[Norton_BMW]

So another day of peeling back the layers of this onion...

@cbud, you should contact JT about your stepper motors. From your pictures it looks like you have the same under-spec'd motors Norton_BMW and I have. I did the torque wrench test (coupled my torque wrench to the output shaft and tried stepping the motor) and the best I could get was ~13ft-lbs or 208oz-in. It's a calibrated mechanical torque wrench so that should be within 1-2ft-lbs. I swapped out the factory motors for some known-good AA 637oz-in motors and the difference is off-the-chart. I used to be able to easily overpower the motors with the hand-crank and now they feel rock-solid.

Moving on to tramming the spindle. Pulling it out of the machine, it's pretty obvious how the factory attempted to tram it out. So far rotating it other directions has only made the situation worse, so I'll have to wait until I can get some shim stock in.


When I was up adjusting the belt on the z-axis to tram the beam, I got looking at the upper structure and boy does it look out of square! It looks like they just didn't have things aligned when it was welded up. I'm pretty much at a loss on how to fix this.

I noted the Z stepper misalignment before I even lifted the unit out of the crate.

I also noted that the misalignment of the various parts in the milling section contributed to the overall inability to tram the mill.

For example on my machine none of the holes in the 1/2" thick steel plates that the Z-axis ball screw thrust bearing flanges were attached to were consistent.

Note the difference in the preceding photos.

I also noted that the ballnut lead screws that lifted the milling assembly was not centered either in the top mounting plate or the moving carriage.

I was never able to tram the mill properly as if I made the tool face perfectly parallel with the milling table it would deviate in the X&Y Axis when traveling vertically.

If I made it not deviate in the X&Y direction during the vertical travel the tool face was no longer parallel.

I also noted that there was an increase in torque required to raise the mill as it got near the top end of the travel and I suspected it was due to the ball screw misalignment.

When I relaxed the six linear bearings by removing the entire top frame, having the milling carriage supported and removed the bottom bolts I measured the 6 vertical linear bearings for alignment using the same tools and techniques as used for ensuring motorcycle forks are aligned,

None of the 6 vertical linear bearings or two Ball Screws share a common axis and deviate randomly from true vertical with respect to the mill head carriage. Given that these are solid hardened steel shafts, this is an issue that cannot be adjusted out by having larger than normal holes in the upper and lower attachment points. As all you are doing is forcing the shaft and bearing assembly to accommodate the differences in x & y coordinates by bending to accommodate the deflection when traveling between the two extremes.

The two linear bearings on the tailstock end are out of true vertical with respect to the mill carriage by .35 mm and .44 mm, they are off by .6 mm with respect to each other over their full length.

The four linear bearings on the headstock end are out of true vertical with respect to the mill head carriage by .15 mm , 22mm, .18mm and .17 mm in random directions and with respect to each other the maximum deviation is .28 mm over their full length.

The two ball screws are out of true vertical .32 and .26 respectively over their full length.

It was useless to try and tram the mill until all these missalignments were corrected.

I initially tried scraping the paint off and it offered a slight improvement but eventually had to grind both the top and bottom of the milling carriage.


The top and bottom of the milling assembly was found to be not parallel.

Additionally the guide holes that the linear bearings and ball screw assemblies were to go it were not bored perpendicular and were actually at an angle.

Nor are the actual landing locations for the 6 linear bearings at the same Z datum on the headstock or by the tailstock.

Plus the attachment holes were crudely drilled and tapped adding to the misalignment issues.

[n1tr0]

That could explain some of my problems. What sort of equipment was required to mill the beam and if you don't mind saying, how much did it cost? I can't imagine doing it on the bridgeport at work. Also what'd you do for the linear guide bore holes? I imagine boring them out perpendicular to one another would have opened up the holes and introduced some slop?

[Norton_BMW]

That could explain some of my problems. What sort of equipment was required to mill the beam and if you don't mind saying, how much did it cost? I can't imagine doing it on the bridgeport at work. Also what'd you do for the linear guide bore holes? I imagine boring them out perpendicular to one another would have opened up the holes and introduced some slop?

I had the milling carriage and the several other parts precision ground at a shop that specializes in rebuilding machine tools.

They ground milling head carrier on both sides.

