Bobs 2024 Build Off Build

[Rat]

5200 RPM max or the 10” cutoff wheel is like 6100 rpm

Personally I'd prefer an abrasive disc because while they wear down and can shatter given certain circumstances... a metal carbide blade will go dull and begin to kickback aggressively and can warp from heat dull or not.

The trade off is pretty negligible overall but the abrasive discs tend to be higher rater than carbide tipped blades.

The other advantage is that the abrasive discs can be thinner. Thinner cuts means less material wastage in the cuts, and there's also the fact that the abrasive discs tend to cut smoother and leave less to debur

 

[ezcome-ezgo]

Also consider that saws designed to cut wood have plastic parts in proximity of the blade that will not like red hot metal bits flying at them at super(or sub)sonic speeds.

 

[Evanguy]

15 Amp 4.3 HP 14 in. Abrasive Cut-Off Saw

Amazing deals on this 15Amp 14In 4.3Hp Abrasive Cut-Off Saw at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Or

1 HP 4 in. x 6 in. Horizontal/Vertical Metal Cutting Band Saw

Amazing deals on this 4In X 6In Hor/Vert Metal Cutting Band Saw at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

For cutting metal quick and easy

 

[bob58o]

I decided the mitre saw would be more useful in the long run. Fire balls be damned.

5000 RPM tool.
6100 RPM Abraisive 10” Cut off wheels.
I think this will get the job done.

 

[bob58o]

Or maybe this one for a few more bucks. $180 on Amazon.

I think it can make compound cuts in larger material than the non sliding 8.25” compound mitre evolution saw EZ^2 posted (shown in last photo).

​

Evolution R210CMS: Compound Miter Saw With 8-1/4 In. Multi-Material Cutting Blade​

 

[bob58o]

Also consider that saws designed to cut wood have plastic parts in proximity of the blade that will not like red hot metal bits flying at them at super(or sub)sonic speeds.

I think you are probably correct.
The one I just posted seems like the best of all worlds. I’d get the 8.25” non sliding one, but I want to be able to do compound cuts in 2.5x1.5” rectangular tubes.

It seems this saw is the most versatile saw in my price range that isn’t listed as a wood saw with the capibility to do the cuts I want in the material I have.

This is why I GAB. I’ve learned a great deal about cutting. Thank you for your assistance.

 

[ezcome-ezgo]

 

[Rat]

I think you are probably correct.
The one I just posted seems like the best of all worlds. I’d get the 8.25” non sliding one, but I want to be able to do compound cuts in 2.5x1.5” rectangular tubes.

It seems this saw is the most versatile saw in my price range that isn’t listed as a wood saw with the capibility to do the cuts I want in the material I have.

This is why I GAB. I’ve learned a great deal about cutting. Thank you for your assistance.

That last one will definitely serve it's purpose well and then some... not that you plan on building or rebuilding a deck or anything, it's design is just all around versatile for sure

 

[bob58o]

I had ball bearings.


Boo!

I found tapered roller bearings online.



YAH!

The bearings arrived in box with this photo.





Hissss!

Inside were these.




Huzzah!

 

[Rat]

I had ball bearings.

View attachment 145811
Boo!

I found tapered roller bearings online.


View attachment 145812
YAH!

The bearings arrived in box with this photo.




View attachment 145813
Hissss!

Inside were these.


View attachment 145814

Huzzah!

Balls work effectively enough, beeing in use for for 150 years or so... rollers are definitely better though.

Primarily IF your steering isn't well locked, comes loose developing a little play, or WHEN the grease settles and displaces as it always does, and you develop som steering play... rollers don't mind as much whether you fix it immediately or not (you should of course) because of how the fit.

Balls caged or loose aside just suffer damage more easily when allowed a little room to roam off track, they are also more prone to allowing the head tube to be forcibly ovaled out from front brake and road hazard forces hammering on them

 

[bob58o]

If I were to attempt to install a bypass using the parts I have, it would look something like this.

 

[bob58o]

The reason these will suck the oil out of them is they are junk from China rebuilt with the lowest quality parts. Lots of them don't even work right out of the box or come part in a few hours. They are $200

Proper bearings good for 18k rpm would cost more then this whole charger does.

If you look at every single one of these that failed on the Internet it's due to coming part internally or runs low on oil and bearings/seals go.

Also they were never designed to be under vacuum

If anybody still reading is one who supports the use of the bypass….

Would setting idle rpm to 2800 with a 3300 rpm clutch engagement negate most harm caused by not having a bypass with lower idle rpm and lower clutch stall speed?

I believe the faster we idle, the less restricted we are, the less “amount” of relative vacuum, the less harm, the less need for a bypass.?

Does this make sense? Are we on same page?
I forgot who it was who recently supported the use of the bypass.

This is underdriven. I think I figured it would only turn about 3000 or 3500 rpm.

 

[Evanguy]

You need vacuum or it will be free revving. You can put a vac gauge on the motor and see what you are pulling.

Really with a draw through setup the SC will always be under vac when the throttle/carb plate is closed. It just has to be. But you don't want it pumping/compressing air for no reason hence the bypass and it makes sure both sides of the SC see the same amount of vacuum so that helps even things out.

Draw though on this blower isn't ideal at all its such a simple blower. Something like a mini m90 would handle what you are doing so much better. I do understand they don't exist though lol.

the bypass will help with excessive heat the most in this case, less load on the motor at idle/closed throttle

 

[bob58o]

No clue how much vacuum I might see. Or how much boost. I think my goal was 6-8psi of boost.

When I say vacuum, I mean relative to atmospheric pressure. 2”Hg vacuum would be about 13.7 psi absolute pressure.

I was just considering different scenarios when I might want the valve open or closed.

Not sure the spring constant ratings of these types of springs, but I was thinking the spring might be 2” relaxed with a 1.5” preloaded (compressed) installed height. Just guessing here for order of magnitude guestimation.

I think I came up with around 41lbs per inch for a spring constant by setting forces equal to each other when boost was 5psi and vacuum was 10”Hg (5psi). 41mm valve is 2.05 sq inches.

 

[ezcome-ezgo]

 

[bob58o]

View attachment 145836

 

[bob58o]

Happy Birthday to me. My saw has arrived.

My puppers:
What’s in the box?

 

[bob58o]

And a 38mm steel cutting hole saw bit.

 

[bob58o]

 

[bob58o]

The blades linked to this saw came with 20mm and 5/8” ID. The included blade has 20mm ID.

I wasn’t sure what size arbor came with the saw.
Many 7” - 7.25” blades have 7/8” ID from what I’ve seen.