[chich2]

Here is the Vid





Chich

[chich2]

Yesterday I cnc drilled the hold down bolt holes in the brace. I then clamped the brace onto the machined surface and faced the top off parallel. After that the knee was raised to full height and locked off. I left the air pressure on the cylinder for added safety to keep the knee from slipping down and then removed the standard Z nut support. The new one was then put into place and measured off against the column. I then drilled and tapped 2 holes and bolted the brace down. All the other holes were then drilled and tapped using the bolt patern in the new brace as a template.

Today I'll machine the brace strut's and fit them to the machine.

Chich

[chich2]

Today I CNC milled the hole in the hollow bar bigger to give the ball nut a bit more clearence. I could only go down 24mm until the depth of cut came close to the shoulder on the shank of my insert cutter. After that I dug out me old boring head and took the hole down to depth. (45mm)
Next thing to be machined was the angle on the bottom of the strutts. I clamped both down together on the table and cleaned up the face with the horizontal spindle. After that I drilled the bolt holes in the strutt's.
I drilled 1 hole in the column and sat 1 brace into position.

That's it for now,
Chich

[chich2]

Next was to draw around the strutt with a pencil and mask around it. I then chiped away all the filler / grout where the strutt will bolt on to the column. This was done on both sides of the column for maximum grip of the strutt to the column. Once scraped and a heavy go over with a wire brush I gave the surfaces a de-grease and a light coat of Zinc undercoat to prevent rust.
I then de-greased all of the other parts of the brace and hosed them off with clean water. An LPG torch was used to heat all the parts up warm to touch to drive off any moisture. This was followed by painting all the brace parts with the same Zinc undercoat and then bolting it all to the machine once the paint had dried. I drilled and tapped all the holes into the column M10X1.5 and did the bolt's up tight.

Now that the Z nut brace is square to the screw and the strutt's are in position, all that needs doing is to weld the strutt's to the base.

Chich

[chich2]

I welded the Z nut support and strut's together yesterday and masked it all up ready for painting. First was a coat of super etch as an undercoat. This went over the zinc as it turns out the zinc is not compatible with the 2 pack top coat I wanted to use. The super etch was allowed to dry for a day. I got some paint colour matched to the machine in a 2 pack paint. I mixed some up and painted all the brace steelwork.
Today the paint is dry so I removed all the masking tape and paper. I could not wait to see the final outcome with a dial indicator on it and see how it went. So far it seems there is NO flexing occuring whatsoever but I find that a little hard to believe. I will be doing some test this afternoon to see for sure.

Here's some pix,

Chich

[cjmerlincnc]

Hi Chick2, I've been reading your post since a year ago I happened to
purchase a similar mill to yours, a ZX7550 what ever that is.

It just has the vertical spindle and the usual Chinese finishing touches.
The only obvious differences I've noticed is the Z leadscrew nut housing is tapered on mine and is 5 1/2" in diameter on the base, there is a rising in the floor casting of about 1/4 inch high for it to sit on, so mounting an air ram is going to be tight.

Having a poke about in the suds sump in planning to cut the hole for the air ram I noticed that the area under the column on mine is solid all the way to the floor with a 4" x 5" hole through to the center of the column.

I'm now at the stage where I need to do the knee mods for the ram and I'm a bit reluctant to go at it with the angle grinder although I know it has to be done to get the ram in.

I also have the added problem of not being able to get the knee off the column to work on it as I do not have any lifting gear or strong beam to throw a rope over to carry the head off the column.

I think with patience, cunning, skill, whatever, I should be able to get the grinder in there and remove that casting rib.

Just a question, have you had any adverse problems due to cutting that vertical rib from the back of the knee?

Also, I'm planning to get oil to all axis, the z axis has no oiling points on mine and due to not being able to remove the knee is going to cause me a headache but I do have ideas so fingers crossed.


Keep up with the good work it has been an informative and enjoyable pleasure reading your project posting.


Cheers
John

[breck]

Hey Chich, looks awsome! I got on this great forum because I am building a cnc router and find you 5 minutes down the road. Andrew said you had retro-fitted a mill but didnt realize you were on here. When are you home next? I will give you a call,I have been meaning to for ages. I'd love to have a closer look. Breck

[epineh]

Hey Chich, looks awsome! I got on this great forum because I am building a cnc router and find you 5 minutes down the road. Andrew said you had retro-fitted a mill but didnt realize you were on here. When are you home next? I will give you a call,I have been meaning to for ages. I'd love to have a closer look. Breck

Hey Breck, well either you are 10 minutes from me or you live practically next door (I live about 5 mins from Chich), I think we should catch up as well, good to hear of another local getting addicted to this stuff

Cheers.

Russell.

[breck]

Hey Breck, well either you are 10 minutes from me or you live practically next door (I live about 5 mins from Chich), I think we should catch up as well, good to hear of another local getting addicted to this stuff

Cheers.

Russell.

