Tuning microsteps, using Bob Norgard's method. (Bob Norgards wesite doesn't exist any more)
Setup for 40 microsteps.
Its recommended to work with two persons: 1 putting marks on the wall, one at the keyboard.
Do the following (after entering values for MsPause etc.):
1. Place motor on a table, at relatively large distance (I used between 5 and 6 meters) from a wall, shaft pointing up.
2. Attach a laser to the shaft.
3. Go to 'two motor track' (in the 'move' menu) and set motors to step 1 microstep at a time. 4. Go to the MSParms menu and move the motor one microstep at a time, using '+' or '-' key,.
5. Place a mark at the laserdot on the wall, after each microstep.
6. Measure the steps with a caliper (cumulative) and enter the numbers in the table below, under 'measured position'.
7. Enter 'new PWM values' in Scope.exe and start again measuring microsteps, until 'new PWM = 'PWM'
The PWM values for the other 20 steps, are the same as 1-20, counting backwards.
I made a spreadsheet to perform the calculations. This spreadsheet can be downloaded by clicking here
ALTITUDE MOTOR			3.765	(mean Alt. stepsize)
stepnr	PWM	measur. position	moved (mm)	ideal position	delta	weight		new PWM
0	0	0	0	0	0	0	0	0
1	16	3.9	3.9	3.77	0.14	0.44	0.0	16.0
2	24	7.4	3.5	7.53	-0.13	0.58	0.0	24.0
3	30	10.9	3.5	11.30	-0.39	0.82	0.0	30.0
4	36	15.8	4.9	15.06	0.74	0.68	1.0	35.0
5	40	18.5	2.7	18.83	-0.32	0.73	0.0	40.0
6	46	22.9	4.4	22.59	0.31	0.78	0.0	46.0
7	50	26	3.1	26.36	-0.35	0.77	0.0	50.0
8	56	30.6	4.6	30.12	0.48	0.68	1.0	55.0
9	61	34	3.4	33.89	0.12	0.82	0.0	61.0
10	65	37.3	3.3	37.65	-0.35	0.74	0.0	65.0
11	72	42.5	5.2	41.42	1.09	0.83	1.0	71.0
12	75	45	2.5	45.18	-0.18	2.10	0.0	75.0
13	77	49.2	4.2	48.95	0.26	1.95	0.0	77.0
14	79	53.1	3.9	52.71	0.39	1.80	0.0	79.0
15	81	56.7	3.6	56.48	0.23	1.65	0.0	81.0
16	83	60	3.3	60.24	-0.24	1.17	0.0	83.0
17	86	63.5	3.5	64.01	-0.50	1.05	0.0	86.0
18	90	67.7	4.2	67.77	-0.07	0.82	0.0	90.0
19	95	71.8	4.1	71.54	0.27	0.76	0.0	95.0
20	100	75.3	3.5	75.30	0.00			100
AZIMUTH MOTOR			3.625	(mean Az. stepsize)
stepnr	PWM	measur. position	moved (mm)	ideal position	delta	weight		new PWM
0	0	0	0	0	0	0	0	0
1	15	3.2	3.2	3.63	-0.43	0.45	-1.0	16.0
2	25	7.7	4.5	7.25	0.45	0.71	1.0	24.0
3	32	12.7	5	10.88	1.83	0.80	2.0	30.0
4	37	16.7	4	14.50	2.20	0.80	3.0	34.0
5	39	18.3	1.6	18.13	0.18	0.73	0.0	39.0
6	46	23.4	5.1	21.75	1.65	0.83	2.0	44.0
7	50	26.7	3.3	25.38	1.33	0.82	2.0	48.0
8	55	30.8	4.1	29.00	1.80	0.67	3.0	52.0
9	58	32.8	2	32.63	0.17	0.70	0.0	58.0
10	64	37	4.2	36.25	0.75	0.70	1.0	63.0
11	70	41.2	4.2	39.88	1.33	0.80	2.0	68.0
12	75	45.2	4	43.50	1.70	2.27	1.0	74.0
13	78	52	6.8	47.13	4.88	1.65	3.0	75.0
14	80	55.3	3.3	50.75	4.55	1.35	3.0	77.0
15	82	58	2.7	54.38	3.63	1.20	3.0	79.0
16	84	60.4	2.4	58.00	2.40	1.20	2.0	82.0
17	88	65.2	4.8	61.63	3.58	0.70	5.0	83.0
18	91	67.3	2.1	65.25	2.05	0.67	3.0	88.0
19	94	69.3	2	68.88	0.42	0.53	1.0	93.0
20	100	72.5	3.2	72.50	0.00			100.0

Go to: computerizing my 20 inch telescope