ideanote
inCAD Library

Make sure to read this before use

What is inCAD Library?

  • Helpful application examples for mechanical engineers.

The Concept of inCAD Library

  • Online application library with a range of ideas for all manufacturing industries.
  • Save design time and learn new design applications when you are concepting new machines.

Disclaimer

  • MISUMI may not offer all parts in each application design. Available parts can only be purchased separately not as a unit shown in each application design.
  • MISUMI does not guarantee quality, accuracy, functionality, safety or reliability for the combination of the parts in each application example. Accept these points prior to use.
  • 2014 Copyright MISUMI
  • The data cannot be used for any purposes (including sales promotion) except for designing your machine.
  • All associated CAD is free. MISUMI reserves the right at its sole discretion to cancel, terminate or modify this offer.
  • MISUMI may change, add or delete application examples posted without prior notice.
  • MISUMI assumes no responsibilities for any damage incurred resulting from your use of the Service or any change, addition or deletion by MISUMI of the application examples for any reason whatsoever.

Features of inCAD Library

  1. Get great new design ideas for these application examples.
  2. Over 200 design application ideas collected from dozens of industries!

  3. Find application examples quickly! Search by function, workpiece shape, etc.

  4. Download the CAD models for each application example.
  5. Log in to download free CAD models.
    Download CAD for the entire application example!

Good IDEA! Button

Click the Good IDEA! Button when you like an application example!

*Can only be clicked once per application example.

  • Upper right corner on the page of application example details

  • Pop-up dialog for CAD data downloading

Back to top

inCAD Library Keyword Search
inCAD Library No. Search

No.000182 Small motor lifting mechanism

Reduces the moment load on the motor shaft.

Rotary Shaft

Product name Rotary Shafts/Straight
Part number SSFHR6-35
Features g6 (ground), h7 (ground) and h9 (polished) are available. Please select based on your applications.
* Orange colored cells in the table below indicate the part numbers used in this example.

Selection criteria

Can be used as a torque rotary shaft.

Back to page top

Available sizes

■Rotary Shafts - Straight

O.D. tolerance Material Surface Treatment
h9 (Cold-drawn) EN 1.1191 Equiv. Black Oxide
Electroless Nickel Plating
EN 1.4301 Equiv. -
h7 (Ground) EN 1.1191 Equiv. Black Oxide
Electroless Nickel Plating
EN 1.4301 Equiv. -
g6 (Ground) EN 1.1191 Equiv. Black Oxide
Electroless Nickel Plating
EN 1.4301 Equiv. -
EN 1.7220 Equiv.
(Hardness: 30 - 35HRC)
Black Oxide
Electroless Nickel Plating

■Sizes

O.D. tolerance Diameter Tolerance Length
(Configure in 0.1mm increment)
h9 Ø3 0 / -0.025 15.0 ~ 150.0
Ø4 0 / -0.030 15.0 ~ 200.0
Ø5 15.0 ~ 250.0
Ø6 20.0 ~ 300.0
Ø8 0 / -0.036 20.0 ~ 400.0
Ø10 20.0 ~ 500.0
Ø12 0 / -0.043 30.0 ~ 600.0
Ø15 30.0 ~ 700.0
Ø20 0 / -0.052 40.0 ~ 800.0
Ø25 50.0 ~ 800.0
Ø30 60.0 ~ 800.0
Ø35 0 / -0.062 70.0 ~ 800.0
Ø40 80.0 ~ 800.0
Ø50 100.0 ~ 800.0
h7 Ø6 0 / -0.012 20.0 ~ 300.0
Ø8 0 / -0.015 20.0 ~ 400.0
Ø10 20.0 ~ 500.0
Ø12 0 / -0.018 30.0 ~ 600.0
Ø15 30.0 ~ 700.0
Ø20 0 / -0.021 40.0 ~ 800.0
Ø25 50.0 ~ 800.0
Ø30 60.0 ~ 800.0
Ø35 0 / -0.025 70.0 ~ 800.0
Ø40 80.0 ~ 800.0
Ø50 100.0 ~ 800.0
g6 Ø3 -0.002 / -0.008 15.0 ~ 150.0
Ø4 -0.004 / -0.012 15.0 ~ 200.0
Ø5 15.0 ~ 250.0
Ø6 20.0 ~ 300.0
Ø8 -0.005 / -0.014 20.0 ~ 400.0
Ø10 20.0 ~ 500.0
Ø12 -0.006 / -0.017 30.0 ~ 600.0
Ø13 30.0 ~ 600.0
Ø15 30.0 ~ 700.0
Ø16 30.0 ~ 800.0
Ø17 40.0 ~ 800.0
Ø18 40.0 ~ 800.0
Ø20 -0.007 / -0.020 40.0 ~ 800.0
Ø22 40.0 ~ 800.0
Ø25 50.0 ~ 800.0
Ø30 60.0 ~ 800.0
Ø35 -0.009 / -0.025 70.0 ~ 800.0
Ø40 80.0 ~ 800.0
Ø50 100.0 ~ 800.0

