Feed v thread

[John5431]

Hey all,
So I bought this about 2 years ago and finally got around to installing it. Battled it for a while until I saw the error message in code composer the compiler was the wrong version. I downloaded correct version and compiled it without errors. I'm running the server motor that James is using and is a 3:1 with 24 tooth to a 72 tooth pulleys, testing I see that the threading is working but the feed in turning is about half the speed at feed setting .008 the carriage is moving about .0035. I did read the post below about different speeds and feeds but i don't have two screws. Would this work for my installation? #241
Thank you
John

[John5431]

I seeI guess I answered the question, no it won't help my issues. I messed with it and it did nothing to speed up my feed. I also messed with the Servo's settings that fixed the feed and changed the threading. I guess I'll just have to live with it, It's still better than switching gears any day.

[hr2burn]

Sorry I don’t have answers for you John, I am perplexed that threading/pitch is correct but not feed. The tie between spindle & gear box is there, but the ratio changes once you step into feed. It’s obviously not mechanical, it has to be in the firmware. Hopefully someone who understands the breakdowns, chimes in. I will dive deeper into the code & see if I come across anything. I would guess a lead screw pitch setting IF there is one for threading & one for turning?

[hr2burn]

Even though you don’t have two lead screws, I would bet you have the 2 lead screws option in play & with different settings…

[John5431]

Even though you don’t have two lead screws, I would bet you have the 2 lead screws option in play & with different settings…

I did use that setting trying different combinations setting microsteps to 1 and leaving resolution at 1000 nothing happened same with 6, 1000 then I tried to drop the resolution to 500 on both 1 & 6 microsteps and got the same results. Yes my gear box is set to 1-1, thanks for looking into this I can follow instructions can build a CNC machine but I'm not a very good programmer it takes me forever to understand it. Oh and saying nothing happened may be wrong I never tested the treading again after changing the settings. Everything is set back to what it was.

[hr2burn]

I’m with you, this coding/flashing is a PIA. Perhaps use the 1.3.0 version? It’s what I use and I don’t believe it has the option for 2 gearings (1 for threading, one for turning) just spit ballin’

[dsgroninger]

One thing I don't see in your description is if your power feed is done with the half-nut on the lead screw or if it's through a gear box on the saddle? On my lathe (Precision Matthews 1030), threading is done with the half-nuts on the lead screw, but the lead screw also turns gears in the saddle gear box at all times. There's an engagement handle to drive the saddle along the ways using this gearing. When gear driven for feeding, the rate of movement is different than directly engaging the lead screw. If I remember correctly, for my lathe it's 3:1 slower for feed than for threading directly from the lead screw.

Here's a writeup that I did on my build:
Clough42 Electronic Leadscrew.pdf

I have a couple of pages about half way through showing changes I made in configuration.h to account for the difference in the gearbox. Hopefully this is helpful for you.

[John5431]

One thing I don't see in your description is if your power feed is done with the half-nut on the lead screw or if it's through a gear box on the saddle? On my lathe (Precision Matthews 1030), threading is done with the half-nuts on the lead screw, but the lead screw also turns gears in the saddle gear box at all times. There's an engagement handle to drive the saddle along the ways using this gearing. When gear driven for feeding, the rate of movement is different than directly engaging the lead screw. If I remember correctly, for my lathe it's 3:1 slower for feed than for threading directly from the lead screw.

Here's a writeup that I did on my build: Clough42 Electronic Leadscrew.pdf

I have a couple of pages about half way through showing changes I made in configuration.h to account for the difference in the gearbox. Hopefully this is helpful for you.

I do have a gear box and half nut, I'll read through your PDF and do some of your recommendations. Thank you for responding and giving me some direction.

[John5431]

Thank you this did work, odd that I didn't see any results the first time but then again the numbers I used were a fraction I needed. My screw is 16tpi and the reason I wasn't seeing much of a difference with putting ( Stepper_Microsteps_Feed 6 ) it just wasn't a big enough value.
Thanks again

[dsgroninger]

Hey, cool! Glad you got it working and happy my writeup helped.