MechMate CNC Router Forum

MechMate CNC Router Forum (http://www.mechmate.com/forums/index.php)
-   MechMates already cutting (http://www.mechmate.com/forums/forumdisplay.php?f=78)
-   -   Cool tables and spindle ordering fun #6 - Brakpan, S.Africa (http://www.mechmate.com/forums/showthread.php?t=686)

Kobus_Joubert Wed 30 December 2009 08:20

3 Attachment(s)
Well I finished the round table today and in the same time did a 950mm x 290mm Hall Table from Cedar wood that I stained. Very happy with what old BBB do for me.

Attachment 7952

Attachment 7953

Attachment 7954

Castone Wed 30 December 2009 12:10

Very nice table , whats next?

Kobus_Joubert Wed 30 December 2009 12:36

1 Attachment(s)
Thanks Leo. I have also made a back massager during the table construction.

Attachment 7955

Here anything goes, I am trying my hand at different things so that one day when I really need to make money with old BBB, I know what my limitations are.

Kobus_Joubert Sat 02 January 2010 05:26

3 Attachment(s)
Decided to make another Hall Table. This time from Teak. The top part with all the flowers done at a very SLOW speed took 25 minutes with a V-cutter. Size of top is 1000 mm x 940 mm. Only one coat of boiled Lynseed Oil for now.

Attachment 7958

Attachment 7959

Pierre decided to wipe down his favourite chair with the lynseed oil rag that I used to do piece.

Attachment 7960

Will do the legs later this afternoon.

Castone Sat 02 January 2010 13:33

Table
 
Kobus ,that is a very fine looking table I like the flowers.

Lex Sat 02 January 2010 23:32

Hoezit Kobus!
A few questions on your Cedar Hall Table.
Did you only do the the flat pieces with Old BBB?
Was the legs done on a saw?
Did you dowel it together?

Groetnis
Johan

Kobus_Joubert Sun 03 January 2010 11:13

Hi Johan, Glad to see you are still alive. Hope the ribs and foot is all healed OK.
Yes all flat pieces done by old BBB. I planned to do the legs as well and started with that little groove on the top. That went well. Then decided to taper the leg and give it a ball at the bottom. The mortises went well, but when I started the taper, there was not enough meat left to keep the edges from splitting and tearing....but like my trappemaker friend in Hilversum Holland said....everybody makes mistakes, but if you can fix that mistake then you are not too bad.... I then took the legs with the mortices and little slots that were perfect and quickly build a taper jig and made the legs taper to cut away my boo-boo.
Next time I will use a bigger piece of wood for the leg and do all the cutting with old BBB.

Lex Sun 03 January 2010 22:49

Thanks for the info. It still surprises me what one can do with the machine.
Yes, my ribs are healed but it cramps sometimes. The ankle goes into a safety boot and that supports it. I have started to work on my machine again and will post pics soon.

hennie Sun 03 January 2010 23:37

Yes I think it is time to start that machine Johan.:)

Kobus_Joubert Tue 05 January 2010 11:06

Question to the experts out there. Will a Nema 23 stepper...something like the Fulling FL57STH76_3006B be good enough for an Indexer ? Maybe with a 3:1 belt gearbox ?

Gerald D Tue 05 January 2010 11:29

Gut feel tells me that Nema23 at 3:1 will work for workpiece diameter of 40mm max.

Kobus_Joubert Tue 05 January 2010 11:57

Thanks Gerald, sounds good...with the stuff that I intend making.

If I am prepared to work at a slower pace...like I do at my age....:D.maybe I can go a bit bigger in diameter...or do I have it wrong Gerald.

Gerald D Tue 05 January 2010 12:20

If the diameter gets big, the cutter will "backdrive" the indexer motor. In other words, the indexer motor will lose steps because the torque will be too high. The bigger the diameter, the bigger the torque needed to hold (or turn against the cutter).

Castone Tue 05 January 2010 15:13

A 5 to 1 works fairly well with a 450 oz Nema 23 . And you can go up to a larger Dia.

Gerald D Tue 05 January 2010 19:38

What diameters (inches/mm) are you talking Leo and how long is that Nema 23?

Castone Tue 05 January 2010 21:09

About 4 to 5" in Dia. The stepper is around 3.5" long not for sure,but I can take some measurements. Here is one to take a look at using the same thing
http://www.youtube.com/watch?v=oFC3lbLdzow Its not going to be a high production set up , but for a job every now and then it would work fine.

hennie Tue 05 January 2010 21:21

Fulling motors with 3:1 gearbox For peaple thats colour blind.
 
1 Attachment(s)
Attachment 8041the spec`s for the motor length is 76 mm

Gerald D Tue 05 January 2010 22:20

Leo, that is a great video. (To get the scale perspective, I think the cutter diameter is 1/4")

Nema 23 motors are available in different lengths, according to the number of magnetic stacks, ranging from 1 to 4 stacks. The output torque multiplies by about the number of stacks. From the video, I guess that Leo's motor is 3 stack, or a very soft wood and a 2 stack.