They realigned the tailstock which was out of alignment with the headstock and not parallel with the lathe bed ways.

Plus they corrected the "rocking" and misalignment that existed in the milling table crossfeed by milling it all true and then scraping it.

The price was originally quoted as being $5000.00, but we eventually worked out a compromise where I did some repairs to a special motorcycle he has and some cash.
It was about $1800.00 out of pocket as well as my time.

When the milling head was precision ground, a small stress crack showed up that later was discovered to be a bondo and sheet metal repair to the milling head carriage.
Attachment 332818
I still have not resolved what to do about the crude casting repair.

I have been trying to assess the best way to correct the misalignment of the vertical bearing and ballscrew holes and have looked at two options:
1. Using a boring head followed by a chuckable reamer and realign and enlarge the holes and then glue in sleeves with a masterbond epoxy I use regularly.

2. Using a boring head followed by a chuckable reamer and realign and enlarge the holes and then install Thompson Linear components that require a larger bore.

regardless all the holes need to be properly drilled tapped, I was thinking about Helicoil, but some holes are too bad to even helicoil them, so I am looking seriously at option 2 that has a different bolt pattern possibly rotating the assembly.
Attachment 332820

[Norton_BMW]

I think the XL belt on my machine isn't actually matched to the pulleys; right pitch, wrong tooth profile. It's tensioned ok, with no load there's no slip, but as soon as it's loaded up a bit, the belt shifts on the pulleys. That's cool that JT hooked you up with a pulley and belt, at this point I'd be happy with technical documentation on the machine and a spindle that doesn't suck. I'm not sure how accurate the FLIR is as I haven't taken any direct measurements with a thermocouple, but after a bit of machining at ~4500 rpm it's too hot to touch. I can definitely understand why the initial units had air cooling to the spindle. Preload on the spindle is at the bare minimum to keep the pulley from rattling so I suspect it's either the quality of the bearings or yet another problem with how it was assembled. I'm running a 2mm end mill so I doubt it's the loads.
Attachment 329152Attachment 329154

After I received my machine, the initial problems I encountered with the Z-Axis Stepper motor and belt misalignment lead me to look at the whole setup including trying to tram the mill.
I decided to do a full analysis of the machine comparing the various readings to the specs on the website at: http://shopmasterusa.com/wp-content/...12/03/shee.jpg

Dec 6th 2015:
I purchased some better tools to measure the tolerances:

A calibrated Fowler .040"/1mm QuadraTest Multimode Electronic Test Indicator 54-562-777
A calibrated 500-506-10 Mututoyo 24” Caliper
A hardened precision ground R8 test shaft with certificate of conformance and measurement
A hardened precision ground MT3 and straight lathe and tailstock alignment shaft with certificate of conformance and measurement

1. Before completely disassembling the mill head carriage I tested the milling spindle and discovered that the spindle runout Spec G1.a was 0.0027 when the maximum was guaranteed to be 0.001.
a. The bottom taper section had no measurable runout. Less than ±0.00005
b. I did not have a probe long enough at the time to measure the upper machined straight section, but ordered one and discovered that there was a slight ovality in the upper section of the R8 cavity where the keyway pin is that caused much of the runout.
c. The original R8 – 20mm collet was defective, both the drawbar hole in the collet and the centering nut for the drawbar were misaligned and drilled an an angular offset, these were both replaced by shopmaster
Attachment 332826

However, it was not the sole source of the Mill Spindle Runout as I noted that the runout I measured was different when bolted into the milling head holder casting than when held in a lathe and just the spindle turned.

It was discovered that the upper and lower faces of the milling carriage were not parallel and there was a major deviation where the milling head top centering clamp bolted on.
Attachment 332822
Attachment 332824
When the bottom flange was tightened the upper section was actually being forced against the side of the bored hole causing side stress on the milling head.

The milling carriage was precision ground on both sides.

I took the spindle out and looked at the bearings:
The Lower Bearing is HIB german technology import substitution TD5207-2RS1/P5
The Upper Bearing is HIB german technology import substitution TD5206-2RS1/P5
Which is just a fancy name for a Chinese substitution for a german designed bearing.
I note that the bearings were quite stiff and were obviously grease filled that would add to the heat generation.

