I cut my head badly on my BT48 today...

[Brady Watson]

Here's the first part of it...and I need to say that what I am showing you is NOT available as a complete assembly from ShopBot. Do NOT call them and ask! They will tell you NAY-NAY! You can buy a BT48. You can buy an indexer. If you combine the 2, your on your own. I can't blame them since it must be a nightmare keeping up with every different configuration & type of user out there.

Ok...that said, I've been putting off doing this conversion if for no other reason than I have been inundated with work...a good thing these days I hear. (Geez...I sound like Yoda...)


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To answer your 1st question, I didn't run it 'PowerStick style' for a number of reasons. 1st, I like the machine's footprint the way it is & adding a powerstick would eat into the floorspace. This is a 1st Gen BT tool, so the drive system on the machine is a little different than the drive systems now shipping, and a bit more difficult to employ. Since most of the time the tool will raster along the indexer's centerline axis, I found parallel to the gantry beam to have the best stability...and last but not least, I can get about 39-40" between centers, which is plenty unless I decide to get into turning long columns, which in that case, I'll just build a dedicated machine.

A while back I made a 3D model of myself (look on the Vectric page...I'm the guy with his arms folded being cut out...seriously (http://www.vectric.com/WebSite/Vectric/cut3d/c3d_features.htm)!) I took the head off of the body and added some hair in ClayTools. The head is pretty basic and adding hair was a snap:


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I then pulled it into ArtCAM and unwrapped it.


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I couldn't see any real distortion, so I went ahead and toolpathed it.


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...and ran it on the BT, first by doing a 3D rough finishing pass in multiple steps


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...and then ran a finishing pass with a 1/8" ball. It was quick & dirty as you can tell by the stepover marks.


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As you can see, the head looks a bit distorted...so there must be something that I missed. This is the 1st full 3D rotary thing that I have cut out since my PRT days...so I am re-learning everything. One of those things just like anything else...use it or lose it!


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If I have time this weekend, I am going to cut the same model using a 4-sided strategy, using PartWorks3D. This would eliminate any skewing of the model caused by areas that the bit cannot get to - look at the nose - it is wider than it should be & width of head is narrower than it should be. Everything in Pro looked good (see toolpath lines), but it cut out skewed. This leads me to believe that my unit values could have gotten messed up as I was tweaking VR etc or something else at the machine is not correct. A full investigation will ensue...

More on all of this later...

-B

[rb99]

Very nice work. Well done.

RB

[gpari]

Not what I was expecting
I'm the guy that likes to look at traffic accidents...

The head looks like the news guy when my kids have been playing with the widescreen remote.

I need to hook up my spindle, I can't stand seeing y'all have fun without me.

Gabe

[khalid]

Brady..Nice work and you are beautiful..Looking as Knight

Just look at your Neck it is thin....I think you have stopped the machine before completing the work... In other word, the machining will be done till your head fall of the stock...and it is true....because you didn't do one thing...
I will explain the things to you a little later because i am going outside to purchase some stuff for my CNC Quilting machine...

I know what u did wrong

Regards

[myxpykalix]

It almost has a "caricature" look to it. You might have something there!

[curtiss]

Are you sure some of the features were not pasted in from Socrates or Plato ??

[Gary Campbell]

Brady...
Nice adaptation! I love this stuff! Did you disable the X or swap it to the B?
Gary

[Brady Watson]

Thanks guys. It's still a work in progress. File creation is no problem, just something awry in the execution. I'll nail it down. Yanno...there's no learning unless you screw up...and there's no learning without chaos of some sort...There are many ways to use the indexer. Using via B axis config with degree raster incrementation is just one. I will explore the other methods and post results when I get to them.

Yeah Jack, it does look that way! Resembles Shaggy from Scoob's crew.

Gary - I never liked the BT factory config with the X as the logical Y and vise versa. I swapped the X & Y as soon as I got it, so as you view the front of the machine (like the pic at the top) the Y is front to back & X is left to right. With a PowerStick it makes sense. Keeping the table in it's original 'short config', it made most sense to swap the axes.

