[MystRacing]

There are a lot of X2 threads on this site so I don’t know how useful this thread will be, but hopefully it can help out some people who know even less than me, or at least people can help me out when I get stuck. I’m planning on showing and explaining things that everybody on this site probably already knows but weren’t totally obvious to me from the beginning. Also I plan on giving an Idea of how long it took me to actually do it.

I was an electronics technician in the Navy, have a 2 year degree in Auto mechanics, and have spent years at the keyboard of a computer in various jobs. The main point of telling people this is to let you know I’m not a machinist, and don’t consider myself to be one, but I do have a background in electronics, mechanics and computers.

I’ve had my X2 for 7 years. I use it primarily for making / modifying parts for RC Cars. I’ve been very happy with it. I work almost exclusively with aluminum and delrin, and find the size of the mill to be a good fit for my purposes. I also have a 7X14 mini lathe (9 Years) and a 4X6 horizontal / vertical Central Machinery band saw. Having had my lathe and mill for quite a while I also have quite a bit of tooling for them including a rotary table and boring head for the mill. So I figured I could pull this off. So we’ll see how it goes.

Here’s my garage/workshop, I got a new computer a while back and remodeled the study which ended with my old desk and computer built into the workbench in the garage.



My X2’s home has been on top of a heavy duty Roll away and I decided to throw in a picture because I’m sure most people have never seen a stock X-2 with a LMS belt drive on it.



I did a lot of reading on the site and gave consideration to the CNC Fusion kit but with the Z-axis issue, and the fact that this is a hobby of mine. I’m supposed to be making parts not buying them. I decided to go with the Hoss plans. Like everyone else that’s followed his design I can’t thank him enough for putting this out there for free. I can honestly say if it wasn’t for his plans I’d have just bought a conversion. I’ve done many a RC Project from scratch on my own and it’s always 3 times the work to be the pioneer on a project, and I’m guessing a lot of people don’t realize just how much work Hoss put into his conversion so a huge THANKS!

For those that don’t know Hoss’s site is Hossmachine Homepage

Here’s a list of the parts I went with.

Metal Stock:
I bought the Metal stock from onlinemetals dot com, I’ve been dealing with them for years and always been happy. They may not be cheap but they have always treated me well.

Hardware:
I went down the list on the site and ordered my hardware and bearing from MSC, and pulleys from SDP. I decided to go with the oldham Couplers from Mcmaster-Carr instead of making solid ones. I pretty much just went down the list on Hoss’s site and ordered what he had linked too.

I couldn’t find the 15/16 – 16 tap where his link goes. I did find one at a machineshop supply house in Colorado Springs.

The rest of the parts I’m using (I’ll update the list if things change so it’ll reflect the final version.)

Roton Ballscrews and Ballnuts

GeckodiverG540 4 axis kit (one G540 + Four NEMA 23 KL23H2100-35-4B ( ¼”Dual shaft with a flat) 381 oz-in + one KL-600-48 48V/ 12.5A 115V /230V power supply)

Mach 3 software.

Miscellaneous connectors (9 and 25 pin) switches etc. as listed on Hoss’s site.

I got a nice package of 8 colors of 20 gage lead wire in 10’ lengths from e-bay.

I went with the multistrand oil resistant wire from Mcmaster-Carr

For the electronics enclosure I ordered a case from CNC4PC (BX2 - CNC Enclosure).

A also bought a G540 Interface board from RCPElectronics (do a search for it in the product announcement forum)

My old computer is an AMD 2600+ running XP Pro.

I also have Autocad and will need to figure out what to use as an interface between my drawings and Mach3 but I’ll address that later.

[MystRacing]

I actually started on this project around the 15th of July ordering the hardware, metal stock, and ball screws. I didn’t post a thread on it till today because I wanted to make sure it was a full go before I posted a thread. After reading about 50 X2 threads that didn’t get beyond the “I’m thinking about doing this” I decided I didn’t want to be responsible for one of those threads. I spent about 3 hours ordering parts on the internet.



So the metal stock and hardware came in toward the end of July but I didn’t do anything except cut the raw materials near to size on the band saw the first weekend. I spent about 3 ½ hours measuring and cutting metal. Everything went well except I cut the Z axis stepper motor mount too short.

A hows that go again – measure once cut twice…… it’s still to short, I don’t get it.

OOP’s; well that metal is now on order for another try.