I did note that the bearing looked to be preferentially bedded in one side of the upper part of the spindle housing and the opposite side of the bottom. This was not in line with the pull on the pulley but rather at right angles to it. More in line with the side deflection that occurred when bolted.
Attachment 332834
Attachment 332836
I measured the upper and lower bearing cavity and noted that there was some slight offset and I am unsure if this was internally bored on both ends as one setup with a long boring bar or if the piece was flipped over to machine the opposite bearing cavity.

I would suspect that the heat generation you are experiencing is due to a compounding of a number of these factors. The style and clearance of the bearings, the grease instead of oil and the any residual misalignment. Many better designed spindle assemblies have dual upper and lower angular contact bearings that operate in an oil bath.

[JTJT]

[QUOTE=Norton_BMW;1934902]I had the milling carriage and the several other parts precision ground at a shop that specializes in rebuilding machine tools.
They ground milling head carrier on both sides.
I still have not resolved what to do about the casting repair./QUOTE]

That was really an expensive, complex and unnecessary way to go about the adjustment. The mill cartridge is designed to be "trammable" by the ring of 6 bolts at the bottom. After loosening the top clamp, shims can be placed between the head around the ring until it is trammed to the table. The top ring clamp is only there to give support against the force of the drive belt, so after tramming the bolts, you just tighten the upper ring clamp. This allows tramming regardless of any variation in the mill head casting.
On generation 1 machines, the factory left open areas in the casting in non-structural places to reduce the weight. However some of the first customers felt the openings in the raw casting looked crude, so we told the factory to close up the openings and finish them. Because they cast these pieces in advance to allow them to cure before machining, they probably had a lot of them done, and just made some patches for cosmetic appearance sake.

[JTJT]

I took the spindle out and looked at the bearings:
The Lower Bearing is HIB german technology import substitution TD5207-2RS1/P5
The Upper Bearing is HIB german technology import substitution TD5206-2RS1/P5
I note that the bearings were obviously grease filled that would add to the heat generation.
Attachment 332834
I would suspect that the heat generation you are experiencing is due to the style of the bearings, the grease instead of oil . Many better spindle assemblies have dual upper and lower angular contact bearings that operate in an oil bath.

We use the standard machine tool grade dual angular contact bearings, and the temperature will go to about 130 degrees within the first 5 minutes and then remain stable for as long as the machine runs. If your spindle runs hotter than that it could be too much pre-load or even a bad bearing. The cartridge is easy to drop out in about 5 minutes, and bearings are available from us free if you are still under warranty. You may also return the cartridge to us for repair. Or you may upgrade to the oil filled style if you prefer.

[n1tr0]

The price was originally quoted as being $5000.00, but we eventually worked out a compromise where I did some repairs to a special motorcycle he has and some cash.
It was about $1800.00 out of pocket as well as my time.

Ya, so there's no way I'm dropping $5k on this machine... That's just depressing.

When the milling head was precision ground, a small stress crack showed up that later was discovered to be a bondo and sheet metal repair to the milling head carriage.
Attachment 332818
I still have not resolved what to do about the crude casting repair.

Ya, I found that thin casting hole & bondo patch on my machine as well. I posted some pictures in another thread, but Shopmaster had it deleted. Apparently it wasn't relevant to the discussion about the quality of their machines.

2. Using a boring head followed by a chuckable reamer and realign and enlarge the holes and then install Thompson Linear components that require a larger bore.

I've used the Thompson guides before on the z-axis guides of an industrial sized 3D printer, just make sure you don't get the self-aligning units. They have a curved race-way so they don't offer any torsional rigidity. I removed the units I bought and mounted them directly in the bored holes of my gantry using c-clips (rather than a flange or pillow-block mount).
I've been using a lot of PBC Linear components in my mechanisms lately and they have some very reasonably priced extra-long linear guides. Now that I'm thinking about it, I should probably go check the shafts and see if they're actually 1 inch or 25mm. If they're 25mm, the double-long guides would probably be a great fit.
ISO Metric Round Flange Mount Wide Linear Ball Bearings (EPF-W) ? Round Shaft Technology

regardless all the holes need to be properly drilled tapped, I was thinking about Helicoil, but some holes are too bad to even helicoil them, so I am looking seriously at option 2 that has a different bolt pattern possibly rotating the assembly.

