Hoss's G0704

[CFLBob]

If it goes 50% too far at .005 and .010, does it go 50% too far at 0.050, or 0.100, and so on? That would say you have a steps per inch problem.

I spent a little time on Automation Technologies and found the data sheets on what you have.

In particular, your motor driver. According to the picture of the KL8070 set you got, the controller is the KL9082. The data sheet is linked on the web page for that part (toward the bottom).
https://www.automationtechnologiesin...rivers/kl9082/
Your NEMA 34 1200 in*oz motors are 200 steps/rev. The data sheet says that you can set it to any one of 16 values for steps per inch: 400, 500, 600, 800, 1000, and up to 10,000 steps per rotation. If you're using a 5.08 turn per inch pitch ballscrew, like the ones in Hoss' plans, I don't see a setting on that motor driver that will give you 1600 steps per inch.

Do you know what the ballscrew pitch is? You mentioned eBay, but no numbers on the screws.

[kies277]

The pitch is 5mm

[kies277]

This is the driver

The pitch is 5mm

[CFLBob]

This is the driver

Interesting to see that. AT doesn't have the datasheet for it displayed on the webpage, and searching for KL-8070 only brings up the kit with the pictures of the other driver in it, but they have the datasheet here (web search found it). Still, you can see all the switch settings on the motor itself - the same table is in the spec.

The 5mm pitch means the 5.08 revolutions per inch that Ken226 said is correct.

I'm also using 1600 steps per rotation of the motor, times 5.08 rotations per inch or 8128 steps/inch. I took a look at them in Mach3 a little while ago, and the tuned value is 8137, which is 0.1% different than computed. I'm also using an Ethernet Smooth Stepper.

I've never seen this sort of weird problem, so I'm guessing here, but in my work life I've noticed that when weird things happen, I should check the grounding. I'd say to check the wiring to the motors and make sure both ends of each wire are connected with no loose connections. Likewise look for loose wires or bad connections in your box that's driving the motors. If you run ground wires, check those.

Also, it's not that's off in only one direction, like only going up or down, right?

Something this weird sounds like it could be software, but if it's one of the big names, I'd assume it's good.

[tjhe]

I've been reading a lot of threads and trying to solve an issue I have and this seemed the most appropriate place to post. The quill/spindle on my G0704 is getting insanely hot, particularly the lower section where the bottom angular contact goes. I pulled it apart and the bearings didn't feel great, so bought some new ones on eBay and installed them today. Everything is still getting wicked hot, I measured 170+ F on the bottom of the quill (big part that doesn't retract into the head), and that was after a long break in process and even taking it apart multiple times and trying different combinations of slight preload change and amount of grease (can't really change anything else it seems). Is there a spec for the preload nut? I get it snug with the bearing and then tighten it barely a hair more since I can't find anything of what or how to preload it the correct amount. I'm using the same 32005X and 32007X bearings that came on the machine (albeit a different manufacturer, still Chinese though) and some multi-purpose Lucas Oil grease that I run in the wheel bearings of my truck. I saw far back that Hoss said 140F wasn't bad for normal running conditions, and higher for break in. Am I just being paranoid, and maybe the original bearings were even fine? Having the quill get so hot I can barely have my hand on it for more than a second or two after running 5 minutes at 2000rpm unloaded doesn't seem normal, especially since most people report temperatures in the low 100s or even sub-100. Really not sure what to do now or how to proceed... Thanks.

[phomann]

This may be a little left field but....

Is it possible that the drawbar is being tightened up against the top bearing holder, rather than against the quill?

I use a Tormach drawbar that is too long so I made a spacer that sat on the outer spindle shaft. It was compressing the bearings causing similar symptoms.
I had to make the spacer sit on the quill instead.

Cheers
Peter


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[tjhe]

This may be a little left field but....

Is it possible that the drawbar is being tightened up against the top bearing holder, rather than against the quill?

I use a Tormach drawbar that is too long so I made a spacer that sat on the outer spindle shaft. It was compressing the bearings causing similar symptoms.
I had to make the spacer sit on the quill instead.

Cheers
Peter


Sent from my iPhone using Tapatalk Pro

I wish that could be the case, but I've left the draw bar out since my first time putting it back together this morning; even then I didn't put any tools or collets in and only hand snugged that top nut thing for the draw bar.

[e53017]

Is purchasing downloads from Hoss still an option? Thx.

[hoss2006]

Is purchasing downloads from Hoss still an option? Thx.

Yes it is, G0704store
Hoss

[e53017]

Ok. Good. Will get on it soon. Out of town working a ton right now.

[dwhempy]

Hello all:

Total newbie here. There is so much info here that my searches have led to frustration trying to find answers .. so please indulge me a few simple (I think) questions.

I have the Grizzly mill and the plan is to convert it to CNC ultimately. It seems to me that Hoss' method is the direction I want to go. So that said, I just acquired the mill and I want to take it apart for its initial cleanup (bought it from a fellow that changed his mind for a substantial discount). That leads me to consider installing the necessary ball screw upgrades at this time. After installation will I be able to configure the mill for use manually? The plan would be to do some milling to get familiar. Perhaps even to mill the parts from Hoss' plans and later complete the CNC conversion. Secondly, I'd still like to be able to do simple manual milling ... is this possible after the conversion? I expect this to be a lengthy project but would like to do it as efficiently as possible (i.e. reduce disassembly steps).