* The size possible to select may vary slightly depending upon the materials. Please see the product pages for details.

Back to page top

Accuracy Info

■Accuracy of Rotary Shafts

Diameter Circularity M Straightness
Ø3 ~ 13 0.004 0.01 / 100
Ø14 ~ 20 0.005
Ø21 ~ 40 0.006
Ø41 ~ 50 0.007

■Length Tolerance

Length Dimension
Tolerance
over or Less
14 30 ±0.2
30 120 ±0.3
120 400 ±0.5
400 800 ±0.8

Back to page top

Small Ball Bearings

Product name Small/Deep Groove/Double Shielded with Flange
Part number FL696ZZ
* Orange colored cells in the table below indicate the part numbers used in this example.

Selection criteria

Suitable for supporting radial motion.

Back to page top

Available sizes

■Small deep groove ball bearings with flange, double shielded

Material: EN 1.3505 Equiv.

(Name No.) Shaft Bore Dia. Outer Cylinder O.D. Flange O.D. Overall thickness Flange
height
FL682ZZ Ø2 Ø5 Ø6.1 2.3 0.6
FL692ZZ Ø6 Ø7.5 3 0.8
FL682AZZ Ø2.5 Ø6 Ø7.1 2.6 0.8
FL692AZZ Ø7 Ø8.5 3.5 0.9
FL673ZZ Ø3 Ø6 Ø7.2 2.5 0.6
FL683ZZ Ø7 Ø8.1 3 0.8
FL693ZZ Ø8 Ø9.5 4 0.9
FL603ZZ Ø9 Ø10.5 5 1
FL623ZZ Ø10 Ø11.5 4 1
FL674ZZ Ø4 Ø7 Ø8.2 2.5 0.6
FL684ZZ Ø9 Ø10.3 4 1
FL694ZZ Ø11 Ø12.5 1
FL604ZZ Ø12 Ø13.5
FL624ZZ Ø13 Ø15 5
FL675ZZ Ø5 Ø8 Ø9.2 2.5 0.6
FL685ZZ Ø11 Ø12.5 5 1
FL695ZZ Ø13 Ø15 4
FL605ZZ Ø14 Ø16 5
FL625ZZ Ø16 Ø18 5
FL676ZZ Ø6 Ø10 Ø11.2 3 0.6
FL686ZZ Ø13 Ø15 5 1.1
FL696ZZ Ø15 Ø17 1.2
FL606ZZ Ø17 Ø19 6
FL626ZZ Ø19 Ø22 6 1.5
FL678ZZ Ø8 Ø12 Ø13.6 3.5 0.8
FL688ZZ Ø16 Ø18 5 1.1
FL698ZZ Ø19 Ø22 6 1.5
FL608ZZ Ø22 Ø25 7
FL6700ZZ Ø10 Ø15 Ø16.5 4 0.8
FL6800ZZ Ø19 Ø21 5 1
FL6900ZZ Ø22 Ø25 6 1.5
FL6701ZZ Ø12 Ø18 Ø19.5 4 0.8
FL6801ZZ Ø21 Ø23 5 1.1
FL6901ZZ Ø24 Ø26.5 6 1.5
FL6702ZZ Ø15 Ø21 Ø22.5 4 0.8
FL6802ZZ Ø24 Ø26 5 1.1
FL6902ZZ Ø28 Ø30.5 7 1.5
FL6703ZZ Ø17 Ø23 Ø24.5 4 0.8
FL6803ZZ Ø26 Ø28 5 1.1
FL6903ZZ Ø30 Ø32.5 7 1.5
FL6704ZZ Ø20 Ø27 Ø28.5 4 0.8
FL6804ZZ Ø32 Ø35 7 1.5
FL6904ZZ Ø37 Ø40 9 2
FL6805ZZ Ø25 Ø37 Ø40 7 1.5
FL6905ZZ Ø42 Ø45 9 2

* Please see the product pages for recommended dimensions of the mating shaft.