If you're going to have the beam in a machine to re-bored the thru-holes, I'd just re-drill a matching bolt pattern to whatever you're using rotated 45 degrees. There's no sense in messing around with helicoils if you don't need to.

[JTJT]

Ya, I found that thin casting hole & bondo patch on my machine as well. [
If you're going to have the beam in a machine to re-bored the thru-holes, I'd just re-drill a matching bolt pattern to whatever you're using rotated 45 degrees. There's no sense in messing around with helicoils if you don't need to.

That was really an expensive, complex and unnecessary way to go about the adjustment. The mill cartridge is designed to be "trammable" by the ring of 6 bolts at the bottom. After loosening the top clamp, shims can be placed between the head around the ring until it is trammed to the table. The top ring clamp is only there to give support against the force of the drive belt, so after tramming the bolts, you just tighten the upper ring clamp. This allows tramming regardless of any variation in the mill head casting.
On generation 1 machines, the factory left open areas in the casting in non-structural places to reduce the weight. However some of the first customers felt the openings in the raw casting looked crude, so we told the factory to close up the openings and finish them. Because they cast these pieces in advance to allow them to cure before machining, they probably had a lot of them done, and just made some patches for cosmetic appearance sake.

[n1tr0]

That was really an expensive, complex and unnecessary way to go about the adjustment. The mill cartridge is designed to be "trammable" by the ring of 6 bolts at the bottom. After loosening the top clamp, shims can be placed between the head around the ring until it is trammed to the table. The top ring clamp is only there to give support against the force of the drive belt, so after tramming the bolts, you just tighten the upper ring clamp. This allows tramming regardless of any variation in the mill head casting.
On generation 1 machines, the factory left open areas in the casting in non-structural places to reduce the weight. However some of the first customers felt the openings in the raw casting looked crude, so we told the factory to close up the openings and finish them. Because they cast these pieces in advance to allow them to cure before machining, they probably had a lot of them done, and just made some patches for cosmetic appearance sake.

To be fair, there were the published specs for the machine, based on which many of us bought the machine thinking we could do the work we wanted/needed to do.
The poor alignment of the rods means that the head travels up and down in a non-linear fashion or has binding/drag issues.
The poor alignment of the pulleys in the upper assembly means that the belt and bearings all wear pretty bad and there's some weird backlash. The big gear reduction of those massive pulleys definitely helps minimize the backlash stuff, but the flipside is they weigh several pounds and can carry some massive inertia meaning that the acceleration profiles have to be super slow.
The head beam's non-parallelism might be compensated for with some shimming, but that upper bracket is a slip fit and at ~22mm tall it really doesn't fit well if the spindle it's clamping onto isn't perpendicular to the surface it's being bolted down on....

I could model up the beam and do some FEA on it and maybe that big hole in the casting is un-necessary, but finding patches and bondo on a new machine feels pretty sketchy. If I bought a new Chevy and found it's bodywork was patched with bondo from the factory, I'd be pretty upset; That's the sort of thing I expect from a car with a salvage title or undisclosed from a super sleazy used car lot. Don't get me wrong, bondo definitely has it's place, I've straightened out the bodywork on more than a few racecars, but I never tried to pass them off as new.

[BIGBLOCK1965]

To be fair, there were the published specs for the machine, based on which many of us bought the machine thinking we could do the work we wanted/needed to do.
The poor alignment of the rods means that the head travels up and down in a non-linear fashion or has binding/drag issues.
The poor alignment of the pulleys in the upper assembly means that the belt and bearings all wear pretty bad and there's some weird backlash. The big gear reduction of those massive pulleys definitely helps minimize the backlash stuff, but the flipside is they weigh several pounds and can carry some massive inertia meaning that the acceleration profiles have to be super slow.
The head beam's non-parallelism might be compensated for with some shimming, but that upper bracket is a slip fit and at ~22mm tall it really doesn't fit well if the spindle it's clamping onto isn't perpendicular to the surface it's being bolted down on....

I could model up the beam and do some FEA on it and maybe that big hole in the casting is un-necessary, but finding patches and bondo on a new machine feels pretty sketchy. If I bought a new Chevy and found it's bodywork was patched with bondo from the factory, I'd be pretty upset. Don't get me wrong, bondo definitely has it's place, I've straightened out the bodywork on more than a few racecars, but I never tried to pass them off as new.

