[Charter Oak]

Bob,

Thank you for an honest and fair review. We can’t apologize enough for the rough setup, but consider that your feedback is appreciated to improve our product and that we take customer experiences very seriously.

We would like to elaborate on some of the points that have been brought up in this thread. Hopefully this will answer questions for some and ease concerns of others.

1: We are not just distributors of our CNC mills. The electronics are designed and built individually in-house in the United States, the mechanicals and mounting systems are designed, machined, and installed here (with some parts imported and others made in America) but the basic cast-iron frame is imported. The frames were originally designed to the specifications of Industrial Hobbies, but that was before we were involved.

2: Our in-house test setup and test procedures are substantial, but we are always looking to improve them. We add to the checklist every time a fault is discovered so that we don't have a recurrence. While the gear heads are part of the imported frames, we carefully drain, flush, and inspect each one, refill them with new oil, run thermal tests on the gear drive, replace the spindle bearings with a higher quality set, and ensure that continuous operation for several hours yields no issues. Based on the problems Mr. Lalonde has experienced, future tests of the limit switch systems will include their homing functionality as well. We're not yet certain what more we can do to decrease the problem of connections loosened in shipping; we already ferrule all the internal wiring by hand and check each connection before it leaves the shop, but we will review further options and are happy for advice. The next version of our CNC (which will be available in August) has far fewer connections and should be less susceptible to such issues.

3: We will definitely adjust our marketing material to indicate that achieving full travel requires overextension, and will adjust our factory Mach3 settings to take into account Mr. Lalonde's suggestions.


4: One other customer has experienced similar computer problems in the past. At the time, faulty boards were suspected and replacements shipped under warranty, but overheating now looks more likely. It doesn't get as hot in Connecticut as out west, so we never experienced these issues during testing. Our newer CNC design has replaced the mobile computer console enclosure with an integrated PC and screen on an armature, so similar problems should no longer be present. We will nevertheless work up a test for this before new-model mills are shipped.

5: Our base cast iron frames undergo third-party quality testing (from a European based inspection firm) before we accept them from the foundry, and we are very strict (we once rejected an entire order rather than ship product we didn't feel was good enough). Bolt hole patterns are not a defined criterion, though, so variation occurs. We're not certain whom Bob spoke with who is displeased with our communication on the matter, because we thought everyone who has asked about bolt hole patterns has been apprised that we can only supply them after we take delivery. If we were slow in responding to a request for information, though, then we certainly do apologize.

6: We have spoken with several foundries in an attempt to have our frames cast in America, but the cost is prohibitive for our machine. We're always looking for new foundries to qualify, though, and as we supply larger machines we look forward to the point where we can have everything cast here without pricing ourselves out of the market.

As changes are made, we will continue to update this thread or redirect everyone to a dedicated thread.

Thank you for all of the suggestions and support,

Charter Oak Automation

[MikeC8]

Handlewanker, why are you posting in this forum if you have no interest in these machines? Quite being a troll and move on.

I like where you are going with your splash try bob.

[Bob La Londe]

The gear head will get mighty hot at higher speeds.

After break in you might go to a lighter oil and under fill it slightly. I ran 10w-30 for a while until I removed the gears. The stock oil level is for 1750 RPM motor.

The stock spindle bearings are TRB and will make a good amount of heat when new. Break in takes a long time. Check the heat a few times when running high RPM to see if they are OK. Break in might be 30 hours or more before it really cools down. If it is too hot you might need to reduce the preload. No heat means no preload.

I can't say the max RPM but the rating for the big end was around 4500 RPM if I remember correctly.

Thanks Dave. I appreciate the feedback. I have run it mostly at higher RPM, and the tool holders where quite warm when removed. I figured that it was from chip heat transfer since I was employing mostly dry machining methods. They were hot enough that I considered putting on a glove to change them, but not so hot that I could not handle them as needed. I dropped you an email yesterday about belt drive parts also.

[MikeC8]

Run the spindle for a hour at those speeds without machining. You will probably find that the tool holder will get just as hot. The bearings are limiting your speed.

Thanks Dave. I appreciate the feedback. I have run it mostly at higher RPM, and the tool holders where quite warm when removed. I figured that it was from chip heat transfer since I was employing mostly dry machining methods. They were hot enough that I considered putting on a glove to change them, but not so hot that I could not handle them as needed. I dropped you an email yesterday about belt drive parts also.

[handlewanker]

Hi, .....just a reply to CHARTER OAK and their expose of their machine's heritage and format etc.....if they were to get the castings for that machine in question cast in USA or wherever, would they still stay with the same design?........ because if they did that is ludicrous to be blunt but truthful.

