Note: For an explanation of this file, see USING THE FLUTTER DATABASE (will open a new window).

	Dia  mm	Dia  inch		Rate @ 3.75	Rate @ 7.5	Rate @15	Rate @30			Notes
NAB reel inner		4.625		0.26	0.52	1.03	2.06
NAB reel outer		9.500		0.13	0.25	0.50	1.00
7" w 2.25" hub reel		2.250		0.53	1.06	2.12	4.24
7" w 2.75" hub reel		2.750		0.43	0.87	1.73	3.47
7" w 3.00" hub reel		3.000		0.40	0.80	1.59	3.18
7" w 4.00" hub reel		4.000		0.30	0.60	1.19	2.39
7" full reel		6.500		0.18	0.37	0.73	1.47
Ampex AG440
Record-to-play distance		2.550			2.94	5.88	11.76				R/P factor
Supply motor
Electrical torque ripple
Positional torque ripple
BB outer race dent			#DIV/0!
BB inner race dent			#DIV/0!
BB ball dent			#DIV/0!
Supply reel inertia idler		1.192		1.00	2.00	4.00	8.00			Barden 38SS
BB outer race dent			2.588	2.59	5.17	10.35	20.70			.7352 pitch	1.37
BB inner race dent			4.412	4.41	8.82	17.64	35.29			.1563 ball dia	0.00
BB ball dent			1.727	1.73	3.45	6.91	13.81			7	1.04
BB cage			0.37	0.96	1.91	3.83	7.66				1.78
Optional scrape idler		0.470		2.53	5.06	10.12	20.23				1.54
Standard scrape idler(CSUN)		0.375		3.17	6.33	12.66	25.33				0.92
Capstan (Std sync motor)		0.237			10.00	20.00	40.01			Barden R6SS	1.90
BB outer race dent			2.655		26.55	53.11	106.21			.6251 pitch	0.18
BB inner race dent			4.345		43.46	86.91	173.82			.1563 ball dia	1.30
BB ball dent			1.884		18.84	37.69	75.37			7 balls	1.91
			0.379
Capstan (Skinny sync motor)		0.120		10.00	20.00					Barden R6SS	#DIV/0!
BB outer race dent			2.655	26.55	53.10					.6251 pitch	#DIV/0!
BB inner race dent			4.345	43.45	86.90					.1563 ball dia	#DIV/0!
BB ball dent			1.884	18.84	37.68					7 balls	#DIV/0!
			0.379	10.06	20.12
Capstan (Servo motor)		0.380		3.12	6.25	12.50	25.00			Barden SR6SS	0.76
BB outer race dent			2.655	8.30	16.59	33.19	66.37			.6251 pitch	1.81
BB inner race dent			4.345	13.58	27.15	54.31	108.62			.1563 ball dia	1.33
BB ball dent			1.884	5.89	11.77	23.55	47.10			7 balls	0.02
BB cage			0.379	3.14	6.29	12.58	25.15				0.84
Pinch roller (Ampex)		2.009		0.59	1.19	2.37	4.75			Bushing	1.91
Pinch roller (Electrosound)CSUN		1.995		0.60	1.20	2.39	4.78			Ball bearing	1.91
BB outer race dent			3.227	1.93	3.86	7.71	15.43			0.537	1.66
BB inner race dent			4.773	2.85	5.71	11.41	22.83			0.363	0.37
BB ball dent			2.490	1.49	2.98	5.95	11.90			8	0.07
Takeup motor
BB outer race dent			#DIV/0!
BB inner race dent			#DIV/0!
BB ball dent			#DIV/0!