Thanks in advance. Dan

[RTTIM]

Quick question:

In the spindle upgrade there are actually 4 bearings that need to be replaced - the two ball bearings on the combo gear, and the two tapered roller bearings in the quill sleeve..correct?

Thanks!

Tim

[CFLBob]

Dan,

I know this is late, (didn't get a notification) so I hope it's useful. Ballscrews don't work in a manual mill. They have no holding torque and rely on the holding torque of the motor driving them.

As for being able to mill manually, with stepper motors and ballscrews, I can move the table manually. I've only used that ability to position things for a drill press type job or position the motor's shaft to get at setscrew. Get a motor with shafts on both ends and put your handwheel on the second shaft. You can feel the magnetic steps and I'm not sure if that translates into marks on a piece (never looked).


Bob

[dazp1976]

Hello all:

Total newbie here. There is so much info here that my searches have led to frustration trying to find answers .. so please indulge me a few simple (I think) questions.

I have the Grizzly mill and the plan is to convert it to CNC ultimately. It seems to me that Hoss' method is the direction I want to go. So that said, I just acquired the mill and I want to take it apart for its initial cleanup (bought it from a fellow that changed his mind for a substantial discount). That leads me to consider installing the necessary ball screw upgrades at this time. After installation will I be able to configure the mill for use manually? The plan would be to do some milling to get familiar. Perhaps even to mill the parts from Hoss' plans and later complete the CNC conversion. Secondly, I'd still like to be able to do simple manual milling ... is this possible after the conversion? I expect this to be a lengthy project but would like to do it as efficiently as possible (i.e. reduce disassembly steps).

Thanks in advance. Dan

Ballscrews are are hell of a lot looser than acme and I'd say you're better off leaving it as is for manual atm.
You could figure out what motors you want to use and fit them early on with the screws and add control elecs later. This will help a little bit to manual mill with the ballscrews.

1 option is to use a belt drive/pulley setup between the motors and screws and have manual handles on the ends of the screws.
Another option is to use dual shaft motors direct drive with handles attached to the rear motor shaft.

I don't know much myself but I've seen both setups used.

[CounterSunkenTreasure]

Far as I know they only come in 4 lengths, 6", 12", 24" and 36".
A g0704 would need a 12 (Y) and two 24's (X and Z).
Cutting them is no big deal, read some tips here.
Need Help! iGAGING DRO SCALES.MOUNTING G0704
Hoss

Is there a reason for a 24" on the Z scale? The manual calls out 11" of travel. Is it due to your head flip mod?

[skyguynca]

I have been running my Hoss G0704 cnc conversion with very few problems for the past 4 years.

This week I decided to change my ATC4 from a 6 tool rack to a 10 tool rack. So I made all the pieces, built up the new 12 inch ATC4. I went into the vb script and changed everything to show the new positions of tools, new tool count and new degrees separating the tools.

Here is the NEW problem, I set the steps for the tool rack about 15 or 16 times now. It does 360 degrees on repeated checks. When I run a dry tool change the tool rack either under or over rotates. No changes to the VB script or to the motor tuning or steps per degree but it will not repeat the rotation for tool changes, every one is different no matter what tool I select. If I go from tool 1 to tool 10, the first time it will under rotate, the next time it might over rotate or under rotate, it is not consistent in the error of over or under rotating.

Any one seen this problem before?

Please all suggestions will be gladly accepted.

David

[Fastest1]

I had a similar issue on my DM3000 lathe. It has a 6 tool changer. For ages it was spot on. It started doing just as you described and I could never find the cause. However I was running Mach3 via the PP. Back in the XP days. It has been on a back burner for a while.

I have been running my Hoss G0704 cnc conversion with very few problems for the past 4 years.

This week I decided to change my ATC4 from a 6 tool rack to a 10 tool rack. So I made all the pieces, built up the new 12 inch ATC4. I went into the vb script and changed everything to show the new positions of tools, new tool count and new degrees separating the tools.

Here is the NEW problem, I set the steps for the tool rack about 15 or 16 times now. It does 360 degrees on repeated checks. When I run a dry tool change the tool rack either under or over rotates. No changes to the VB script or to the motor tuning or steps per degree but it will not repeat the rotation for tool changes, every one is different no matter what tool I select. If I go from tool 1 to tool 10, the first time it will under rotate, the next time it might over rotate or under rotate, it is not consistent in the error of over or under rotating.

Any one seen this problem before?

Please all suggestions will be gladly accepted.

David

[rwskinner]

Really, either backlash, something is slipping, or the stepper is loosing or gaining steps due to the extra mass.
Try slowing it way down and back the accel off and see if it improves. When I went to 12 tools, I had to slow it down some, but it is still really fast.

[phomann]

Yes, i agree. It definitely sounds like it’s missing steps. It could be due to extra weight, etc.
check that the motor settings acceleration is not too high.
As suggested, try slowing everything down.

Cheers

Peter


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[Fastest1]

Yes, i agree. It definitely sounds like it’s missing steps. It could be due to extra weight, etc.
check that the motor settings acceleration is not too high.
As suggested, try slowing everything down.

Cheers

Peter


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In my case it wasnt missing steps nor had any loose hardware.
And it wasnt consistent in the amount traveled positive or negative.
This was years ago. It was damned infuriating. Especially after running trouble free for years.
I always suspected an automatic update but couldnt track it to anything.
Slowing down accel etc never made any change.



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