You used motor plate for XY motors in your model, the Z axis motor plate has different mount points

Yes, I used the design proposed in the dxf file of rischoof : http://www.mechmate.com/forums/showt...&postcount=385

He didn't design the Z axis copatible plate so I do it.

But do you think this reduction box is a good choice ?


Hardouin

its ok but you should try to make mount flanges like in Z motor plate for proper spring tension on the rack

Hello !

I drew the large plate for the Z axis.

The result in 3D software :

https://lh4.googleusercontent.com/-l.../CaptureZ2.png

https://lh4.googleusercontent.com/-P.../CaptureZ1.png


Here is the dxf file :

Attachment 13606

It looks working well but it's the first time I make dxf (I am beekeeper and carpenter !) so if someone could check it it would be great !


Hardouin


PS :

3D sketchup models for the two gearbox are here :

reductionXY.skp

reductionZ.skp

that's it.... keep up the good work!

Hello !


I have just discovered the belt reduction made by surfcnc :

http://www.mechmate.com/forums/showt...&postcount=852

Is it a better design ?

What is the better ratio : 1:3 or 1:4 ?

Help me ! :rolleyes:


Hardouin

Ideal resolution for a MM is anywhere between 3:1 to 4:1 for a good compromise between speed, resolution and backlash if you go with Belt Drive transmission.

Gearbox I have found 7.2:1 is perfect on the 4 machines I have been part of fabricating.

its very nice and practical to keep the dust out of belts as my friend Vlada did

here is the picture from his thread

http://i67.photobucket.com/albums/h3...018_resize.jpg

Hardouin,

Nice 3d drawing for a bee keeper and carpenter.
for the reduction: I choice 1:3 because the size of the timing belt pulley. If you build 1:4 the contact area from the belt on the small pulley is going to be very small and the chance the belt is moving over the pulley is going to be bigger.

the 1:3 gearbox practically. With the motor's I have, voltage I choose and way of connecting my stepper motors, the 1:3 gearbox has enough torque for working en my corners are smooth without visible chatter.

Also a point what I want to say, when I run in the end-stops, or the machine is touching something and blocked, what do you except what's happening?
broken parts, by the huge amount of torque, breakers which are tripping by getting overpowered ?
I my case, my motor start stolling, and I activate the emergency switch.
after I start up again. everything still works fine.
That's the balance you need to find!
When I activate my limit switch by moving to far on a axis, I can replace my sensor cable by a dummy connector which has a switch to give the correct signal. After I move away my axis to a save position I have to remove the dummy and place the original cable back, when I forget this, next time I run in the hard end stops. And Yes this happened two times

Keeping dust out of the gearboxes is a good Idea. I was planning to make some nice covers when the machine was working. So I will make some covers from mdf with the mechmate which are fitting over the distance bushes. When a cover is mounted, I should inspect them regular. I once damaged my planer belt because particles could not get out by the cover. after this, I made a hole in the underside of the cover

During the last couple of years I read this forum, I didn't see complains about lack of power (torque) on there mechmates
People have more problems getting the gears and pulley's fixed on the axis.

Jr's belt drive design
 

I have spent quite a bit of time searching and reading is a dfx of jr's belt drives available somewhere. I have plans and I am getting ready to start finally I am planning to use it as a plasma cutter.

I have these sets. They work the geared motor plates

http://www.cvsupply.com/servlet/the-...-Plates/Detail

Will support up to 4:1

I also have belt and pulley setups available for 3.3:1

Jeep if you need JR's drawings I received them from him during my build. PM me your email of you want them.

Mike's are easier to assemble that's for sure. So consider them too.

Hi, I did use this design also for the Z axis. It does work only if you attach the spider to the first slot. You can see it here http://www.mechmate.com/forums/showt...t=czech&page=2.

Danilo, I'll take you up on a copy of JR's drawings for eval if you don't mind, thanks

Here they are

https://dl.dropbox.com/u/3884089/Tra...%20To%20Go.zip

Thank you very much

Professional
 

Wow, That is a professional doc. Is there a .dxf file? Where are people buying the gears?

sdp-si ?

So to those who have been using xl belts: After the first installation and tension set on the belts Did you ever REtension/adjust tension on them? Are you constantly chasing a good tension on them? Or did they hold tension over time and never need adjusting after installation?