My machine had none of the issues you mention, but did require some final adjustments and tramming once it was in place. After travelling 10,000 miles from China and being handled by who knows how many forklift operators, there is no way they could retain 100% of the factory alignments. Adjustment of the linear rails is a simple matter of dropping the head down, loosening the bolts to let them self align and then raising it up and doing the same. Mine runs up and down smoothly with no drag or bind. JT sent me the tramming instructions and it worked fine, I cannot imagine why anyone would go through all that expensive milling etc for such a simple adjustment. As far as bondo goes, there is no machine tool that does not use bondo to smooth the castings before painting, regardless of the price. BTW, bondo on new cars is common to smooth seams and to repair damage from factory to dealer delivery. It's not a structural issue, only cosmetic. Having read your posts on the various issues, I see most are simple adjustments probably requiring less time to do than it takes to take pictures and post on this forum. I think people need to make a decision early on if they are either happy or unhappy with the machine. If you are unhappy, but decide you can adjust things and make it work, fine, but if you are going to be aggravated every time you walk into the garage and see the machine, you will be far better off to just package it up-ship it back and move on to a different machine. There is nothing to be gained by torturing yourself on a daily basis. JT has always been good to me over the years with warranty and service, and he has a very generous return policy as well.

[Norton_BMW]

[QUOTE=JTJT;1934978]

I had the milling carriage and the several other parts precision ground at a shop that specializes in rebuilding machine tools.
They ground milling head carrier on both sides.
I still have not resolved what to do about the casting repair./QUOTE]

That was really an expensive, complex and unnecessary way to go about the adjustment. The mill cartridge is designed to be "trammable" by the ring of 6 bolts at the bottom. After loosening the top clamp, shims can be placed between the head around the ring until it is trammed to the table. The top ring clamp is only there to give support against the force of the drive belt, so after tramming the bolts, you just tighten the upper ring clamp. This allows tramming regardless of any variation in the mill head casting.
On generation 1 machines, the factory left open areas in the casting in non-structural places to reduce the weight. However some of the first customers felt the openings in the raw casting looked crude, so we told the factory to close up the openings and finish them. Because they cast these pieces in advance to allow them to cure before machining, they probably had a lot of them done, and just made some patches for cosmetic appearance sake.

The opening that was closed up on at least 4 machines, mine, N1tr0's and two others, were not " the factory left open areas in the casting in non-structural places to reduce the weight" they are at a key structural area of the milling bridge. Hence the appearance of bondo cracks after being clamped and precision ground to true up the top and bottom faces.

Since all 4 machines have the same "repair" at the same location and span three shipments from China, they appear to be a systemic casting flaw.
Attachment 332982
At first I thought that the issue might be a core shift during casting but looking at the consistency of the casting defect I believe that the error originated in the master that was used to prep the molds.
Note how the face is offset between the from and back of the casting.
Attachment 332984
There are internal recesses cast in for the vertical linear bearings and the shift in the master resulted in the recess breaking through hence the hole.
Note the area where the repair screws are tapped in is only 2mm thick, the other side nearly 10mm thick outside the indentation. Attachment 332986
Attachment 332988
The long sidewall on the bridge was also made thinner than the opposite side, this was corrected by applying additional bondo as well.

[BIGBLOCK1965]

I would say the same to you as to the other guy, if you are really that unhappy, you should just package it up and ship it back. After re-reading all your posts, and your "microscopic" inspection of nearly every part, it is hard to believe you did not see the cosmetic patch on the mill head before doing all that expensive machining. That would have been the time to just send it back. I'm a gearhead, not an engineer, but my lifetime of experience and the work I am doing on my machine says that it has no structural weakness at all. The entire mill head is supported by the 2 ball screws in the center part of the casting, the linear rails only serve to guide it up and down and do not take the cutting forces. All of the areas of any stress in your pictures show the full 3/4" thickness of the casting. Considering the horsepower of the motor and the overall machine design, there could never be sufficient force generated in any direction to affect the casting.