Back to page top

Performance info.

■Load info of Small deep groove ball bearings with flange, double shielded

(Name No.) Shaft Bore Dia. Outer Cylinder O.D. Basic Load Rating Allowable Rotational
Speed rpm
(Reference)
Cr (Dynamic) N Cor (Static) N
FL682ZZ Ø2 Ø5 169 50 85000
FL692ZZ Ø6 330 98 75000
FL682AZZ Ø2.5 Ø6 208 74 71000
FL692AZZ Ø7 385 127 63000
FL673ZZ Ø3 Ø6 208 74 71000
FL683ZZ Ø7 390 130 63000
FL693ZZ Ø8 560 179 60000
FL603ZZ Ø9 570 187 56000
FL623ZZ Ø10 630 218 50000
FL674ZZ Ø4 Ø7 222 88 60000
FL684ZZ Ø9 640 224 53000
FL694ZZ Ø11 715 276 48000
FL604ZZ Ø12 957 345 48000
FL624ZZ Ø13 1300 485 40000
FL675ZZ Ø5 Ø8 217 91 53000
FL685ZZ Ø11 715 281 45000
FL695ZZ Ø13 1080 430 43000
FL605ZZ Ø14 1330 505 40000
FL625ZZ Ø16 1729 670 36000
FL676ZZ Ø6 Ø10 465 196 45000
FL686ZZ Ø13 1080 440 40000
FL696ZZ Ø15 1350 530 40000
FL606ZZ Ø17 2190 835 38000
FL626ZZ Ø19 2336 885 32000
FL678ZZ Ø8 Ø12 515 252 40000
FL688ZZ Ø16 1610 710 36000
FL698ZZ Ø19 1990 865 36000
FL608ZZ Ø22 3350 1400 34000
FL6700ZZ Ø10 Ø15 855 435 15000
FL6800ZZ Ø19 1716 840 37000
FL6900ZZ Ø22 2695 1273 34000
FL6701ZZ Ø12 Ø18 926 530 13000
FL6801ZZ Ø21 1915 1041 33000
FL6901ZZ Ø24 2886 1466 31000
FL6702ZZ Ø15 Ø21 937 582 11000
FL6802ZZ Ø24 2073 1253 28000
FL6902ZZ Ø28 4321 2259 26000
FL6703ZZ Ø17 Ø23 1000 658 9500
FL6803ZZ Ø26 2233 1456 26000
FL6903ZZ Ø30 4588 2565 23000
FL6704ZZ Ø20 Ø27 1041 729 8500
FL6804ZZ Ø32 4015 2462 21000
FL6904ZZ Ø37 6381 3682 19000
FL6805ZZ Ø25 Ø37 4303 2932 18000
FL6905ZZ Ø42 7001 4540 16000

Back to page top

Gussets

Product name Gussets/Tapped Holes/Standard Holes Position/Standard Perpendicularity Type
Part number RBBW30-30-6
* Orange colored cells in the table below indicate the part numbers used in this example.

Selection criteria

Suitable as L-shaped reinforcement

Back to page top

Available sizes

■Rib - Tapped Hole Fixed Dimensions

Precision Type Material Surface Treatment
Standard Grade
(Perpendicularity: 0.05 / 100)
/
Precision Grade
(Perpendicularity: 0.02 / 100)
EN 1.0038 Equiv. -
Black Oxide
Electroless Nickel Plating
EN AW-5052 Equiv. -
Clear Anodize
Black Anodize
EN 1.4301 Equiv. -

