Deckel GK pantographs. What can it do?

I've read the earlier threads here on the Deckel GK12/GK21. Have also watched a few Youtube videos.

Have also read the brochures below.
Deckel GK12-21

The above brochure says the GK12 is suited for "very delicate relief work, lettering, linear patterns and light milling cuts, on dies and molds"

The same brochure says the GK21 is suited for " copy milling work on dies and molds of all kinds"



Here's some of things I would like to make:

* Modifying an existing belt buckle. Making a custom belt buckle. I would 3d print a belt buckel of my design using an FDM or Resin printer. Using the 3d printed version as the master can I make one out of steel on the GK12 or do I need a GK21? I do not need to take heavy cuts and time is not an issue.

* Model locomotive wheels, connecting rods, dome, chimney, buffers and various other little bits. The outside profile of a wheel would be turned on a lathe. Can I use a GK12 to mill out the cavities between spokes, using a 3d printed model as the master, or do I need to step up to the GK21? Same goes for connecting rods, chimney, buffers and dome.

* Various little automotive widgets.


What are the most important tooling and accessories?


Looking at the above brochure and Arno's old thread, both machines can only go down to 1 : 1.50 pantograph raito. Does it mean that the master needs to be at least 1.5 times larger than the intended prototype?

Hi Spud:
If your intention is to actually mill anything, then I would choose a Deckel KF1 over a GK any day of the week.
The KF series of pantographs were intended for copy milling and have the rigididty and the provisions for leverage, using your body weight to actually allow you to control a cutter that's constantly trying to grab and bounce on the workpiece.
In addition to their ability to copy 1:1, they have provisions for scaling down...I believe it was a maximum of 1:5 but it's been decades since I last ran one and I can't remember for sure.
They also allow you to uncouple only one axis at a time which is a necessity for roughing.

So while a GK engraver could theoretically nibble out what you want to do, it's not the machine for you if you ever want to make a habit of this kind of work.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

implmex said:

Hi Spud:
If your intention is to actually mill anything, then I would choose a Deckel KF1 over a GK any day of the week.
The KF series of pantographs were intended for copy milling and have the rigididty and the provisions for leverage, using your body weight to actually allow you to control a cutter that's constantly trying to grab and bounce on the workpiece.
In addition to their ability to copy 1:1, they have provisions for scaling down...I believe it was a maximum of 1:5 but it's been decades since I last ran one and I can't remember for sure.
They also allow you to uncouple only one axis at a time which is a necessity for roughing.

So while a GK engraver could theoretically nibble out what you want to do, it's not the machine for you if you ever want to make a habit of this kind of work.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

Click to expand...

Hello

Yes a KF would be better suited for some of the work I may do in the future, but the thing that puts me off about the KF is the size and weight. If possible I would like to make do with the much lighter GK12 or GK21.

All things I intend to duplicate or build using a 3d printed model as the master, will be small things, weighing just a few pounds.

The KF1 footprint is not much different than the GK12 and GK21.

Big difference in cutting ability, it's about on par with a Bridgeport mill.
The KF1 "Effort required to trace detail work" on small items is very high- the GK12 and 21 are better suited for that.

The GK12 has a lighter "touch" and is easier to operate on small detail work and engraving, but very limited in cutting power for material removal.
GK21 is passable for engraving, OK for light milling if you are patient and taking light cuts, depending on the type and amount of material being removed.
KF series are too stiff and heavy for any kind of engraving, they're intended to rough out and finish mold cavities in steel.

You need a fair amount of kit to be productive with these, at a minimum- workholding, a Single Lip cutter grinder like the SO/SOE to make tracers and cutters, collets to hold the cutter and tracer tips, a selection of cutters/blanks and styli/tracer tips. Good lights and some kind of optics if you are doing small detail work.

Haven't seen many of the special accessories available seperately, so try to get everything you can with the machine.
Parts and accesories are still avaialable in Germany through Franz Singer and others, expect to pay.

There are some special attachments/accessories that are required to do things like trace a cavity pattern into a raised, mirroring, rotary fixtures, extension tables- many of them are designed to enable creating the masters, - if you can 3D print the masters you will likely be fine without them.

Colt45 said:

The KF1 footprint is not much different than the GK12 and GK21.

Big difference in cutting ability, it's about on par with a Bridgeport mill.
THe KF1 Effort required to trace detail work on small items is very high- the GK12 and 21 are better suited for that.

The GK12 has a lighter "touch" and easier to run on small detail work and engraving, very limited in cutting power.
GK21 is passable for engraving, OK for light milling if you are patient and taking very light cuts.
KF series are too stiff and heavy for any kind of engraving, they're intended to rough out and finish mold cavities in steel.

You need a fair amount of kit to be productive with these, at a minimum- workholding, a Single Lip cutter grinder like the SO/SOE to make tracers and cutters, collets to hold the cutter and tracer tips. Good lights and some kind of optics if you are doing small detail work.

Haven't seen many of the special accessories available seperately, so try to get everything you can with the machine.
Parts and accesories are still avaialable in Germany through Franz Singer and others, expect to pay.

There are some special attachments/accessories that are required to do things like trace a cavity pattern into a raised, mirroring, rotary fixtures, extension tables- many of them are designed to enable creating the masters, - if you can 3D print the masters you will likely be fine without them.

Click to expand...

To make a custom belt buckle out of steel, using a 3d printed master, can I get away with a GK12 ?
If not, then what about the GK21?

Same question for model railway parts. HO gauge, O gauge and Gauge 1; nothing larger.