Hi Russell, I am the other way I think (Bellenden Ker). And if I am right, I think Andrew has spoken about you as well. He was going to give me your number I think, so I could come and see your router but we never got around to it. He is the reason that I "got addicted" so to speak. I can do the fabrication side of the router no worries but I am going to need his help with electronic side as I have no clue. I got a good few days on the school holidays so got in and have the frame 80% done, X and Y are sliding nicely still thinking about how I want to attack Z. I'm really getting into it and am lovin it! Isn't it funny whats just down the road, and Chich as well. We should catch up soon. Breck

[epineh]

Hi Breck, I think we could probably help out a little with the electronics, I will PM you my details. Are you going steppers or servo's ? (I could help more with servo's )

Cheers.

Russell.

[chich2]

John,
(cjmerlincnc) Thanks for the post and the question. To try and sum up your question as quickly as possible I guess my reply to you will be:
1. Because your machine does not have a Horizontal spindle I would not bother automating the Knee. I only did it because I also have a verticle spindle and wanted CNC use of both spindles AND I have huge runout on my Quill from factory. If your Quill is a good fit when it is extended all the way out and has no radial movement then I recomend you CNC your quill. In this case, when milling a job you would set up your knee in roughly the correct possition and lock it off so the quill does the actual CNC movements.

2. From your description, your base is made a lot better than mine so I'd be hesitant cutting holes in it. If I was to do this again to a HM-52 think I would make a drive mechanism that connects directly to the sides of the column and drives the knee off the column rather than the base. Then flexing and leverage would therfore be eliminated. I think it would be made to fit snug against the column and knee so it is rigid and VERY direct acting in it's movement. The weight of the knee would be offset by counterweights on roller chains up and over the column, with the weights hanging behind the column just like the head does on an industrial CNC machine.

3. I have not seen any adverse effects from removing the vertical rib from the back of the knee.

Hope this has helped you. Feel free to ask more questions if you ned to.

Chich

[chich2]

Hey Brek,
Small world huh? Been a while since we crossed path's. And now were Yarn'in on an international forum. BIZZARE!!!!! Yea home made CNC gear is pretty addictive!!!!! I see you have chatted to Russel in the thread as well........ Great bloke to know when it comes to affordable CNC drives. :stickpoke Russ has successfully designed and built his own srevo drives which do a great job driving his CNC router. Nice rigid machine too.

I sholud be home again this weekend if all goes well. Andrew will tell you where to find me.

Chich

[cjmerlincnc]

Thanks Chick2 for your quick response. You put forward some very good points. I like the idea of driving the knee from the column. I'm pretty set with the ram idea because it's easy and simple to do and later I plan an auto toolchanger and need all the space on side of the mill for it plus the quill wouldnt be up to continuous daily milling for too long before it got sloppy. The counterbalance knee idea is probably the best method but involves a hell of alot more work and design if I want to keep the swiveling head arrangement. I'm planning putting a high speed (10k rpm) head on the other end of the ram for small 3D work.

I'm currently sorting the knee oiling situation.


If I get anymore questions I hope you don't mind if I send you a PM as I dont
want to mess up your excellent build log/posting.


Cheers
John

[chich2]

John,
I would like to see a thread with your tool changer when you build it. I think the CNCZoner's here would also like to see a thread of your machine conversion. Great idea for the high speed spindle on the ram.
Yes please PM me with questions if you have them or post them in the thread if you feel someone else may also be interested in your question.

Chich

[chich2]

Hello ZONERS!!!!

Here is my latest work with the converted HM-52. The brace job on the column has worked a treat and I have been doing some cool stuff with the machine. Here is my latest job. It is a cooling water jacket off an old Mercury outboard motor my dad is restoring. He said the part is no longer available from the manufactuer any more so I said I'd make him one.

First thing to do was measure it up. I did this with a height gauge, and used my table as a surface plate. I measured every single thing I could along the part's X and Y lengths. This made it real easy to draw later. I downloaded the trial version of CADEM's milling program CAPSMILL. The software is easy to use but from my experience it has lots of bugs!!! Could just be my PC too as I havent tested it on another PC. ANYWAY, CAPSMILL generated the toolpath and away I went.

Chich

[chich2]

Here are some Vid's of the job.









Chich.

[cjmerlincnc]

Hi Chich2, Nice work mate. Yes I do intend to do a project log of my mill. I've got lots of photos as I've progressed and as soon as I've completed the axis's I'll start putting a log together.

Keep up the good work.

Cheers
John

[epineh]

Awesome job on the water jacket Chich ! You will have to make another one to sit on the mantlepiece

Russell.

[evo4wrx]

Hey been slowly getting everything together and taking some of your advice from a previous email...would I be better off to convert the quil rather than the knee to get my Z axis?? Its the same Hafco as your except the 3 phase version. I see what you mean by the base flex....

[FPV_GTp]

wooooooooooooooo CADSmill is not cheap CAPSmill £ 1350 +VAT


Nice work chich2

cheers