[Norton_BMW]

My machine had none of the issues you mention, but did require some final adjustments and tramming once it was in place. After travelling 10,000 miles from China and being handled by who knows how many forklift operators, there is no way they could retain 100% of the factory alignments. Adjustment of the linear rails is a simple matter of dropping the head down, loosening the bolts to let them self align and then raising it up and doing the same. Mine runs up and down smoothly with no drag or bind. JT sent me the tramming instructions and it worked fine, I cannot imagine why anyone would go through all that expensive milling etc for such a simple adjustment. As far as bondo goes, there is no machine tool that does not use bondo to smooth the castings before painting, regardless of the price. BTW, bondo on new cars is common to smooth seams and to repair damage from factory to dealer delivery. It's not a structural issue, only cosmetic. Having read your posts on the various issues, I see most are simple adjustments probably requiring less time to do than it takes to take pictures and post on this forum. I think people need to make a decision early on if they are either happy or unhappy with the machine. If you are unhappy, but decide you can adjust things and make it work, fine, but if you are going to be aggravated every time you walk into the garage and see the machine, you will be far better off to just package it up-ship it back and move on to a different machine. There is nothing to be gained by torturing yourself on a daily basis. JT has always been good to me over the years with warranty and service, and he has a very generous return policy as well.

@Bigblock1965
I cut my eye teeth on a wrench and was a gearhead long before I became an engineer at 30. I am still a gearhead at heart; I get the understanding that N1tr0 and others (now silent, but who previously posted in these forums about their individual experiences with lack of quality on the Millturn 2015/16) fall in the same category. It does not take an engineering degree to recognize that the issues that my machine arrived with had nothing to do with the fortnights or furlongs traveled on the slow boat from China. It was not the stevedores roughly manhandling the crate that bent the Z-axis pulley or may have caused minor shifts in the machine that affected the accuracy. Rather the fabrication techniques and inspection practices, or lack thereof, before it was crated that have contributed to the vast majority of the issues.

Most are not simple adjustments as you suggest and these machines are the summation of all the inconsistencies contained within:

As an example of the lack of QA/QC or proper fabrication techniques, not one threaded attachment hole for the linear bearings or ball screws in the milling bridge were properly drilled or tapped:
• in some cases, too big a drill was used for the tap size.
Attachment 333006
• None of the holes were drilled or tapped true vertical.
Attachment 333008
• In many cases the holes did not properly line up with the bolt pattern requirements and had to be forced, or drilled and tapped a second time.


Shopmaster claims that the machine is manufactured to ISO9001
“QUALITY-
Our machines are built to stringent CNC standards and carry
the ISO9001 certification. There is NO OTHER 3 in 1 machine
built to higher standards than the MILL TURN.”

It is inconceivable that my machine and N1tr0’s are the only two with serious lack of quality control; as there is no evidence of any ITP or corrective action applied as required under ISO9001.
Just a simple visual inspection before leaving the factory would have noted the severe angle my Z-Axis stepper (others experienced the same thing) and crank wheel were at. Likewise, my first manual cranks up and down noted the Z-Axis belt was skipping (due to a hole drilled in it at the factory) in addition to hearing grinding sounds from the bearings on the toothed idler wheels that had too short a shoulder and were side-loaded and damaged during tightening.

You claim that the “ As far as bondo goes… It's not a structural issue, only cosmetic.”
Please look at my post with more details on the bondo!

You state “Having read your posts on the various issues, I see most are simple adjustments probably requiring less time to do than it takes to take pictures and post on this forum.”
Many of the systemic design and fabrication issues that these machines have take a great deal of time to uncover the root cause, the measurement and photographic documentation is but a fraction of that time. It’s the time it takes to respond to cheerleaders for the brand like yourself that takes most of the posting time. What would you think if the Big Block engine you were blueprinting or hotrodding had head bolt holes in the block as crudely drilled as those I illustrate above?

I started to note issues with the machine before it was ever lifted out of the crate frame. I was very unhappy by the end of the first month. I have all the emails back and forth to Shopmaster documenting everything and expressed my unhappiness many times before it was ever powered up.

You “cannot imagine why anyone would go through all that expensive milling etc for such a simple adjustment”.
I even have an email from shopmaster about getting quotes to true up the milling bridge/carriage. Other than repair/replace the few smaller clearly defective parts, shopmaster never pays for any repairs and always wants the machine shipped back at the buyers cost. None of the parts you send then are freight or postage due.

