[abfa9358]

Okay back to stuff I understand. The spindle is coming together really quickly now, tonight I made the bearing clamp plate and drilled out the bearing housing for the M4 screws that connect the motor to the bearing housing. I made an expanding stub mandrel to machine the clamp plate as its only 0.190" thick (it was cut from 3/16"sheet).

I think I'm going to be delayed by the arrival of a Raspberry Pi, which will form the basis of a really cheap computer for my eldest son, I'll get a screen from cash converters. I'm going to see if I can get him using Linux as an alternative to Windows. As he gets older (and if he's interested) I'll get him going with Python as a programming language. I grew up with BASIC and I am fairly hardcore VB / VBA programmer. I delve into C and Fortran as required for hobby stuff, however I wish I had time to develop my Python and TCL skills.

So, very off topic question, what would people recommend as a programming language for a six year old to start to learn?

Also a few recommendations
1. BF30 is a great base machine..
2. Have a go at building the spray/splatter coolant nozzle, it clears swarf and blasts lube all over the tool, if you use a flexible air pipe then the nozzle can be moved onto other machines and it uses b****r all coolant.

[abfa9358]

Well here it is! Not tested yet but assembled and turns really nicely. Its around 4" and just over 2" dia. I think it will be just the job for engraving and PCB drilling etc especially with 20V and 60A going through it!

The design did change a bit but I think its better for it. I machined the M4 cap screws down a tad to make them fit neatly in the body.

The bearings at the front are small angular contact bearings backed up with a collar that came with the motor and a wavey washer to give a bit of pre-load.

All the bearings were just a nice tap fit on the CTC ER11 chuck shank, the motor came apart no problem and assembled on the shaft with just some light taps of my 6lb hammer:devious:

I had read that some people had to lap the collet chuck shank to get a fit with the bearings and motor but for me it all went together with no issue.

If you plan to do this, take some time to make expanding mandrels for mounting the various parts on - this really helps keep thing concentric which is important as there are four bearings tightly mounted on to the chuck shank within a few inches of one another - so there is very little room for miss-alignment.

I need to design a mount for it, cooling and fix up the sparky side of things....

PS does anyone know how to stop the text of your post getting hi-jacked by these blasted ad links????

[Dylwad]

Looks good

Not sure about the links, I use tapatalk now for cnczone, too slow and WAY too many ads when using a computer. Hope cncadmin is enjoying all of the revenue!

[007CNC]

looks good...
did you replace the brushless motor shaft with an er straight shank?
I think that is a better way to do it. For my setup, I had the spindle separate from the motor, and the motor drove the spindle with a gear belt. But I think this is a better setup if you can get it all properly alligned -- more compact and no need to worry about the belt breaking under heavy load.
What angular contact bearing are you using? what size is the er shank?

[SCzEngrgGroup]

Looks good

Not sure about the links, I use tapatalk now for cnczone, too slow and WAY too many ads when using a computer. Hope cncadmin is enjoying all of the revenue!

Use Chrome, and install the AdBlock add-on. I get no ads whatsoever.

Regards,
Ray L.

[rowbare]

You can opt out of it:
CNCzone.com-Machinist Community Forums - Site News - How can choose to disable Skimlinks?

bob

[abfa9358]

Thanks for the info on the links, I didn't realise that it was a revenue stream for the 'zone.

Yes I replaced the motor spindle with a parallel shank ER11 collet chuck from CTC. Shank is 8mm dia. and a nice tight tap fit on to the motor (also has a grub screw in the motor).

To get everything aligned I made some expanding mandrels i.e. steel bar with an M6 threaded hole with a deep counter sink, taper off an Allen screw head slot the bar to form 4 quadrants and then machine to a nice tight fit in the reference bore of the part, then tighten the M6 screw to wedge the quadrants apart. Remember once you've machined to size don't take the mandrel out of the chuck - you should be able to mount / demount the part without loosing concentricity. For a direct drive over such a short distance everything must be pretty well aligned otherwise it will bind.

The bearings are E8 magneto bearings 24mm x 7mm x 8mm bore, not the nicest things but only a few quid - so thrash them to death take 'em out and throw them away put in some more.

As I said earlier the spindle is for engraving and very light milling using small cutters - example is routing and drilling a pcb with 0.7mm carbide drills and a 1mm PCB router. The main spindle really isn't fast enough for this work. Also the spindle needed to be cheap and "throw" away - I cannot justify £300 on a VFD spindle.

I attached the sparks to it last night, ran it at 20V and a couple of amps. At these settings it has a satisfying whine + more then enough torque to drill 2mm holes in bright mild steel. Also at these settings nothing get hot, the ESC is cool, the motor is warmish and the bearing housing stayed nice and cool,

[LongRat]

Can you remind us what ESC you are currently using? Not sure it has been posted.

[abfa9358]

Sure, its one of these
Hobbywing Pentium 60Amp Brushless Motor ESC Speed Controller

[LongRat]

Ah, I have one of those in one of my planes. Never missd a beat, amazing value for money. It runs an outrunner motor on an 11x7 prop from a 3S 4500 LiPo. Maximum current is around 40A.