Unknowns
Reel idler shaft/flywheel resonance
Capstan motor shaft/flywheel resonance
Head resonances
Transport frame resonances
Tape-induced resonances
Standard scrape idler		0.400		2.97	5.94	11.88	23.75
Pinch roller (Electrosound)		2.500		0.48	0.95	1.91	3.82			Ball bearing
Ampex MM-1100
Spooling motors
Torque pulsations
BB outer race dent
BB inner race dent
BB ball dent
Scrape flutter idler
Capstan
BB outer race dent
BB inner race dent
BB ball dent
Commutator slots
Pinch roller		2.005		0.59	1.19	2.38	4.76
BB outer race dent
BB inner race dent
BB ball dent
Tape timer
BB outer race dent
BB inner race dent
BB ball dent
Roller guides
BB outer race dent
BB inner race dent
BB ball dent
Ampex ATR-100
Record-Play spacing		1.890	gap-to-gap			7.94
Supply motor
Commutator slots
BB outer race dent										NSK 6201-13
BB inner race dent
BB ball dent
Incoming tension idler		0.747		1.59	3.19	6.37	12.75				1.16
BB outer race dent			2.960	4.72	9.43	18.87	37.74				1.85
BB inner race dent			5.040	8.03	16.06	32.13	64.26				0.30
BB ball dent			3.580	5.71	11.41	22.82	45.64				0.76
Timer roller				0.50	1.00	2.00	4.00				1.42
BB outer race dent			2.960	1.48	2.96	5.92	11.84				1.43
BB inner race dent			5.040	2.52	5.04	10.08	20.16				1.50
BB ball dent			3.580	1.79	3.58	7.16	14.32				0.61
Scrape flutter idler*		0.375		3.17	6.33	12.66	25.33				1.91
Capstan		2.385		0.50	1.00	2.00	4.00				1.42
PC pancake motor	141 steps			70.50	141.00	282.00	564.00				1.99
BB outer race dent			4.103	2.05	4.10	8.21	16.41			SR8	0.21
BB inner race dent			5.897	2.95	5.90	11.79	23.59			10 balls	2.00
BB ball dent			2.639	1.32	2.64	5.28	10.56				1.74
Outgoing tension idler		0.845		1.41	2.82	5.64	11.27				1.58
BB outer race dent			2.960	4.17	8.34	16.69	33.37				0.63
BB inner race dent			5.040	7.10	14.21	28.41	56.82			8 balls	1.94
BB ball dent			3.580	5.05	10.09	20.18	40.36				1.98
Takeup motor
Commutator slots
BB outer race dent										NSK 6201-13
BB inner race dent
BB ball dent
*one sample measured .371" o.d.
Otari MTR-20
Supply motor
Tension rollers		0.786		1.51	3.03	6.06	12.12
Incoming roller		1.889		0.63	1.26	2.52	5.05
Flutter idler
Capstan		0.356		3.33	6.67	13.34	26.67
Pinch Roller		1.502		0.79	1.59	3.17	6.35
Timer		1.909		0.62	1.25	2.50	5.00
Takeup motor
Otari MTR-90
Supply motor
Incoming tension arm roller		1.180			2.02	4.04	8.08
Incoming roller guide		1.574			1.51	3.03	6.06
Timer roller		2.384			1.00	2.00	4.00
Scrape flutter idler		0.630			3.78	7.55	15.11
Capstan		2.389			1.00	2.00	3.99
Outgoing roller guide	See Incoming guide above
Outgoing tension arm roller	See Incoming tension arm roller above
Takeup motor
Otari 5050
Supply motor
Timer roller		1.192			2.00	4.00	8.00
Capstan		0.305			7.78	15.55	31.11
Pinch roller		1.500			1.59	3.18	6.36
Takeup motor
3M M23, M56 & M64
.5 - 300 Hz NAB					0.07	0.04
250 - 5k Hz NAB
.5 - 5k Hz NAB					0.09	0.05
Record-play spacing		6.100				2.46
Spooling motors
Commutator slots-M23&64			24.000			12 - 25				.945 OD,.315 ID,.315 thk,1 plastic shld			38SFTX6?
BB outer race dent			2.756			1.35 - 2.8				0.77
BB inner race dent			4.244			2.1 - 4.3				0.5
BB ball dent			2.246			1.12 - 2.25				7
Commutator slots-M56			32.000			16 - 33				1.178 OD,.393 ID			200SF?
BB outer race dent			2.571			1.3 - 2.6				1.02
BB inner race dent			4.429			2.2 - 4.4				0.592
BB ball dent			1.750			.88 - 1.8				7
Capstan		1.910			1.25	2.50	5.00				0.10
Upper bearing (DB pair)										Barden 103H pair	0.00
BB outer race dent			5.352