Thanks.

Haven't touched mine since I put it together.

I have the oddball xl belt reduction here of single reduction 7.22:1 on three of the axes, a 4:1 single on another plus a 16:1 double reduction on the last and they are still tight.

Nice, thanks for the info guys.

So I considered the following but didnt go this route: Someone needs to make an adapter that converts the smaller notched shaft on the geared stepper motor (gearbox removed) up to a .5" shaft for a regular pinion.
This way people could go the regular route of getting geared steppers at first to "cut your teeth" so to speak, Then use the geared steppers to make their own belt drives latter without repurchasing motors.

Like I said, I considered it but didnt do it.

On a separate note I cut steel for the first time yesterday. WHAAA HOOOO! very happy with the results. This was done with my worn out 7.2gearboxes and worn out pinions. I couldnt believe how nice the edge was considering all the wear on the parts. Over 1000hrs on machine and its got some back lash now but holy cow, cutting steel is a huge deal. I dont have any modifications to the gantry or spider (as some claim need to be in place to cut steel...chopper.) Stock Mamba MM with worn out gearboxes and the edge looked laser cut. Needless to say I am ecstatic about it. Gerald I know you have moved on now but I just wanted to thank you again for your efforts in getting the MM out to the people. *thumbsup*

Pics or it did not happen ! :D

if i may ask, what were your rpm, feed rate and bit for cutting the steel?

Oh it happened :) Ill do more of it on Friday and take pics for you. My phone cant focus that close. Ill have a different camera on Friday and do another cut.
I was running my router speed dialed all the way back. On my router it says thats 10,000rpm Not sure how accurate that is?

Feed: It was my first test and Im sure could be dialed in better but I was at 60ipm with the depth per pass at .005" I added cutting oil to the top surface and a few drops during cutting.

The bit: I really think this was a key factor. It is a 3 flute carbide .25"dia. They have the shallow angle on the flutes. I dont have a link because the bit is used and was given to me. Sorry. Ill take pics of the bit on Friday as well.
Its kinda like this bit at amanatool but I think the flute angle is not that steep.
The bit wasnt even warm to the touch the metal WAS warm to the touch but was not hot. Granted the cut didnt last very long. I was really pleased.
Pics or it didnt happen... I can respect that, this is the internet after all .. :)
Friday.

Edit: Oh and my bit seems to be darker in color.
Edit again: Its still Wednesday here the forum says its Thursday so .. In a day and a half.

just teasing ya, but looking forward to some eyecandy :)

Its time..So I battled software today for some reason. Maybe updates to what I use to make files IDK. I was getting the ends of the arc dont match the start of the arc. Even old files were doing it. Absolute/inc in mach3 With about 60 potential options checked/unchecked anyway... I need to study up on that some more. BUT!!! I did get my first part cut out of steel today!!!!!
Hopefully these pics are to your liking ..

http://s13.postimg.org/n8f7eps87/IMG_0435.jpg

http://s15.postimg.org/4s2xx4hwr/IMG_0436.jpg

http://s30.postimg.org/mwsjzt9xd/IMG_0439.jpg

http://s30.postimg.org/4wjcvfhq9/IMG_0437.jpg

http://s8.postimg.org/duwpah945/IMG_0443.jpg

I had some Z/depth problems, the piece was suspended so it was hard to accurate z height, This allowed the part to drop as it approached the thin skin left holding it in place. This left the familiar thin skin that has to be removed. My tabs were to small also. I think what we are most concerned with in this post is the edge quality and IM VERY Happy with the edge. I mean Im going weld it here and there and some sanding will surely come into play at some point. Unsanded the part slips onto that hub nicely and has to go on straight or it binds going on.
Cant wait until I flood the table with coolant and get my belt drives on there.
I did have to babysit this cut and keep adding drops of cutting oil.

Edit:
Also after the cut the bit was barely warm. My motors were warmer, and when I say warm Im talking about not even close to hot but barely noticeable to the touch. It was a little scary at first just thinking the bit was going to shatter or something but Im alive and off to work. The Mechmate is such a monster.

Nice :D what cut parameters did you use this time ?

Wow...very nice and impressive!
Mark