As far as the indexer goes, it is running as a B axis. No Unit Value 'magic number' like back during the PRT days. The BT moves in X,Y,Z,B. It is running in degrees. All of the indexer hardware was adapted to run on a PRS Standard configuration. The headstock is an 18:1 PK series motor and I have another G203 in the control box. I pulled the Alpha 10:1 off of the factory mount and put the PK motor in it's place. There's no doubt that the Alpha 10:1 is superior to the PK...I just didn't want to hack the PRS control box apart to adapt the Alpha driver. The Gecko fits right in
The Alpha setup has a keyed 12mm shaft, a special chuck adapter and a OneWay Talon chuck. Rather than machine the adapter or wait for a new one to be machined and shipped from Canada, I opted to take a ride over to Penn State Industries. (took me 2.5yrs to finally get over to the place) I bought a Barracuda chuck on sale for $199, which came with all kinds of goodies (and it's Titanium coated for a little *bling*). I also got an adapter for the chuck that I could adapt to the PK motor. They also had a few different steb drive centers and steb live center for cheap...The Robert Sorby stuff is good quality, but I didn't see the need to spend $70 for what PSI had for $16.

More later...I'd like to explore PWorks3D and 4-sided milling using it...

-B

[khalid]

29 Lines, 5 Paragraphs, 422 words, 2190 characters...
Hope you will do it...

[rb99]

Are there no dust collectors for indexers?

RB

[toddmaci]

Brady,
Very nice work. Are these the head and tail spurs from PSI? How do you like them.

Item #: LCENTQC1
Item #: LCENTTS2

Todd

[bill.young]

Could it be?


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[zeykr]

I think it's a very good likeness of shaggy!

I'll ask the expert when she gets to my shop later today - my 5 year old daughter really likes shaggy and scooby!

Maybe scooby should be the next effort?

Part numbers and mfg on parts you all have used to build indexers would be handy. I've got an experimental indexer made from a cheapo grizzly drill lathe but would like to build up something better.

[mikeacg]

Brady,

I was just about to email you some rough drawings of my idea for an indexer for my Buddy when I came across this. I would still like to get your opinion on my 2 designs if you wouldn't mind.

However, in looking at your post and considering the distortion I was wondering something. Does the 3D toolpath adjust the cut length for the depth of the cut? I see things more visually so I may not be making this clear but let me try to explain what I mean. If you made a flat design file as wide as the circumference of the piece you are cutting and toolpath it, you are basically defining the surface (which would represent the outside of the cylinder or the part's circumference) as the Zzero and any cuts into the part would be cut along a short circumference (as the diameter of the cylinder at that depth would be smaller). Does that make any sense or am I totally off in my thinking? If the file does not adjust for depth I would expect some distortion - close to the surface areas would be more accurate than the deeper areas. I haven't seen an indexer yet or a wrapped file since I am new to the ShopBot world so I don't totally understand the concept but in looking at the other post about unwrapping the file I was wondering about that kind of thing happening.

Mike

[mikeacg]

Brady,

What is the maximum diameter you can get with your indexer - under 5" (Maximum Z)?

Mike

[Brady Watson]

Mike,
My setup will do about 8" in the round.

I'm tracking down the distortion issue...so far it is pointing to the SB post processor...More when I get it nailed. Back to the shop to walk the walk...

I'm proofing out all of these 'theories' that have seem to come out of the woodwork since I started talking about unwrapping a few days ago. Lotsa talk...few photographic examples.

-B

[Brady Watson]

The post processor I used for Pro was not correct...so that's why it is oblate when it cut. I'll have to contact Delcam next week and figure out what is the correct post and if the "latest" existing one needs tweaking. If anyone out there has successfully unwrapped and turned anything 3D recently using the ShopBot XB post, please forward it to me for comparison to the one I have.

I'm out of time for today, but I wanted to post my latest result.


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-B

[toddmaci]

Brady,
Very nice work X2. Are these the head and tail spurs from PSI? How do you like them.

Item #: LCENTQC1
Item #: LCENTTS2

Todd

[Brady Watson]

Thanks Todd. Yes, I got them from PSI. They work great & BOTH have spring-loaded centers so that the part self-releases. The chuck is kick arse & came with all kinds of goodies and 3 sets of jaws.

Yep - those are the part numbers.

Contact me offlist if you are going to buy the 'cuda chuck from them.

-B

[toddmaci]

Thanks Brady,
I do not plan do purchase a cuda chuck. I have the talon one that came with the Indexer. Is there much of a differnce?

[Brady Watson]

Nope...All of the Nova-style chucks are pretty much the same. Wasn't sure if you had a homebrew setup or factory SB setup. Sounds like you have the factory setup. Oh...do yourself a favor and throw the dead center in the trash. You will never use it.

