| English | Deutsch

HEXAGON Newsletter 181 - May / June 2020

by Fritz Ruoss

FED2+: Self-defined loops w/o peek stress by loop

When choosing the loop you can choose "other .." if no loop according to EN standard is used. So far, the bending stress and reference stress at the loop transition area had also been calculated. However, if the loops are rolled up or screwed in, the bending stress at the loop transition must not be taken into account. Now you can use "SigmaLoop = 0?" Mark with a cross. Also for suspended loops (e.g. HiSo spring from Hirsch-Federn) the loop stress is relatively lower than the torsional stress in the spring body due to the connected end of the loop (fix-loose bearing).

FED2+: Extension spring in horizontal view and hook loop drawing

The extension spring drawing is now available in vertical and horizontal view, with and without text. Since it was possible to enter a different coil diameter for the eyelets, tension springs with hook loops sometimes had been drawn too large. The error has been corrected.

FED7: Printout Sections

Just like in FED6, you can now also list the axial distance aW between 2 turns in FED7. The resolution can be entered as a fraction of a turn (e.g. 0.25 for 90 °).

The spring manufacturer needs the information to measure the finished spring. Please note if the coil diameter changes: aW is the height distance between 2 turns (component z).

```      n = 6      nt = 6     nE1 = 0     nE2 = 0    sections = 10

COILS
nx    nx+1     Nr. Nr.+   Lx[mm]   Lx+[mm]    aW[mm]     Dmx    dx
0,00    1,00     E1     2    0,000    38,473    24,373    83,0   13,8
0,25    1,25      1     3    7,743    49,218    27,076    83,0   13,8
0,50    1,50      1     3   17,555    60,460    28,505    83,0   13,8
0,75    1,75      2     3   27,853    71,702    29,149   112,0   14,4
1,00    2,00      2     4   38,473    83,280    29,807   112,0   14,4
1,25    2,25      3     4   49,218    94,943    30,424   134,3   15,0
1,50    2,50      3     5   60,460   106,690    30,630   134,3   15,0
1,75    2,75      3     5   71,702   118,565    31,263   134,3   15,0
2,00    3,00      4     5   83,280   130,440    31,260   149,4   15,6
2,25    3,25      4     6   94,943   142,315    31,473   149,4   15,6
2,50    3,50      5     6  106,690   154,190    31,300   157,0   16,2
2,75    3,75      5     7  118,565   165,938    31,473   157,0   16,2
3,00    4,00      5     7  130,440   177,600    31,260   157,0   16,2
3,25    4,25      6     8  142,315   189,178    31,263   157,0   16,2
3,50    4,50      6     8  154,190   200,420    30,630   157,0   16,2
3,75    4,75      7     8  165,938   211,662    30,424   149,4   15,6
4,00    5,00      7     9  177,600   222,407    29,807   149,4   15,6
4,25    5,25      8     9  189,178   233,028    29,149   134,3   15,0
4,50    5,50      8    10  200,420   243,325    28,505   134,3   15,0
4,75    5,75      8    10  211,662   253,138    27,076   134,3   15,0
5,00    6,00      9    E2  222,407   260,880    24,373   112,0   14,4
5,25     -        9     -  233,028      -         -      112,0   14,4
5,50     -       10     -  243,325      -         -       83,0   13,8
5,75     -       10     -  253,138      -         -       83,0   13,8
6,00     -       E2     -  260,880      -         -       83,0   13,8
```

LG2: Lubricant Database

Until now, the lubricant had to be selected between ISO VG2 and ISO VG 1500. Now you can also select a lubricant from the lubri.dbf database, or enter another lubricant by specifying the kinematic viscosity at 40 ° C and at 100 ° C.

With ISO VG lubricants, the viscosity for various temperatures is converted according to DIN 51563 for mineral oils.

For lubricants from the database or self-defined lubricant, enter the following: Kinematic viscosity at 40 ° C and 100 ° C, density at 15 ° C. From this, the program calculates the kinematic viscosity and the dynamic viscosity from 0 ° C to 100 ° C according to DIN 3996.

WN1: Quick1,2,3,4

Text heights and table sizes have been optimized in Quick View1,2,3,4 of WN1.

