Thought I'd cut through the chase and ask everyone's opinion is for the best CNC 4th axis under $1,000 is?
Best "Affordable" 4th Axis
- Thread starter dunkelcustomcue
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Thanks Willee. I was looking to get some of the experts opinion on what they thought was the best. I looked at Ebay see a lot of different ones for sale. Seen many belt drive and a few direct drive. I would think direct drive would be more accurate.
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It is the other way around, direct drive will have less torque . Belt and pulley be like 3 to 1 or 4 to 1 , which means motor has to make 4 revolutions to one turn of pulley on 4th axis . Direct drive is 1 to 1 . Unless it is a harmonic drive set up, but they would start around $2000 for a good drive
Thanks for the info. When will yours be available?
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i am planing to start next week on them
There's a reason most of the high-end indexers use a worm gear drive. I've owned my Haas indexers for more than 2 decades, and I've adjusted them for backlash twice in that time. The worst error I've had, after many years of use, was roughly 0.020 degrees, which translates to 0.0002" on the surface of a buttsleeve. After adjusting them the "error" is too small to measure.
TW
Actually, harmonic drives are still relatively rare in the field of commercial machine work. Currently, the vast, VAST majority of industrial indexers utilize the worm gear model. However, the actual point to be noted is you will not find BELT-DRIVEN indexers in any industrial application that calls for accuracy and/or rigidity.
TW
By saying that, your saying any machine running servos will not be rigid or have accuracy . 40 tooth belt and pulley set ,you have no problem with accuracy for what you need.
I myself see lots of machines with harmonic drives daily. Also run a complete machine 6 axis with harmonic drivers on each axis .
Worm gear set up is more expensive for a good one than belt and pulley set up. But 1/10 the cost of Harmonic drive
Um, tell you what... how about I say what I say and you say what you say, and you keep your words out of my mouth? Think we can agree on that? 'Cause I didn't say a damn thing about the accuracy of servos, or anything that can be so interpreted.
Yeah... at first. But timing belts wear and they stretch, and both those things happen the more and the harder you use them. So you can count on "accuracy" for a while, but you can't really count on rigidity at all. If you believe otherwise please point to any industrial-grade indexer in the class of a standard Haas 5C unit (or similar device) that uses a timing belt for their drive and I will happily stand corrected.
Be that as it may, worm gear indexers surely outnumber harmonic drive system by a thousand to one, if not much, MUCH more.
Exactly. My application list would look like this:
1) Belt drive indexer = suitable only for the lightest applications and least required accuracy;
2) Worm Gear Drive = rigid enough for most medium to heavy machining operations requiring a very good degree of accuracy and repeatability;
3) Harmonic Drive = rigid enough for most medium to heavy machining operations requiring the highest degree of accuracy and repeatability... but too expensive for a typical cuemaking oppertaion.
TW
harris cue comp
Banned
4 axis
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OK No problem,
I believe he was asking for 4th axis under $1000 for doing pool cues. MAYBE if doing steel or aluminum he might need more. A high quality real worm gear set up is around $8000 for a new one. But you can spend 300$ or $400 and get same job on pool cue with belt and pulley. Add a brake and would be even better the belt and pulley set up if cutting larger cuts .
i also said about servos on a machine, is that almost every machine will have belt and pulley set up .
Also on ebay you will see stepper motor attach to shank as direct drive. Some with gear box and all kinds.
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Not everyone aspires to only index, hence the concern for real accuracy
Apparently old cue makers have no clue as to what there saying. What in the hell does high speed spindle have to do with a 4th axis. And, what in the hell is a high resolution VFD spindle?
I am not an experienced machinist, just a basement hobbiest guy, and cannot comment on the other options, but I have one of the 50:1 harmonic drive 4th axis units from ebay and it works fine for me, with virtually no backlash. I have noticed that some ebay sellers advertise their belt-driven units as 'harmonic' drives, obviously in error. I have disassembled mine and confirmed it is indeed built upon the strain wave concept. There were less expensive versions than mine, which, shipping included, was around $400 with an 80 mm chuck.
FWIW
mac
FWIW
mac
RBC
Deceased
Robert,
While you are correct that just simple indexing can be done with simple devices, it' still smart to let people know the ups and downs of all the choices.
A very common problem among those who are venturing into more intricate designs is backlash in the indexer. And, rigidity pretty much falls into the backlash category.
One of the big waste's that I see new cue makers experience is to just buy what they need right now without thinking far enough ahead. In many cases, the new guy doesn't know what's that far ahead, but he can certainly ask.
With the availability of what's out there these days, it's certainly worth going over all of them. Thomas is very well equipped with the commercial indexer. Is it overkill? Maybe, but it works for him and I'd certainly rather fudge to the "it works" side than the "it doesn't work" side. This is a lesson I've learned the hard way. I'm pretty much a cheap bastard and want to make everything to save a buck. But I've learned that some things are much better to just buy.
I have a small harmonic drive that I pirated from a small servo that came off a wire bonder I bought at an auction. My plan was to build a small frame to mount it in and attach my A axis motor to it with a coupler. But now, I see actual harmonic drive 4th axis setups already built for under $500. To me, that's money well spent if it's made anywhere half way decent. I now have seen another cuemaker purchase one and has good things to say about it. I will probably give it a try. I'm not worried about the drive itself as the design is pretty solid. If it actually has bearings on all the rotating members, it should be a good component. I'll use my motor though.
