The Workshop Progress thread 2018

[mechman48Participant @mechman48]

Neat work Muzzer; super finish.

George.

[mechman48Participant @mechman48]

Set up flywheel for machining concentric to crankshaft, used between centres set up which proved crankshaft running straight without any sign of bending. Only needed 0.3mm touch up on ea. side to get concentricity…

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As we all know CI is crappy stuff to machine & gets into every nook & cranny so it's a major clean up coming up.

​George.
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[jimmy bParticipant @jimmyb]

Finished the toolpost grinder today!

Found out 150W motor is no where near the power needed and that the 12mm spindle ER16 collet spindle probably not man enough.

Jim

[Joseph Noci 1Participant @josephnoci1]

Hello Jim,

What about some pictures?

I am surprised that 150W is not enough…And a 12mm spindle should be fine! Unless you are using 100mm x 20mm diameter wheels and taking of 50thou a shot….

Pics below are of two toolpost grinders I made using Brushless RC motors – the larger motor is 70mm diameter, the smaller is 50mm diameter. The smaller motor drives an ER11, 10mm diameter spindle, the larger an ER16, 12mm diameter spindle.

2nd Last Pic shows the larger spindle/motor fitted to a small tool&cutter grinder, turning an 80mm diameter diamond wheel. Last pic is the smaller grinder on the Maximat V10P toolpost position, truing the Chuck jaws. For scale, the chuck is 150mm diameter. The grinder's motor appears larger than it is, cause the camera was closer to it..

Joe

[jimmy bParticipant @jimmyb]

Excellent Joe!

I'll take some pictures when I return to the shed, I hurt my back in the shed, which partly explains my defeat!

Your set up is exactly what I had in mind! What size and type of stones are you using for external grinding? I've only tried some cheapo 6mm shank stones, (I'd guess about 30mm dia and 15mm long). Also, what sort of speed are you running? I guess I have geared for about 9,000 rpm.

I'm using round Polyurethane belting to drive the spindle. When I first joined the belt, it was a bit tight and the motor wouldn't even turn over, I made a slightly longer belt, (very loose) and got it to run ok(ish).

Thank you Joe.

Jim

[Joseph Noci 1Participant @josephnoci1]

Hello Jim.

The smaller grinder goes from 3000RPM to around 12000RPM at the spindle. The motor drivers via a 6mm green poly belt, like yours I believe. The ratio of motor to spindle is around 4 to 1.

I use all sorts of wheels on this one, up to about 25mm diameter, down to 6mm diameter, where the 12000RPM is a tad low…

The larger grinder uses a toothed rubber belt and pulleys, with a drive ratio of 3 to 1 – the max spindle speed is around 6000RPM since I use bigger wheels on this one – up to 100mm diameter, 6mm width.

I suspect the problem you have lies in the gearing – the motor you have is I presume a standard 1400rpm or 2800rpm AC synchronous motor? If so, it will most probably not have enough torque to drive the spindle at 9000rpm…

If your motor is a brushed AC/DC motor, then its speed should be quite higher, and the subsequent gearing lower, and it should work. EMCO ,long ago, mad a very nice toolpost grinder for the MAXIMAT series lathes, and it used a brushed motor or around 120watts, and that work very well, with wheels up to 50mm x6mm – slow feed and light cuts, 'just' sparking..

Generally, I use stones of around 25mm to 50mm diameter for outside grinding, from 6mm wide up to 15mm wide.

I also use 40mm cup wheels to grind a face when needed. Speeds are from a table for the wheel diameter versus material ground, and wheel makeup..a 25mm Al_Oxide 150 grit wheel on outside work on hardened steel pins I may run at 7000rpm to 10000rpm, for the final finish.

Joe

Here on the smaller grinder you can see the poly-belt drive, and a drawbar held drive spindle with a 15mm wheel mounted.

Here on the larger grinder you see the toothed belt drive

[jimmy bParticipant @jimmyb]

Thank you Joe.

I'm using this to power it

Thank you for the info and the pictures. Hopefully I'll be able to take some pictures tomorrow.

Cheers Jim

[MuzzerParticipant @muzzer]

Finished my ballnut bracket yesterday – drilling and machine tapping the M4 and M10 holes, chamfering them, then splitting the yoke in the bandsaw with 2 parallel cuts to form a 3mm slot. Finally, some edge breaking / deburring with diamond files and deburring tool.

The curious blue lighting effect is presumably due to the low light levels and the way iPhones work. It's almost dusk here and this was natural light from the skylights and windows. It's actually sitting on a piece of white A4 paper.

No obvious cockups and no broken tools. Good result!

Murray

[mechman48Participant @mechman48]

Yesterday … assembled all the pieces for my vertical cross, did a trial attempt at timing, put some air into it, the brass inlet valve works ok,… but air is passing the spool valve, not sealing correctly… so it looks like another strip down & check on spool valve fit etc. Ho hum another one of those days…

George.

[Anonymous]

Posted by Muzzer on 29/04/2018 20:19:30:

No obvious cockups and no broken tools. Good result!