Castone Wed 06 January 2010 07:18

Gerald yes the cutter is .250". I think a guy named Thom made the vid and the machine, but I have the same setup as a 4th axis. You can run hardwoods at near that speed. Of coarse the MM could push this around with no problems at all. But this is a good cheap setup to test the waters and will work fairly well as long as you dont take too big of a step over. Programing 4th axis programs takes a little practice. Of coarse the software is getting better every year. You could always make your setup so you could upgrade the motor later, but a 4th axis gets old quick as with mine it is in several parts and is collecting dust. When it warms up I may mount it to the MM.
Just hate to see someone spend alot of money on a 4th axis and find out it is not all that great. And depending on what you make ,programs can be quiet long.

hennie Wed 06 January 2010 07:46

Leo for the DIY man with a MM and a 4th axis it is heaven think of all the things one can make for your house,yes i agree with you it is not easy to do the programing but once its done it is for keeps.I on the other hand are not going to get the 4th axis but will be converting one of my lathes to do my turning MM style. first the metal lathe and then the wood lathe.

Kobus_Joubert Wed 06 January 2010 11:39

Thank for the video Leo. Phoning around today I found the agent in SA for Fulling steppers....and surprise surprise found their prices not too bad. Until this afternoon had the idea of buying their 1:7,5 geared stepper, but when I went into the workshop to check on my old wood lathe I decided the following.

I will try use this old wood lathe...that I don't use... and mount it on old BBB. Will replace the V-belt pulley system from motor to headstock with a belt system. Somehow I have to connect the stepper to the headstock, and instead of a direct coupling, make use of toothed gears and belt. This way I can get some ratio going. This way I can buy a bigger stepper without a gearbox witch should be cheaper....something similar as in that video. ... Any thoughts in this regard will be appreciated.....I really don't matter cutting up that old wood lathe to get this going.

Don't know how well V-Carve pro will be on the new GADGETS for spirals and flutes, but will have to wait, try and see how it progresses.

Castone Wed 06 January 2010 17:01

Kobus , I think that would work out just fine, should not be too hard at all to convert over. I might even try that myself later on its a real good ideal. You would already have a good chuck ,tailstock and live center. So have you ordered the parts yet?

Kobus_Joubert Wed 06 January 2010 21:26

The stepper I can get off the shelf about 20 minutes drive from my work. This company also sell some electronic components and the L298 - L297 chips are available from them as well for R 35.00 each. So maybe for this I will just put together a PC board and see what happens.

Kobus_Joubert Fri 08 January 2010 12:22

Ok I have decided what to do. Not spending any extra money on extra stepper and driver...which after the long Christmas holidays are a bit on the low side.... I will lock my gantry in the X-Position in the middle of my indexer / lathe. Use the one stepper from the X-Axis and mount it on my indexer and give it a try. A bit of work, but until I am sure that indexing with my available software is workable this will have to do. At some stage if all goes well and I am happy with it all working....which I am sure it will be... I will invest in another stepper and driver.
I measures my table and see that a 300mm (12 inch) diameter thing will be able to be carved on old BBB.
Any thoughts on driving the indexer with my existing pinion...or should I get some sort of coupler to connect the stepper straight onto the headstock ?...after removing the pinion...

Gerald D Fri 08 January 2010 12:34

First prize for you will be to mount a big gear wheel on (or behind) your headstock and then run an x-motor with its pinion gear against the big gear wheel.

To get similar feeds/forces as your x-axis, the big gear wheel needs to be the same diameter as the job that you are cutting.

Kobus_Joubert Fri 08 January 2010 12:44

Then I can use the SPRING method to keep the pinion on the big wheel. Good idea there Gerald.

Do you think this gear if made from ALU will be ok Gerald....then maybe I can cut it myself.

Gerald D Fri 08 January 2010 12:57

Alu will surely give you some life in the hobby environment, but it will obviously wear out faster than steel. If you can make it 16mm thick, the risk of breaking teeth should be quite low. Another option is to maybe laser-cut 10mm thick steel.

Kobus_Joubert Sat 09 January 2010 08:09

3 Attachment(s)
Had a productive and enjoyful day. Finished the legs on the last table then this afternoon I decided it's time to change the old lathe into my indexer. Started by taking it apart.

Attachment 8096

Then look at the old stand and measured up the height that I needed to be.

Attachment 8097

Was very lucky. I had to cut it dirctly under the last brace. Did this and then re-assebled it. Moved it into position and brought the Z-axis into position. I am very happy with the way it is working out. I don't have to cut up the old lathe. All I have to do now is to figure a way to connect BBB's table to this stand. One idea is to weld an angle iron to the frame and bolt it onto BBB's table frame. Or to put some rawl bolts into the floor and secure it this way.

Now where is that 300mm gear to fit onto the back of the gearhead ?

Attachment 8098

Kobus_Joubert Sat 09 January 2010 08:43

Uploaded a video showing me cutting motrices for the table leg. Takes some time setting up, but once done all 4 legs are done in a very short time.

http://www.youtube.com/watch?v=pQqbFGKj8vo

Kobus_Joubert Sat 09 January 2010 10:38

Gerald, you said that if I want to turn a 300mm diameter piece I should go for a 300mm gear on the end of my indexer. As you know I run Module 1 rack. Does this mean I need a 300 tooth gear. I measured the space and I can easily swing a 300mm piece of wood there.

Do you think Nusaf or anybody else in SA would have such a big module 1 type gear?
If I try and find software to draw this in CAD, is the pressure angle 20% for this type of gear. Thank's Kobus


All times are GMT -6. The time now is 02:27.

Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.