Hi Matt
Under motor selection it does say the belt drive is better as far as backlash is concerned. If the price is ok woud you be interested in getting 2 sets made at the same time.

Hi Matt,
3.2 :1, interesting combo !!
I too am planning to make my trany,

Attachment 4792

Attachment 4793

not only to save a few $$$....but mostly and the obviously, doing it for this sefl fuzzy fun feeling of making your own...:D

I managed in the past to find source & material (drive, driven gear & belt) to get 3.0:1 reduction, but could not find source & material to configure 3.2:1 ?
Could I ask you to tell us more about your source & part# for your gears & belt set up so we all could look it up ?
Thanks in advance, Robert ;)

Hey Robert,

Nice CAD model. What pitch belt are you using there?

Funny we a re talking about this today because my pulleys and belts arrived today.
Attachment 4794

I have gone with the T5 (5mm pitch) size. To get the 3.2:1 i have chosen a 15T &48T combo. Used with a 56T (280mm) belt gives a centre distance of ~55mm. This only gives 5 teeth engaged at any one time which is 1 less than the recommended 6 so i went with the wider 16mm to compensate. It allows for quite a compact design.

I sourced them from a local supplier. www.piesau.com.au i'm sur they can be sourced easily anywhere.

Matt,
My drawings and part for this drawings are strictly for a temporary conception purpose. I used for this set up a “XT pitch” with a 3/8” wide belt.
I understand it may be “frail” for our MM set up !!
Haven’t gone spending the required in verifying & calculating this YET :o
This tempo set up has an easy 6teeth engaged, so I stop at that and figured when time comes I’ll take the required time to select the proper set-up...TBC !

Out of curiosity, would you know who makes (what brand) are those pulleys ?

Gear reduction
 

This post was originally put in a thread of it's own, but it became clear that it was another belt drive....

I made this drawing after looking at JR's drawings. It is made using two flange bearings, the oringinal motor mount design other than changing the holes size for the bearings and one laser cut mount. The flange bearings are recessed into each of the plates. This would be a low cost build for gear reduction.Once I get one put together and it will work properly, everyone is welcome to a copy of the drawings , as long as Gerald does not have a problem with me doing that.

Leo, the only big area of concern is the backlash between the gears. Maybe some springloading can be arranged?

Keeping them clean doesn't seem to be a big issue - the belt guys don't seem to loose sleep over dirt that might get into their drive. We don't have hassles with our z-axis rack/pinion either.

You are welcome to post drawings.

(As you have drawn it at this stage, your flanged bearing will foul the gantry)

Gerald, if I'm not mistaken, that looks like a belt drive, drawn with "belt removed for clarity".

Leo, I think placing the flanged bearing on the other side of plate that attaches to the gantry will solve the fouling, if you have enough room in there.

Leo picked the title "gear reduction" in a new thread separate to the belt reduction thread, so I assumed the novelty was in having gears instead of belts. But I wasn't quite sure so I changed the title to "gearbox" and kickstarted a gear discussion - it is worthwhile discussion, even if Leo meant something else (that has already been exhaustively covered) :)

Don't know if those flanged bearings exist in true life - they look a lot slimmer than the stuff I can get around here.

if gears are the point of discussion - my friend with the chinese machine has them all over the 3 point of motion.

its a simple spur gear arrangement - with a metal gear on the stepper and a nylon gear on the shaft providing the drive to the pinion.

I told him that if this does not last long enough we always have the beltdrives to replace em!

RGDS
IRfan

Belt drive
 

It is a belt drive design. I know it has been talked about in great detail. All I am trying to do is make it a little cheaper and easier . The bearing is from Mcmaster Carr Part # 5913K71. $11.33 each. Turning the bearing over did fix the clearance problem. I will post some pics when I get one together.Thanks , Guys

I think Leo's contribution is quite novel and a welcome contribution to the belt reduction concept. It makes a belt reduction drive feasible for those with only basic tools available to them (which is what i thought the concecpt of the MechMate was about?)
The bracket would be low cost if added to the initial order. If you mount the plates to a face plate on a lathe then you could bore the bearing holes to suit flanged bearings like these.
Attachment 5305
The total cost should still be less than geared motors and you would have better performance w.r.t. backlash.