-B

[mikeacg]

Brady,

How did you get 8" out of your Buddy? I thought we only had 5"...

This is a great thread! I can't wait to see where you go next!!

Mike

[Brady Watson]

I raised the gantry up another 6". The Z axis has yet to be extended to reach the top of the AL base plate. The other option is to drop the table down, but that would mean drilling 8 more holes in each leg and the control box will be a tight fit.

Next?...I've got some neat 2D stuff that I haven't seen anyone else do via CNC that I will be doing. I also have a big 16" swing indexer that is slated to go on Big Bertha. It will function both as an indexer and as a CNC wood lathe. The indexer is so versatile in function and how it can be programmed, that there is no wonder there is so much confusion surrounding it. Hence the video concept showing everything from file creation to finished cut part. I could do a video right now that just shows software, but unless I can prove what will work by actually doing the work and cutting, then that type of video would be nearly worthless, and not really what people want.

-B

[ron_varela]

Brady you sure it's the postP? I have had some bad files but was due to error on my part, others I know who have done wrapping have not had this problem. files made in the Y and X postP seem to work fine

[mikeacg]

Is there any reason I can't remove the aluminum guides on the top of the frame that were used with the old aluminum table? I don't plan to ever take the powerstick off and I would like to get them out of my way so I can add some rollers like the new Buddy has to give me support across the 48".

Mike

[Brady Watson]

Mike,
Post up or email me a pic of your powerstick & the v-rollers. I'd say more than likely you can remove the original X rails if you are using the powerstick. Be aware that you are still going to be limited in the Z to the point where you will not be able to clear the tailstock, headstock chuck or turn parts bigger than maybe 3" in diameter - unless you raise up the gantry or lower the table.

-B

[mikeacg]

Brady,

I need to send you my drawing. My control box is outside the frame so I think I could get a pretty good sized piece down in the frame from the pinion gear to the side - like 20" long and at least 20" in diameter. I'll shoot the sketch over and you can tell me if I am totally off-base on this. Thanks in advance for being so helpful!

Mike

[ghostcreek]

Has anyone else put a indexer on a Buddy? I am looking into trying, but i don't want to reinvent the wheel! Thanks to all for your in put.

[dana_swift]

I have an indexer on my BT-32, I mounted it on a 4' powerstick then it is just an optional table like the 2' or 8'.

Using the powerstick also allows longer peices to be turned. I don't know the exact maximum length, but very comparable to the 32 inches that I have across the table normally.

D

[gwerner]

Ghostcreek

I mounted an indexer on the X (powerstick) on my BT-48.

I've raised my gantry, and gained valuable space.

So far, so good. You can see it here cutting a PVC litho from 6" pipe.

http://www.youtube.com/watch?v=JcfjjJgpAvo

-Greg

[myxpykalix]

wHAT DEPTHS DID YOU SET YOUR TOOLPATHS FOR WHEN MAKING THE (****):o round lithopanes? I know you said the pipes are not exacly round but did you "skin it" first or just go a little deeper with your toolpaths?

[gwerner]

Jack-

I experimented with the necessary depth of cut gradually until I found it was just cutting all the way around. I used the cylinder gadget in Aspire.

When I had a "true cylinder" (Skinned it), then I re-zero to the top of the cylinder, and setup a new file using the wrapping gadget, not to exceed my remaining material thickness for the lithophane.

I measured the height of the pipe, and subtracted a few inches from each end for clearance to determine my "material size" in Aspire.

I checked the pipes remaining thickness with a micrometer.

I opened a new Aspire file and set the size, imported my photo, constrained it with a box around the picture, then subtracted the height of the photo.
I needed to make sure it wasn't going to cut through, so I checked the remaining material below the file. It looked about right. .015 - .020

I cut the rough toolpath with a 1/4" end mill.

The finish toolpath was cut with a 1/8" ballnose.

I used the indexer post processor for both.

[Brady Watson]

I have a pair of Bosch 6" extrusion 'risers' for raising the gantry/table sides up for extra clearance when using the indexer on a BT tool. This is what I did when I had the indexer on my BT48.

Email if interested in purchasing them + hardware & plates to mount them on the tool.

-Brady

[shilala]

Good stuff here for the start of my indexer info hunting.
Thanks, Brady!!!