort to solve. as a master of machining and engineering is this one small issue with $5000 (or so) mill beyond your scope?

suck it up sunshine. you're at least 50% to blame here. either hire someone to fix it, fix it yourself, or sell it.

... and please stop telling us how sharp you are. your typing suggests otherwise.

Loadedagain
10-28-2006, 06:02 PM
the only reason i'm bothering replying once again is my experience with these mills. i personally run 2 on a small production line and i've helped assemble two other. one with stepper motors. they are an extremely good value... read... "bang for the buck".


No, its bringing the dicussion back on point, the source of the problems is the quality of the product not the skills of the customer.

i fail to see what your past and present jobs have to do with the backlash on a ballscrew.


And here we are again back to this being somehow my fault. So tell me, how would one research a product that is fairly new to the market beyond asking lots of questions and reaching out to the scant few other customers who had purchased the kit?

i think quoting your post best answers that point: "If you want to say that I was ignorant and duped by a fast talking salesman then okay I was". you were purchasing a very specialized and complex piece of machinery in kit form. this is not like going to walmart to buy lego.

the ih kit may have been brand new when you got yours, bt....:
1) chinese square column mills have been on the north american market for at least 10 years.
2) servo and stepper motors have been around for decades
3) ballscrews have been around for decades
4) google was available before you bought your mill and you personally admitted you had been posting on forums.

ignorance is a pretty poor excuse for a customer complaint mate, thus my 50% evaluation.



You don't know what you are talking about. You assume that I was as knowledgeable of such things when in fact at the time I purchased the kit I was not aware of the down side to stepper motors verses servo motors. Further, I was told the stepper motor was actually superior to a servo motor in this application due to the heavy loads on the Z axis. If you want to say that I was ignorant and duped by a fast talking salesman then okay I was.

you're correct. i made a mistake. i assumed since you had posted you were a machnist, your brother owned cnc machines, and you had extensive experience with them that you knew the difference between a servo and a stepper... silly me.


Its not one small issue, I can only guess that you are blind or otherwise choosing to ignore the many problems I have noted about this mill.

can you say that for sure?

basic root cause analysis. i assumed since you explained you were "very smart" you had looked into the issues and analyzed the situation.

if it were my mill i would look at components til the problem was remedied.

#1 - your background is apparently one as a machinist. elimenating the mechanicals should be no problem. dial in the z axis and manually raise and lower it a few times. does it drift? yes? your problem is the ball nut or ball screw, or loose bolts/brackets. repair as required.
#2 - you now know a parallel port is not something you should connect to directly. there are many problems associated with doing so. invest the $25 for a cheap breakout board, or drop $100 for an expensive one... i assume at this point in your mill experience you now know the old addage is true... "you get what you pay for." ... buy a good one!

once you get through that you have probably fixed the problem. if you haven't i welcome a pm. i will personally walk you through it, or if i'm not available one of my co-workers will(like myself, they are also professional engineers with years of cnc experience).



Yeah? Explain the math on that to me. Kit arrives with missing parts, parts that don't fit other kit parts, parts that don't fit the mill, parts that break in short order, parts that fail within a year or so, machine has WAY more backlash than the zero backlash they advertised, machine can't maintain position on Z since day one and the manufacturer can't figure out why or how to fix it. These are the facts yet this is somehow 50% my fault, thats nice, thanks for your support have a nice day.

those are the fault of the supplier in some cases, thus my giving 50% blame to him.

BobWarfield
10-28-2006, 06:21 PM
Geez guys, let's calm down on this one. CNCPlastics is taking another path, he was unhappy with his IH Mill, others are very happy with theirs, myself included. No harm in that, it happens all the time with lots of products. There are obvious some "lemons" in every batch.

CNC, I wish you the best of luck with that Hurco mill. I'm sure it'll be great fun. We'd love to see you post some pix in another thread about the parts you are making with it. Showing finished parts is something I think we do too little of around here, and anyone that's got some to show for their trouble is a genius craftsman in my book!

Thanks for sharing your experiences with us, CNCPlastic.

Best,

BW

philbur
10-28-2006, 06:21 PM
I'm curious as to the reason for all the edits. Did CNCplastic get an offer he couldn't refuse, or is it more devious than that. No reason for all the edits is given.

Regards
Phil


Please Delete

CNCPlastic
10-28-2006, 06:43 PM
Please delete

CNCPlastic
10-28-2006, 06:52 PM
Please delete this post

CNCPlastic
10-28-2006, 06:54 PM
Please delete this post

Loadedagain
10-28-2006, 07:07 PM
Loadedagain I see there is no opportunity to have an intelligent conversation with you. Have a nice day.

i thank you for deleting your posts. this thread was not the right place to vent. as mine are not defamatory i'll leave them.

my offer of help still stands. and failing that i would be happy to buy your machine at a reasonable price.

