[chuck99z28]

What are the options?

Seems most people use Dremel's or other rotary tools.
Of couse there is the Wolfgang Spindle.

But, has anyone seen anything else worth looking at?

[Jay C]

Using a Bosh Colt with Precise Bits precision collet system. Posted a video in another thread. That's a 1206 SMD resistor I'm using. I also used to use a Proxxon IB/E.

[powerr]

what was the run out on the bosh colt? I am looking for something new.

[chuck99z28]

I'd like something High Tech. In the $500 range.
With zero runout and varible up to 30,000 rpms or so.
And a 1/8" collet.

That would be cool.

[rowbare]

I'd like something High Tech. In the $500 range.
With zero runout and varible up to 30,000 rpms or so.
And a 1/8" collet.

That would be cool.

It would be cool, but I think you will have to reset your expectations some. $500 can get you an honest runout under a thou at the spindle taper and if you're lucky, your collet won't introduce much more. To reliably get under a tenth at the spindle taper you are probably talking 5 figures... I saw a picture of an inspection certificate for an older Precise spindle recently. Runout at the spindle bore was .00004, with a collet, .0004. Collets for this spindle are $200 each, bearing replacement is in the 4-5k range.

bob

[stevespo]

There are a range of Chinese spindles that may meet your needs. The .8kw with an ER11 collet would do nicely for milling PCBs (and many other materials as well). The top speed is 24K. To get more RPM would require some looking around. Maybe one of the Kress models...

Steve

[chuck99z28]

Ok, in reality, how about less than 0.001" runout. Or around 0.001".
And 20,000-30,000 RPM, And electric, not pneumatic.
And about $500.

So we have commercial rotary tools and routers.
The Wolfgang Spindle.
The growing collection of Chinese spindles.

Anything else other than homemade devices?

Chuck

[ghassall]

In the process of building one of these.
http://www.rcgroups.com/forums/showp...2&postcount=26

Waiting for my motor and speed controller to arrive. Should have been here last week.
With the 890KV motor and 24V should be good for 20K RPM.
Was going to do a belt drive but the direct drive is so simple.

[Jay C]

Keep us posted. I just happen to have an extra K2 mount so who knows I might try this some day

[Drools]

ghassall, I will be following the progress of your spindle. Maybe if the project works out, we could convince someone to just sell the housing. I do not have a lathe so making one of these is out of the question. However I could put one together if I had a housing to work with.

[eSilviu]

Sorry, but you are far beyond today's technology (accesible to anyone)...

http://www.rcgroups.com/forums/showp...2&postcount=26

[ghassall]

Michael Hammer is the guy who cast and build the one in the rcgroups thread. The thread is all about the build of his router.
I took the easy way out and bought a 75mm diameter round extrusion 150mm long. It only cost A$20 which included the cutting charge. Will get two housings and so left over out of that and much simpler then casting one. Will have to try some casting one day.
I have access to large lathe and mill at work so it will be an afterhours project.
Still waiting for my motor and ESC to arrive. Been two weeks now which means it is lost somewhere. HK to Aus is normally a week, max.
I have attached two designs. A square one which will easily bolt to the Z and a round one that can be mounted in an existing router mount.

Gareth

[eSilviu]

I took the easy way out and bought a 75mm diameter round extrusion 150mm long. It only cost A$20 which included the cutting charge.
Gareth

I choose the even easier way: replaced the 8mm shaft from RC motor with "C8 ER11-100L Straight Milling Lathe Chuck Holder _US"...
No aditional costs (for now).

I will use motor mounts.

[chuck99z28]

I simply don't have access to such tools to build one.

I may try a chinese spindle some day.

[ghassall]

My package arrived today.
1 x Turnigy 890KV motor
1 x HobbyKing 100A ESC

Tools? As eSilviu posted you can run the collet chuck in the original motor bearings. Just press (hammer) the original motor shaft out and put the collet chuck in. Simple.
I might try this while I am building the bearing mount. I will be using it for wood, wax, and other hard materials so i do not think the original bearings will be up to the task of the side loading. For PCBs it should be fine. Also 608 bearings are cheap to replace, they are skateboard bearings.

Attached are some photos of the motor, ESC and the motor with the original shaft removed showing how the collet shaft could be installed.

Gareth

[Drools]

I found the specs of the motor.

Model: TR50-45
Input Voltage : 8~22V (3~5S Li-po)
Kv : 890 rpm/V within 10%
Dimentions : 50mm X 45mm
Shaft diameter : 8mm
Weight : 260g
Recommended model weight : 900~1500g
Power equivalent : .36,2stroke
Stator Dimensions: 40x10mm
Speed Controller Required: 60A+
Estimated Power: 700W +

If I read this correctly the RPM is 890RPM per volt with a voltage range of 8~22V.
That works out to 7120-RPM@8VDC and 19580-RPM@22VDC. 10% tolerance.
Q1-What kind of power supply would you need to run this motor?
Q2-Would an old PC power supply work?
Q3-Is the motor rated for continuous duty, i.e.: can is run for an hour or 2 @ 15K-RPM?
Q4-Are skate bearings rated for the speeds? i.e.: 20K RPM...
Q5-What kind of torque would one expect at 7K and 15K?

[ee_t]

I found the specs of the motor.

If I read this correctly the RPM is 890RPM per volt with a voltage range of 8~22V.
That works out to 7120-RPM@8VDC and 19580-RPM@22VDC. 10% tolerance.
Q1-What kind of power supply would you need to run this motor?
Q2-Would an old PC power supply work?

Sure, if its reasonably rated. Additional output capacitance might help.

Q3-Is the motor rated for continuous duty, i.e.: can is run for an hour or 2 @ 15K-RPM?

If its adequately cooled. You will notice in the rcgroups thread a propeller was added to the top. Since you are dealing with FR4 here I would be careful with this as it can throw dust into the air. They mention some ducting solutions, and I think that would be a good idea.

Q4-Are skate bearings rated for the speeds? i.e.: 20K RPM...

Quick google of 608zz rpm gives rating of ~34krpm.

[Drools]

Are these bearings what you are using?
http://www.vxb.com/page/bearings/PRO...FWE45wodQmIE5g

[ghassall]

I am planing on using 608 bearings.
I went the super easy way today and mounted the ER11 collet chuck in the motor using the original bearings. This was easy to do but i am not sure if the life of the bearings but it is worth trying until i get the new mount made.
I tested the run-out of the chuck without a collet installed and then with a 4mm ground hardened chrome plated rod.
No collet <0.01mm (more like 0.005mm) hard to measure with my set-up
Shaft 5mm from collet <0.015mm
Shaft 55mm from collet <0.06mm
So surprising this is within ebay specs for these collet chucks.

At this stage I am planing on running it off a 12V car battery, or two in series for 24V.
I will do some testing over the coming weeks and will post my findings. I am still is the process of commissioning my machine.

Gareth

[Jay C]

How much have you spent thus far?