BP Clone Conversion

[Cartierusm]

I thought I'd start a more specific thread dealing with my conversion.

I took the bed off and removed the screws. Checked out everything. I think it'll work. I thought about having the bed scraped or ground or whatever but the local guy wanted $3500. I went ahead and redrilled all the lube holes and tapped them for 10-32 to use quick disconnect pneumatic fittings, I'm going to use them for oil of course. I did also pickup the correct oil for the head and ways or at least the closest I could find. I got the correct way oil and for the spindle I got grade 15 instead of 22, I figure thinner is better than thicker. A gallon of each. I used to use 10W motor oil. I'm still deciding whether I need to use little valves so I can concentrate the oil to where I want it. The only reason I think this is necessary as everything will take the path of least resistence. So in my mind if there is an area that the oil flows easy then it will go mostly there. With valves I can make sure it's getting everywhere. For the head I did the same thing quick disconnect fittings. But I'm going to use a cheap hand oil can and just push the hose onto it so I can manually lube the spindle with the correct oil.

I also ordered rolled ballscrews from Hiwin, I asked 10 times to different people and they are zero backlash and use one nut. It comes with the yoke.

I ordered off ebay a bearing bracket for a bridgeport to see if my clone mill was the same as no one I know has heard of the brand, it's called a First Mill, Dwayne at Elrod said it's a non-U.S. version of Sharp. Who knows? Anyway I got the bracket today and it matches up perfectly which is a relief, especially since the bearing holes on my bracket and the BP one match. I was a little worried because the bearings my mill uses are much largers than a BP. The BP 6204 is 20mm I.D. and the bearings I have on my mill are 1", so quite a difference. But everything is good. What is real good is the bracket I bought is going to be used as the Ballscrews I ordered are the BP replacement ones and they are much cheaper than having ones made from scratch. If I had a lathe with a Spindle bore big enought I would have just done it but I don't and if I had them sent out it actually would have some out more expensive, plus I would have had to build my own double nut to make it backlash as I have no real knowledge with oversizing the balls and my way I've done before and am familiar. But I don't have to now as the ballscrew I got is zero backlash. Anyway I'll be using my new BP part as the floating side.

I also got my Power Supply from Keling 72V 20A, a monster. I was real nervous hooking this thing up to my current CNC as when I upgraded from Keling last time it was disasterous. What happended last time is I went from 24V to 48V on 5056 Keling Drives and blew all my drives, not my fault but a design flaw as Keling sent me new ones and they blew. I convince him I knew what I was doing and the only thing that could blow those drives according to their specs was crossed voltage and that definately wasn't the case. So for a hundred or so he let me upgrade to 8078 drives. I posted all this a long time ago on here but the skinny was the 5056 drives were way faulty as my motors used to heat up to 130F and since it was my first CNC I didn't know this was not correct. THen I hooked up my 8078 drives with the new Power Supply and of course everything worked perfect and the motors never got hot even after long cutting. Now skip forward to today I was REAL nervous hooked up this PS as I didn't want to go through the same thing, but thank God it started up fine and the cnc runs, now I have to tune the dam thing, but I'm sure I'll get way more power and speed, not that I needed it, but I need the PS for the 1200 oz/in. motors I got coming.

Next thing I posted whether I should keep the brand new DRO I just bought. I bought one because my old one went tits up and I purchased it before I decided I was going to convert my mill. Then I neede to pull the table anyway to redo the oil lines as the old ones had finally broken. When the table was off I decided to go for it. I think this is going to be the best decision I ever made. So I decided the DRO is already paid for and I've purchased all the parts for the conversion so I figured it will be absolute verification that everything is working perfect all the time. It will give exact feedback to the table movement, plus it will help with the setup and tuning of mach with regards to number of steps and screw mapping. Also if I do need to use the mill manually I have a DRO, but anything that would require a DRO I would CNC anyway. The only reason I would use it manually is to clean up an edge.

I also went ahead a machined on my other CNC a Power Draw Bar. I didn't but the plans as it's a very simple thing to make, plus I had all the parts in stock. I buy pneumatic cylinders all the time.

I can't think of anything else to say now. Here are some pics of everything, enjoy.

My goal is after it's all together maybe work on making it able to do rigid tapping, but once I'm confotable with using a Tapmatic on CNC maybe I'll just stick to that as I've got a big Tapmatic a 70. For larger sizes I'll be thread milling.

[Cartierusm]

One more pic.

[asuratman]

Hello,
Your knee mill is the same brand with mine "First", made in Taiwan. I convert mine the same as yours using Hiwin on x and y. I have problem to convert z quill, it is not rigid. I try to use Elrod, they quote expensive for my budget. What do you want to do with your z axis.

[Cartierusm]

I'm going to make my version of the elrod system. Not too complicated just lots of parts.

Which Hiwin ballscrews did you get rolled or ground? Any problems with the conversion?

Don't suppose you have any pics of the conversion? I would love to see some.

[asuratman]

Hello,
I have dismantle all cnc stuffs. I have Hiwin ground ball screw 9" X 42" for x and y, it cost me usd 500 a year ago direct from Taiwan. Motors are 3 ea ametec. Control 3 ea gecko G320. I will try one more time to cnc-ed it when I get my quill kit. I will post it. Have you bought elrod z kit. Its nice design and look rigid. How much does it cost you. I will follow up your built.

[thosj]

I'm new here and will be watching this thread and others as I'm started converting my 1987 Enco clone which I bought new in 1987 and have used manual with Mitutoyo DRO since then.