It needs a complete redesign, still with the same dimensions for travels etc, but a redesign to take advantage of 21st century thinking on all aspects of current CNC machining, starting with the slideway arrangements.

If they're stuck in the mud on the design, then I think the future of that machine will be very limited....just my honest opinion.

This is my last comment on this thread as it appears too many people are steeped in sympathy as opposed to honest criticism.......so adios and have a nice day.
Ian.

[Bob La Londe]

Handlewanker, why are you posting in this forum if you have no interest in these machines? Quite being a troll and move on.

I like where you are going with your splash try bob.

Its an open forum Mike. While am not crazy about the way the Wanker heavily weights his replies in a negative manner, he has had a few little things that might be of value to say as well. His comments about high speed setups were very parallel to some of my own thoughts on that subject for example. Just have to weed through the negative hyperbole to find the little useful hints. To bad they are not really germane to this topic.

Thank you for the comments on the splash/trip tray. I was going to finish it with 80/20 but the stuff is outrageously expensive. It would take nearly $400 to complete the enclosure with 80/20 and that doesn't include acrylic sheet, hinges, sliding hardware, or door latches. I think instead I am going to cut up my last sheet of .125 5052 and use it to make the structure to attach doors and and panels to.

[MikeC8]

For 80/20, check these guys out Solenoid Valves, Relays, Machined and Applied Motion Products They strip old equipment down and sell the parts out of their warehouse, and through ebay. we buy most of our 80/20 stuff from them, sold by the pound. Its far cheaper then buying new. The hardware is only $5/lb, extrusion is $3/lb I think?

[arizonavideo]

If the tool holders are just warm than that is good for a spindle with TRB bearings. TRB have over three times the contact area of AC bearing and are much stronger than A/C 's but at high speed they will just make more heat so the preload level is really important.

If you can hold the tool holder in you hand then it is fine. It will run even cooler with a little time.

The lower bearing has a dust cover but there is no seal in there. If you blow off your work all the time and more so if you blow steel chips off then you will want to make a seal to keep out the crud.

It needs to fit the spindle really loose of it will melt.

You need to post a picture of big fish to make us beginners feel unworthy.

Dave

[Bob La Londe]

LOL. If I ever catch another big fish I'll post a picture. The biggest I've caught so far this year was a 5.5 pounder on a popper on light line.

Actually, I've been so busy keeping machines running I just haven't had the time to fish seriously like in past years. Maybe its time for another hike in canoe adventure.

[Randall]

Bob
Did the Charter oak mill tram up well.
If you answered this I apologize

Randall

[Bob La Londe]

Bob
Did the Charter oak mill tram up well.
If you answered this I apologize

Randall

It trammed up to within a couple tenths over the length of my tram bar in X quite easily, and it didn't move much when I tightened up the head rotation collar. I didn't check it over the entire working length, just one quicky in the middle of the table. Its a little off in Y yet, but I haven't done anything with that. When I do Y' I'll probably have to shim the base of the column slightly. Its not off by much, but its enough I can tell from the tool marks depending on which direction its cutting. Probably a couple thousandths in 3 or 4 inches.

[Bob La Londe]

I haven't had time to work with this mill for the last several days. Not since my last successful part actually. I've just been to busy with other jobs, but I have fallen behind on a few machine parts jobs, so I figured I better hop on this. Because we suspected something being heat sensitive in the machine I added a push fan to force air into the cabinet. I added two air deflectors to the inside. One directs half the flow towards the computer motherboard, and the other deflects air over to the side of the cabinet where it can be felt up front where the controller, breakout board etc are located. It moves a lot of air.

I was hoping that would be enough, but it wasn't, or heat sensitivity isn't the problem. About ten minutes into a job the thing locked up. It showed an E-Stop, but the computer was locked up solid. No input accepted. Had to turn off the main power to restart it. Then I finished adding a duct from the air conditioned office so the air being forced in would be definitively cooler.

I relocated my part, and restarted the job. It hardly ran at all before it shut down again. It didn't lock up this time, but it e-stopped on its own again. This was with forced cool air going into the cabinet. I was standing there when it did. and I noticed something else. About half a minute before it shut down the spindle slowed down momentarily.

I had bumped acceleration up to 18 i/s/s, and hoping that was maybe just a little too optimistic I dropped it back down to 15 i/s/s and restarted the job again. Its been running for about 30 minutes now, but the overall temperature for the day has broken also.

I have the inner duct secured with electrical zip ties, but I need to run to the store for some duct ties.

[Bob La Londe]

Some days I feel like a total idiot... No. I didn't find the cure to all that ails, but I did find one thing that may have caused some of my false E-Stop conditions. I never ran across this problem on my Hurco mill because the proximity switches are all covered.

