Reply with Quote2005
i assumed they would be plenty beefy for what i need.
i will take some pics of my end bracket when i put the table on.. hopefully tomorrow...
diycnc,
that is look really sexy,
What diam screws did you go for........
How about some pictures on the end supports and how you managed to install them ( they are tiny buggers )
Awesome work!
thanks
2005
i assumed they would be plenty beefy for what i need.
i will take some pics of my end bracket when i put the table on.. hopefully tomorrow...
Sounds awesome diycnc,
I went for 16mm on my RF45 conversion, I suspect there will be no whip as the max length I have is 38inches.
Good work and keep it up!
Thanks!
Hey diycnc,
http://novakon.net/resources/Ball$2BScrews$2Band$2BBall$2BNuts.pdf
Check that out, they mention preloaded for zero backlash.
are they using oversized balls or what is the deal here?
might be a good idea to check it out before you over load your preloaded design - I am using 2 nuts per axis my self so overloading it with our OWN preloading might prematurely destroy it or some thing!
Thanks
well with the double nut on mine and both ends supported i i should be able to spin this faster than i would ever need to.
i got 24inches per minute with 12v so at 72v i should get 144 ipm if thats not fast enough i can go from 4:1 to 3:1 and get 192 ipm
Right but I am not worried about spinning faster,
I am worried about premature failure of the nut or screw........CHECK your BALLS lol.
you need to know how its preloaded - if its preloaded + you preload the other with springs, then you could be adding waaay to much load on the nuts and screws, You know?
Right running servo motors, you can change the gearing up, since you have 4K of rpm to play with...........I think 144 is plenty. Although you are converting a BP
More travel - Sounds sexy
How big is that screw? Looks kinda small for a BP.....Originally Posted by diycnc
here is how i set mine up on my Bridgeport conversion
Regards,
Ray L.
the 2005 screws are good for 2500lbs dynamic load, i have preloaded to 150lbs only 1/16th of the total load. the should live quite a long life.
Sure thing diycnc,
My main concern is understanding how novakon.net states they are zero backlash nuts, Obviously novakon and Chai are identical screws nuts and bearing blocks.
Just makes you wonder how exactly the nuts can achieve such a low digit in terms of lash. Any thing that is not normal and aids in preload to the first nut, will only add to your 150lb preload on the second nut, You fallow me?
over sized balls would only reduce backlash, offset ball tracks in the nuts would also only reduce backlash.
the only way to have 0 backlash is to preload with a second nut using more pressure than you will encounter in regular machine operation.
my machine may have a bit of backlash when cutting forces are greater than 150 lbs but oh well... i will just do finish passes..
preloading with a second nut should have little to no effect on the longevity of the nuts. as i stated earlier i only am loading it to 1/16 of the total load rating. also for the price of these screws i can afford to replace them if the machine gets enough usage to wear them out..
hey diycnc,
that makes sense, Another fellow pointed the offset ball track out to me the other day.
Like you mentioned the amount of preload you got on there is peanuts, and to chance out the screw X years down the road is worth it.
Hope you don't mind, But I rifled through your pictures on imageshack,
Lots of questions, do you have MSN? I would like to address some of them but this thread is probably not ideal for that!
Thanks
pmed you my msn info.. i don't know what pics you were looking at but i doubt they are mine as i only uploaded the one pic of my machine and about 100 of my car on image shack
do yo think i will ever need more than 2350lbs cutting force with a 1 1/2 hp milling head? i am thinking that if i had a big enough bit in there that it wouldn't snap with those kind of forces then i am guessing that the 1 1/2 hp motor would stall out.. i may be wrong thou..
Force is not the issue, stiffness is. Even a 5/8" screw would be capable of driving far more force than that machine can really use - typical max. machining force would be on the order of a few hundred pounds. Knee mills typically have 1-1/4" leadscrews, and commercial CNC conversions typically use at least 1" ballscrews. There's a reason for that. I did mine with very high-quality 1" ballscrews, and it's surprising how "springy" they are - I wish I'd gone with 1-1/4". I routinely push about 2-1/2 HP through 1/2" endmills when roughing. Yours look like 3/4"? Those would typically be used on a machine about 1/2 that size. You may find them a bit "soft".
Regards,
Ray L.
i guess if i find it problematic i can upgrade to 2505 screws as the use the same end supports. the only problem with the 2505 screws is i would need a bigger yoke to fit it in there.
i have started a separate thread below to discuss my machine in the hopes of getting this one back on its original track.
http://www.cnczone.com/forums/showth...025#post646025
Very nice setup there!. What are those aluminum piping for?here is how i set mine up on my Bridgeport conversion
how to tell if it's a RF-20,25,45??? I think my mill is a rong fu? but I am not sure because it doesn't say rong fu but from RF-25 manual it looks the same.
15mg, id say those pipes are for the one shot lube system.
As for your RF.......It could be a clone.
Round column or square?
there are lines going to the ball nuts that end in a grease fitting under the table, there is also a line that goes to the lube system for the ways. i was going to lube it all with the same lube but i though the way lube would be to thin for screws.
I got a round column one i'll post a pic as soon as I'm done mounting the motors cause now is too ugly to show to people
btw
I am a very worried customer of linearmotionbearings2008 I have paid the guy through paypal for the following items:
Chai Guixuan
RM.320 XIECHENG BUILDING, NO. 778 LONGQUAN ROAD,BEICHEN DISTR.
Tianjin
Tianjin
300000
China
+86 02226755283
linearmotionbearings2008@yahoo.com.cn
Qty Description Unit Price Amount
1 RM2505-600/1100/1600mm with nuts 246.00 246.00
Subtotal: $246.00
Shipping: 149.00
Currency is in U.S. Dollars (USD) Total: $395.00 USD
Chai Guixuan
RM.320 XIECHENG BUILDING, NO. 778 LONGQUAN ROAD,BEICHEN DISTR.
Tianjin
Tianjin
300000
China
+86 02226755283
linearmotionbearings2008@yahoo.com.cn
Qty Description Unit Price Amount
1 2.2kw spindle and VFD inverter 470.00 470.00
Subtotal: $470.00
Shipping: 60.00
Currency is in U.S. Dollars (USD) Total: $530.00 USD
I've paid him on 7/29/2009
2 days ago I email the guy asking when is he going to ship the goods but till now no reply from him, usually he respond to question very fast.
Should I be worry or not guys? Tell what I should do.
btw those items I have paid are not listed on his store at ebay
Hi 15mgtar
During the emails I had with Chai I noticed there was a delay over the week endings as well as due to the time zone differences. Suggest you also make sure that you are emailing within the ebay messaging system. In my case machining of the ends of the screws took about a week on top of the postal delay. Hope that you recieve a response soon followed by the ballscrews etc.
Kind regards
Pat
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