The ball screws and nuts showed up in the third week of July. I ordered a single 48” piece, I usually order extra because I make mistakes as noted above. First thing I did was put the lead screw in my 7X14 and got out a parting tool. If it was possible for a piece of metal to let out a deep belly laugh, that’s exactly what the ball screw did when the parting tool touched it. I have a QC tool post which isn’t the most rigid item in the world but it was pretty amazing to watch it bounce like a big chunk of rubber when it hit the threads. That obviously was going to result in needing a new lathe so I quickly gave up on that idea. I decided to go ahead and cut the screw to 3 lengths with my dremel with a cutoff wheel which worked fine. I then put my original tool post on and a new carbide insert in the cutter. This worked just slightly better than the parting tool. If you’re willing to try and cut the hardened threads off .0005 at a time it may be possible to cut a Roton Ballscrew on a 7X but I decided from a practicality standpoint my 7X just wasn’t up to the task. I took the 2 ballscrews that need the end turned to a real machinist. More about the Z-screw I decided I could handle later. I spent about 3 hours on that folly.

I really got started on the weekend of August 6-7. I spent 11 ½ hours between the mill and the lathe roughing out the parts. A large amount of the time probably 4 hours was spent on the z-axis upper flange. That’s a lot of metal to be turned and bored with a 7X lathe, but doable. On Monday I sure didn’t feel like I got much done but at least the project was underway.

On Wednesday – Friday of the next week I spent 2 hours each night doing a little milling and finished the 3 parts below.

[MystRacing]

This last weekend (August 13 – 14) I spent 12 more hours machining parts on the mill. I feel a lot better about the project now. Finally feel like I’m making some good progress. The X and Y motor mounts, Y axis spacer, z-axis spacer, z-axis inner block, z-axis ball screw mount, and z-axis stepper mount supports are all pretty straight forward to make on a X2.

The z-axis ball screw mount threw me a bit of a curve. I have a boring head I got from Grizzly years back and without thinking about it too much I bored the 1.255” center bore then adjusted my height to cut the 0.25” deep X 2.338” bore and went to work. Shortly there after I realized my boring head would do a maximum bore of about 1.8”. Just to really demonstrate my ignorance it looks like you could put a boring bar in horizontally and do a larger bore if the center though bore was around 2”, but in this case that wouldn’t work. I expect some real machinists will be happy to straighten me out on that.

I decided to get out the rotary table and the dial test indicator. I’ve never used my rotary table for anything except drilling holes in wheels to mount the wheel and for bead lock rings. It seems like mounting much of anything on it is always a challenge. My solution in this case was to drill 2 holes in line with the center bore and directly mount the part to the rotary table. Right or wrong it worked quite well. It’s nice to have finally used it for something more than drilling holes in a circle.





On the other parts I used my 3 jaw chuck mounted to the rotary table to mark the hole locations. With the rotary table and 3 jaw chuck mounted I have about 4 inches of Z space for the work piece and tool so anything I do has to be done with a collett. This is one of my main reasons for wanting to go CNC. Basically all I can accomplish is marking the hole locations.

Here's the parts from this weekend,

[MystRacing]

Now on to where I’m at today. I have a few things I have yet to figure out.

First is really just a question for Hoss if he reads this. I made the Z-axis inner block and spacer block before I read the note that I didn’t need them. So the question is there any reason not to go ahead and use them? I assume the holes in the support brackets line up with where the inner block would be anyway. I guess I'll figure that out soon enough if Hoss doesn't read this.

The second is I tried to tap the roton Z ballscrew after drilling the hole and it felt like the tap was hitting the hardened portion of the thread. I was wondering if anyone has threaded the Roton screw and if so did they have trouble. I’m thinking about cutting it down (I left it overly long just in case) and attempting to go ¼-20 instead. I may have just missed on the tap alignment But I used a tap guide on the lathe to start it so I don’t think so.

And finally on the Y-axis ballnut stop block, I haven’t made up my mind how to best approach rounding the top of it off. I’m thinking mount it offset on the rotary table, but it also seems like it might be a lot easier to just take the grinder to it.

[hoss2006]

Very nice write up so far!
You can use the inner block and spacer along with the side brackets if you want, it'll be extra
sturdy that way.
Nice work.
Hoss

[MystRacing]

Very nice write up so far!
You can use the inner block and spacer along with the side brackets if you want, it'll be extra
sturdy that way.
Nice work.
Hoss

Thanks once again!

[photomankc]

I take it you have the 5/8" ball screws right? What kind of tap are you using? I have tapped them with a 5/16" internal thread into those with no problem using a nice fresh HSS tap. It was stiff but very doable. I did use a spiral point tap so none of the 2 steps forward one step back dance but that meant that I drilled deeper to allow plenty of relief at the bottom for chips.

The screws are mondo-hard down to a bit below the bottom of the thread groove, and it tappers off in hardness quickly after that. In the center they work like cold-roll. I doubt you are trying to tap hardened metal but even soft steel and Irwin hardware store taps can be difficult.

I have a local place I can get HSS tooling from to include taps. Well worth the investment.

