[Halfnutz]

Bought new HF33686 and was horrified at vibration, chatter and noise durring heavy metal cutting. I figured something was wrong with unit but after tearing head down isolated problem to basic design, inherent in all machines, probably all versions(comments on this?).
Noise was coming from under pulley. I thought I needed a new spindle or yoke, its called the "spindle taper sleeve" HF part no. 6. Grizzley Part No. 306. I talked with service dept. at HF and they are clueless. so called Grizzly and told them I bought a used G1007 and got on the phone with those guys. This is a trick Ive used with my HF 9x20 Lathe and a couple other HF tools. The guys at Grizzley Know alot about these machines,the HF guys are just not real familiar.
Anyway fix is a $3.00 10 minut monthly maintenance item. Pack that Mo Fo full a greeze. I covered the spindle end, the spline, with some sticky red grease and packed the tapered spindle sleeve full from underneath with the quill droped down. This may be able to be done from above through the top of the pulley, but I allready had it apart so I went up & in from the front. COMPLETELY DIFFERENT MACHINE NOW. It runs smooth and has very little chatter. I dont know if everyone just tolerates the machines like it was, or if mine was unusually bad or what, but at Grizzly they told me all of the machines are like that -"real noisey". Man what a difference. Next item is ballscrews. I cant deel with the slop in the table. Then the CNC conversion. I will post all with lots of photos as I go.
Note: Pulling head apart was nothing. It was very easy to drop out the spindle and re-assemble in less than a half hour.

[HomeCNC]

I did not have any vibration problems with my Enco mill/drill on all speed except the upper two. I solved my vibration problems by using the power twist belts on the pullys. Now I can have the spindle all the way up to 2000 RPM and the shaking is gone from the table.

[Halfnutz]

I got the v-belts on order also every bit helps, but the problem I was having was more noise and chatter than vibration, only in steel. it was just hammering away, under the pulley. Do you have play in your spindle(rotational/). I have also found that all of the noise and chatter is probably due to my ineptness more than anything else. By changing spindle speed most of the vibration can be removed. I have lots to learn about cutting speeds in different types of metals, tool selection, cut and feed rates etc.

[Halfnutz]

Grease has really not entirely pleased me so I went back into head and tightened up bearings in spindle. This was done by tightening a retaining nut and lock nut on top of bearing assembly. Machine runs very smooth. There is essentialy no vibration at all, even cutting CRS. I am pleasantly suprised at how smooth and powerfull this thing is. Here are pics of head tear down

[Halfnutz]

Bolted unit down to floor and greatly heped with problem. Machine runs really smooth now. Ordered ballscrews to begin conversion.

[HomeCNC]

Good luck with your conversion.

[smallplanes]

Does anyone sale plans or a kit for a cnc conversion on this machine? What will it cost for a full conversion ready to cut metal? I just bought a machine just like this one form Harbor Freight Tools.


Thanks
smallplanes
S.C.

[sin-city-custom]

What is a CNC conversion? I have no lathe experience except with drum and rotor lathes.

Thanks,
Dave

[Halfnutz]

(SmallPlanes) Ive found one ready to run bolt on kit, just do a search "CNC Mill/Drill Conversion" and you will find it and some others. A ready to run machine is around 10,000 and the kit for your machine is around 5,000 I think. If you do the majority of the work yourself it can be done for 1500 - 2000. depending on the way you go. Software alone can cost 2000. These machines require a ballscrew conversion for any kind of decent performance then you need steppers or servos and encoders, a controller hardware box, the stepper/servo drives, a power supply, the cabling, a computer, CAD and CAM software and then the custom machining, pulleys, bearings and motor mounting hardware. Its definately not a weekend project, unless you got the 5000.00 for a complete kit. If you got 10 grand for a machine I think it would be foolish to spend it on one of these, get a Enco or Jet Bridgeport clone and convert it. Thats just my humble opinion. Im doing it for the fun and learning, and my budget is tight, so this is the way to go I think. (SinCity) If you want to see a machine in action check out Jeff's site at www.homeCNC.com and run the movie file. He has nice plans for sale and some hardware also. Here is a pic of my home made flood system made out of a garden sprayer. It works great. (Response to next post added on 2/25) The coolant I am using is Sta Lube Soluable oil which is a mineral/vegetable oil base in an emulsion. Its cheap, about 5 bucks a quart and gets mixed up to 50/1 Im using it at 20/1. I never thought about it going bad, but I bet it could! Ill have to use it up quick. I also put a small hole in the corner of my table to drain the stuff into a small bucket. I really like the set up, the paper clips hold the thing in any position and its adjustable for both spray pattern and flow rate.

[HomeCNC]

I like your coolant system! That is one thing I do need to add to my CNC mill/drill. The chips build up so fast and I'm tired of spraying WD-40 from the can

What brand of coolant are you using? I have read people here that had problems with coolant going bad with things growing in it. YUCK!!! That has made me affraid to try a coolant system.