Certainly is; I'm going to have to up my game on the CNC mill to match!

Andrew

[John HaineParticipant @johnhaine32865]

Inspired by another thread, I got one of these 133 mm backplate castings from RDG…

…and created a lot of cast iron dust to liberate this:

A new toolpost to mount my Dickson QC holder much more rigidly on my S7, replacing the topslide. A straightforward turning/milling job. As well as more rigidity I wanted to improve the repeatability of changing tools when CNC turning, so the post is located laterally by a fence down the side against the x-slide:

And by a stop at the end:

which is bolted down to a tee slot after pressing firmly against the base. So should I ever have to remove it then it can go back in the same position. There's also a dowel pin locating the Dickson block relative to the post to stop it shifting through the cutting force.

I will now need to recalibrate all the tools as the position will have changed a bit relative to the topslide.

Now I just need to clean up all the CI dust that seems to have covered everything in the workshop.

[Michael GilliganParticipant @michaelgilligan61133]

Looks good, John

MichaelG.

[john feeneyParticipant @johnfeeney58965]

Hello Joe,

I have a Stettler 64-110 internal grinding machine. It has an internal spindle driven by a high frequency motor.Unfortunately this motor is beyond repair ( speed range was from 6000 to 24000). I have thought of using a "model" motor, probably a water cooled inrunnner. All these motors use an electronic speed control (ESC) and are generally low voltage and high current from a battery. What power supply system do you use ? is it battery or mains.

I have looked for mains supplied power supplies for electro plating, say 10V/ 50 Amp but quite expensive. Also how do you control the speed of the motor. ( I have flown model aircraft where the speed is controlled by the size of Prop. used)

The machine also has an air spindle which runs at 96000 rpm and can grind bores down to 0.8mm diameter. Don`t think I`ll be using it very often!

Regards

John Feeney

[John HaineParticipant @johnhaine32865]

Lots of high current DC PSUs on eBay at reasonable prices – e.g. 12V @ 33A for £18.50 – what volts & amps do you need?

And look for "servo tester" on eBay – these are gadgets that generate the standard variable pulse set by a knob, to test servos and ESCs that would normally be connected to an RC receiver. Seem to cost about a fiver.

[Neil WyattModerator @neilwyatt]

Posted by Muzzer on 29/04/2018 20:19:30:

The curious blue lighting effect is presumably due to the low light levels and the way iPhones work. It's almost dusk here and this was natural light from the skylights and windows. It's actually sitting on a piece of white A4 paper.

Nice work.

The one-click auto adjust in Photo paint restores a much more natural colour balance. Did you have your phone camera's light balance set to 'tungsten'?

[Roderick JenkinsParticipant @roderickjenkins93242]

I, at long last, made striker arm for the Dore boring and facing head that I bought on ebay a couple of years ago

This is a pretty cumbersome beast, not nearly as nice to use as my Arrand boring head, but it does have the facing function and screws onto my Sharp mill which has a Myford nose thread. By the way – Does anybody know where I can get a 3/8" indexable boring tool?

Cheers,

Rod

[John HaineParticipant @johnhaine32865]

Rod, you could try JB Cutting tools.

Or make one?

Edited By John Haine on 02/05/2018 17:32:29

[MWParticipant @mw27036]

Posted by John Haine on 02/05/2018 09:38:47:

Inspired by another thread, I got one of these 133 mm backplate castings from RDG…

….

You can be very creative with those backplate castings! I'm sure I've got three 5" castings laying around waiting to be done with one purpose in mind or another…

I was a little bit uninspired by the selection of "engineery" magazines on offer this week at WH smiths, so I struck out and went down a different alley for a change, the "wood worker" magazine

and I'd say I'm glad I did, lots of good tips, even for this hobby to be found in them. 

 

Michael W

Edited By Michael-w on 02/05/2018 18:02:53

[Ex contributorParticipant @mgnbuk]

Rod,

How about one of these Ebay 352259180098 & turn it down from 10mm to 3/8" ?

Also available in 6, 7 & 8mm diameter taking the same CCMT0602** inserts to sleeve up. Searching "SCLCR" brings up most of them.

Nigel B

[JasonBModerator @jasonb]

Rod, Glanze (Chronos) do a set, I have the 1/2" ones at the top of the page and use them all the time.

I'm not sure if a lathe boring bar will work as they tend to set the tip at an angle

[Roderick JenkinsParticipant @roderickjenkins93242]

Guys,

Thanks for the input. As Jason says, I don't think a lathe type boring bar will do. My searches turned up the Glanze set but I don't really want to spring for £100. I was hoping to find a single tool like this with a 3/8" diameter shank:

I could probably turn down a 1/2" one if necessary.

Cheers,

Rod

[John HaineParticipant @johnhaine32865]

Why wouldn't a lathe one work? The geometry should be just the same whether the tool or the work rotates.

[Mark RandParticipant @markrand96270]

nearly got finished with the welding trolley I've been knocking together. The welds are unimpressive, but the paint job makes them look good in comparison. Still needs some plumbing and electrical work doing. I'd like to make some cable racks but I'm not sure if the extra width it'd need is worth the convenience.
 

