[hoss2006]

So i take it that power tapping capability is still to be determined? I guess this also makes me wonder if you able to do power tapping with the stock setup and cnc spindle control?

I did power tapping with the stock motor, 3/8-16 in steel plate went fine but
a 1/2-13 attempt sheared the R8 pin. With a better pin who knows. Tapping under cnc control is still a project on the list.
Hoss

[hoss2006]

Hoss, you probably know this already but if you increase the pulley diameters the load per-tooth of the belt drops accordingly, and likewise if you increase the wrap angle (especially at the smaller pulley where the tooth load is much higher and wrap angle is much less).

And 3/8" belt width might be a little small for such a lot of torque too.

I figured the 3/8 belt wouldn't last long with the 1100 watt motor but it is what's on there now so I might as well test it for sure.
The belt can handle quite a bit, come on, a 1 inch depth of cut is pretty stout for any machine and it did it with the stock motor.
That's more than most people would ever even attempt, certainly not under normal situations.
One of the reasons for doing these tests is to show that throwing on a massive motor might not make sense if the machine can't make use of the power. There has to be a legitimate reason for me other than just bragging rights. I figured it would need a bigger belt and that'll be next, then we'll see if the mill is rigid enough without any column stiffness mods to put that power to use. It can be a slippery slope.
Hoss

[hoss2006]

I am sure you mentioned this elsewhere, but what 1100 watt motor are you using?

It's from a WMD30MV from Weiss Machinery in China.
Projects2
Hoss

[mrcodewiz]

yup, the stock motor and 3/8 belt has no problem with .5 doc either.
The point of upgrading will be to exceed the 1 inch doc @ 4 ipm
otherwise it's a waste of money.
Hoss

This is a legitimate question so don't take it that I am questioning your intent - and I know a lot of what you are doing is experimentation. What is the benefit of being able to do a 1 inch cut @ 4 IPM vs. a .25 DOC @ 16 IPM (which the mill appears to be capable of in stock form, or close to it, with the belt mod)?

[hoss2006]

Nothing wrong with doing a lighter faster cut, I'll be doing (have done) HSM so I'll do cuts like .025 @ 150 ipm.
The point of doing the deep cut test is that it pushes the mill to it's limit as far as rigidity goes.
That's the benchmark, the stock motor handled 4 ipm, we'll see what the 1100 ipm will be.(can't go any deeper with the test endmill)
If I use a shallow depth for a benchmark, I might run into rpm, chip load and/or stepper limitations too.
The other purpose of the tests is to show that if someone plans to run within the capabilities of the stock mill
mounting a more powerful motor is a waste unless they just want to say, I have 2.8 hp.
Hoss

If my longer v belt gets delivered tomorrow I'll be able to try those pulleys next.

[gd.marsh]

Hoss,

I really like the coiled oil lines .. I know McMaster Carr has them ..
Just wondering if you found a better (less expensive) source?

[hoss2006]

Hoss,

I really like the coiled oil lines .. I know McMaster Carr has them ..
Just wondering if you found a better (less expensive) source?

They were only $6 a piece for the 1/4" ones I used at Automation Direct.
Single Tube Products
Hoss

[hoss2006]

DOH! It dawned on me today that I was jogging not feeding when I tried the XL belt with the 1100 Watt motor.
I was jogging at 10 not feeding at 10 IPM when it stripped the belt, I was technically feeding at 25 IPM.
Put a new XL belt on and FED at 10 IPM and it breezed right thru the stock.
A 15 IPM attempt though snapped the belt.
Still successful as it was able to do 250% better than the stock motor.
Hoss

[ame=http://www.youtube.com/watch?v=kETrcuy3l0k]G0704 1100 Watt Motor Hogging Test 1 XL Belt.wmv - YouTube[/ame]

[rwskinner]

I see the DOC was 1" but how much deep was your side cut? Looked around 50% or so. What RPM?

[hoss2006]

1/2 inch width of cut @ 2500 rpm
Hoss

[gun_mike]

Hey Hoss,
I came across this in the machinery's Handbook a while ago while building my mill. I found it very useful in determining and adequate sized belt. Hope it helps.
Mike

[michaelthomas]

I have been using the GT2 3mm belts on other projects......they can take an awful lot more power for a similar widths than the XL's. Seems like you already had something else in mind, though.

FWIW, the GT2 belts also have much less backlash at a given tension......handy to know for positional systems, anyway.

[michaelthomas]

Here is the chart.

[hoss2006]

Hey Hoss,
I came across this in the machinery's Handbook a while ago while building my mill. I found it very useful in determining and adequate sized belt. Hope it helps.
Mike

Thanks, I'd been going by a pretty similar chart from this pdf.
http://www.naismith.com.au/pdf/timingpb.pdf
Just had to prove them right.
Hoss

[hoss2006]

I have been using the GT2 3mm belts on other projects......they can take an awful lot more power for a similar widths than the XL's. Seems like you already had something else in mind, though.

FWIW, the GT2 belts also have much less backlash at a given tension......handy to know for positional systems, anyway.

I mentioned a while back I looked at HTD type pulleys but they are harder to find and more expensive.
The XL pulleys are ones I made myself so I can't use a GT2 belt.
Thanks though.
Hoss

[hoss2006]

You got me wondering about the GT2 pulleys so I spent the last couple hours collecting
a bunch of data for the pulleys, GT2 3mm's and GT2 5mm's to see what could work.
SDP-SI carries them and the prices aren't too terrible.
The 3mm's are nogo, they are just too small to be able to work with the belt drive,
not enough width or flange diameter to work with on the spindle side.
The 5mm's which are pretty close to XL pulleys could be used for a single pulley quill version setup
but they have less meat and flange diameter than XL's to do a double pulley setup.
I may consider making a non quill double GT2 5mm pulley version but it would be another $75+ for parts.
Think I'll just stick with the L belt since it's a 3/4 wide belt good for up to 8 HP.
Hoss

[SgtSpyder]

I’m almost done redoing my quill pulleys for the treadmill motor. I’m using GT2 5mm pulleys from SDP-SI. The ones I got were solid pulleys unlike the XL’s. Did single pulley on the spindle and just swap the motor pulley for High and Low.
A 6A55-034DF1516 2 $16.44/Each
A 6A55-040NF1516 1 $16.79/Each
A 6A55-020DF1508 1 $13.10/Each

[hoss2006]

A couple of the same pulleys I figured to use, good luck.
Hoss

[Luis Van Damme]

Is this same machine as Opti BF20? What is the cheapest CNC kit for this?

[hoss2006]

Is this same machine as Opti BF20? What is the cheapest CNC kit for this?

For the most part it's a similar machine, motor and spindle being the main difference.
MTW carries the same kit as from Optimum that come with the motors.
https://www.machinetoolswarehouse.co...t-p-16334.html
Optimum Machines: Complete and add-on kit BF20
You'll have to contact Schlitt for their kit prices.
Präzisionstechnik Schlitt
Cncfusion may one day finally have a kit for sale but you'll still need to get the motors, drivers, etc.
CNC Fusion :: View topic - Sneak Peak: first kit pics.....
Hoss