Loadedagain
10-28-2006, 07:23 PM
he was unhappy with his IH Mill, others are very happy with theirs, myself included. No harm in that, it happens all the time with lots of products. There are obvious some "lemons" in every batch.

my concern here is not with lemons, but what caused the lemons. are people purchasing what they perceive as turn key machines? the person who assembles the machine has the power to make a rocket or a lemon. i suppose as more are sold there will be more "people off the street" showing up expecting a $5,000 machine to do what a $50,000 machine does.

given a short amount of time and some basic troubleshooting my bet is we (cnc zone community) could easily walk plastic through the proper setup of his machine. it's a shame he gave up.

the bottom line here as someone else said earlier in the thread... "there's no replacement for experience".

ps. my offer to help and/or buy his mill still stands.

CNCPlastic
10-28-2006, 07:31 PM
Please delete.

CNCPlastic
10-28-2006, 08:02 PM
Please delete this post

the4thseal
10-28-2006, 08:28 PM
CNCplastic- what state are you in? I would love to haul your machine away instead of it going to the land file.

Loadedagain
10-28-2006, 09:31 PM
i have a great deal of confidence in the ih product. so much that i will pay to fix plastics mill.

here's the deal:
1) i will buy plastic a breakout board of his choice. right now. shipped to his address. he can install it. we'll go over the connections prior.

2) i will go to wherever his mill is with one of my machinists (who he is to be decided, but he will have over 20 years experience) and get it running. we will do so within one working day. i'm a mechanical engineer with controls and electronics background so i will troubleshoot the electron side.

the result:

a) i will foot the bill an apologize on this forum for anything i've said to make plastic feel poorly... if we do not fix it. and i'll wash his car... just for fun.

then i will pay to have it carted away from his house using a garbage hauler of his choice.

b) if we fix it he pays for our flights and buys us dinner (with drinks :) ). i'll suck up the labour.

CNCPlastic
10-28-2006, 11:27 PM
Please delete this post

kimoyo
10-28-2006, 11:51 PM
Thanks but I'll pass, I decided tonight the old fail-o-matic is headed to the scrap yard whoohoo!!! I hope it gets reborn as a cast iron sewer pipe!

That's not even an IH mill! I don't see the reason for all your posts. Quite a few people have told you how to cheaply (breakout board) and quickly solve what looks like a rectifiable situation. You even got an invitation for someone to come to your place and fix it for you. After all your posts, it seems like a bunch of bs.

Richards
10-28-2006, 11:52 PM
I'm totally amazed at the differences in attitudes among members of this forum. Most seem to be excited about life. They're excited to learn new things and explore the possibilities that come with new knowledge and new equipment. Their attitude reminds me of a day in First Grade more than fifty years ago when the school principal visited our class to give a demonstration about magnetism. I watched in fascination as he performed various experiments; but, the experiment that totally captivated me was his last one. He tied a paper clip to a string, tacked the string onto a bottom shelf, and placed a magnet on an upper shelf. The paper clip was suspended in midair, pulling the string tight. He placed his hand between the paper clip and the magnet to show that he hadn't tricked us. I sat as close to him as I could and stared with my mouth open. A few minutes later, I heard the teach say, "Michael. Michael. Michael. Would you please join the rest of the class and take your seat.?" I had been so caught up in the moment that I hadn't realized that everyone else had returned to their seats.

I'm still that way and I think that most of your are too. New things are exciting. New problems are invigorating. Possibilities are endless. A few seem to see things otherwise. What a shame. Life is too short for those of us who are filled with wonderment and too long for those who aren't :)

Loadedagain
10-29-2006, 12:25 AM
Thanks but I'll pass, I decided tonight the old fail-o-matic is headed to the scrap yard whoohoo!!! I hope it gets reborn as a cast iron sewer pipe!

my offer stands. you've likely given up on a product due to lack of knowledge and experience. please reconsider.

i've learned alot form the 60+ year old guys who've been running machines for years. #1... "the machine will cut whatever it's told to"... period!

Adobe Machine
10-29-2006, 12:29 AM
Something wrong in plastic land, I detect..

Adobe (old as dirt)

CNCPlastic
10-29-2006, 12:46 AM
Please delete this post

CNCPlastic
10-29-2006, 12:48 AM
Please delete this post

Loadedagain
10-29-2006, 01:26 AM
I see the insults just keep coming, thanks Loaded I appreciate your input.

insult? afraid not. i'll order you a breakout board tonight. my treat! you try it to see how it works.

if you're still unhappy i'll buy some plane tickets. worst case scenario a few grand go down the drain and we have a nice dinner. hey... at least we have a love of chopping stuff with machinery in common. there will be some decent dinner conversation, then... i may tuck my tail and wash your car or you pay for my plane... who knows... i guarantee we'll all learn something.

the4thseal
10-29-2006, 01:55 AM
When someone offers to give me a hand, when I am have a hard time, I accept. When someone offers to make it right, I let them. cncplastic if you are gong to build a machine of your own design, you might want to get what you have working. What will be learned from the experience will be of great use in further projects. It just seems like a great waste of a good oppertunity. Just my two cents.

CNCPlastic
10-29-2006, 09:46 AM
Please delete this post