You talk highly of JT and mention “he has a very generous return policy as well” Have you ever tried to return a machine?

Having the buyer pay for the return freight so shopmaster can “make arrangements with a local CNC vocational training school to test the machine and record the results” is throwing good money after bad.

Myself and others who have offered to get (or actually paid) a machine tool inspection professional do a critique on the machine does not alleviate the buyer from the cost of return freight. Shopmaster has never agreed to getting a mutually acceptable independent inspector to look at my machine on my premises.

I have talked with some former owners before they agreed to returning their machines, (non-disclosure agreements were part of their returns, hence their silence thereafter) and all had to pay the return freight and none were compensated for the time and money spent before returning it.

While I can’t speak for N1tr0 or others, I believe that it is a very valuable exercise to document all the things that we are doing to our machines to bring them to the level of quality and precision that they were advertised as having before leaving the factory. To that end we are spending our time and money as the corrective action feedback loop that the factory alleges to have under ISO9001 but apparently has never implemented.

This should not be our job as it was what we all paid Shopmaster for when we bought the machines and since Shopmaster does not have an online forum for owners/users to share their experiences and offer their proposed solutions for open debate, then CNCzone is offering a very valuable service. Moderators who get pressured into removing posts that document the trials and tribulations of getting the Millturn machines up to the acceptable level of performance and precision that they were advertised as having are doing an extreme disservice to all forum members for the sole and exclusive benefit of a single manufacturer in contravention of the independent ideals of this forum.

[Norton_BMW]

How do you know your tail stock height was dead on? The proper way to check that is to put a center in the chuck and another in the tail stock and then move them together so the points touch one another and then clamp the tail stock down to see if it stays put. Since the table is so big on these machines you can't get the tail stock any where close to the chuck even when it's fully extended! I'd try the taper extender to get the centers closer but Shopmaster failed to include it with my machine even though it was supposed to be included with my new machine. Anyone reading these threads without a Shopmaster machine, I'd suggest you buy something else.

@rocketman
I had a few challenges with my tailstock as well.

The accordion bellows between the milling turning carriage and the base of the tailstock would collapse and bind. I bought a second one that was shorter and hold them in place with rare earth magnets glued into the plastic hold down plates.

My tailstock was slightly off centered and I ended up getting it machined and then scraped it to line up properly, However I noted that it would deflect under load due to the thin gib retaining plate.
Attachment 333012
I did a setup to measure the deflection:
Attachment 333014
Attachment 333016
Attachment 333018

I did before and after tests and fabricated a 1/4" thick gib retaining plate

The Gib screws were tightened to 15 Inch Lbs for each test

Pressure Deflection Before Vertical Deflection Before Sideways Deflection After Vertical Deflection After Sideways
0 0 0 0 0
10 0.003 0.001 0.001 0
20 0.008 0.002 0.003 0
30 0.013 0.003 0.005 0
40 0.019 0.004 0.008 0
50 0.028 0.005 0.011 0

Attachment 333020

Attachment 333022

This is the final result after the gib plate was replaced and 50 lb force.

[instructor37]

I started to note issues with the machine before it was ever lifted out of the crate frame. I was very unhappy by the end of the first month.
Moderators who get pressured into removing posts that document the trials and tribulations of getting the Millturn machines up to the acceptable level of performance and precision that they were advertised as having are doing an extreme disservice to all forum members for the sole and exclusive benefit of a single manufacturer in contravention of the independent ideals of this forum.

Well, I have to agree with the other guy, you are just torturing yourself keeping the machine. I don't know how long you have had it, but if you were unhappy at the end of 1 month, you should have just packed it up and sent it back for a refund. Even if it cost you a couple hundred in freight, at least you could buy another machine and get on with your work, rather than spending your life disassembling this one and measuring every part. At this point it is clear you will never use it, so further inspection is just an exercise in self flagellation.
BTW- the moderators here do a good job maintaining the forum and preventing it from deteriorating into a name calling contest. Shoptask does have its own forum as well at Delphi Forums Login - Welcome! Please log in.

