Deckel FP2 gearbox transmisson ratios

Hi Deckel-fans,

my english is not perfect, so I hope, you can understand, what's mentioned.

I wanted to know the exact transmisson ratio for speeds and feeds of my Deckel FP2 (1st generation, built in 1958).
Without opening the gearboxes, I examined only the upper gearbox (for the spindle speed).

While the "Spindelbock" is unmounted yet, it is possible to count the teeth of the gears in the gearbox for the speeds by looking trough the small gap around the upper gear (the 202 mm (=7,95") long gear with 38 teeth).
For counting the teeth, some color at the tip of a rod was transferred onto one tooth of each visible gear.
Two non-visible gears were touched with a probe tip while another (visible) gear on the same shaft was watched for one full turn.

My results:





motor speed: 1410 rpm (stamped into the type label)
effective diameter of pulley1 (motor): 94 mm (=3,7")
effective diameter of pulley2 (input of gearbox): 188 mm (=7,4")

In the following data, the first number is the speed [rpm] on the dial scale, the second number is the numerator and the third number is the denominator of the fration.

Horizonatal milling:
40: 468 / 8855
50: 128 / 1925
63: 481 / 5775
80: 1476 / 13915
100: 5248 / 39325
125: 1517 / 9075
160: 696 / 3289
200: 7424 / 27885
250: 2148 / 6435

315: 6669 / 16100
400: 456 / 875
500: 9139 / 14000
630: 21033 / 25300
800: 18696 / 17875
1000: 28823 / 22000
1250: 4959 / 2990
1600: 8816 / 4225
2000: 20387 / 7800

Vertical milling (because additional gears in the vertical milling head):
40: 144 / 2737
50: 512 / 7735
63: 148 / 1785
80: 5904 / 55913
100: 20992 / 158015
125: 6068 / 36465
160: 13920 / 66079
200: 29696 / 112047
250: 2864 / 8619

315: 5643 / 13685
400: 20064 / 38675
500: 7733 / 11900
630: 21033 / 25415
800: 74784 / 71825
1000: 28823 / 22100
1250: 109098 / 66079
1600: 387904 / 186745
2000: 224257 / 86190

To get the mathematical speed, calculate:
Spindle speed = (motor speed) * (diameter of pulley1) / (diameter of pulley2) * (fraction see table above)

Example:
At dial scale value 400 rpm for horizontal milling, the fraction is 456 / 875.

1410 rpm * 94 mm / 188 mm * 456 / 875 = 367,4 rpm as mathematical spindle speed


My conclusion:
Deckel obviously calculated with 1500 rpm (motor speed) for dimensioning the gear ratios. If I'm right, all real spindle speeds should be lower than the values on the dial scale.


Why the fractions of the gear transmission ratios are interesting?
If the number of teeth of the feed gearbox is known, too, then it is possible to calculate the exact taper slope angles, that are possible to produce with a facing-and-boring-head (like Wohlhaupter UPA 3) on the FP2.

But I don't want to open the gearbox for the feeds.


Questions:
1. Who can confirm the number of teeth of the gears for the speeds (shown in the table above)?
2. Who can confirm, that the real spindle speeds are lower than on the dial scale?
3. Does anybody know the number of teeth of the gears for the feeds?

Cheers,
Karl


P. S.: With this forum software, I never got uploading pictures working proper. If the pictures are too small, I would be happy, if a friend will upload them.

Hi Karl,

Here are the "full-sized" images. The descriptions of the gears are very useful to have on record. Unfortunately the forum software reduces these photos in size significantly on posting, and I don't know how to make them larger than this.

Don, any suggestions? These are .png files.





Instructions to upload photos in the future are:
(1) Click on your user name at the top of the page
(2) Go to "Albums" on the left
(3) Create a new Album
(4) Upload photos to Album
(5) Look at photo in Album. At the bottom is a BB (Bulletin Board) code. Cut and paste that into your forum post

Cheers,
Bruce

Hi Bruce,

thank you for the instructions. I tried them in the past and now (with a linux operating system on my computer).
As soon as the picture is in the forum software, it's resized or poor quality - bad for pictures with sketches and/or text.

Here are direct links to the png-files to a german picture-hoster:
https://abload.de/img/deckel_fp2_gearsces7h.png
https://abload.de/img/deckel_fp2_speedsnqsqv.png

(The two red numbers I didn't count in real. They were written in the spare part manual.)

See/compare below the results from trying to upload in this forum software.

Just I try to upload the compressed png-file as attachment. It worked for the smaller filesize, but the 192.6-KB-file failed, because the zip-filesize is limited to 97.7 KB.

Renaming .png to .pdf or in .doc resulted in: PDF and .doc are limited to 19.5 KB.


Converted to a high quality jpg, after uploading resulted in a poor quality-98.8-KB-jpg:






The Table above has poor quality. Better quality as png-file (please unzip):
View attachment Deckel_FP2_speeds.zip

I'm happy, that now I'm able to upload photographs better than before.
For pictures, that contain lines and/or text, I don't know how to upload to get a useful quality within thin forum software, yet.

Cheers,
Karl

WOW!.....lots of work here to get the data tabulated and check all the drive ratios. I do like the chart and the enlarged drawing you posted..Very interesting, but not sure what the end target is....
Some additional variables....Here in the US we have 60 cycle power so the motors run faster...Further lots of these machines at least here are running on VFD's so the motor speed is
not exact, and quite variable...
Further, there are FP2's ( and FP3's) that have 2500 RPM spindles using a two speed motor.....

