Hello Guest it is October 19, 2019, 09:01:32 AM

Author Topic: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?  (Read 21215 times)

0 Members and 1 Guest are viewing this topic.

Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #40 on: October 14, 2012, 12:43:49 PM »
Unless you're using the worlds worst CAM, rapids will amount to a VERY small percentage of your total machining time - typically just a few percent.  As Hood indicated, higher acceleration is of more value for most applications, especially for 3D work, where low acceleration can increase your machining time many fold.  100 IPM is a perfectly reasonable rapid speed for a BP, and you'll gain little by going much beyond that.  As Terry indicated, you start going too fast, and the machine will start shaking, and walking all over the shop.  Plus, of course, when things go wrong with fast rapids, they can go very wrong, VERY quickly - before you have time to hit the big, red button.  I have servos on mine, and it's quite capable of running 350 IPM, but I run at 200 IPM, because there's just nothing to gain by going faster, and the chances of a destructive accident are much greater.

Regards,
Ray L.
Regards,
Ray L.

Online BR549

*
  •  6,902 6,902
    • View Profile
Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #41 on: October 14, 2012, 01:13:14 PM »
(;-) Yes EVERY movement takes time BUT that is what CNC is all about when it is running it is NOT your time. You can be doing something else while it runs. 

Add all the rapid times together and it will STILL be just a minor fraction of the total time to cut. Spending time to optimize the cutting is WHERE you save your time(;-)

(;-) TP
Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #42 on: October 15, 2012, 04:35:23 PM »
OK Guys... Ill stay with what I have and try it out.  Thanks for you advise on the subject. Ill probably be back with a little news on the project.

Best regards

Leif
Software in use :

Mach3
Cambam
Cutviewer
Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #43 on: December 02, 2012, 08:32:30 AM »
Hi Gropper,   How are the Chinese Steppers working out for you,   I was thinking about doing the same thing on a Series 1
R2C3 I just got my hands on, ( SEM DC motors are there but drivers and controllers are shot) ( was going to use MACH 3)

 I am not interested in speed,  I just want to be able to mill shallow grooves in plate aluminum for urethane molds,
I am new to this group and CNC in general so any suggestions from group also is appreciated.

I thought about keeping servos and using Dugong drives but I also want to be able to repair quickly if needed in the future, and I am not sure how easy and expensive it would be to find a servo replacement if needed
« Last Edit: December 02, 2012, 08:43:21 AM by POLY-MAN »
Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #44 on: December 02, 2012, 01:08:36 PM »
Hi,

After a little tweaking, the set has been a nice surprise to me, the speed and precision is more than I ever expected, so I`ll recommend the set to anyone who need a good performance without paying a kingdom......  Make sure you have ball screws on the machine OK, those acme screws need a bit of software compensation almost every time you use your mill.  The Long set I bought is OK for a Bridgeport, that's my opinion on the issue.

All the best

Leif
Software in use :

Mach3
Cambam
Cutviewer
Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #45 on: December 10, 2012, 04:02:31 PM »
I have 870in/oz Pacific Scientific Hybrid Nema 34 single stack stepper motors on my series 1BP.

I retrofitted ballscrews and run a 3-1 reduction. PS is 70v 800W(IIRC) and I run G203V drivers.

I get 80 IPM rapids and regularly cut at 20 to 50IPM.

870In/OZ in this setup has been plenty! No need for monster motors!
Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #46 on: December 11, 2012, 06:35:24 PM »
Hi Natefoerg,

I guess the higher voltage and a bit better drives make your setup performing close to the Long set
that I bought on Ebay .....

All the best

Leif 
Software in use :

Mach3
Cambam
Cutviewer
Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #47 on: December 11, 2012, 09:31:35 PM »
I can say that good brand name steppers and Gecko 203V drivers have left me with nothing but good performance. I can run for hours at 50ipm and never loose a step.

Very happy with my setup, and it was affordable. (I bought the motors surplus- new take offs from demo machines, I cant imagine what they cost new...)
Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #48 on: December 12, 2012, 12:09:42 PM »
I tried a test with my Bridgeport....... drilling ten 1 mm holes diagonal on a piece of alumina
and the machine was set to repeat the hole process 125 times,  all holes were totally
perfect, so no lost steps here either, but the geckos are fine .... I tried a set last year on a
mill from Taiwan.
Software in use :

Mach3
Cambam
Cutviewer
Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?
« Reply #49 on: December 14, 2012, 01:13:38 AM »
Well, maybe this test needs a little explanation to be understood.....  the holes where diagonal to the milling table and the mill drilled the same ten small 1 mm. holes 125 times, and all were still perfectly circular after the entire process , I guess that's a pretty good way to look for lost steps.

Leif
Software in use :

Mach3
Cambam
Cutviewer