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Member postings for Mike Donnerstag

Here is a list of all the postings Mike Donnerstag has made in our forums. Click on a thread name to jump to the thread.

Thread: Myford Super 7 (with gearbox) Leadscrew Removal
19/05/2020 20:23:55

I have a Myford Super 7 with a gearbox. The lathe dates from around 1982, serial number SK151723.

I need to replace two bushes in the apron and I understand that to replace these I need to remove the apron, and to do this I need first to remove the leadscrew.

To this end, I've removed the gear quadrant, the gearbox cover and the grub screw from the gear at the left end of the leadscrew. I've also removed the bolts and dowels from the leadscrew bracket from the right end, which is now hanging down from the end of the leadscrew.

I tried using a brass drift to knock the leadscrew out of the gear below, but found that, even though it is moving, it is incredibly tight. I'm just wondering if I'm doing the right thing, and need some reassurance before I use more force! Also, if anyone has done this in the past, is it reasonably easy to reassemble once I've replaced the bushes? Also, do I need any special tools to replace the bushes?

A photograph of the progress so far is below:


Many thanks,


Thread: Bending 1/8" Steel Plate
15/05/2020 12:45:58

On silver-soldering again, if I am able to get the workpiece(s) up to a dull red heat, is that a good indication that I should be able to silver solder it?

15/05/2020 12:23:02

I'm trying to keep costs as low as possible, as this may be a one-off job. Do you think these vermiculite bricks from eBay would be okay for a small hearth (£10 for 5 bricks, delivered):


Thread: M-DRO Magnetic Tape / Linear Encoder 
15/05/2020 12:02:31

I bought the Universal 3-axis kit with magnetic encoders. I went for the ES-12B graphical LCD display:


Thread: Bending 1/8" Steel Plate
15/05/2020 09:35:58

I have another question regarding silver soldering or brazing the crank onto the handle. This is a larger item that I've silver-soldered in the past. Can anyone tell me whether they think my yellow bottle Bernzomatic/Rothenberger torch would get the item hot enough to silver solder? From my limited research I understand that silver soldering is done at a temperature where steel becomes (at least) a dark red heat. Am I right?

A summary of my equipment and materials follows:

  • The joint to be soldered is 3/4" mild steel rod to 1/8" x 1" mild steel crank
  • The torch is a bernzomatic on a yellow MAPP gas cylinder
  • The solder is Cooksons silver solder wire
  • The flux is Johnsons EF flux
13/05/2020 09:20:51

It worked perfectly (well, certainly satisfactorily) with a 15” adjustable wrench and some scrap metal ‘padding’ between the jaws. No bashing, only leverage needed.

Once again, many thanks to everyone who replied. I love this forum!


13/05/2020 08:24:49

Thank you all so much for the information. I have my big engineering vice bolted to a big chunk of wood that I hold in my 9" woodworking vice, so it won't be anywhere near as solid as being mounted directly to the bench, but I'll give it a go bending the steel cold later (once I've walked the dog!). I'll also look into buying one of the vice jaw benders, though I have to admit it isn't often I have to bend something this thick.

Once again, many thanks to all,


12/05/2020 21:55:12

I'm sure this should be a simple one: I'm making the Hemingway Myford Spindle Driving Handle (mandrel handle) and I need to bend two angles on the 1/8" thick mild steel bar for the crank (around 7/8" wide). The bend radius is not critical, though the two angles need to be 'reasonably' accurate to ensure the two ends of the bar end up parallel (like a Z, though with obtuse not acute angles). I have already shaped the piece and drilled the two holes.

The tools I normally use to bend (much thinner) sheet steel are:

  • A large Record engineer's vice
  • Two long pieces of 5mm angle iron
  • A handled Sykes Pickavant tool made from tool steel that is used for bashing onto without bruising the work
  • A big hammer!

I also have a MAPP gas torch that may be useful to soften the steel prior to bending. If I use this, does the bend area need to be heated to red hot or would the steel soften enough to bend it at a lower heat?

I assume that many people on this forum have done a similar thing with 1/8" sheet steel. I'd be very grateful for any advice you have for me, including how I might apply the necessary leverage.

As always, many thanks in anticipation,


Edited By Mike Donnerstag on 12/05/2020 22:21:57

Thread: M-DRO 2-axis mill console functions
05/05/2020 09:54:40

JasonB: I just downloaded the Sino manual and the parameters are:

  1. Processing plane (XY, XZ or YZ)
  2. Centre coordinates
  3. Radius
  4. Tool diameter
  5. Maximum cut
  6. Start angle
  7. End angle
  8. Tool diameter modification (inside/outside arc)

This makes far more sense to me than my Easson, which substitutes the Start and End Angle parameters (6 and 7 above) for the Start and End Coordinates. This makes it difficult if not impossible to program an arc of something other than 90deg. Also, it seems to get confused when I try to program a 180deg arc in the XZ or YZ planes, though of course this can be done in two steps with opposing 90deg arcs.