P.S. Halfnutz... Thanks for plug on my plans.

[Halfnutz]

No problem Jeff, your site is a real inspiration, its what got me interested in this, I had allready decided on buying the mill and when I saw your site I was hooked.

Well, after going down every cost saving avenue I can think up I keep circling back to where I started. There are a million ways to compromise on this thing but only one way to do it really well. Ballscrews, Gecko drives, Servos w/ encoders, and a big power supply. Any deviation from this basic scheme really seems to cut performance significantly. I would love to use Kerk or some other type of leadscrew, but nothing has the high efficiency , linearity and performance of a ballscrew. There are a number of multi axis controllers available, but someone compared it to like having a full size truck with a 1.5 liter 4 cyl. engine. The Geckos have the power to really move the big 450oz/in motors along, the others dont. I'm not real clear on why steppers arent as good as servos, but they definately arent and they require encoders, another added expense, but worth it from my understanding. The only thing I havent settled on is the software and the power supply. I have heard people using Dos systems and others with expensive Windows based programs. Any feedback on software choice would be appreciated. Of course I would like to spend as little as possible, but I dont want to waste a lot of time learning something that will ultimately have to be abandoned. I had ordered ballscrews at one point, and then I changed my mind (fortunatly the same day so it didnt cost me). I thought I could find a less complicated alternative, but I dont think anything else will work well on the size mill I have. So its back to where I started, I will have to re-order them next week I geusse. Unless someone can tell me a leadscrew of some type will work adequately...

[Halfnutz]

Update -
Ballscrews are on order. I got a 6 ft. Rockford 5/8", 0.200" lead piece of screw stock and two pre loaded nuts on arbors with mounting flanges and wipers all for $300.00. I decided that I had enough to do machining the ends and getting the angular contact bearings and screws installed, so I opted out of building the pre-load assemblies. I could have saved $ 100.00 by making my own pre-loads, but then I would have to make a mounting flange and some kind of wiper assembly. I will get to do all of that on my Z axis anyway.

I have got the mills spindle bearings broken in just like some old leather boots now with around 14 machine hours on them, and I have the pullies set at 2500 RPM allmost allways. The finish at high speed verses lower speeds is significant, and the HF seems to love screaming along at full throttle. To re-iterate, it didn't come out of the crate that way! I couldn't stand it when I first turned it on it vibrated so bad! I re seated the spindle bearings by tightening them, and then backing off the pre load on them over a 3-4 hour run untill they are smooth, with no measureable run-out, but much tighter than the machine came shipped. Also a pair of link type drive belts to cut down some vibration, and really bolting her down to concrete tight. It runs very smooth and quiet, with no vibration and cuts steel like butter at the high speed setting now. I am overall pleased with its performance and can't wait to get the table tightened up!

I also broke down and bought a kit from Hobby CNC. It is a "complete" kit with three 200 in/oz steppers. It should suffice for my little Homier 12spd. and get me some practice moving the motors around and designing parts. Then once I get my big HF mill converted I can use it for my lathe. lI finally got DeskNC for DOS running on my old computer. I am blown away at how complicated this whole process is due to the myriad of different directions people have gone in. Oh well, I wanted a hobby to occupie some of my extra time and energy (but not this much money).... I just had no idea how much crap I was going to have to wade through.

Anyone using DeskNC? How about HobbyCNC's board? Any comments/suggestions would be appreciated.

[smallplanes]

I'm a Cnc Machinist and i run cnc mills every day for a living, and i can tell you that if you are trying to machine steel at 2500 rpms that you are turning to many rpms. If you are using a 1/2 hss end mill in 1018 steel you should be around 750 rpm's and a 3/4 hss end mill around 500 rpm's. The bigger the tool the slower the rpms'. Now if your machining aluminum you can use 1/2 hss end mill around 2300 rpm's but if your trying to machine a part with no coolant i would no go that high. I program and set up 4 Mori Seiki milling machines every day and i bought a HF milling machine for my back yard shop it's a good little machine for the money but i don't think it would do good at high rpm's. This is just my thinking. I'm not sure of the program you are talking about i use Bobcad for drawing but i hand type every program our machines has Fanuc controls on them.

Thanks
smallplanes

[DAB_Design]

Sorry for maybe going a bit off topic here, but "i use Bobcad for drawing but i hand type every program". Isn't that like chiseling a stone tablet when you have a piece of paper and pen right next to you?

