Belt drive in the works !

[Cruiser]

Dzastr, I think the stock bearings are deep groove ball as they have a wiggle and says spin me. there are two on the driver which the spindle slides into and is pretty firm with both bearings. the stock bearing on the driven shaft which connects to motor is same and with the little spinner on the end which rides in bottom of box i'd be prone to switch my angular with the stock so the shaft will hold angular into play and the stocker can do support. but the way it all fits together i don't really it will matter or make any differance. what really counts is getting the parts and putting it all into play. with the call a little while ago i find that everything is available except the smaller pully which will mount on the spindle driver. The other concern is that i ordered the correct belt, with a 6.102" or 155 mm center distance my belt selected will fit "net". But ! will everything nest together as planned ? The way things have been going lately ! I'm worried and i'll be several weeks for the little guy to arrive off back order to find out. So I sit and wait and ammuse myself here wondering, what did I miss ? what did I forget !

[Cruiser]

Just a short update, I did switch the two bearings per above puting the AC on shaft side and the stock on support side and it made all kinds of differance. It is now maybe 300% more rigid as the AC now has axial load (minimal) the shaft when assembled will hold the AC solid. Most of my parts will be in next week with the small driven pully being out 3 weeks !

[RICHARD ZASTROW]

Cruiser, I have to start over.(my fault, I didn't realize the spindle was a quill type. Now driver etc. makes sense) IN AN IDEAL WORLD, the gear or "soon to be belt" driver would be supported on both sides with a bearing. Since the driver really sees mostly radial force. It sees only the axial force from whatever friction is involved with the splines on the spindle shaft moving thru the driver.
The spindle shaft (again, in AN IDEAL WORLD) would have at least two bearings or sets of bearings supporting radially and axially. The axial support is needed to counter the push and pull of cutting tools and maintain position axially.
The clearance built into typical nonA/C bearings will have some degree of end play. How much your application will tolerate is up to you and your wallet. Personally, I,d go with A/C's but I don't pay for them, my client's do.

Guess what I found in my desk drawer? An SKF double row cylindrical roller bearing with a 20mm ID, 42mm OD and 16mm Width. The cage is brass or bronze and hold the rollers in alternating positions so they are not next to each other. The inner race also is shouldered on both ends to retain the rollers. The outer race is plain, it can slide right off the ends. My desk is kindalike your tool box.
Well, gotta go, Good Luck

[RICHARD ZASTROW]

Cruiser, That bearing I found turned out to be an SKF high precision NN3004K 1:12 taper bore spindle bearing. This is supposed to be part of an extremely stiff spindle bearing setup SKF calls "The NN Solution" in a brochure I had laying around in my archives dated 1989. I am getting old.

[Cruiser]

Well, after ordering parts for this adventure twice now and cancelling twice ! Today I worked with the salesman (who really earned his oats) till we had a working system of parts that are available and ordered ! they will be in late next week. As for the spindle bearing, we did some crunching there too and i bought the AC and a seal for the bottom, and i already have a store of AC's for the top. So today I pulled the gearbox (empty!) off the machine and started to do the conversions in play. I still have one conversion that i haven't mention'd but i did give it a name "Can't E Lever" ! can ya figure it out ? My gear ratio has changed with todays engeneering to give me a top rpm of just over 5800. So I should have aluminum speeds covered and maybe still be able to work steel with small endmills. Hopefully i'll have the heavy work done this weekend and have it ready to just install and try out. I am seriously hoping that getting rid of the gear noise will elliminate the problems of noise interferance with the electronics. That box really got noisy after the spindle bearings going out and changing the oil. We shall see !

[Cruiser]

"A thousand Words" !
I am progressing quite better than expected with my rendition of "can't e lever" ! read (can't even lever)

[davo727]

Cool! Looking forward to seeing more. Why the milling on the side of the column? Dave

[davo727]

Oh, maybe you are mounting the rail and bearing blocks on the side of the column and connecting the Z slide and bearing blocks with a plate, thus transferring the cantalevering force to the bearing blocks instead of the Z slide dovetails?

[BobWarfield]

Ah, very good. I've been writing about putting linear slides on an Asian lathe for some time and now someone's going to do it. Should be interesting!

The router jig is presumably making a nice true spot for the rails to be bolted down on. Does everything clear the existing dovetails?

If I were going this far, I'd be tempted to move the ballscrew out of the column and fill that column with epoxy/granite ala Davo's base.

Best,

BW

[kimoyo]

Cruiser, very cool thread!

Are you changing tapers also?

Why do you feel the cantilever mod is necessary for your mill? Do you think you will see a big improvement?

[Cruiser]

the tapers if spindle is what your refering to NO i'm using same spindle but new bearings. The cantelevering is only a problem when pressure is applied that can lift the head and with the added pressure needed in the gib to make the differance then it starts spreading the dove and making it difficult for the drive, this will take the pressure needed to lift and hold the weight of the box and allow me to back off the gib to near neutral and hopefully relieve the friction tremendously. I've been thinking of doing this since i got the machine and first tried setting the gib and noticed what was happening and did some measuring. Now if it just works as planned. I am drilling now, i made a custom tap drill bushing and i've been clamping measuring and and and etc ! Warning don't use the high carbon taps, only high speed ! The surface milled with the router turned out satisfactory, its not perfect by any means, but is is trued to the axis now close enough that it'll work. the most important measure at this time is the trueness to the slide along the axis and i'm setting it to the nut ! (so far) only 20 more holes to go. the brackets to hold the bearings on the rails will have to wait till i have the mill running again. OH I washed the slides off after the milling to get rid of the cast dust and found that it didn't want to drive anymore, that means the molylube i put on the slides really does do wonders against stickion. I will put some more on after my final cleanup ! As for moving the ball screw and filling the collumn, I'd say Just a waste of time ! The collumn is plenty stout now, just needs this and the set screw helpers for aligning, and it'll do fine. and when the belt drive comes in I'm hoping it all works out too .....

[Cruiser]

This is an update, i got the rails mounted and looking good. then i cleaned up a bit more and smeared molylube on the slide & run it in some and found out the bad news ! I went just a bit too low and heard the triplets go tink tink katink in the chip pan. they were easy to find but seems i have created more work necessary that i don't want to do ! This is enough for now i guess, i'm tired. Probably should have kept this part quiet & to myself huh ?