A pile of aluminum chips that fall on a limit switch will cause it to trip off the machine. DOH! The X switch right on the front of the saddle is easily triggered this way. What gets you is that it says external E-Stop is activated, when it happens while executing code. It doesn't say limit activated. I think my morning project tomorrow will be to break a piece of sheet metal to fit from end to end of the table and protect that proximity switch from false activations.

[RustedOut]

A pile of aluminum chips that fall on a limit switch will cause it to trip off the machine.

My Y switch did that to me after I sent the head home which caused all the chips being held in my rubber Y-Z way covers to fall on the switch rod. That was the first time in all the years I've been running my mill that had happened, but the potential is always there now that I know what's happening. I think my solution is going to be to make a wider way cover so the chips fall completely off the mill. Been thinking on a telescoping cover for there and have an idea of something not too complex I want to try. I have a big cover over the X switch and the Z switch is up and out of the way so I don't have any concerns with them.

I also have problems with my computer locking up and have thought for some time it's heat related. The possibility is there for the mill to just continue it's last command even though the PC is totally locked up. So if the last thing it sees is a rapid down by a key stroke, it's going to just keep going and the limit switch isn't going to stop it. E-stop does though if you can catch it in time. I got my shop air on now and lock ups are rare. But just before I turned it on the PC wouldn't run even a minute and would lock up at times during the launch of Mach. Frustrating, I'm near the end of my wits with this, but it's one of two PC I have for the mill and they both do it. And they are completely different makes of PC's, but with the same motherboards. I've put additional cooling fans in them, but nothing has helped except for the air conditioner. The PC resides about two feet from the window air unit. I know some of the machines where I used to work had small air conditioning units built into their electronics cabinets. I have wanted to build an all in one PC and monitor that contains control switches as well, but the cabinet will be smaller than the case the PC resides in now. I have to solve the lockup problem first.

Bob

[Bob La Londe]

Here's hoping I have most of the headaches behind. I was about ready to grab one of the XP boxes I use to control my other machines. They are older machines, but they run in the shop. An on cabinet air conditioner is a great idea. I may look into some options on that. I hate the air duct laying across the floor.

[Bob La Londe]

Nothing Special to see here. I just whipped up a shield for the X-Axis proximity switch.

Its interesting that you mentioned that a wider way cover in Y would be a good idea for the same reason. Paul at Charter Oak sent me a piece of Burna Rubber and a couple mounting bars for a rear Y axis cover to try out and review as to suitability and longevity. A couple hours before I saw your message I sent him this as part of a message. "Personally, I think I would also have gone with a slightly wider piece. 12 inches just barely goes out to the edges."

[RustedOut]

Mine is an XP Pro system. It didn't used to have this problem, but showed up a bit over a year ago. I've stripped everything but Mach and MachStdMill off of it and turned off most everything in the OS. It makes for stressful machining. I had considered moving to a newer OS, but I just don't believe that'll cure the problem as it follows into different PC's. Lately I've been wondering if migrating to Mach4 when it becomes available would be the answer...on a different OS entirely.

Bob

[RustedOut]

The rubber is what I got now for the Y-Z cover and I hate it. Chips stick to it like glue. It does go from the back of the saddle to the bottom of the Z slide, so in concept it's the right direction, just the wrong choice of material. If or when I get around to making a new version, it'll be made of metal. My front Y way cover is metal, but the limit switch resides above it. So I used a metal piece like yours, but it's much wider. All my chips end up going to the back of the machine because of that cover. I have a full chip enclosure in the works, just got a lot of other things to do that's more important than that right now.

Bob

[Bob La Londe]

Paul just sent me a message that they are sending me out a new computer for the controller to see if that cures some of the idiosyncrasies. I'll keep you posted.

[Bob La Londe]

No more drawer slides...

I just scored this little guy for one of the two door slides on the new mill.
Slightly Warped Linear Motion 12mm Rail Guideway System 2000mm Shaft Support | eBay

Slightly warped ?!? So what. If I drill the holes close enough o straight it will be good enough for a door rail.

Now if I can just find another one at such a smoking price.

It will mount either on the top of bottom and stretch nearly the full width of the enclosure. That way I can make the doors any size that's convenient. My thought was with something like this they will be self sweeping. I probably only use the support in sections so there are gaps for the chips swept back by the bearing sweepers to fall through.

I got the idea because David de Caussin made the doors on his Fadec UMC-10 using linear rails.

It will work roughly the same way as the drawer slides I used on the Hurco, except I plan to use one on the top and bottom.