I was hoping for something more intuitive and dynamic from a DRO with a graphical display that wasn't cheap! I'm also amazed by the poor quality translation in the manual. For example, the manual states an advantage of the R Function is that it 'can machine virtually all kind of ARC, even the intersected ARCs', however the Simplified R function's disadvantage is that it 'cannot machine more complicated ARC such as interested ARC and etc.'. Perhaps someone could help with a translation from Chenglish to English?

04/05/2020 17:07:40

Further to my previous post, if anyone has done any arc/radius milling in the XZ or YZ plane using an Easson ES-12 DRO with scales fitted to all three axes, I'd be very interested in their experience.

Thread: M-DRO Magnetic Tape / Linear Encoder 
27/04/2020 20:32:45


I wondered whether you came across several things about the DRO that I was disappointed about:

1) The 'Universal' brackets are generally too large for a home milling machine, and custom brackets therefore have to be made.

2) The manual has a very poor translation to English and is inconsistent in its terminology. The radius functions really illustrate how poor this is. I would have excused the large title of 'Basic Fucntions' on page 1 if the technical content was well written.

3) The two radius functions on the display are transposed. When you press the 'Simplified R' button (large R), it actually gives you the more complex (small R with a graphical symbol) radius function, and vice versa!

4) Wouldn't it be easier for an arc function to need to specify the centre coordinate, radius and start and end angles, rather than the centre coordinate, radius and start and end coordinates?

5) The manual gives no information on the limitations of the radius functions, for example I am trying to find out whether I can cut a wide arc in the XZ direction, as in the illustration below. For a DRO with a graphical screen, I am sure the radius function could be made far more intuitive to use with better software and a well-written manual.

example arc

6) The right-most function on the display MR (memory recall) does not seem to have any effect when pressed, and is not explained in the manual.

If anyone from Machine_DRO is a member of ME, I'd be interested in their comments, including whether there is a software update available to solve any of these problems.


Edited By Mike Donnerstag on 27/04/2020 21:02:16

27/04/2020 13:02:15

KenJ: I've just uploaded photos of my installation - I bought the Easson 3-Axis with Magnetic scales from Machine-DRO and installed this on my Sieg SX3 last week.

Please see the posting headed 'Sieg SX3 and Machine-DRO 3-Axis Kit' for more information. I hope there's something there that helps. For interest, I installed the Z-axis scale and reader inside the column.



Thread: Sieg SX3 and Machine-DRO 3-Axis Kit
27/04/2020 12:58:29

Many thanks to everyone who commented on this post. I decided to install the Z-axis inside the column, as far back as possible to ensure the cable does not foul the Z-axis leadscrew. Photos follow:

complete installation.jpg

dro display.jpg



z-axis at bottom of travel.jpg

z-axis at top of travel.jpg

z-axis cable.jpg

I'd be very interested if anyone has any comments.


Thread: M-DRO 2-axis mill console functions
27/04/2020 11:39:23

I have the 3-axis Easson DRO kit fitted to my Sieg SX3 and have been trying to interpret the dreadful English translation in the manual. I too have been experimenting with milling a radius (or 'arc function' ) in the vertical plane. I am wondering what limitations the DRO has in this respect. Specifically, is it limited to a quarter circle?

For example, would it be possible to mill a radius into the top surface of some material, as in the example below:

example arc

If anyone has done this using a DRO arc/radius function, I'd be interested to know.

Edited By Mike Donnerstag on 27/04/2020 11:40:49

Thread: Sieg SX3 and Machine-DRO 3-Axis Kit
14/04/2020 16:13:58

Interesting! Many thanks Martin.

13/04/2020 17:59:42

Hi Ron,

Thanks for that information. I think I'm coming to the same conclusion - the 'fit-everything' kit actually fits nothing well, and needs extensive modification to achieve a usable result, albeit ugly. For a much neater result, it seems that making all of the brackets from scratch is the only way, and probably the way I'll go for each axis.


13/04/2020 16:01:56

That's great - many thanks. It sounds as if you've done some interesting modifications. Looking forward to the photos.



13/04/2020 15:45:38

Hi Martin - many thanks for the photos. By 'controller box' do you mean the display? Do you have any other photos? Are these the optical encoders?

13/04/2020 15:18:48

The 'Universal Fitting Kit' is proving to be universally frustrating! Has anyone used the fitting kit or has everyone made up their own brackets for fitting the DRO scales and head? If anyone has actually used the fitting kit, would you be able to post some photos?

Edited By Mike Donnerstag on 13/04/2020 15:19:33

10/04/2020 10:44:13

JasonB: Many thanks for your photos. The kit I was recommended by Machine-DRO to buy is a universal mounting kit with magnetic scales. I went for the 3 axis kit with the LCD DRO:



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