 

 

 

 

Edited By Mark Rand on 02/05/2018 22:58:37

[Ex contributorParticipant @mgnbuk]

I'm not sure if a lathe boring bar will work as they tend to set the tip at an angle

Can't see why it should make a difference ? If I use the boring bar in the lathe (set correctly on centre) to machine a bore larger than the minimum specified for the tool in a rotating workpiece, or rotate the same bar set on centre in a boring head to generate the same diameter bore in a stationary workpiece, the tip is presented in the same way to the bore regardless ?

I have used larger diameter lathe boring bars in larger than ME size boring heads at work (admittedly into graphite components, not metal) & they have worked fine without rubbing, and have also mounted lathe internal screwcutting tools in milling chucks & using them as fly cutters for thread milling on CNC milling machines.

I have the bars I linked to & intend to try them in my 2" boring head – just require the 1/2" to whatever reducing sleeves making to be able to try them out. I'll report back after doing so, though these projects do seem to take longer than initially anticipated !

Nigel B

[Joseph Noci 1Participant @josephnoci1]

Posted by john feeney on 02/05/2018 11:25:23:

Hello Joe,

I have a Stettler 64-110 internal grinding machine. It has an internal spindle driven by a high frequency motor.Unfortunately this motor is beyond repair ( speed range was from 6000 to 24000). I have thought of using a "model" motor, probably a water cooled inrunnner. All these motors use an electronic speed control (ESC) and are generally low voltage and high current from a battery. What power supply system do you use ? is it battery or mains.

I have looked for mains supplied power supplies for electro plating, say 10V/ 50 Amp but quite expensive. Also how do you control the speed of the motor. ( I have flown model aircraft where the speed is controlled by the size of Prop. used)

The machine also has an air spindle which runs at 96000 rpm and can grind bores down to 0.8mm diameter. Don`t think I`ll be using it very often!

Regards

John Feeney

Hi John.

Pity about that motor being FUBAR…That sounds like it was a very nice one. John, the larger motor on my grinder is capable of delivering around 1.8kW, fed from 45 volts via a suitable (LARGE) ESC. Of course, that is with very intermittent duty, maybe 30 seconds with forced cooling. A 40 amp power supply would be required then. However, I use a variable DC power supply, from 12V up to 36volts @ 5 amps max on the toolpost grinder application. Obviously, if the application is say a surface grinder driving a 150mm x 25mm wheel and you are pushing the DOC, then many more amps and volts are needed.

In my grinder application I run way below such ratings..

In my case, a 50mm x 10mm ALoX wheel on outside grinding does not slow the motor that I notice, with voltage set to 20V and current draw is around 3 amps.

Speed control has some variables – Most ESC's work better when set for full speed – less losses in the drive FET's, etc. The motor speed variation is also less at full speed setting, so I use a servo tester, as mentioned, as the 'secondary' speed controller, generating a pulse width output of 1ms to 2ms – normaly set to 2ms (max) and left at that.

I then vary the motor speed by varying the power supply voltage, and that works a treat. The motor speed is by far much more stable under varying loads. As you know, the motors have a KV rating, this being the RPM per Applied Volt – My bigger motor is a 400KV motor, so turns at around 12800 RPM @ 30 volts, and 8000 RPM @ 20 volts.

This is an outrunner, and sizeable outrunners ( '1KW' types..) are available even up to 1200KV – that would give you around 20000 RPM @ 20 volts…You need to check the motor specs – the higher KV motors generally have lower maximum applied voltage limits else they would run dangerously fast…If your torque requirements are low, you can always step up with pulleys. Bearings are of course an issue – these are hobby motors, and running one at 15000 RPM for a half an hour is hard on the bearings – fitting good ones may be worth while. I do dynamically balance the outer cage as well ( there is a post I did on that process – made quite a difference in the screech..)

Big inrunners are more difficult – they are not as well cooled, the bearings tend to be smaller, the drive shafts are invariably much thinner, and they draw a LOT more amps, even running un-loaded. I have a 1KW inrunner with a 6mm shaft, motor is 55mm diameter, 70mm long – is a 4000KV motor, and has a max applied voltage rating of 16 volts – thats 64000 RPM (!!) – just running on the bench at no load it draws 18 amps at that RPM…and needs lots of cooling!

The smaller inrunners are much better – and are used a lot in 'copters – driving the main rotor via massive down-gearing, but generally are 3 or 4mm shaft size…

So, bottom line, use an outrunner, maybe 400KV to 900KV, and size it for your load requirements – a 50mm to 70mm OD motor will do most anything! Use a variable power supply ( continuous is nice, but switched – 12v, 16v, 20v, 25v, 30v is great as well). If you use a big motor, shafts of up to 12mm are easily available, and easily swapped for a long shaft ER series collet chuck.

BTW – the power supply need not be regulated – a tapped transformer ( 6 to 8 amps or so) giving 10v, 14v, 18v, etc AC outputs, with a bridge rectifier into 20,000 uf of filter capacitance, with a selector switch, will work just fine.

Joe

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