Shopsmith Forums

i just purchased an shopsmith air compressor model DM-B i dont have a manual for this. im wondering at what speed i should operate it at. any info on this would be greatly appreciated.

I'm not sure how similar this model is, but there's a manual for the Magna D-M at VintageMachinery.org.

Specs show 1590 RPM. This came out back when the 10ER's were made, so they gave instructions on which pulley sets to use for that speed.

Here's a Guide for the Speed Dial Settings and relative RPM

SLOW 700
A 750
B 850
C 950
D 1050
E 1150
F 1300
G 1450
H 1600
I 1750
J 1900
K 2050
L 2200
M 2400
N 2600
O 2800
P 3000
Q 3250
R 3500
S 3800
T 4100
U 4400
V 4700
W 5100
FAST 5200

I would use H as a top speed setting, yet be aware the Speed Dial Adjustment and Drive Belt condition will have an effect on actual speed.

Good idea to inspect the belt, and adjust the speed dial to insure you are in range.

Also, a safety tip for any Shopsmith is to detach or decouple any accessory or SPT from the headstock before you power it on. Any SPT can run at slow without coming apart. You will find folks here with Bandsaws that didn't fare well coming on in High.

Another reason for readjusting the speed to slow when you turn off the machine as a standard practice.

everettdavis wrote:Specs show 1590 RPM. This came out back when the 10ER's were made, so they gave instructions on which pulley sets to use for that speed.

Here's a Guide for the Speed Dial Settings and relative RPM

SLOW 700
A 750
B 850
C 950
D 1050
E 1150
F 1300
G 1450
H 1600
I 1750
J 1900
K 2050
L 2200
M 2400
N 2600
O 2800
P 3000
Q 3250
R 3500
S 3800
T 4100
U 4400
V 4700
W 5100
FAST 5200

I would use H as a top speed setting, yet be aware the Speed Dial Adjustment and Drive Belt condition will have an effect on actual speed.

Good idea to inspect the belt, and adjust the speed dial to insure you are in range.

Also, a safety tip for any Shopsmith is to detach or decouple any accessory or SPT from the headstock before you power it on. Any SPT can run at slow without coming apart. You will find folks here with Bandsaws that didn't fare well coming on in High.

Another reason for readjusting the speed to slow when you turn off the machine as a standard practice.

Multiply the settings above by 1.6 to get the lower shaft rpms.

I.E. "C" = 1520 rpm.
....."D" = 1680 rpm.

The Sawsmith "2400" assumes a reduction with the pulleys.(2/3?)

Be advised that this is a "diaphragm" style compressor, not a piston design.

There is a rubber (of some kind) disc, sealed on the edges, and a crank off the
input shaft, pumps the center up and down.

If you remember Holley carburetors, kind of like the accel pump, or
vacuum secondary dashpot. (Also like the vacuum advance on a distributor.)

That diaphragm, if original has outlasted it's design life, quite a few lifetimes
ago.

steve

skou wrote:Be advised that this is a "diaphragm" style compressor, not a piston design.

There is a rubber (of some kind) disc, sealed on the edges, and a crank off the
input shaft, pumps the center up and down.

If you remember Holley carburetors, kind of like the accel pump, or
vacuum secondary dashpot. (Also like the vacuum advance on a distributor.)

That diaphragm, if original has outlasted it's design life, quite a few lifetimes
ago.

steve

Not quite true. The original was a diaphragm compressor. The later models were not. I didn't believe it either. There is a thread here that shows it. An oil less piston compressor. That is what the newest SS compressors used.

jsburger wrote:

skou wrote:Be advised that this is a "diaphragm" style compressor, not a piston design.

There is a rubber (of some kind) disc, sealed on the edges, and a crank off the
input shaft, pumps the center up and down.

If you remember Holley carburetors, kind of like the accel pump, or
vacuum secondary dashpot. (Also like the vacuum advance on a distributor.)

That diaphragm, if original has outlasted it's design life, quite a few lifetimes
ago.

steve

Not quite true. The original was a diaphragm compressor. The later models were not. I didn't believe it either. There is a thread here that shows it. An oil less piston compressor. That is what the newest SS compressors used.

The 'original' is the subject at hand. So the comment be true!

You are Correct JPG.

The lower auxiliary spindle turns 1.6 times faster than the other two, or between 1120 RPM and 8320 RPM.

It was a bit confusing as the manual showed Mark 5 with it driven from Lower Auxiliary shaft, and Mark 2 from the upper Auxiliary Shaft (Quill Speed) I have some photos of that somewhere that I will dig up and post later

Here's a Guide for the Speed Dial Settings and relative RPM for Quill and Auxillary Shafts

Quill Lower Aux
SLOW 700 1120
A 750 1200
B 850 1360
C 950 1520
D 1050 1680
E 1150 1840
F 1300 2080
G 1450 2320
H 1600 2560
I 1750 2800
J 1900 3040
K 2050 3280
L 2200 3520
M 2400 3840
N 2600 4160
O 2800 4480
P 3000 4800
Q 3250 5200
R 3500 5600
S 3800 6080
T 4100 6560
U 4400 7040
V 4700 7520
W 5100 8160
FAST 5200 8320

Everett

And the original was indeed a rubber diaphragm.
Link to thread from which photo came http://www.shopsmith.com/ss_forum/viewt ... 35#p123435
Everett

jsburger wrote:

skou wrote:Be advised that this is a "diaphragm" style compressor, not a piston design.

There is a rubber (of some kind) disc, sealed on the edges, and a crank off the
input shaft, pumps the center up and down.

If you remember Holley carburetors, kind of like the accel pump, or
vacuum secondary dashpot. (Also like the vacuum advance on a distributor.)

That diaphragm, if original has outlasted it's design life, quite a few lifetimes
ago.

steve

Not quite true. The original was a diaphragm compressor. The later models were not. I didn't believe it either. There is a thread here that shows it. An oil less piston compressor. That is what the newest SS compressors used.

You made a mistake?

That is like Spock making a "guess."

Seriously, I was looking into one of these some time ago, and discovered that.
Compressor was cheap, fit my Franken-ER, but would only be a novelty to me.

So I already knew, just from the picture.

(On the other hand, I just dug up an ER gooseneck
light.)

steve