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Power Pro Critique.

Posted: Thu Oct 28, 2010 8:28 pm
by wa2crk
Hi Gang;
I just received my Power Pro Headstock yesterday and I assembled everything last night so I decided to post a review. Hope I don't ruffle any feathers.
The most noticeable thing is the weight difference between the two units. The PP is about 20 lbs heavier than the old headstock. With this in mind I wondered about any way tube deflection caused by the increased weight. I put a straight edge across the way tubes at the midpoint with the headstock moved to the far left end and measured the distance from the straight edge to the floor. Then I moved the headstock to the center of the way tubes and took the same measurement and there was no difference. Hence no deflection.
Before I installed the headstock I reset the bench and way tubes in the castings ans removed some "wobble" that was occurring from corner to corner of my frame. I also cleaned the way and bench tubes and then installed the new headstock.
The first thing that I noticed that it was more difficult to move this headstock along the way tubes than the old one. This is probably due to the heavier headstock and the fact that I did not wax the way tubes yet!!!
The other thing that may be a contributing factor is the rough finish on the inside of the casting holes that the way tubes go through. Although I did not feel any burrs or other roughness, the finish was unsightly to say the least. The headstock did not leave any scoring marks on the way tubes and I don't think they will because the aluminum is softer than the steel.

Detail of way tube bore hole
[ATTACH]10739[/ATTACH]

detail 2 of waytube bore hole
[ATTACH]10740[/ATTACH]

Thus far I am very pleased and impressed. There was a slight rattling noise at midrange speeds but it was not excessive. I have not done any cutting yet but that will come this weekend and I will be back.

The following table shows the SS preset speed. The SS indicated speed the Tach speed and the approximate limits of a +- 5% error. The electronic tach I used for this test is from Harbor Freight and is rated at +- 5%. I believe that from other tests that this tach is on the low side, so adding the error factor to the tach reading comes very close to the SS reading

Preset SS indication Tach +- 5% error +-
500 491-501 478 25
900 890-900 870 45
1350 1340-1355 1311 67
2000 1980-2001 1932 100
3450 3435-3458 3318 177
9500 9460-9510 8966 475

For programmed speeds I only took two readings
250 236-255 242 13
5000 4985-5018 4784 250

Bill V

Posted: Thu Oct 28, 2010 8:30 pm
by wa2crk
Hi;
Sorry about the compressed grid. I had it typed ok on the edit screen but the spaces were removed when it got posted. Don't know why

Posted: Thu Oct 28, 2010 8:39 pm
by SDSSmith
Bill, As I understand it you received a complete headstock from SS. Did you choose the new headstock or refurbished headstock option?

Posted: Thu Oct 28, 2010 8:39 pm
by mickyd
Explain these numbers again Bill.

9500 9460-9510 8966 475

Posted: Thu Oct 28, 2010 8:40 pm
by mickyd
Explain these numbers again Bill

9500 9460-9510 8966 475

Posted: Thu Oct 28, 2010 9:19 pm
by wa2crk
Mickyd
The first number is the preprogrammed number on the headstock panel
The second hyphenated number is the PP headstock readout of RPM. This display rolls around rapidly.
The third number is the reading on the tachometer that I used.
The third number is the error factor of my tach.
If you were to add the error number to the tach readout on the headstock you will come very close to the programmed speed.
I am very sure that my tach reads on the 5% low range. I don' know why this site likes to compress grids and take out all of the spaces. I may try to type it in again and see if I can get it right.
Bill V

Posted: Thu Oct 28, 2010 9:26 pm
by wa2crk
SDSSmith;
I chose an entirely new headstock. I had just completed a rebuild of my old one in Feb cause one of the motor bearings went bad so I replaced everything. I will keep the other as a spare. My daughter has a 510 and my son (USAF on this forum) has two. So it might be needed!!!
Bill V

Posted: Thu Oct 28, 2010 9:30 pm
by keakap
wa2crk wrote: I don' know why this site likes to compress grids and take out all of the spaces. I may try to type it in again and see if I can get it right.
Bill V
Are you familiar with writing html?

(specifically tables?)

Posted: Thu Oct 28, 2010 9:33 pm
by wa2crk
Keakap;
No I am not familiarwith the format. I just supposed that if I type it in with the spaces it will post it with the spaces.
Bill

Posted: Thu Oct 28, 2010 9:35 pm
by wa2crk
SDSSmith;
I opted for a new headstock. I just rebuilt my 1983 unit in Feb or March this year and I will keep it as a spare. My son has two units and my daughter has one, so it might get some use.
Bill V