Very nice write up by the way. I really enjoyed just reading through it. You have a nice knack for telling the story. Especially the part of the 7X10 vs the screw. My 10x22 moaned and groaned trying to cut that stuff so I can imagine the little 7X14's complaints! I finally quit trying to cut it. I drill and tap for a machinable stub and loc-tite that into the ball screw then turn that down into my finished end. Works great, just make certain the threads are clean and oil free before you mate them up and it will hold fast with the loc-tite. Another variation is to simply make it a press fit vs threading it. Heat the screw, loc-tite the stub, and slide together. When it cools it will have a death-grip on it.

[MystRacing]

I take it you have the 5/8" ball screws right? What kind of tap are you using?

I drill and tap for a machinable stub and loc-tite that into the ball screw then turn that down into my finished end.

Thanks for the information.

Yes on the 5/8" ballscrews. I was using a cheap tap I'll grab the phone book and see what I can find locally, or order a good tap if I can't find a good place.

Adding a machinable stub is a great idea. I wish I had posted before I took them to the machine shop.

[RPCElectronics]

Beautiful work so far! I am almost to the point where I need to tackle my Z axis and I was having a hard time understanding the bearing setup. Your pictures and description really helped. Thanks!

[RPCElectronics]

A hows that go again – measure once cut twice…… it’s still to short, I don’t get it.

The old man I used to work for liked to say:

"Measure it with a micrometer, mark it with chalk and cut it with an axe."

God bless that man! He left us a few months back and every time I step into my shop to mill something, I think of him.

[MystRacing]

Beautiful work so far! I am almost to the point where I need to tackle my Z axis and I was having a hard time understanding the bearing setup. Your pictures and description really helped. Thanks!

Thanks! I was actually thinking before you even mentioned it thast I should post a picture of all the parts that go up top for clarification. I spent quite a bit of time scratching my head before it finally clicked how it all went together.

So just stack from one side to the other.



Here's a picture assembled. I have no noticable back lash without a shim. I guess the addage about the blind squirell sometimes rings true. I was expecting to need to do some shimming.



I got the Ball screw threaded tonight. I found a shop in town and with a american made HSS spiral tap it's like cutt'n butta :cheers: thanks photomankc I have been assimilated now I'll be spending a bunch of money on good taps.

Here's my process; with a cheap tap using the same method I ended up with a siezed and then broken tap. I did hand tap it both times I just use the lathe with the tap guide to line it up.

[hoss2006]

I have 2 assembly breakdowns I thought made it pretty clear for the Z axis.

[eartaker]

Why rotate the nut and not the screw?

[hoss2006]

Why rotate the nut and not the screw?

Because that's the way it works.
Hoss

[photomankc]

Why rotate the nut and not the screw?

There is nowhere to run the screw through the head or column as I see it. The screw is fixed to the top and raised by spinning the nut. The other Z axis designs I see have the screw off to side which would seem to always have a tendency to want to skew the head as they move as well as getting covered in chips. Pretty neat way to do it really, directly pushing and pulling right at the Z saddle.

[MystRacing]

I have 2 assembly breakdowns I thought made it pretty clear for the Z axis.

Your drawings and explanations are excellent. The issue I had was visualizing what the thrust bearings looked like. Once I had the parts in hand there was no confusion. Basically what I'm saying is my issue was my ignorance not your drawings. I tell ya; you give us books and we just eat the pages.

[eartaker]

Because that's the way it works.
Hoss

Hoss, that explains nothing... You have been on this forum for a bit now, that is something a troll would say.

photomankc,

Thanks, that's what I was wondering. I am currently working on a different X2 Z design that rill run the screw through the column but that will require me to slot the column. I know the design your going off of works but just wondered the advantage.

[hoss2006]

Hoss, that explains nothing... You have been on this forum for a bit now, that is something a troll would say.

No, a troll asks a question he already knows the answer to so he can promote
his idea that he thinks is better. You've been in contact with me before, you are well aware how it works.
Hoss

[eartaker]

No, a troll asks a question he already knows the answer to so he can promote
his idea that he thinks is better. You've been in contact with me before, you are well aware how it works.
Hoss

I never tried to "promote" anything, I also never said your design was flawed. Simply asked why do it that way. I stated what I was working on and there is nothing to say I won't do the same on mine, but in a different way. You are right, I do KNOW how it works but wondered why. Why go off a design that you don't understand the advantages of. I have not once criticized your work. The troll comment was a response to your statement. Have fun with this and don't take things so personal. You have critiqued my work in the past and I never took offense to it.

[hoss2006]

Don't know why you took my comment so personal and felt the need to call me a troll,
that I take personal,
but I have better things to do than continue this conversation any longer,
good luck with whatever design you decide to go with.
Hoss