Prs standard

[david_white]

What will a prs alfa do that a prs standard won't. I will probably be buying a bot soon and just need a little help understanding the difference between the to thanks.

Dave

[Brady Watson]

Dave,
The Alpha has positional feedback, meaning that if you push the steppers a little too hard, they will self-correct. The Alphas also have about 2 times the cutting force of a Standard, and the electronics are more robust. The Standard will also cut up to 12" per second, where the Standard is limited to about 6 to 8 IPS depending on what you are cutting. The Alpha is a production quality tool. The Standard is still a good tool that will work very well, but if you do a lot of cutting or demanding work, the Alpha is the better choice.

-B

[jhicks]

Looks like Brady has a pretty good comparison as usual. Given that my PRt runs pretty well and gets us what we need, I'm OK but would really like to increase cutting power and speeds while not sacrificing or better yet improving accuracy. I have the ascension control box and am content that it delivers clean code and can run faster but the limit now seems to be motors, missed steps when pushed too hard.(read not much over 180 IPM) on wood but maybe 480 on soft HDU etc on 3D stuff)
I'm familiar with the mechanical tweaking that may help on gantry stiffening etc but it still comes down to the motors I think.
What is best way to upgade motors? Are micro steppers with gear reduction the best answer and any idea how much? I've investigated more powerful motors and gear reduction as aftermarket solution and think that may be the way to go but before doing that I wanted to see if Shop bot offered any canned solution.
Not being quite as technical on these issues as others, it seems someone might have the perfect solution already for the PRT.
Any feedback is appreciated.

[nick]

Hi Guys, My concerns as well...I have a prs standard coming any day now...and was concerned about the real limitations between to two models what is effected at the tool ...quality issues, or just twice as long to cut...

I was told this is a good starter setup...so we'll start small and grow into something else as needed...

[rhfurniture]

Horses for courses. I make high end chairs in small batches and my prt 4G (as prs standard) will do everything I want. If I were making kitchens and trying to process 10/20/30 sheets a day, then it would have to be the biggest and best. There may have been one or two times in my 3-4 years when Alpha closed loup self correction might have been useful, but never essential. But then I do not push it to the limit(speed).

[richards]

It takes a lot more than just faster motors to make a machine cut twice as fast. I have a PRT-Alpha, but I rarely run it faster than 5 or 6-ips. It can cut at 10 to 12-ips, but the quality of cuts made at high speed leaves a lot to be desired.

Even with my 3-hp spindle and two FEIN vacuums, I can't cut one-pass through-cuts without having the material slide around (on most pieces).

To get acceptable edge smoothness and acceptable dimensions, I normally use three passes on most perimeter cuts. Two passes climb cutting and one full-depth conventional pass (leaving about 0.020 inches of 'skin' to hold the parts together).

The 'positional feedback' feature of the Alpha motors has not been much help to me. Because all three axes are not connected in a feed-back loop, I've found 'divots' in a cut when one of the motors partially stalls and then recovers. So, whether a standard motor misses steps and ruins the cut, or an Alpha motor partially stalls and ruins the cut, the cut is still ruined.

I'm not trying to talk anyone out of buying a PRS-Alpha. My good friend Jeff Bishop, who only lives a few miles from me, has one and it is a wonderful machine. But, if your needs and your budget dictate a PRS-Standard machine, you'll be getting a perfectly good machine that will give you excellent quality cuts at perfectly acceptable speeds. On the other hand, if your business plan shows that you've got to make fast, deep cuts, then you'll need the Alpha model AND the biggest vacuum you can buy AND the largest spindle you can find AND you will still have to deal with cutter/machine flex. In reality, what we're really comparing is a PRS-Standard that will cost about $10,000 with computer and router to a PRS-Alpha that will be much closer to $30,000 with computer, large spindle and VERY large vacuum.

[mitch_prest]

this is the information I have been looking for.. its fine to have all that speed and power, but if you can't use it on a regular basis is there any reason to get it.. like buying a porsche and never going on the highway. I have been trying to decide between alpha and standard.. and it sound like the standard will do what I want 90% of the time.
now.. on that note .. can you get a 96x60 standard. and where on the new bots would the additional yz mount go .... can you mount them back to back.. has anyone actually put the second yz on a new bot with the aluminun extrusion....

mitch

[wberminio]

I have a prs standard,4hp spindle.Based on my use,mainly cabinetry parts,
this was a good combo.I could always upgrade,later.