Building your own belt drive transmission
 

Hi, I have designed and built two sets of transmissions with 4:1 drives that are now being tested on two different mech mate machines with great results, they are quite actually very simple in design and I am thinking of offering them for sale as a kit, or a completed transmission, so depending on what your skill level is you will be able to use them, and I was wondering what the response to this would be here, if there would be enough of a demand to make this worth while, and keep the costs down so they are affordable, you could use a cheaper nema 34 motor on these transmissions and out perform the oriental motors with the gear reductions, and have less money in them,
let me know what you think.......
Thanks
//chopper

I will try to go a little deeper into these, they are made of steel, and utilize the original motor plates, I machined a bearing cup to fit into the hole in the original motor plates and welded them in, cut the holes into the new motor plate and slotted the holes for the motor to allow for belt tension adjustment, and also made a second bearing cup to fit into the new motor plate and welded them on, then machined a motor adjustment plate to fit between the motor and the new motor plate, this plate fits around the motors round extrusion on the front of the motors to allow the motor to fit flush to the new motor plate and allows for easy belt tension adjustment, the shafts are made from cold rolled steel, and have flats machined into them to accommodate the set screws in the 72 tooth pulley and the gear pinion.
then two plates were cut from band iron to hold the new motor plate to the old one at the proper distance so the pulleys would move freely with out binding or rubbing, and were welded in place, the clearances were checked and adjusted
as needed for proper fit of the pulleys....
these are made of steel so they could be welded to the original motor plates
and so they wouldn't wear out, also if a bearing locks up and galls a bearing cup, the cup can be replaced easily.

more pictures..... let me know if there is any interest in these I am thinking of maybe a kit with the bearing cups, new motor plates and the shafts,and band iron plates
or completed transmissions with everything but the motors, these will out perform plastic and aluminum, you will be able to get better,smoother,quieter cuts, than with the oriental motors with the 7.2 gear reductions for less money
it is quite amazing when the the backlash is removed how much easier the machine will cut through your material. it is almost effortless.
//chopper

Welded steel . . . . . now you have my interest! :D

I like it!

Beautiful craftsmanship Chopper.

Gerald,
if it isn't steel it isn't real! just and old expression from my metal fab days....
Doug thank you for the compliment,
I also wanted to ad that the parts came from stock drive here is their link http://sdp-si.com/
the 72 tooth pulley is part number A6A3-72NF03716 @ 31.97 each
the 18 tooth pulley is part number A6A3-18H3716 @ 10.98 each
the belt is a 200xl with Kevlar reinforcement part number A6B3-080037 @ 7.61 each
I bought the bearings locally, I think they were about 6.00 each ( I tried some cheap internet supplier but the bearings were crap)
the steel plates were scraps that I had laying around say 10.00-20.00 worth for all 4 transmissions I also went to my local steel supplier and acquired some cold rolled .5 inch steel round stock to make the shafts the rest is just time...
//chopper

Chopper, what level of machining (what tools), did you need to do?

Pulley reduction drives
 

While a belt reduction is not a new idea i thought i'd share pics of my pulley reduction drives. I got a friend of a friend to machine them for me from 1/2" 6061. Its only a 2.4:1 drive.

Pulleys and pinion bored to size and shaft. Still have to put flats on the shafts.
Attachment 5376

Machined plate. The counterbore for the motor is slotted by 3mm total (+/- 1.5mm) for belt tensioning.
Attachment 5374

Machined second plate. These were made to fit snuggly in the motor bracket plates.
Attachment 5375

The mounting screws protrude by a little over 2mm in the pics but i didn't have the spring washers fitted yet.
Attachment 5369

Attachment 5370

A with the pinion (not fastened yet, just sitting there)
Attachment 5371

Yes, the belt does clear the spacers :)
Attachment 5372

Attachment 5373

Well done Matt. Great pictures.
These should work well.

Jayson.

Great work Matt.:) Very professional. Thanks very much for sharing such detailed pictures.:) We are standing by to see how they work for you.