Also, there are many precision rotary devices available on ebay and at equipment auctions that are pretty much everywhere. These are extremely high quality devices and they can be easily adapted to our use. And, they have near zero backlash.
So all of these are choices that I think the OP should get to here. I'm happy to throw my opinions and choices out there, but that's so the OP has choices to research for himself. I don't feel the need to convince him, or anyone else for that matter, that my choices are what's best for him. Where these situations derail is when the people who are offering their thoughts and opinions start to do battle with each other over who is right and who is wrong. There isn't a right and wrong. The purpose is to provide information to the OP so he can choose for himself.
Oh, and I'm with Jake in that I also question what you meant with "high resolution" spindle. Were you talking about the runout? Just curious.
Royce Bunnell
www.obcues.com
On a machine I built for Jerry McWorter back in the 90's I bought a manual 5C-collet indexer for $160 new. It was an Asian import that closely resembled the Haas indexer of that period. The same class of indexer can be purchased for just over $200 today: www.ebay.com/itm/SHARS-VERTICAL-HORIZONTAL-5C-COLLET-SPIN-INDEX-FIXTURE-0004-NEW-/350256693801?pt=LH_DefaultDomain_0&hash=item518ced0229
I bought a large worm and worm-gear set from Stock Drive Products for another $125 or so. I took my own Haas indexer apart and studied th construction, then I machined similar housing and mounts for the imported indexer. FWIW, the Haas indexers of that era were built the same way, from an existing manual indexer.
I added a NEMA 34 motor mount and a stepper motor, creating a CNC indexer that was every bit as accurate as my Hass for under $300 total parts cost and 2 days work. The same job could be accomplished today for well under $500, so it is HARDLY necessary to spend "$8000" to end up with a high-precision worm-gear indexer.
McWorter used that indexer for many, many years before upgrading to an indexer with a larger through hole than 5C allows. but as far as I know the indexer is still working fine for the new owner.
Okay... except that the servo-driven belt and pulley set ups found on "almost every machine" are NOT being used to index parts. They're being used to drive linear axes by turning ballscrews. The "rigidity" of those applications comes from the angular contact bearings holding the ball-screws, NOT from the belt and pulley drive aspect.
So, just to be clear, "almost every machine" is NOT using servo-driven belt and pulley systems for indexing - that is decidedly what would referred to as a "home/hobby" solution.
TW
(PS: I routinely machine metal parts on my 4-axis machine for jigs, drive centers, and other tool-related items. I can't imagine getting the clean accurate results I get if I was using aluminum timing pulleys and rubber belts to rotate and index those parts.)
Well , there is steel martin sprocket pulleys, there is carbon fiber timing belts. Rubber belt ? Never heard that saying before.Some reason multi quote didn't stay.
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Hi,
As a mariner there is and old saying I wish to share.
Motor boats are designed to motor well.
Sail boats are designed to sail well.
Motor-sailors motor and sail but don't do either well.
I am not an expert by any means and am finding my way concerning the 4 th axis geometry and application on a cue. What Royce stated rang true as many new people have blinders on concerning what they may need or want down the road. That has been a truism in my shop concerning many pieces of equipment over the years. So to the new guys the best advise is to very careful before making any purchase.
You can search for one thing that will do both 4th axis and also spin blanks at 150 to 200 rpm for a reasonable price like the Motor-sailor but you can also have two separate machines. That was my solution.
If I did not already have my first machine when I upgrade to a new CNC, I would set up a variable speed controlled DC motor with a dead center and spur system as my tailstock for spinning blanks and connect a live center attachment on the headstock. When using the A for 4th axis or just indexing you could attach that live center to the tail stock shaft if it was designed to be interchangeable.
Ten or twenty years ago it would not be practical to have two machines for most independent CMs. VCRs were 1200.00 when they first came out and we all know that the price came down with consumer demand and mass production. While bench top CNCs will never see as big of a price reduction as VCRs did, they have certainly allowed a successful cue makers to afford more than one in their shop.
Having a second CNC or binnacle machine in your shop is not a bad idea. If one takes a shit you can keep working concerning ring billets and inlays to keep up production while repairs await parts ect.
JMO,
Rick
As a mariner there is and old saying I wish to share.
Motor boats are designed to motor well.
Sail boats are designed to sail well.
Motor-sailors motor and sail but don't do either well.
I am not an expert by any means and am finding my way concerning the 4 th axis geometry and application on a cue. What Royce stated rang true as many new people have blinders on concerning what they may need or want down the road. That has been a truism in my shop concerning many pieces of equipment over the years. So to the new guys the best advise is to very careful before making any purchase.
You can search for one thing that will do both 4th axis and also spin blanks at 150 to 200 rpm for a reasonable price like the Motor-sailor but you can also have two separate machines. That was my solution.
If I did not already have my first machine when I upgrade to a new CNC, I would set up a variable speed controlled DC motor with a dead center and spur system as my tailstock for spinning blanks and connect a live center attachment on the headstock. When using the A for 4th axis or just indexing you could attach that live center to the tail stock shaft if it was designed to be interchangeable.
Ten or twenty years ago it would not be practical to have two machines for most independent CMs. VCRs were 1200.00 when they first came out and we all know that the price came down with consumer demand and mass production. While bench top CNCs will never see as big of a price reduction as VCRs did, they have certainly allowed a successful cue makers to afford more than one in their shop.
Having a second CNC or binnacle machine in your shop is not a bad idea. If one takes a shit you can keep working concerning ring billets and inlays to keep up production while repairs await parts ect.
JMO,
Rick
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