Do you think a winch would provide consistent pulling pressure to replace the ratchet strap?
I’m not saying I doubt you… but just curious…
Where did you get that information? Is there some standard calculation for this? This is the first time I’ve seen it mentioned this way
I don’t want that to come off the wrong way…
I’m just interested to learn if there is some way to calculate that. Sometimes understanding things like this makes things simpler for me in my head.
The more bits like this I pick up, the easier “feeds and speeds” seem to become for me
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You could also put a pully at the front of your table so that you can use hanging weights.
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I have done this. I used bottled water and I just tied it to a string. I used a pipe instead of a pulley and I am certain it was effective. 10kg seems like a lot to me. If be more interested in 1kg.
I think I’ll use a cable tensioner, will be way more precise
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In machining all the parameters can be calculated 
This is a long read, You can find all the math here:
I created my own sheet to calculate all
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oooohhhh… let me know if you ever decide to share that sheet 
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It’s made for personal use, I’m not good with spread sheets, so, if you don’t know how to use it you will mess things up 
There are online tool that works way better
hmm…I don’t know of any. Do you know any that have cutting force, etc all calculated.
I’m pretty good with spreadsheets, so I’m not concerned with messing it up… but I understand if you don’t want to make it public.
I don’t think that is right. I mentioned to someone I did most things assuming a 9kg with HEAVY aluminum cutting. They actually confirmed they use similar numbers.
The Fszero calc is how I originally got that number if I remember right, I have since tried that in a few other calcs to verify as well.
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Think of it like this, Slap that strap on the router and pull that machine through some wood, I bet you are under 1kg easy.
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I think these come out well if you are careful with every single parameter, it can be very hard to get it right. The load is a chip with a present moon area so I think load is very hard to calc.
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DAng this does feel pretty high to me. in terms of deflection.
Shoot matter of fact let me check again. I think aluminum is 9lbs or 4.08kg, maybe that is why that deflection is so high, let me run the numbers.
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You saw me trochoidal my way through 8mm thick aluminium, there was minimal flex, so I don’t really believe we get to 10kg…
SLOTTING with a 1/4" endmill at 5.3mmDOC 8mm/s recommended speed 15k RPM just over 9LBS of load.
I would consider this an extreme load since I have never tried it.
So maybe 4kg would be a better pull test, 5 if you want to see more deflection.
Super excited to see what you get.
I used a coat hanger bent into an oval to pull instead of a strap so there is no flex.
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Notice the power required to cut this extreme load…0.21kw. The next person to say they need 2.2kw spindle is getting kicked in the shin.
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Man! That hurts just thinking about it
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People have to understand that the only important thing is to have constant RPM even under load, 800w is more than enough!
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Yeah I think all the drama started with the import “800W” spindles were far from 800 actual watts more like less than 400 at ideal rpm. I have no experience with the better/larger ones. So I think a bunch of people think 800w is not enough and I agree with you, they would be very wrong.
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I’ve check all the math inside my spreadsheet, and I found a wrong value in the conversion from HP to Watts. Now is right, I entered your values in the highlighted line, and that was the result:
There could be differences because of the K Factor of the material, that’s experimental, so you can find slightly different values.
Anyway 4kg should be a good point
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