More direct approach might be to use a mechanical tachometer to give the actual spindle RPM for any given ratio and motor.....Vintage Jones Motrola Multiple Range Hand Tachometer Antique | eBay

Or: Jones Computak Ct 2 Measurement Tachometer Gauge Meter | eBay

There are also pretty inexpensive non contact strobe style tachometers that just need a piece of reflective tape stuck to the outside of the rotating part....Run the machine, turn the sync dial till the
rotating tape "freezes" , read the RPM....Perhaps the above RPM testing methods might not be accurate enough for your needs.....
Think there might even be a strobe/tachometer app for the I-Phone......

As to the feed rate...Some Heidenhain DRO's read out the feed rate on the box directly when the slide/scale moves....My Positip 855 does this.....
again the actual feed rate by calculation will be a function of the real motor speed.
Also believe there will be feed rate differences between the inch models and the metric versions if you are calculating by gear ratios.....

Thanks for posting, just curious as to your end use here...
Cheers Ross

Hello Ross,

thank you for the hints. There are some, I didn't know/expected.

Actually I'm interested in the transmission ratios of the gearbox for the feeds to calculate the exact angles for cones, that can be made with a facing-and-boring-head mounted on my FP2 (metric version built in 1958). Perhaps the data could be useful for other FP2-users, too.

Getting this information about the spindle speeds is like warming up, because the data were easy to get, while the "Spindelbock" is unmounted.

This Deckel FP2 is my first milling machine. With most machines, that are new to me in my shop, I like to understand, how they do work in detail. And I like to have best possible information in the spare part list.

RPM-measuring should be no problem - if my FP2 is working some day.
My Colchester Chipmaster has got such a tachometer, that could be interesting for other measurings, because it can show one position after decimal point (programmable):
Frequency Counter & Tachometer 99999r/m Rotate Speed tester Meter dc 12v 24v | eBay

I don't know the differences between the metric and the inch versions. Most manufacturers would change as less gears as necessary (and the thread pitch). If Deckel should have made a complete other internal design for the different versions, I would not be surprised.

Cheers,
Karl

Hello,

in the table above, there is one error in the table for the fraction-values at speed 250.

Here is the corrected file for LibreOffice Calc:
View attachment FP2-speeds.zip

Calculated speed values for theoretical motor speed 1500 rpm:


Better quality:
View attachment DeckelFP2Speeds.zip

(For pictures with lines and/or text, the JPG-format is useless, while PNG-format makes lossless quality at less file size.)

Cheers, Karl

Karl:
Thanks for the explanation...Big difference on the Euro and Inch machines is in the pitch of the lead screws....
Guess one would have to sit down and do the full calculation of the gearing to get the feed rate (final) for each version to know exactly..

Cheers Ross

Hi Ross,

to only one Deckel FP2, I have access. Two other Deckel FP2 I have seen; both type were metric versions of the early 2nd generation (one is Bruce's machine).
Therefore I don't know only some minor differences about the FP2-versions.

Motor speed (the only value that affects the physically unit "time") and pitch of lead screws are just two variables, that are easy to handle in the same calculation sheet.

If all for the calculation needed data are given, then I would do the full calculation again. So, if anybody knows the number of teeth of the gears: be my guest.

Cheers,
Karl

Hi Deckel-Fans,

the numbers of the gear teeth in the feed box of a Deckel FP2 (first generation, built in 1958) completes the sketch.
Because the forum software fails to attach a png-picture as full size (for such sketches, jpg-format is not useful), here an external link to download the picture:

https://abload.de/img/deckel_fp2_gears6njqk.png

Cheers,
Karl

Wow, this is what i call Focus!
Four years later and still getting the ratios sorted out.....My hats off,man!
Not sure that i could remember what the original goal was after this much time.

Here is the short story to posting large photos:
At the page, click on your log in name. Your profile will open.
Should be a tab for "Albums"
Click to open an album...give it a name.
There will be a tab to download photos.
Clock and browse your computer to find the location of the source photo.
Down load the photo. Be sure to save it.
Double click on the photo once down loaded and saved, it will open in a larger window.
Below the photo is a dialogue box showing its location on the bulletin board (BB).
Copy the location (control C")

Start your post or answer an existing post here on the board (open a 2and window)
Paste the BB address into your post.(control V)....your photo will appear when you save your post to the board.

Do not post large photos in this manner....A picture around 1000x780 pixels will fill the page, anything larger will need to be scrolled to view.
Downloaded photos will remain on the board as part of your profile.
UN-posted down loaded photos will be removed after a day or so.

How do you get a full size embedded image?

Cheers Ross

Thanks to Charly DE and the other experts who have put forward this detailed diagram of the FP2 gears.
I am exploring the possibility of cutting small modulus gears using the helical milling device and a vertical head mounted hob.
Knowing the detail of the gear train has paved the way for me.
Josep

If I wanted to know the movement on the axes at a given setting of spindlespeed and feed I would turn the spindle 10 or 20 times at that setting and see how much it moves on my DRO
First keep one feed setting and go through all the high speeds Then one on the low speed to get that ratio
Then go the same way through all the high feed settings and once with a low feed setting All with a constant setting of the speed
You only need to do it about 20 times or so to be able to calculate all the ratio

Peter

Yes, but in the short feed, 8 mm/min, you need a lot of turns to see 2 turns of the lead-screw. And I have the handicap of a worn lead-screw.
And finally, for my proposed, I can only use the short feed.
Josep

fusteret said:

Yes, but in the short feed, 8 mm/min, you need a lot of turns to see 2 turns of the lead-screw. And I have the handicap of a worn lead-screw.
And finally, for my proposed, I can only use the short feed.
Josep

Click to expand...

You do not have to do them all
Just all settingswith high feed low gear and then just one setting on high feed high gear gear and one low feed high gear
The rust you can calculate then
A worn leadscrew is only bad in those spots where there is a change in pitch because of the wear
And that influenzes the gear counting methode even more as mine

Peter