[Mad Welder]

Excellent build thread and very informative........the thought of using an RC DC motor for engraving and HSM with minimal DOC's never entered my mind till your thread, and thanks for the YouTube links fantastic........and as you said it's hard to justify spending big money for another VFD .........love the photos keep them flowing.....

Thanks for sharing

[Arich0908]

I currently in the process of doing this.
Can I recommend a power supply. This was my solution. May I add it was very cheap i paid 30$ for a 24v 100amp power supply.
A simple high quality 12Volt 100Amp Power Supply- Part1 - RC Groups
https://sites.google.com/site/tjingu...ts/diy-24v-47a

[abfa9358]

Wow 24V and 100amps! Bit OTT for my application, make sure you check the connections before switching it on.

I'm designing the mount at the moment, I found lump of 7075T6 in the scrap box which will do.

[abfa9358]

I've now made the mounting bracket and space plate from 1/2" BDMS. I've mounted the motor and plates on the mill as a test hence the use of over length M5 screws. All looks good. The motor will be enclosed in a 60mm OD Perspex tube and the ESC will be mounted on to the tube in a box with a small fan blowing air over the ESC and through the motor.

As an aside, things have been a bit delayed as I steamed up my 71/4 gauge Atlantic this weekend and whist to trying free off the steam water pump I managed to break part of the pilot shuttle valve drive. This pump was build circa 1950 by my Grand Father, so I need to make an apology to the engineering ether and also make a good repair that will last another 50 odd years!

[FannBlade]

Both great looking projects.

[abfa9358]

Its been a while since I posted here, but I made some more progress on the little spindle.

I've built the cover for it, made out of 60mm OD Perspex and attached to a metal box via a custom spacer block. There are air holes in the tube and a recess in the spacer to allow air to flow through the motor and electronics which will be housed in the box. I will add some high flow filters (old tights + a bit of cotton wool) to ensure that the motor is isolated from the machining chips.

I've also had a bit of luck on ebay, which is not normally the case for me. I found an 80mm MT3 facemill with 10 inserts the other day being sold for just under £50. I also managed to buy a very nice Vertex tool and cutter grinder from a guy over in Swansea. It was made in 2003, but as described it really is in good condition. I've been looking for one for around 18months now, downside is that it came from a shed clearance implying that its owner had departed this world. Sad really, but at least its come to a good home...

[abfa9358]

The project is not dead! just moving slowly....
Over the last few months I completed most of the mechanicals of the spindle, it is now mounted on the BF30. The last thing I made was a dust / filter for the top end of the perspex tube. With the addition of some cut outs from a pair of tights, a very fine filter with high air flow was made.

I've mainly been working on an rpm meter for the motor and this has led me back in to the world of PIC mcu's. With a bit of reading and coding I created an interrupt driven system capable of handling from 10rpm upto 99999rpm.

Initially, I got it working with an LCD but have now switched over to a MAX7219 driver and five 7 segment LEDs. All code was written in Proton PicBasic, the MPLAB IDE was invaluable for debugging the interrupt routine.

The MAX7219 is a bit fiddly to get going - it is very sensitive to supply decoupling you must follow the datasheet recommendations for capacitors otherwise it behaves in a very odd way. Also it doesn't seem to like running for any length of time with the intensity registers set to 31/32 - blank digits after a few minutes. Also, also it is a good idea to add 10k pull downs on the SPI lines as you can see from the pic.

I built the MAX7219 PCB from scratch and etched it in my updated bubble tank i.e. one that now "bubbles" in a safe manner. The traces are 10 thou with a 15thou spacing - this came out really well with good sharp tracks. V2 of the board will separate the digits from the MAX7219 and connectors. I think if all goes well I'll make another board for the lathe.

I've had another bit of good luck on ebay, I found an old tapping head (4mm - 10mm) and won the auction at just under £30. Chuck back jaws were broken but soon mended with some ground flat stock which was then hardened and tempered - works a treat

[LongRat]

Sweet board. Now you have a fast spindle, you could rout the next one for your lathe and save messing with the chemicals! Done plenty of PCBs on my BF30, looks crazy in a sledgehammer and nut kind of way but works fine.
Would be good to see a video of the spindle running with the tacho and everything.

[abfa9358]

A bit more progress. Lashed up drive tonight and everything seemed to work okay, [ame="http://www.youtube.com/watch?v=CCuEZEw_NKI"]video[/ame] quality is a bit poor but you can get the idea.

Also finished the cooling fans, I found some really fine stainless gauze on ebay - its woven and just like cloth and make really good coverings for the fans.

Next job is to wire up the sensor for the pic tacho and then its good. to go.

[abfa9358]

On the home straight now. Just been designing the rpm sensor cover, basically the IR sensor sits on a small 3/8" dia PCB and pokes through a hole in the perspex motor casing, it is connected to the main PCB by four stiff solid wires and will have a blob of sealant to stop it resonating. I will paint the motor casing black/white to give a square pulse for the PIC to detect.