Member postings for Richard Kent 1

peak4 - Bill, I have seen that review before.

I think the overall quality of the PSU and Micromot 60, which is the model I have, is good.

I think some minor design improvements would be beneficial though.

@peak4 - Bill, The middle 'polarising' pin simply fits into a hole in the plastic casing of the PSU and is not electrically connected, nor does it operate any kind of switch.

I have double checked and can confirm that the middle pin plugs into a blind hole.

I think Maurice Taylor  is correct in saying it is just a bad design. If the middle pin was longer you could not insert the plug at all if you had it the wrong way.

See photo below..............

Edited By Richard Kent 1 on 07/06/2022 22:14:13

Russell Eberhardt -

Maurice Taylor - Great observation - never considered that until you said it - Perhaps you should put that suggestion to Proxxon.

Knowing the plug design is at it is I'm guessing it would be easier to upgrade the capacitor to a non-polarised one rather than modify the plug but the choice is yours.

If I purchase any more of these 12V Proxxon tools I think the capacitor upgrade will be the first thing I do.

It's not that the exploding capacitor does the tool any harm, it just scares the life out of you!!

By the way these tools run at between approximately 12V-18V depending on the speed setting.

I prefer the speed control on the transformer rather than on the tool but Proxxon do various options.


 

Disclaimer: This is NOT engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do!

Edited By Richard Kent 1 on 07/06/2022 19:18:08

Maurice Taylor - You're welcome.

I wanted to let you know that once I started using this tool I doubt I will ever go back to using anything else.

They are quite expensive but the quality and smoothness is on a different level.

If you search google for Proxxon you will see a site called germantools.

Their prices are quite good.

I don't want to post any links out of respect for the rules of this forum as it will be seen as promoting or advertising.

I hope that helps.

Edited By Richard Kent 1 on 07/06/2022 18:50:01

SillyOldDuffer - You quoted ............"Only Proxxon know why they fitted a 1uF electrolytic, and they are therefore are more likely to get it right than Richard's suck it and see method or my guesswork."

I've heard WORSE from BETTER  

Having said that I tend to agree that they chose a 1uF for a reason and yet the drill runs quieter and more smoothly with 100nf.

My guess is this capacitor is mainly there for RFI suppression reasons as capacitors which are used for this purpose are normally mounted as close to and directly across the motor.

As an aside, the PSU is deliberately half wave rectified and speed control is achieved with a thyristor.

Disclaimer: This is NOT engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do!
 

Edited By Richard Kent 1 on 07/06/2022 18:57:12

@Maurice Taylor - Maurice, see below.

You also have the option of swapping out the collet system for a 3 jaw chuck.

I have a 3 jaw chuck on order from Chronos.

The Micromot 60 is fitted with a collet system with 6 interchangeable collets as standard but I wanted the option of using drill bits which are outside the range of the collets.

I also have a Dremel but the Proxxon is a much better tool for various reasons including low noise level and smoothness.

See photos below of the connector..............

Edited By Richard Kent 1 on 07/06/2022 18:23:10

Russell Eberhardt - Russell, thanks for your input. I thought the same as you --- "However, Proxon must have a good reason for using a 1 uF capacitor in the first place"

However, I tried both a 1uf and 0.1uf (100nf) and I found to my surprise the motor quieter and smoother with the 100nf capacitor.

100nf also seems quite a common size for this application - Also known as a 104 capacitor.

As for the voltage rating. The higher the better within reason.

I read somewhere that a suppression capacitor should have a voltage rating of at least 3 times the working voltage so if you use a capacitor with a higher working voltage it is not a disadvantage.

Normally a manufacturer will choose an electrolytic capacitor due to their capacitance density and low cost. However, they have the disadvantage of having low tolerance to reverse polarity.

However, as you can see this physically larger capacitor fitted fine.

If I had one of those O-So-Silly-O-Scope things (oscilloscope) I would be able to give you more details about how effective this capacitor is at suppression.

Russell, this tool will work without the capacitor but will not give optimum performance.

I think the BANG!!! caused more harm to me than it did the drill! - Like a FIRECRACKER going off right next to you! 

Disclaimer: This is NOT engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do!

Edited By Richard Kent 1 on 07/06/2022 16:34:18

Edited By Richard Kent 1 on 07/06/2022 16:36:30

Emgee - If I was YOUNG and CLEVER like you I would never have put that connector in the wrong way

Unfortunately the plug is somewhat obscured when viewed from above and to make matters worse the pins still ensure an electrical connection even when the connector inserted the wrong way

Problem is easily solved with a replacement non-polarised capacitor though




Disclaimer: This is NOT engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do! 

