Ball screw, singe and double nut ball screw and accessories, precise ball screw, ball screw - Ningbo David Mechanical and Electrical Making Co., Ltd.

Lead precision. Lead precision of ball screw of DAVID Mechanical and Electrical Making Co., Ltd. takes ISO 3408-4 as base, and according to using range and requirements, it is divided into orientation ball screw assembly (P) and transmission ball screw assembly (T), and the precision is divided into seven grades, they are 1,2,3,4,5,7 and 10, grade 1 is the highest.
Change volumes within random 300mm journey and 2 π radian journey are as follows:

Symbol	Inspection content	Symbol	Precision grade
Symbol	Inspection content	Symbol	1	2	3	4	5	7	10
1	Change volume within random 300mm journey	V300p	6	8	12	16	23	52	210
2	Change volume within random 2π radian journey (this item is only suitable for P type ball screw assembly)	V2πp	4	5	6	7	8

Clearance at axial direction. Preloading grade of axial clearance of COMTOP precise ball screw is as follows:

Grade	P0	P1	P2	P3	P4
Clearance	With	Without	Without	Without	Without
Pre-pressure	Without	Without	Light	Middle	Heavy

Reference values of selected precision, clearance, preloading grade and screw cap

Precision	Preloading and clearance	Screw cap	Screw
C10	(P0) with clearance	Single screw cap	转造级螺杆
C7	P1 or P0 (Standard)	According to COMTOP catalog	转造或研磨级
C5	P1 or P2 (Standard)	According to COMTOP catalog	研磨级附导测表
C3	P1 or P2 (Standard) or P3	According to COMTOP catalog	研磨级附导测表

Clearance (P0)
转造级及研磨级 ball screw (P0) max axial clearance Unit: mm

Dimension of outer diameter of screw	Max axial clearance of 转造级 ball screw	Max axial clearance of 研磨级 ball screw
Miniature ball screw with diameter of 04-14	0.05	0.015
Middle dimension of ball screw with diameter of 15-40	0.08	0.025
Large dimension of ball screw with diameter of 50-100	0.12	0.05

Reference value of preloading (P2) in common use

Specification	Spring force of single screw cap (KG)	Spring force of double screw cap (KG)
1605	0.1-0.3	0.3-0.6
2005	0.1-0.3	0.3-0.6
2505	0.2-0.5	0.3-0.6
3205	0.2-0.5	0.5-0.8
4005	0.2-0.5	0.5-0.8
2510	0.2-0.5	0.5-0.8
3210	0.3-0.6	0.5-0.8
1040	0.3-0.6	0.5-0.8
5010	0.3-0.6	0.8-1.2
6310	0.6-1.0	0.8-1.2

Precision of axis

Model\ Grade of outer diameter of guide screw	C7	C10
1605 1610 2005 2505	0.04mm	0.10mm
2510 3205 3210	0.07mm	0.17
4005 4010 5010	0.10	0.20

Precision and testing method of precision of ball screw’s installation position:
Take axes A of 螺纹沟面 as frame of reference to test run-out value of circumference at radial direction.
Take axes F, which lies in the supporting part of screw, as frame of reference to measure coaxial degree of accessories’ installation position.
Take axes E, which lies in the supporting part of screw shaft, as frame of reference to measure right angle degree of the surface of supporting part.
Take axes G of screw as frame of reference to measure right angle degree of screw cap’s datum plane or the installation surface of flange.
Take axes A of screw as frame of reference to measure coaxial degree of circle (cylinder type) of screw cap’s peripheral.
Take axes C of screw as frame of reference to measure parallelism of peripheral of screw cap (flat type installation surface)
General run-out valve of screw axes at radial direction.
The precisions here take JIS B 1191、1192 as standard.
B: Testing method of precision of installation position:

Put the ball screw on V-shaped cushion iron of AA at the time of testing, meanwhile, let testing head of the two dial indicators vertically touch surface of axial column respectively, slowly turn guide screw and write down change range of reading of the two dial indicators, calculate max tolerance of the reading, that is required warp, then check the guide screw with checkout apparatus, control this warp within allowed range through the control to guide screw.

Note: allowed error
When l6>l, the allowed error is t7a<=t7p(l7/l)
When testing, put the ball screw in V-shaped cushion iron terrine of AA, let the gauge head vertically touch column surface of guide screw at the distance of 15, turn guide screw slowly, write down max tolerance value of the reading, test within fixed measuring interval over and over again to receive max value.

Note: when l1<2l5, can be measure at l1/2