I just ordered Hiwin ground ballscrews, they were $862 plus shipping. They shipped today!!

I will use mostly Keling/CNC4PC stuff, 1125 oz/in servos, all the stuff they have.

I will build X/Y brackets myself, first. I have them roughly designed, bearings ordered for the X/Y screws.

I am mostly interested in copying Elrod Z!! I will be watching that closely!! I want to get X/Y running on Mach3, and use the CNC to do the rest of the parts to make life a bit easier. I also work at a local university machine shop (I'm retired) and have almost the exact same equipment there as I have at home so I can work back and forth.

If anyone can post a thread that has info on an Elrod Z retro, I'd love to find it. Haven't found anything much on Z.

Don't mean at all to hijack the thread, just saying I'll be following and any info you post will be appreciated!

[Cartierusm]

What are the specs for the ballscrews? Length, diameter and did that include ball nuts and did that include end machining? Because the price they quoted me for ground BP replacements were $1150, not bad, but if I bought the raw stock I would still have to pay for the end machining for anther $300 so it would have been cheaper to order the kit. I also don't see that much benefit of the ground over the rolled for me. A screw stays the same and as I just put on a brand new DRO I'll be able to accurately map the screw exactly and the ballnuts are zero backlash.

Thosj, keep searching there are a few threads that deal with the z conversion.
Vince's BP CNC conversion
JDs BP J-Head CNC Conversion Blog

Asturaman, no I didn't order the kit from elrod, I'm a machinist so it won't be hard to make at all.

[thosj]

When Hiwin quotes the ballscrew kit for BP, they quote each piece, but when you order the kit, they take 30% off! I even asked about that because they had on the quote "For a complete set (X-Axis, Y-Axis, Yoke), a 30% discount applies." I asked if it was already off in the quote and they didn't answer. My quote, yesterday (!) was $1232 for a BP 9 x 42 set. Today I got the order confirmation and they charged my cc $862.40, exactly 30% off! They're semi-difficult to deal with, they never seem to know what they're doing and they send you to a sales person for your state. Mine was Andrea even though Erik Olsen shows as the actual sales person on my quote. I guess this Andrea is a Rep. for Wisconsin!!

I guess if you were quoted $1150, you might be actually paying $805. Was your quote for rolled and what size machine? If the difference between ground and rolled is only $60 I'm glad I got ground! If for no other reason then they look cool.

I never asked about end machining!! I somehow assumed they were machined. I can't imagine they sell two ball screws and a yoke a Bridgeport and not have the ends machined. If not, I'll be machining I guess!! We are, after all, professionals!!! I'd almost prefer they weren't as then I can get the bearing shoulders where I want 'em and not have to design around where they are with my brackets, long as the stock is long enough and not too hard!! I'll email Hiwin and see what they say about end machining now that they have my money.

[Cartierusm]

The difference isn't $60, I paid $550 for mine, so $300. I figure for almost double more I'd stick with the rolled as the only difference is the lead error which they say is .0003, which is hard to believe but that's what the rep emailed me twice when I asked. Thosj if you ordered the kit then they will have machined ends.

You post is a little confusing did you order some VXB bearings too? Which the double set or individuals?

[Cartierusm]

Still deciding whether to use aluminum or steel for the brackets. I got a quote from my metal supplier for 5" x 36" x 1" AL $50, for 5" x 36" x 2" AL $92, for Steel 5" x 36" x 1" $40 and for 5" x 36" x 2" Steel $112 because of the weight.

So if I use aluminum I can use my cnc router to machine it, does a pretty good job. I machined a bearing hole the other day at .625" and it came out .628" and it's pretty consistent so I'm thinking I'll just start small and work my way up trying the bearing each time. But after having said all that I think once the cnc is up and running I would want Steel brackets anyway to take all flex out of the equation.

So the questions is do I do aluminum now or use a machininst I know and give him the CAD and see if he'll make me a deal with the steel? I think I answered my own question.

[thosj]

I DID order the vxb bearings, two pair, for X/Y.

I emailed Hiwin and they say the ends are machined to BP Series 1 without power feed dimensions, so that'll be just like the acme screws in the machine now.

I think aluminum for the brackets. 1" or so. If you build up a box with say 3/8 x 1 1/2 or 2, bolted up, that'd stiffen it a lot. I'm thinking polycarbonate covers so I can watch the pulley's and belts whirr around!!

I ordered servos and power supply stuff from Keling today, and some other electronic stuff from CNC4PC. This should keep me entertained designing stuff, installing the ball screws which shipped today from only 200 miles from my house, and working on electronics and drive boxes. I'm going to hold on Z until I get X/Y going, which will probably take me months!!

[HimyKabibble]

Originally Posted by Cartierusm The difference isn't $60, I paid $550 for mine, so $300. I figure for almost double more I'd stick with the rolled as the only difference is the lead error which they say is .0003, which is hard to believe but that's what the rep emailed me twice when I asked. Thosj if you ordered the kit then they will have machined ends. You post is a little confusing did you order some VXB bearings too? Which the double set or individuals?

I'd be willing to bet the salesmonkey you talked to is an idiot, and slipped the decimal point one place to the left. The only Hiwin rolled stock I've ever seen is 0.003"/foot, as is MOST rolled stock. I've *never* seen a rolled screw with a lead error of 0.0003"/foot. Most ground screws aren't even that good. The best rolled screws I've ever seend are the Nook XPRs, which are 0.001"/foot.

Regards,
Ray L.