[n1tr0]

Well, I have to agree with the other guy, you are just torturing yourself keeping the machine. I don't know how long you have had it, but if you were unhappy at the end of 1 month, you should have just packed it up and sent it back for a refund. Even if it cost you a couple hundred in freight, at least you could buy another machine and get on with your work, rather than spending your life disassembling this one and measuring every part

Ya, in hindsight, I certainly wish the Shopmaster wasn't the first CNC I purchased so I could have been better equipped to immediately recognize all the problems, but that really wouldn't have been any help.

While I don't see a return/refund policy on the Shopmaster site anymore, the cached copy from when I purchased my machine said

you are required to keep the machine for the full 12 month trial to insure you have spent sufficient time to learn the machine

That's long enough that there's really no guarantee I can actually get my money back and the fine details said you were basically sending the machine back to be put on consignment sale... Then there's the fees for different payment methods, restocking fees, the shipping each way is at the buyers (my) expense, nothing can be modified or need repair, etc... I'd hardly call that generous and it certainly doesn't accommodate cases where we've gotten defective, mis-represented equipment...

I haven't seen anyone calling anyone else names yet. This forum has an outstanding policy on free speech

All patently false or defamatory statements will be removed as soon as possible after we become aware of them.
All other posts which are challenged by any party (commercial or not) will be examined to determine whether they make false or defamatory statements. If the posts do not contain such statements, those posts will be permitted, regardless of whether the objecting party believes they are damaging.

I think all the critical posts you'll find in this thread show very well documented problems which are clearly not "patently false", nor are they "defamatory".

I particularly appreciate this bit from the policy and I think it's particularly applicable.

The policy we keep is by no means one-sided. To the contrary, it fosters many benefits for commercial advertisers. In our experience, a manufacturer who professionally and politely engages a dissatisfied customer can often turn that customer into a lifelong spokesperson for the company. Moreover, astute manufacturers and retailers often use feedback they find on CNCzone as a barometer of their performance in the market

[BlackICE1]

How can you learn about the machine if it doesn't work correctly as received and if you modify or fix it to work you invalidate the "warranty?"

I had some minor problems and some disappointing results using the milling functions of my Patriot. That said, I think it was the right choice for a beginner like myself to learn more about machining and CNC before spending 3+ times more for better machines without understanding what superior qualities I would like in them. One also has to consider the space requirements of better CNC lathe and milling machine vs. a Shoptask.

[instructor37]

[QUOTE=BlackICE1;1935766]How can you learn about the machine if you modify or fix it to work you invalidate the "warranty?"

/QUOTE]

The solution is very simple, on our machines, whenever we made any changes, I sent an e-mail to Shopmaster explaining what we were going to do and asking if it would alter our warranty. Then we just documented the response for future reference. They were always very accommodating, offering advice and telling us of any potential problems that might arise from the changes.

[instructor37]

While I don't see a return/refund policy on the Shopmaster site anymore, the cached copy from when I purchased my machine said That's long enough that there's really no guarantee I can actually get my money back and the fine details said you were basically sending the machine back to be put on consignment sale... Then there's the fees for different payment methods, restocking fees, the shipping each way is at the buyers (my) expense, nothing can be modified or need repair, etc... I'd hardly call that generous

The warranty and return terms are pretty clear and simple, and if a person is uncertain about them, they should either contact the seller and ask for clarification, or simply not purchase the machine. Once you purchase a product you are agreeing to the terms of their warranty. The Shopmaster warranty is standard form boiler plate language almost identical with all other companies selling tools- Grizzly, Smithy, Enco etc. Tormach is an exception, as their policy runs on for many pages of legal language, and actually does not offer any return policy that I could interpret.

[n1tr0]

Once you purchase a product you are agreeing to the terms of their warranty.

I don't want to see this thread devolve into legalese and get away from discussing the actual machine and our problems & fixes, but In the USA, we have federal and state consumer protection laws people may want to exercise. These are not limited by what the manufacturer puts on their website unless products...

Virtually all consumer product purchases come with an implied warranty of merchantability, meaning it is guaranteed to work as claimed. For example, a cellular phone that is unable to receive calls is in breach of an implied warranty of merchantability since it was not fit for sale.

Likewise a mill that can't possibly meet its advertised performance...
There are legal recourses and people should really go talk to a lawyer before making further posts if they want to go that route.

For the moment at least, it seems easier to discuss the problems with fellow owners and see if there are some fixes we can make.