■Sizes and Dimensions

Precision Type Short side Long side Thickness / Tapped Hole Dia. Tapped
Hole Depth
30 40 50 60 80 100 EN 1.0038 Equiv. / EN 1.4301 Equiv. EN AW-5052 Equiv.
t6 t9 t12 t16 t6 t10 t12 t16
Standard Grade
(Perpendicularity: 0.05 / 100)
/
Precision Grade
(Perpendicularity: 0.02 / 100)
20 M3 M3 Diameter x 1.5
30 M3 M6 M3 M6
M5 M6 M5 M6
40 M5 M6 M5 M6
M6 M8 M6 M8
50 M5 M6 M5 M6
M6 M8 M6 M8
60 M5 M6 M5 M6
M6 M8 M6 M8
80 M5 M6 M8 M5 M6 M8
M6 M8 M6 M8
## M5 M6 M8 M5 M6 M8
M6 M8 M6 M8

Back to page top

IDEA NOTE Reducing moment generated on the motor shaft.

Wire winding drum is fixed on each end, one on the motor axis and second end on shaft supported by bearing.

  • TERMS AND CONDITIONS FOR USE OF CAD DATA
    Your access to the CAD data that MISUMI Corporation (hereinafter referred to as the Company) posts on this site (including 3D CAD data, intermediate 3D CAD data and 2D CAD data; hereinafter referred to as the Data) are of products manufactured and/or sold by the Company (hereinafter referred to as the Products) assumes that you have read and accepted these terms and conditions which govern your use of the Data. If you do not agree to these terms and conditions, you must stop using this website and the Data. You must not use the Data for any unlawful purpose or in any manner inconsistent with these terms and conditions.
    1. CAD Data
    The Data is prepared for assisting the Company's users in the CAD design process by providing dimensions and other Product information. In order to provide the best speed and stability working within this site, the Product drawings were simplified to reduce the size of the Data. For instance, some of the Products are shown without the oil groove shape, screws or spring shape. Also, please be aware that the tolerance, surface roughness and/or chamfer of the Data may vary from the actual Products.
    2. Disclaimer on Data
    While the Company has carefully prepared the Data, accuracy of the Data is not guaranteed and is subject to the variances as described above. The Company may also modify, add or delete the Data at any time without prior notice. The Company assumes no liability for any direct, indirect, consequential or special damages that you may claim resulted from your use of the Data or any changes to or deletions of the Data regardless of the reason. The Company provides no warranty as to the quality, accuracy, functionality, safety or reliability of the combination of Products and parts. Example applications and combinations of the Products are provided for illustrative purposes only.
    3. Copyright
    Copyrights to the content and the Data belong to the Company or the manufacturers of the Products. The said copyright is protected by the Copyright Act and international treaties. The use (including duplication, modification, uploading, posting, transmission, distribution, licensing, sales and publishing) of the Data except for the purpose to use the Data described above without prior approval of the Company is not allowed. The Data cannot be used for any purposes (including sales promotion) except for designing your machine. If you violate this provision or the laws or regulations, the Company may prohibit you from the use of the Data, the Company’s site and/or take legal action. So long as you comply with these terms and conditions, the Company grants to you a non-exclusive, non-transferable, revocable license to access and use the Data for the sole purpose of assisting you in designing machines that incorporate products.
    4. Disclaimer of Warranty
    ANY AND ALL CONTENT APPEARING ON THIS WEB SITE IS PROVIDED FOR INFORMATIONAL PURPOSES ONLY. THIS WEB SITE, ITS CONTENT AND ITS LINKS ARE PROVIDED ON AN "AS IS" AND "AS AVAILABLE" BASIS AND ARE USED ONLY AT YOUR SOLE RISK, TO THE FULLEST EXTENT PERMISSIBLE BY LAW. THE COMPANY DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, OF ANY KIND, REGARDING THIS WEB SITE (INCLUDING ITS CONTENT, HARDWARE, SOFTWARE AND LINKS), INCLUDING AS TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, TITLE, NON INFRINGEMENT, RESULTS, ACCURACY, COMPLETENESS, ACCESSIBILITY, COMPATIBILITY, SECURITY AND FREEDOM FROM COMPUTER VIRUS. THE COMPANY WILL NOT BE LIABLE FOR ANY DAMAGES OR LOSSES, INCLUDING DIRECT, INDIRECT, CONSEQUENTIAL, SPECIAL, INCIDENTAL OR PUNITIVE DAMAGES AND/OR LOST PROFITS, IN CONNECTION WITH USE OF THE INTERNET, THIS WEB SITE, ITS CONTENT OR ITS LINKS
    Further, the Company will not be liable to you for any failure or delay by the Company to provide access to the Data or any of its obligations under these terms and conditions where such failure or delay is the direct or indirect result of any circumstances beyond the Company's reasonable control (and the Company's obligations will be suspended for the duration of such circumstances).
    5. Policy of Third Parties
    You may be required to separately agree to third party's policies if you use third party software to create or browse the Data or use a third party’s CAD data. In this case, the Company does not assume any responsibility for defects of such CAD data or the software of the third party or violation of their rights. Understand them before use.

