gearbox ratio sweet spot setups

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bertieboy
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gearbox ratio sweet spot setups

Post by bertieboy »

Hi, First post i think? Howdy all, got my centroid acorn box in the mail yesterday and im in australia. I will take my time and get it all retro fitted to my homemade/local made cnc table. I wanted thc and i bought the hypertherm xp45 for the thinner stuff. I looking at the purchase of servos and closed steppers.... as my old setup ran a grbl , i dont have stepper drivers as the grbl could power them straight up... so do the closed steppers need seperate drivers i know the ac brushless servos dont so that makes it comparable in price. Anyway my main question is what gearbox systems are you all running? small belt setups? those ebay enclosed ones? any pics?... I ve got a lathe mill etc so I might make up my own...as I have rack and pinion, im led to believe its not going to be fast enough....anyway any pics of setups would be great if possible. and obviously we dont want any backlash/ sloppyness ?
Cheers Pete
Joey
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Re: gearbox ratio sweet spot setups

Post by Joey »

Hello Pete welcome to the forum!

Can you create a Google Photo album so we can better help with your setup? I prefer Gearboxes over a pulley/belt system. Really it isn't that big of a deal between the two. As far as closed loop steppers Clearpath's have the drives on the motors and are highly recommended. I think most Chinese closed loop steppers have a separate drive.

I think you won't have a problem with speed especially since your able to choose the size of motors to match your reduction and table size. A lot of forum threads have a Google photo album of there machines. Shawn has belt reduction and Clearpath's that you can check out in his thread/album. https://centroidcncforum.com/viewtopic.php?f=65&t=6526.

Jeff built his table with Avid 3:1 belt drives and Gecko open loop steppers. You can see his build album here. https://centroidcncforum.com/viewtopic.php?f=65&t=6423
jcoldon
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Re: gearbox ratio sweet spot setups

Post by jcoldon »

Steppers i found using 900 oz 34 motors . 8 wire wired series wire 72 v gecko vampire drive . with 3 to 1 reduction 1 inch pinion gear 20 deg rack
it speeds 1200 ipm acceleration setting .15 this is very fast stepper driven table That with 30 percent reduction for safety. check my build posts . i used several drives . found AVID cnc pro drives to be best option for steppers . using servo depend on servo size DC or AC weather i use 5 to 1 or 10 to 1 what pinion gear to choose based on weight .. in most cases my table out runs servo tables in it class for half the costs the combo used every day . it all about Propper motor selection and gantry weight and slide system. you can use 5 to 1 with 1.75 pinion get close results . but build mount and buy planetary cost more . i have a FB page cnc plasma table builders . in file section there DXF file gantry riser i designed for 20 mm linear slides and avid pro drive . it very simple . works well use the same combo parts you be cutting like a 20 k table . just ask on form who did the same . why reinvent the wheel i did that the hard way LOL

plasma requires speed high acceleration no velocity slow down good resolution at slow and high speeds for good cuts it not like a mill or router . post your build pic
ShawnM
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Re: gearbox ratio sweet spot setups

Post by ShawnM »

Joey wrote: Fri Mar 03, 2023 12:34 pm Shawn has belt reduction and Clearpath's that you can check out in his thread/album. https://centroidcncforum.com/viewtopic.php?f=65&t=6526.
Slight correction, my plasma table has the Clearpath servo drives but I have planetary gearboxes on the X and Y and the Z is direct drive from the servo to the ballscrew. No belt reduction. The gearboxes came on the table from ShopSabre and I'm not sure what the ratio is but is can move at 1500 inches a minute which is crazy fast. I slowed it down to 850 IPM.

I'm sure Joey talks to many plasma table owners/builders and can easily get confused as to who has what. :?

Pete, if you have the budget for the Clearpath servos I highly recommend them over any stepper drive, open or closed loop. I agree with Joey, they are just simply far superior than any stepper on the market. The drive and motor are in one nice, neat package.
Joey
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Re: gearbox ratio sweet spot setups

Post by Joey »

ShawnM wrote: Fri Mar 03, 2023 3:49 pm
Joey wrote: Fri Mar 03, 2023 12:34 pm Shawn has belt reduction and Clearpath's that you can check out in his thread/album. https://centroidcncforum.com/viewtopic.php?f=65&t=6526.
Slight correction, my plasma table has the Clearpath servo drives but I have planetary gearboxes on the X and Y and the Z is direct drive from the servo to the ballscrew. No belt reduction. The gearboxes came on the table from ShopSabre and I'm not sure what the ratio is but is can move at 1500 inches a minute which is crazy fast. I slowed it down to 850 IPM.

I'm sure Joey talks to many plasma table owners/builders and can easily get confused as to who has what. :?

Pete, if you have the budget for the Clearpath servos I highly recommend them over any stepper drive, open or closed loop. I agree with Joey, they are just simply far superior than any stepper on the market. The drive and motor are in one nice, neat package.
Thankyou for the correction Shawn!
bertieboy
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Re: gearbox ratio sweet spot setups

Post by bertieboy »

Well thanks fellas, much obliged for the info and refrences and even the link to files!... I will do some research and I will see what speeds i get out of my setup atm with the grbl...and go from there, because it might be a little light in the extruded gantry and rails, Im a welder fabricator by trade so the table frame I made,is light but strong and on wheels for shop space etc. it cuts well but you guys have given me a good reflection of where I need to start, and I might even build another table altogether as mines running atm even with a cigweld plasma machine. because i need it for work, the new build might be an smarter option. I will open a photo folder too. i will try my best at posting frequently but im not solely focusing on this, I have alot of builds going on with work, but I need the thc and love the specs of the acorn and im down this rabbit hole and lovin it lol.... im fairly new to cnc too but i will follow up on all you guys have written so cheers. In australia stuff works out alot dearer so I will weigh it all up. the acorn plasma setup cost me around $2400 landed so.....Im liking the sound of the clearpaths and less hassle too. But I do appreciate all your comments and advice, cheers, I will keep you guys posted. Pete
ShawnM
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Re: gearbox ratio sweet spot setups

Post by ShawnM »

Hi Pete, please keep us up to date on your build. We love seeing new builds.

Some additional advice/recommendations from your last post. You’re a welder, build a STEEL frame that is heavy and NOT on wheels. An aluminum gantry might be ok as you need a gantry that offers high acceleration/deceleration. Even a light weight steel gantry is good. You don’t want the table moving and shaking while it’s cutting. You want a heavy base and a lighter gantry. Look at any industrial plasma, mill or router, the base it heavy for a reason. Just my 2 cents.

On another note, I vacationed in Australia about 10 years ago, all up and down the east coast from Sydney to Port Douglas. Best vacation ever.
cnckeith
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Re: gearbox ratio sweet spot setups

Post by cnckeith »

plasma sweet spot.png
Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html
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