Gerald,
I used a late to turn the bearing cups,
an iron worker to cut the plate and punch the slots
and a welder, on the shafts I used a mill to cut the flats.
//chopper

here is a picture of a sign cut on my friends mechmate using the above transmissions, no sanding this is straight out of the machine, I don't know if you can see the detail in the v carved letters and the 3-d carving around the center of the Maltese cross where the ladder, helmet etc. are,.
the absence of cut marks and machine marks is obvious.
//chopper

Chopper, I have converted all your pics to .jpg's and removed the facility to load .bmp files. They were unreadable to some of our users. Also, a .bmp file takes up a lot of memory space - the pics are now a third of the memory size without any obvious loss in quality.

Gerald,
thanks for converting the pics, I don't know much about that stuff
//chopper

Lovely matt - that Alu will sure help a lot to dissipate the heat from the motors, tellin from experience!

Hey Chopper. Lots of great work! Thanks for sharing.

Just a tip about pictures...now that you'll be using .jpg, you'll find that you don't have to resize your pictures down so much. .jpg seems to be MUCH more efficient than .bmp, so you can resize to say, 650 X SOMETHING and the picture will still fit within the guidelines. On the Forum the pictures will be a lot bigger and easier for us to see what you're showing us. In IRFANVIEW, when you select SAVE AS, you'll need to select the format .jpg rather than default to .bmp. Just a thought.

Chopper,
Those transmissions look top notch. Does your friend have a build log here? If not get him to post some pictures with blue and logo and get himself a serial number! :)

Heath,
no, he doesn't have a build here and neither do I on mine, I guess I didn't see the need since my machine is similar to Sean's #5 and that it isn't Blue
but I don't mind sharing the changes I made I think that is where my machine differs slightly from others, just like the transmissions, I had an Idea to do something like JR"s transmissions but I wanted to have a higher ratio than he used and I also decide to use steel, I believe for many reasons that using steel is better, and it allowed me to fit a higher ratio into the same space of JR's aluminum units for one, thanks for the comments, for those of you who PMed me and for those who want to know I will be determining a cost for both the completed units and for the kit, and maybe an assembled unit with out the pulleys and belts,
thanks for the feed back keep it coming...
//chopper

Chopper,
There have been other guys on the forum with non blue, and they still got a serial number! :) Yellow, Black, White and Red have all been used for one reason or another. Lets see some pics if you have the time.

Chop,
Thanks for the shout-out! :D
Ah, just post a pic or two, that's what keeps us all in this together...pictures.

Cheaper I understand since OM are $250 apiece, but why better?

Pablo,
the difference between the 7.2's and the belt drive is the backlash in the geared drives on the 7.2's there is about 5 thousands back lash,
I know this is not much and will probably depend on what you are cutting to see the difference, with the belts the back lash is eliminated making the cuts smoother, less power is need to make the cuts, since your router/spindle doesn't have to work as hard to do the same work, it is kinda hard to explain but one you see it in action you will understand, I wouldn't have believed it my self if I didn't see it, I made a set of these for a friend of mine and he said the same thing, that He wouldn't have believed it unless He seen it for Him self,
it is quite really amazing difference, since I installed the belt drives I leave my router set at 8k and never move it it cuts sooooo much better...I hope that helped //chopper

here are some more pics of the belt drives, I think these will be better tha the other ones//chopper

one more

They look great! I like the adjuster screw for the motor tensioning. Very handy.

I'm guessing your shaft is a straight shaft with no steps or shoulders on it? (So you can remove the shaft to install/replace the belt). Do you have any teflon shims/washers either side of the large pulley?

Matt,
yes the shafts are straight held in by the set screws on the pulley,
and no there are no washers or spacers between the pulley an the bearing
there is about 10 thousands gap between the pulley and the bearing,
I haven't experienced any rubbing from this, but if you desired you could you could put them in there, but since it is up against the bearing center that spins with the shaft there is no issue//chopper

how many teeth of of smaller pulley mesh with the belt??

Ifran,
if you look at post 19, you can see that the belt contacts about 1/3 of the pulley, it has 18 teeth, with would put it at about 6-7 teeth
//chopper