    CAD Data Download (Unit Assembly)

    CAD Data Download: File Format
    生成

    Thank you for downloading the data.

    Click the Good IDEA! button when this application example is helpful.


    This data is utilized in order to list more useful application examples in the future.

    Cautions on the CAD data

    1. Assembly data shows the assembly drawings in the concept design phase. The sole purpose of the data is to explain the structure and functionality of the assembly and is not considered nor to be used as a final design.
      You will need to edit the Data so that it meets your specific design conditions.
    2. The CAD data unit assembly consists of sub-assemblies.
      Each sub-assembly unit can be used as it is or can be edited.
    3. * The part in the frame is a sub-assembly unit.

    4. The Data for fabricated parts is based on easy-to-edit dimensions and shapes in sketches and histories.
    5. The Data including the third-part components are made by the Company.

    Back to top

  • * Unit assembly CAD data consists of some sub-assemblies.
       Each sub-assembly unit can be used as it is or can be edited.

Application Overview

Purpose

  • Purpose
    • Reduces the moment generated on the motor shaft. When the allowable moment is exceeded accidentally, the motor will not be effected.
  • Operation
    • The motor axis and shaft are fixed with the wire winding drum. The workpiece is moved up and down by rotating the drum.

Target workpiece

  • Shape: Block
  • Size: W40 x D40 x H25mm
  • Weight: 0.3kg

Design Specifications

Operating Conditions or Design Requirements

  • Up and down stroke: 2000mm
  • External size: W104 x D141 x H94mm

Required Performance

  • Load: 3N

Selection Criteria for Main Components

  • A motor with torque of 0.03 N・m or more is selected to pull up the load of 3N.

Design Evaluation

Verification of main components

  • Selecting the motor from the required load moment.
  • Motor selection
    • Conditional values: Distance between shaft axes and wire attached to the load. d1 = 11.5mm
    • Workpiece mass: W = 0.3kg, gravitational acceleration g = 9.8m/s², rated torque T1 = 0.05N・m
    • Moment generated on the motor M1 is
      M1 = d1 / 1000 x W x g = 11.5 / 1000 x 0.3 x 9.8
      = 0.03N・m
    • Thus,
      Moment generated on the motor M1 = 0.03N・m < Rated torque: T1 = 0.05N・m Thus, the workpiece can be elevated.

Other Design Consideration

  • In order to minimize parts, only one bearing is used and the coupling is eliminated.