Edited By Richard Kent 1 on 07/06/2022 15:00:31

My Proxxon Micromot 60 Drill Drill Went BANG!!!

As you can see from the photos below, it is easy to insert the power connector in reverse which causes the original 1uF Electrolytic Capacitor to go BANG!

Not only does this scare the life out of you is also means there is no suppression capacitor on the motor which results in a less smooth and noisy motor.

Simply replace the original capacitor with a high quality 100nf Polyester film or Ceramic Capacitor which are non-polarised (Also know as a 104 capacitor)

I found a 100nf capacitor to work best and this is a standard value for small DC motors.

Choosing a non-polarised capacitor will ensure that if you make the same mistake in future your Proxxon drill/grinder will simply rotate in reverse

Photo below shows the 1uf Original Electrolytic Capacitor next to the New 100nf Polyester Film Capacitor.

Disclaimer:

This is NOT engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do!
 

Edited By Richard Kent 1 on 07/06/2022 14:26:15

Colin Heseltine - That looks great

I was going to purchase something similar on ebay made from solid aluminium but I wanted something with a larger 40mm disc due to the extra lifespan better m/s rating. I also had some 40mm discs in stock.

I also wanted a setup which would allow me to grind other things if every necessary.

Therefore the simplest solution for me was to manufacture a mandrel with a larger 'back plate' to prevent the disc from flexing too much during operation.

I also managed to source a suitable box from ebay to store everything.

The Proxxon 60 is extremely quiet during operation compared to my Dremel which is why I wanted to use it. It also has a surprising level of torque due to having a DC motor.

But once again, your device looks great
 

Disclaimer: This is not engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do or say

Any attempt to ignore this warning can result in severe physical or psychological damage!

Edited By Richard Kent 1 on 04/06/2022 16:45:58

I'll have to get The Moderator in on this one!

This kind of talk must surely be banned!!

Actually, you could have a good point! 

Disclaimer: This is not engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do or say

Any attempt to ignore this warning can result in severe physical or psychological damage!

Edited By Richard Kent 1 on 04/06/2022 13:58:37

Proxxon Mini Grinder too! Only the best here!

Don't even talk to me if you own a Dremel!  

Edited By Richard Kent 1 on 04/06/2022 13:09:05

Hopper - See disclaimer below and I recommend you do your own research................

Just checked a few internet sources and generally speaking these smaller discs are rated to 30,000 rpm but please check before you buy.

Whatever you do ensure you wear appropriate PPE.

I use Bolle Pilot Goggles.


 

Disclaimer: This is not engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do or say

Any attempt to ignore this warning can result in severe physical or psychological damage!

Edited By Richard Kent 1 on 04/06/2022 10:55:12

Joseph Noci 1 - Try sharpening at different angles and see what works best for you.

Perhaps post the results here for discussion?

I use this tip angle for welding up to 160A with a water cooled setup and the results are excellent.

If you are using a non-water cooled setup then the electrode, collet and collet holder will suffer heat degradation issues.

My overriding advice is to try different options and see what works best for you.

Disclaimer: This is not engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do or say

Any attempt to ignore this warning can result in severe physical or psychological damage!

Edited By Richard Kent 1 on 04/06/2022 10:24:21

You're right Mark. I used a bench grinder for years and that was exactly what happened.

When using these small diamond discs ensure you set your mini-grinder speed to 20,000 rpm or above as it tends to grind more efficiently.

My Proxxon has variable speed control and I have experimented with different speeds.

Disclaimer: This is not engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do or say

Any attempt to ignore this warning can result in severe physical or psychological damage!

Edited By Richard Kent 1 on 04/06/2022 10:30:23

@Baz - He (moderator) has a rule book and a big stick if you do that 

Besides, I don't want anyone getting their knickers in a twist!

Edited By Richard Kent 1 on 03/06/2022 22:39:58

@Andrew Johnston - I've heard worse from better  

Edited By Richard Kent 1 on 03/06/2022 21:39:48

A post which might be of some use to Tig enthusiasts...............

1. Manufacture a small quick release bracket for your Proxxon grinder
2. Manufacture a mandrel with a larger flange from an 8.8 grade standard coach bolt
3. Purchase a 40mm diamond disc
4. Sharpen your tig electrodes quickly and easily
5. For best results grind towards the top of the diamond disc so that grinding is inline with the tig electrode length
6. And Lastly - STOP talking about it and just go and do it!

Once you have tried this method I doubt you will ever go back to using a standard bench grinder.


Disclaimer: This is not engineering advice so do not UNDER ANY CIRCUMSTANCES follow what I do or say

Any attempt to ignore this warning can result in severe physical or psychological damage!

Edited By Richard Kent 1 on 03/06/2022 20:38:20