I haven't been selling power transmission parts for a number of years, but I think you can do MUCH better than Mcmaster on pricing from Applied Industrial Tech, Kaman Industrial, or Motion Industries. Just look in the yellow pages under "power transmission".
BEARINGMAN, Thanks for the suggestions and reminders. We don’t buy enough spider couplings to worry about a few bucks. I think (2) couplings and (1) spider cost about $9.00. They aren’t supplied with the base. Have used McMaster for years. Extremely happy with their customer service, selection and shipping.
what type of screw is supplied, i think its just a std lead screw...? Is there an option to supply the base and z with ballscrews/nuts or is it possible to retrofit your design easily with off the shelf screws and nuts? What's your take on the neccessity of converting to ball screws, accuracy, backlash etc...?
Spunky - Thanks for that link. When I have more time I’ll elaborate some on P/C.
Acondit – Thanks for the order.
Nine_16 – 3 of many. We’ve had 2 order for use with routers. One’s building his own column and another is adapting a router to the Mini Mill column. “I’m looking forward to user pics” Me too. And videos. “assuming I have the x2 base by then”. We are a few days behind. Mostly because of being careful that it is the best it can be. I didn’t want to ship and then say. “Ah sh**, why didn’t I do it that way”. I want these to be the same as units shipped 3 years from now. Some changes listed below.
1. Base mounting holes.
2. Moved the Y backlash nut 1” forward and reversed the screws so they are easier to get to.
3. Increased the Y screw length for future column that will give over 12” of Y.
4. Made the base 1” thicker from 3” to 4” to give better hand clearance when squaring x to y
5. Increased Y rail length to 19 7/8” from 15 7/8”
6. Added additional mounting holes on back of base for a column we will offer in the future. (distant future)
7. Added more re-bar in base, table and the plate that joins x & y.
8. Maybe half dozen other little things that aren’t worth mentioning. 1’8” here, 1’4” there type stuff.
Saris – Ballscrews? We have had several emails about ballscrews. This is my take. On a small machine you need as much resistance to the force of the bit as you can get. If you have a monster table that weighs 400 or more pounds then that adds to the resistance. If you have a small table then it will move easier. Ballscrews or so free they don’t offer any resistance. Our backlash nuts are tight. Our rails are tight. It takes a pretty strong hand to manually turn our screws and move the table. I like that. That’s exactly what I went for. Rather than having a table floating on THK’s and ballscrews you have a table that is tight to the rest of the machine and what ever you bolt it to. Besides, we’re talking a small cut area here so I’m not terribly concerned with ipm. My goal was 60ipm and I would have accepted 35ipm with 30v, 2.5a & 276oz.in. We ended up at 90ipm. Is there a ballscrew option? No. Retrofitting to ballscrews would be a no-brainer if someone wants to do it. We’ve had a few ask about ordering without any screws but then ordered with them anyway. “What's your take on the necessity of converting to ball screws, accuracy, backlash etc...?” Our nuts have no backlash. The leadscrew bearings have no backlash. If any backlash develops in either it can be adjusted out in minutes. Accuracy is dependent on the leadscrew, coupling and motor/controller. We use Keystone leadscrews. I believe they are rated .003 / foot and Nook is rated .001 or .002.
Thanks for the quick reply harlow! I really like the design as I was looking for greater y axis capabilty from the stock X2 of a piddily 5.5". One question: what options are there for a 4th axis cnc that would work best with your design? I imagine anyone can build a platform on the end of the table, or incorporate a mount into the risers mounting, but is it possible to add generic mount inserts to the left end of the table? Or if thers a simpler option.... Thanks alot, also are u in the Los angeles area?