WN4,WN5: Quick4 View

New Quick4 View shows drawings and tables in an A3 drawing head.

ZAR3+: Backlash

The backlash of the worm gear is calculated and printed out if tolerances have been entered or tolerance zones have been selected under "Edit \ Quality" ("wheel 1" is the worm and "wheel 2" is the worm wheel).

```       ----------------------------------------------------------------------
min.torsional backlash            jtmin    mm            0,075
----------------------------------------------------------------------
max.torsional backlash            jtmax    mm            0,316
----------------------------------------------------------------------
torsional backlash min.ang.       jtmin    °        0,342°    0,0524°
----------------------------------------------------------------------
torsional backlash max.ang.       jtmax    °        1,442°     0,221°
----------------------------------------------------------------------
```

ZAR1+, ZAR5 Multistage: Backlash Calculation

The angular backlash in degrees is calculated from the backlash and the center distance tolerance. Example of a gear stage with dw1 = 100mm, dw2 = 400mm, jt = 0.1mm, a tol = 0 (center distance tolerance neglected).

jt1 deg = jt / (dw1 / 2) * 180 ° / pi = 0.11 °

jt2 deg = jt / (dw2 / 2) * 180 ° / pi = 0.028 °

The backlash of gear 2 can also be calculated from the backlash of gear 1 and the gear ratio:

jt2 deg = jt1 deg / u

In multi-stage gearboxes, the backlash of the individual stages is multiplied by the gear ratio up to the input stage. Example: 3-stage gear u = 4, utot = 64, jt1 deg = 0.1 ° for all stages.

jt2 deg = jt1 deg / u = 0.025 °

Backlash of the input shaft with the output shaft locked:

jt1tot = jt1i1 + jt1i2 * u + jt1i3 * u˛ = 0.1 ° + 0.1 ° * 4 + 0.1 ° * 16 = 2.1 °

Backlash of the output shaft with the input shaft locked:

jt2tot = j21i3 + jt2i2 / u + jt2i1 / u˛ = 0.025 ° + 0.025 ° / 4 + 0.025 ° / 16 = 0.0328 °

Or also: jt2tot = jt1tot / utot

In ZAR1+, the calculation of the entire backlash of multi-stage gearboxes is included in the calculation and printed out. However, the calculation of multi-stage transmissions in ZAR1+ is only a prerequisite. The selected tooth thickness dimensions (e.g. e25) and center distance tolerances (e.g. js7) apply to all gear stages. If you deviate from this and calculate each gear stage individually with different tolerance classes for an optimized gear, an exact recalculation can be useful.

For multi-stage planetary gears in ZAR5, the calculation is similar if you first calculate the gear ratio and backlash of the input and output shaft in degrees.

Printout from ZAR5 with 4-stage planetary gear (u tot = 1000)

```       tolerance zone DIN 3967      S-P-H       e 25      e 25      e 25
----------------------------------------------------------------------
torsional backlash I/O (Input S, Output C)  jtmin/jtmax°
----------------------------------------------------------------------
i    n1 /min   mn      u      jImin   jImax   jOmin   jOmax
----------------------------------------------------------------------
1      1450,0  2,50    5,625   0,408   0,984   0,073   0,175
----------------------------------------------------------------------
2       257,8  5,00    5,625   0,285   0,640   0,051   0,114
----------------------------------------------------------------------
3        45,8  8,00    5,625   0,207   0,470   0,037   0,084
----------------------------------------------------------------------
4         8,1 16,00    5,625   0,132   0,289   0,024   0,051
----------------------------------------------------------------------
torsional backlash I/O min   jtmin  °            32,1      0,03
----------------------------------------------------------------------
torsional backlash I/O max   jtmax  °            70,8      0,07
----------------------------------------------------------------------
```

4 planetary gear stages with driving sun gear, output carrier, ring gear fixed.

Angular backlash of the input shaft with the output shaft locked: 32.1 ° to 70.8 °

Angular backlash of the output shaft with the input shaft locked: 0.03 ° to 0.07 °

ZAR1+,5,7,8,ZAR1W,ZARXP,WN2,4,5,WNXE: drawing border = ring diameter

If an outer diameter was entered (for ring gears this is the negative bore diameter), then the drawing limit on the screen is now the ring diameter (no longer the outer diameter of the toothing).

