Finished up the motor side pulley today. The second pulley went much faster than the first... The UPS man is supposed to be bringing me the correct length belt tomorrow so progress can continue. Up next will be the belt tensioner arrangement and making some clearance for the belt (its a little to close as is).
(Plans fresh from the engineering department....)
(Blank chucked up ready to machine)
https://youtu.be/jlVN27TVW9w
(A quick time lapse of drilling the 3 holes that bolt the pulley to the motor flange)
https://youtu.be/14SSBQNH-Dk
(a few photos showing the pulley mounted to the motor.... "ready for action")
(a "cut away" showing the belt drive in its current state)
Thanks!!!
I have a question and I'll ask it here instead of starting a new thread. I have planned on making a weighted base for the Grizzly supplied cabinet that will have adjustable feet, a wider foot print and be ballasted with concrete. This will give the machine a much needed increase in working height and also add some stability.
Is this a dumb idea? Would I be better served on finding a existing tool cabinet with drawers and mounting the machine on that? The factory stand is cute but doesn't have much storage, especially if one puts a small coolant reservoir and pump on the bottom shelf.
What have you folks used to raise the working height and/or make the thing a bit less top heavy and 'tippy'?
Stuart
A lot of progress today... Completed the sticker mod and called it a day!
:cheers:
I picked up the drive belt from UPS today..it's from McMaster and it's a poly-vee 200J6, which is a J belt, 6 groove and 20" long. It fit perfectly. I ended up with a driver pulley at 3 1/2" and a driven pulley at 2 1/2" which gave me a final ration (over driven) of 1.4:1. With my 1725 motor at 60hz, I'll have a spindle speed of 2415 RPM and when jacked up to 120hz with the frequency drive it will give me 4830 RPM. My son seems to think we need massive RPM's for small end mills zooming through aluminum. The drive is a 1 HP Hitachi sensorless vector unit so hopefully, I will have good power under 60hz and, if need be, and I want to scatter the motor, it will go up to 400hz!
The use of the Leeson IEC motor and those pulley sizes made everything fit on top of the spindle casting with adequate4 room to tension the belt, for a power drawbar and plenty of room to construct some type of way cover for the upper half of the exposed Z ball screw/column. So far, everything has worked out well...wonder what gremlin is waiting in the wings!
Stuart
Update..
Received some replacement upper bearings for the spindle drive "barrel shaped" thing. Went with some shielded Koyo's. Finished up the motor mount, machined slots into the plate to allow adjustment of belt tension. Also started measuring up what kind of room we have to work with for a power draw bar. Been going back and forth running the numbers and pros and cons of a multi stage pneumatic or air over hydraulic intensifier draw bar..... still thinking about it. Here are some photos & videos from the journey!
(bearings)
(had to drill the holes for the motor mount plate to bolt to)
https://youtu.be/4_K2RsDQKaM
(motor mount plate showing newly machined slots)
(motor bolted up with some tension on the belt)
(Video showing the back of the motor mount plate getting trimmed and beveled on the milling machine)
https://youtu.be/zm5SCSak4uQ
(and lastly some photos showing the room we are working with for a power draw bar)
Thanks! Questions, comments concerns...?
Stuart & Nick,
You have done a fantastic job on this conversion. Even though I am converting a RF45 I keep reading back thru this thread to get ideas.
I might just have to copy the way you attached the spindle pulley, brilliant!
Any more progress since the last post?
Kurt
Kurt,
Thanks for the kind comments, and yes, we're still slaving away. I purchased all the stuff to build a DIY air over hydraulic power draw bar...then purchased all the stuff to build a multi-stage pneumatic draw bar..then purchased a factory Enerpac air-hydraulic booster off a gent on eBay to go the hydraulic route again. I don't have a clue on what I'm doing but have all the crap to head off in any direction I want...LOL
My big holdup right now is trying to figure out Belleville washers. I have read all of Ray's posts on PDB's, have scoured the net and downloaded informational papers and I've even called Century spring and talked to them. I'm still baffled...probably making it a whole lot more complicated than it really is.
I won't let this thread die..Nick and I will be posting more stuff very soon...as soon as I graduate from 'Belleville 101".
Stuart
Awesome build! Keep up the great work!
Sent from my QTAIR7 using Tapatalk
Hello! Back with a long over due update! We have been working on the power draw-bar cylinder. Borrowed some parts from a 2 inch pneumatic cylinder ( the piston, shaft and cylinder) to build the new hydraulic cylinder. The draw-bar cylinder will be connected to a Enerpac 16 to 1 hydraulic intensifier. Being that we have more than enough draw-bar pressure at our disposable the bellville stack will be between 3500-4000 pounds. Now that the cylinder is pretty much wrapped up, the plan is to build the rest of the draw-bar around it... stay tuned and feel free to ask any questions.
(The shaft and piston from the donor cylinder......... and the blue print for the cylinder (lol) )
(The cylinder sleeve)
(The outer cylinder on the lathe)
(Steel cylinder ready to have sleeve pressed and glued in)
(Apply sleeve retainer and insert)
(You can see the sleeve and the end cap / cylinder mount screw holes)
(The piston, return spring(a stiff valve spring that was shortened), and the re-purposed aluminum internal stop)
(Cylinder with shortened / adjustable shaft. The little hole in the body of the cylinder is a vent)
(The project manager making her rounds)
Thanks!!!
It looks great. How about a few shots of the intensifier?
A lazy man does it twice.
Here are some photos of the Enerpac intensifier. Picked it up on ebay for great price, its a older model but seems to work great.
I would love to see you go full linear with this build. You have all the tools you need to do it
This project is a real learning experience for me and I'm spending some nice time in the shop with my son. I'm not sure I consider the G0704 to be a real workhorse of a machine...at least for the kind of work I'm used to, but the CNC aspect of it may open up my eyes a bit. If I were to go crazy on this stuff I think I would contemplate a large gantry type machine with servo's and automatic tool changer. For right now...at the ripe age of 70, the little Grizz is more than enough.
Stuart
No pictures today, but an update nonetheless. I started making the 'top hat' for the power draw bar today and things went sour in a hurry. The top of the spindle on these machines is threaded 20mm X 1.0. My design called for my top hat to screw onto these threads which would also secure the poly belt pulley to the spindle. After hours of fussing it finally became apparent that the factory threads were cut slightly out of line with the spindle axis. How this happened is beyond me! This wouldn't allow the top hat to seat flat on the pulley and also resulted in about .015 of lateral run out.
As Nick (my son) stated..if nothing else is done right on this conversion, the spindle has to be perfect. It must be balanced, true and quiet. The Chinese thread job was not going to let that happen.
So...3/4" X 16 TPI is real close to the existing size, but not much would be left of the threads if I merely threaded over the existing ones. My plan is to tig weld up the threaded portion, then single point it 'dead nuts' in the lathe with the new 3/4" X 16 thread.
I'll take my camera down to the shop and get some pictures of this when I do it.
Stuart
I had success re-treading the end of the spindle!!! It was quite the task setting up the spindle in the lathe and dialing everything in perfect. 3/4 - 16 threads were single pointed after the spindle was setup in the lathe. Now time to proceed with the top hat portion that will thread onto the newly corrected spindle threads. Also picked up some 4140 for the clamping part of the power draw-bar as was as the draw-bar its self!
(newly "minted" threads!!!)
(top hat in progress)
(top hat progressing....)
(soon to be "clampy" part of draw-bar)
(the thing that says draw-bar on it....)
Thanks!!!