Hi again Spud:
Colt 45 makes a great point when he writes about how clumsy a KF1 is for engraving compared to a GK.
But he also points out the converse truth...the very thing that makes the GK's so nice for engraving also makes them pretty unsatisfactory as milling platforms.
So is there one of each in your future?

I've never used a GK, but I have lots of hours on a KF1.
The engraver I had access to was a GK (12?) clone from Taiwan...I tried to use it once only for a little shallow mold cavity when the KF1 was tied up and never again.
It was pretty close to hopeless.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

Spud said:

To make a custom belt buckle out of steel, using a 3d printed master, can I get away with a GK12 ?
If not, then what about the GK21?

Same question for model railway parts. HO gauge, O gauge and Gauge 1; nothing larger.

Click to expand...

Post a few photos of the kinds of belt buckles and other parts you have in mind and the materials and heat treat condition you want to use.
If you want to make a rodeo rider's big ol' silver belt buckle with some kind of raised lettering or design, and are patient- a GK12 will do fine.

No idea what the railway parts you are mentioning but I imagine a GK12 would be ideal for anything "model" related.
The smaller or more intricate the part is, the more likely it is a GK12 type part.

To oversimplify-
GK12 is an engraver for small, light, delicate work. Can do some light milling, especially in "easy" materials. 50 years ago, these were commonly used for commercial marking on everything from watches to camera lenses and all kinds of stuff in between.
GK21 can do engraving but is more of a light milling/duplicator type machine, can do light milling in a wider range of materials. Intricate detail work will start to get tiresome.
KF series is a relatively heavy duty milling/duplicating machine meant to mill dies and molds in steel. Unsuitable for intricate work.

There is some overlap between the three.
Having the cutter grinder on hand is vital to using one of these machines.

Colt45 said:

Post a few photos of the kinds of belt buckles and other parts you have in mind and the materials and heat treat condition you want to use.
If you want to make a rodeo rider's big ol' silver belt buckle with some kind of raised lettering or design, and are patient- a GK12 will do fine.

No idea what the railway parts you are mentioning but I imagine a GK12 would be ideal for anything "model" related.
The smaller or more intricate the part is, the more likely it is a GK12 type part.

To oversimplify-
GK12 is an engraver for small, light, delicate work. Can do some light milling, especially in "easy" materials. 50 years ago, these were commonly used for commercial marking on everything from watches to camera lenses and all kinds of stuff in between.
GK21 can do engraving but is more of a light milling/duplicator type machine, can do light milling in a wider range of materials. Intricate detail work will start to get tiresome.
KF series is a relatively heavy duty milling/duplicating machine meant to mill dies and molds in steel. Unsuitable for intricate work.

There is some overlap between the three.
Having the cutter grinder on hand is vital to using one of these machines.

Click to expand...

Not the rodeo style buckles. Flat style belt buckles. I haven't drawn anything up yet, it's just some ideas in my head at this point, but I know exactly what it is going to look like.

As for model train stuff: Ho, O and Gauge 1 wheels would range anywhere from less than an inch in diamter to 3-4 inches. Wheels and connecting rods like below picture.

After some thinking and pondering on the replies in this thread, it looks like what I need is a GK21 and a KF1.

On the GK21, if you use the spindle lift mechanism to slide it up and down, say if you are engraving individual letters, for example, and lift the cutter out of the way to move laterally, then there has to be some clearance between the spindle and the housing that it is clamped into. On my GK21, this clamp force is simply adjusted with a Allen key head bolt. However, you now have added potential run-out to the engraver if it is used as a milling machine. Normally, this play is held tight by a spring mechanism that also tensions the drive belt (a round cord). But if your spindle side forces exceed the spring force in any situation, bad things happen. So when they say limited milling, they meant it. Depending on the situation, you could just tighten and loosen the bolt as required. It is a beautiful machine within its limits. One comment, I would be partial to the smaller GK12 as the spindle can apparently fit right into the S0 cutter grinder, reducing potential spindle run-out; but the GK21 is a bit more heavy duty, and it only cost me $200 (Canadian) so I could not argue. The value of either the GK or the KF is enhanced by the accessories that come with it, collets and stuff.

I know this is an old thread but wanted to point out that the home hobbiest will be very happy with a gk12 for almost any modelling work. Belt buckles should be a breeze to. I used to machine/engrave everything from plastic to non ferrous alloys, mild and high carbon steel as well as tool steels like A2, D2 and O1. The harder the steel the slower going it is, it takes time and a lot of patience to get things right.
I have downsized significantly and have a little Deckel G1L now. It's capabilities have suprised me. I have machined, non ferrous alloys, mild steel annealed high carbon steels, O1 and even 4140HT (about 30-32 RC with excellent results. Part size has genrrally been under 3/16 thick and 1 1 /2 T x 5" w. It will handle thicker parts, I just haven't needed to yet. It's very slow going and a I get best results using endmills in the 1/8" or smaller range for harder materials. Just my experience so far with it.
I much preferred the gk12 for machining work but I can't say I'm disappointed in the G1L by any means. For hobby work where your not on the clock you can still do amazing things with with a smaller machine. The bigger reduction range (1:1 upto 50:1) is a great feature.
Mine is on a four wheel swivel base with levelling feet, it can be moved out of the way when not in use. I wouldn't be able to have a pantograph without it being mobile.
It's easy to get lost in machine specifications and it's not easy to make a decision, especially if you've never used or perhaps even seen one in person. They often aren't the right choice if your goal is to support yourself and be competitive when quoting jobs. Don't discount the smaller machines if your a home hobbiest building things solely for your enjoyment.