ZAR4: variable normal module

In the case of non-circular gears, one can calculate either with a variable module (m = 2 * r / z) or with a constant module. With a variable module, the min and max value of the gear pair is now displayed in the input window. If the m1,m2 printout disappears due to changed input: Click on "Calc" for recalculation.

Modification index in ISO 7200 drawing header

Previously, if the ISO 7200 title block was configured, "Rev." field shows the next modification index (version number Rev. according to ISO 7200). If there was no modification, it always shows "A". However, because it is not clear whether "A" may appear in the field if there has not yet been a modification, you can now configure (File \ Settings \ Drawing) that the field remains empty if there was no change, and shows "A" if there was one modification.

Network option "copy dbf->temp" prevents database modifications

As only now found at the customer, databases can no longer be changed if this option is set (error message: No Write Access to dbf directory - temporary directory used"). If you want to change databases, you must first switch this option off. Basically, we do not recommend changing databases yourself. At least one should not change existing data records, better add new record, copy the data record to be changed and change the data in the copied record. And then make sure with later software updates that the modified dbf file is not overwritten.

VAT reduction

Quite unexpectedly, the German federal government decided in June to lower VAT from 19% to 16% for 6 months, which should already apply on July 1st, 2020. For our customers in Germany, our products become about 2.5% cheaper (a 100-euro product for originally 119 euros then costs 116 euros). Commercial customers who are entitled to deduct input tax ultimately do not really benefit from this.

Coronavirus - constructive solutions for buses and trains

Local public transport is also avoided after the corona pandemic has died down. From the fear of being infected with viruses. And the others find it annoying to wear a mask for hours.

The bus and train designers should come up with something that you can travel on public transport without risk of infection and without a mask. For example, a bus or train wagon with 15 instead of 2 doors and as many mini compartments with only one seat group and similarly little space as on the plane. Without passage to the front or back, 15 or 20 separate compartments with only one door: to the platform. The door is unlocked with a bank card, and travel expenses are debited when you get out. The question remains whether and how the mini compartments are disinfected in pandemic times? Just like on a plane, quote from "Mask requirement and social distancing at Eurowings": "When you get on, we will hand over a disinfectant wipe". That means: you have to clean your place yourself.

And in post-Corona times, the railway wagons and buses can be used as a first-class compartment: first-class travel also by bus and subway.

Coronavirus - area calculation

What is the difference between a Tönnies canteen and a Lufthansa cabin? Answer: The passengers in the Lufthansa plane sit closer together than in the Tönnies canteen. Lufthansa has ordered that the middle seat should also be occupied. According to Lufthansa, this is not a problem because of the good ventilation (with air circulation!) and the mouth and nose protection of the passengers (brought from home). Profit before security. An Airbus A319 has 25 rows of seats, each with 2 times 3 seats. Fully occupied 150 passengers. The passenger compartment is 18m long and 3.5m wide, which makes 0.42m˛ per passenger. There are more than 2 passengers on one square meter.

Corona virus - learn from China

There were 83,000 coronavirus infections and 4,634 deaths in China. That is only 6 infections and less than 1 death per 100,000 inhabitants. For comparison Germany: 240 infections and 11 deaths. What did China do right and the world wrong? On January 23, 2020, China isolated the city of Wuhan and the province of Hubei: flights, trains, ferries, long-distance buses stopped. Had you done the same thing as China a day later and stopped all flights, trains, ships, travelers from China worldwide and refused entry, the rest of the world would have been spared a lot of suffering.

Coronavirus vaccine victims

Some power-obsessed German politicians (for example, the Swabian Minister of Culture Eisenmann, who would like to replace the Baden-Wuerttemberg "grandfather") demand that everyone be vaccinated. The rulers want to determine that 80 million "fellow citizens" a drug is injected into the bloodstream. In contrast, the belief in the pharmaceutical industry is unlimited. Vaccination without risks and side effects? If only every five thousandth of the 80 million people cannot tolerate vaccination and die or suffer permanent damage, the number of vaccine victims in Germany is higher than the number of corona deaths.

Pricelist | Order | E-Mail | Homepage