[Halfnutz]

Well I can agree that you certainly know more about this than me, and your advice is appreciated. I have been running at high speed for the last week just messing around and seeing how the machine acts. It seems to cut much cleaner at higher RPM. I allways use coolant when cutting steel, and now that I have a system set up I run alot of it. I have had up to a 3/4 4 flute HSS end mill cutting CRS at top speed, but granted, not for long, and just to see how it does. I will take your advice and slow down some, however for surface contouring in aluminum, which is mainly what I am concerned with and plan to do with the Harbor Freight machine, with a 1/8 to 3/16 HSS 2 flute ball end shouldn't I be running at the high end? I thought faster was better if the machine can handle it?

[smallplanes]

Well i hand type because my Bobcad post prosseser for my Fanuc 18I control does not work just right. It does not write the code just like i like it, i know i can get it fixed by Glenn at bobcad but i have not the time to stay on the phone. I am the only programmer set up guy that we have and i'm stretched to the limit,we also have 7 Mori lathes but my brother is the set up programmer for that. This is a small family run cnc machine shop and we learned everything we know by hands own experience no school just a lot of trial and error.


Halfnutz
Yes if your going to be running that small end mill in aluminum you do need high rpm's and coolant. You can also use Kerosene on aluminum it works good but i would not run it tru a coolant pump you can brush it on or maybe use a window cleaner bottle to spray it on. If you have the machine running steel at that high rpm with no chatter then your doing pretty good. I know you say you are just playing around with it but one thing i can tell you is it will wear you tools down very very fast even with coolant at that rpm. You are also right it does feel like it cuts a little better at higher rpm's and look a little better but its because you are doing more rubbing than cutting. Aluminum can be a butt to machine some times too, if you are going to slow with your feed you will sometimes get a piece of aluminum to stick right on the cutting edge of the tool and it will mess up your finish. The same goes for trying to drill aluminum but if you us the K-1 on it and push kind of hard on it you will be ok.

Thanks
smallplanes

[Halfnutz]

I started out using oil thinned with turpentine, I liked it, I still have a spray bottle full of it for little stuff, but I set up a flood system with the emulsion oil you mix with water for bigger cutting. I havent used allot of it but it seems to work well. Aluminum is what I will eventually do a lot of work with, so maybe I'll end up back with the squirt can. Is the emulsion coolant, the white water mixed stuff any good for alluminum? You like BobCad? I gotta buy something here soon, I have a couple 30 day trials now of CAD X11 and CadMax. Learning how to use a Cad program is a pain. Is BobCad freindly? Do they have a good tutorial?

[smallplanes]

I use solubail oil in my machine's and it works good,but it has one draw back it will start to stink if it's not cleaned out regularly. I like the Bobcad i have the V20 but have not had time to mess with this version much. I have V19 and thats what i have been using i'm still not that good at it but i can draw what i need. I have wrote a few programs with the bobcad but it's not just right yet, i need to get the post set up a little better for my machine's. It has great manuals that come with the software ,and an oppsion of some learning cd's. I would get the cd's if i were you they realy help a lot. I like the bobcad but it does have a few things i don't like about it,but thats life right. It is great with engraving. I bought a CD off of ebay that is a good speed and feed cd i think you need to try and get it it was only $29 and it is a must have. Here is the address CNC-ZONE SOFTWARE 1224 Sandusky Street #B6 Fostoria,OH 44830-2769 USA Its called CNCSpeed the web address is www.cnc-zone.com it must be sold on this site i'm not sure i bought it before i new this site was even here. I allready know how to figure speeds and feeds but it has a lot more stuff on it than that. If you need anything else let me know.

Thanks
smallplanes

[Halfnutz]

Update:

Well, the ballscrews came in, and some other things have happened. I got my kit from Hobby CNC and put it together without a hitch. Nice kit. So I started looking at my Homier and its Z system with no fine downfeed, and decided that in order to convert it I would have to do way too much work. Besides I was looking for a reason to buy a mini mill, and, well....

So I ordered Ron Steeles plans and a Sieg X2 from HF for 450.00 (it can be had for 450.00 only at the store locations from the manager) and started making swarf....
Voila!... another project!
Jeff's plans from HomeCNC were also ordered and parts are being made for it as well. I know a zealot would disdain from my use of "plans", but, well, I dont care. I am not a glutton for punishment, and I know what my imagination is capable of. Both sets of plans are tried and true conversions so I dont have to worry about spending several hundreds of dollars and ending up scratching my head and my #$%$ thinking "...maybe I should have tried it this way.....". Like I said, I know my self well enough to know better. Man, it sure does feel good to have chips flying once again!

I've also settled on TurboCad for design (I got a valid copy of V9.2 Deluxe for 15.00) and TurboCNC and/or DeskNC for software. I have both control packages excersizing the HobbyCNC kit on an old laptop and while both work fine, DeskNC is eisier, but TurboCNC seems like it will be more versatile in the long run.

[smallplanes]

It looks and it sounds good. How long did it take you to make the conversion?When you guys convert these machines do you make the spindle speed programable?


Thanks
smallplanes