Explore Similar Application Examples

Page - / -

Part List

No. Part Name Sample picture MISUMI Part Number
For Price and Days to ship click on Part No.
Quantity
1 Rotary Shaft SSFHR6-35 1
2 Deep Groove Ball Bearings FL696ZZ 1
3 Bearing Spacer CLBUS6-9-3.8 1
4 Ribs RBBW30-30-6 2
  • The part list above contains only MISUMI parts.
    The list of parts and machined products of other manufacturers than MISUMI can also be downloaded by part list download (CSV).
  • TERMS AND CONDITIONS FOR USE OF CAD DATA
    Your access to the CAD data that MISUMI Corporation (hereinafter referred to as the Company) posts on this site (including 3D CAD data, intermediate 3D CAD data and 2D CAD data; hereinafter referred to as the Data) are of products manufactured and/or sold by the Company (hereinafter referred to as the Products) assumes that you have read and accepted these terms and conditions which govern your use of the Data. If you do not agree to these terms and conditions, you must stop using this website and the Data. You must not use the Data for any unlawful purpose or in any manner inconsistent with these terms and conditions.
    1. CAD Data
    The Data is prepared for assisting the Company's users in the CAD design process by providing dimensions and other Product information. In order to provide the best speed and stability working within this site, the Product drawings were simplified to reduce the size of the Data. For instance, some of the Products are shown without the oil groove shape, screws or spring shape. Also, please be aware that the tolerance, surface roughness and/or chamfer of the Data may vary from the actual Products.
    2. Disclaimer on Data
    While the Company has carefully prepared the Data, accuracy of the Data is not guaranteed and is subject to the variances as described above. The Company may also modify, add or delete the Data at any time without prior notice. The Company assumes no liability for any direct, indirect, consequential or special damages that you may claim resulted from your use of the Data or any changes to or deletions of the Data regardless of the reason. The Company provides no warranty as to the quality, accuracy, functionality, safety or reliability of the combination of Products and parts. Example applications and combinations of the Products are provided for illustrative purposes only.
    3. Copyright
    Copyrights to the content and the Data belong to the Company or the manufacturers of the Products. The said copyright is protected by the Copyright Act and international treaties. The use (including duplication, modification, uploading, posting, transmission, distribution, licensing, sales and publishing) of the Data except for the purpose to use the Data described above without prior approval of the Company is not allowed. The Data cannot be used for any purposes (including sales promotion) except for designing your machine. If you violate this provision or the laws or regulations, the Company may prohibit you from the use of the Data, the Company’s site and/or take legal action. So long as you comply with these terms and conditions, the Company grants to you a non-exclusive, non-transferable, revocable license to access and use the Data for the sole purpose of assisting you in designing machines that incorporate products.
    4. Disclaimer of Warranty
    ANY AND ALL CONTENT APPEARING ON THIS WEB SITE IS PROVIDED FOR INFORMATIONAL PURPOSES ONLY. THIS WEB SITE, ITS CONTENT AND ITS LINKS ARE PROVIDED ON AN "AS IS" AND "AS AVAILABLE" BASIS AND ARE USED ONLY AT YOUR SOLE RISK, TO THE FULLEST EXTENT PERMISSIBLE BY LAW. THE COMPANY DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, OF ANY KIND, REGARDING THIS WEB SITE (INCLUDING ITS CONTENT, HARDWARE, SOFTWARE AND LINKS), INCLUDING AS TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, TITLE, NON INFRINGEMENT, RESULTS, ACCURACY, COMPLETENESS, ACCESSIBILITY, COMPATIBILITY, SECURITY AND FREEDOM FROM COMPUTER VIRUS. THE COMPANY WILL NOT BE LIABLE FOR ANY DAMAGES OR LOSSES, INCLUDING DIRECT, INDIRECT, CONSEQUENTIAL, SPECIAL, INCIDENTAL OR PUNITIVE DAMAGES AND/OR LOST PROFITS, IN CONNECTION WITH USE OF THE INTERNET, THIS WEB SITE, ITS CONTENT OR ITS LINKS
    Further, the Company will not be liable to you for any failure or delay by the Company to provide access to the Data or any of its obligations under these terms and conditions where such failure or delay is the direct or indirect result of any circumstances beyond the Company's reasonable control (and the Company's obligations will be suspended for the duration of such circumstances).
    5. Policy of Third Parties
    You may be required to separately agree to third party's policies if you use third party software to create or browse the Data or use a third party’s CAD data. In this case, the Company does not assume any responsibility for defects of such CAD data or the software of the third party or violation of their rights. Understand them before use.

    CAD Data Download (Unit Assembly)

    CAD Data Download: File Format
    生成

    Thank you for downloading the data.

    Click the Good IDEA! button when this application example is helpful.


    This data is utilized in order to list more useful application examples in the future.

    Cautions on the CAD data

    1. Assembly data shows the assembly drawings in the concept design phase. The sole purpose of the data is to explain the structure and functionality of the assembly and is not considered nor to be used as a final design.
      You will need to edit the Data so that it meets your specific design conditions.
    2. The CAD data unit assembly consists of sub-assemblies.
      Each sub-assembly unit can be used as it is or can be edited.
    3. * The part in the frame is a sub-assembly unit.

    4. The Data for fabricated parts is based on easy-to-edit dimensions and shapes in sketches and histories.
    5. The Data including the third-part components are made by the Company.

    Back to top

Back to top