Hi All,

This is goin to be the build log for my machine, the earlier log for the machine was a www.mechmate.com, since the group there was more focussed onteh mechmate I am moving the thread here where I can get more answers to my Q's. Welll for a start the machine was the inspiration from the Mechmate but does not resemble it in any way. I am active on the thread where theUHU controller are discussed and have made a controller based on those boards.

For a start look at the pictures of the build, and the previous stuff could be seen at http://www.mechmate.com/forums/showthread.php?t=196&page=2

I thank Gerald for Inspiring many!

RGDS

Irfan

I had a few Q

before answering them you might want to take a look at the link in the previous forum where there is the history of this router build. And yes benny's belt based router also inspired me!

1. for the timing pulleys which i will be using to drive the pinion can i use just the grub screws to hold the pulley's in place or is it necessary to have a key to bind it with the shaft.

2. If only grub screws can be used tehn how many, I was about to put 3 each 120 degree apart........is it OK

3. I expecting a center distance of 325mm, will that matter much?

4. I will be using a HTD 8 mm pitch belt. is it OK

Regards
Irfan

everything is just MHO

1. & 2. Set screw should be ok. I maybe would grind small flat on the shaft for set screw. One screw on flat and another 90* away should be more than enough, bu i suppose 3 will not hurt.

3. This will depend on how many tooth the pulleys are, i believe there is recomended number of teeth that should be in contact with belt at all times. But if enough teeth will be in contact, i would think it would be ok.

4. 8mm pitch HTD belt should be good. Mayne difference between belts are amount of backlash and tooth profile(i think). HTD shouldnt have much backlash.

everything is just MHO

1. & 2. Set screw should be ok. I maybe would grind small flat on the shaft for set screw. One screw on flat and another 90* away should be more than enough, bu i suppose 3 will not hurt.

3. This will depend on how many tooth the pulleys are, i believe there is recomended number of teeth that should be in contact with belt at all times. But if enough teeth will be in contact, i would think it would be ok.

4. 8mm pitch HTD belt should be good. Mayne difference between belts are amount of backlash and tooth profile(i think). HTD shouldnt have much backlash.

Thnk you rustamd, I have a 1:3 reduction , meaning a 20 teeth pulley and another 60 teeth one!

Pretty heavy duty machine. What is your intended use? It looks good so far. Keep up the work and pictures. I'll help where I can.

Irfan,
Just catching up on your progress on the router, I've a suggestion in the form of a question. could you mount the jackshaft & servo motor in between the rails of the gantry ? second Idea, if the threaded hole for the set screws are deep enough, put a second set screw on top of the first. this will prevent vibration from loosening the setscrews.

Hey Irfan,
Where in India are you?

Irfan,
Just catching up on your progress on the router, I've a suggestion in the form of a question. could you mount the jackshaft & servo motor in between the rails of the gantry ? second Idea, if the threaded hole for the set screws are deep enough, put a second set screw on top of the first. this will prevent vibration from loosening the setscrews.

Paul I cannot have the Jackshaft in centre cause there's where the Y sliding comes into picture. Its like typical shopbot!

Cool Idea for the set screw stuff. I will get that incorporated!

Regards
Irfan

Hey Irfan,
Where in India are you?

I am in Bangalore! now changed to Bengaluru!

Pretty heavy duty machine. What is your intended use? It looks good so far. Keep up the work and pictures. I'll help where I can.

Intended Usage:

1. Wood Carving
2. Foam molds
3. Wax Patterns
4. Wood Prop manufacture
5. Wooden Patterns.

I will keep all updated on progress, i work on my machine every weekend's so the progress will be a bit slow. Any way's I am committed to complete it by January. So you will see a lot of Pictures.

That looks huge. What size is the cutting area?
Scott

That looks huge. What size is the cutting area?
Scott

Originally planned to take up 4x8 ply sheets , there is more width to the working area (more than 4' ) to accommodate for a possible tool changer and a rotary 4th. axis

Got some volunteers to align the angle iron to the rails, the gantry moves pretty smoothly though with all the weight. Though there is requirement for lot of nick and nacks.

look for the video http://www.youtube.com/watch?v=7zKjLyAKXdQ

Designed the belt and pulley arrangements for the X drive to the pinion, a 1:3 reduction straight. total reduction is 1:6 @ 625Watts and 3Nm Torque continuous. Thats amount 3*6= 18Nm of torque continuous for the X drive. One thing I learnt is that for this type of gantry u need a lot of weight to keep it running smoothly!

:wave: :banana: i have to find volontair totest my mechmate too ?

2. If only grub screws can be used tehn how many, I was about to put 3 each 120 degree apart........is it OK


TWO is better. that forces the side of the pulley to the shaft. with 3, you could have only the three screws touching. not as strong.

put the pulley on, tighen screws LIGHTLY, remove pulley and file flats where the screws will be. when you tighten them, you will make a mark. if the mark is below the pipe diameter, the pulley will slide on and of easily. if the mark is higher, it will lock the pulley in place.

Dave

Designed the belt and pulley arrangements for the X drive to the pinion, a 1:3 reduction straight. total reduction is 1:6 @ 625Watts and 3Nm Torque continuous. Thats amount 3*6= 18Nm of torque continuous for the X drive. One thing I learnt is that for this type of gantry u need a lot of weight to keep it running smoothly!


If you have 3:1 from the motor to the jackshaft, and 3:1 from the jackshaft to the pulley, you have 9:1

if you have a 20 tooth gear on a 20 dp gear rack, then each rotation is 3.14159 inhces (same as pi )

The wonderful part about using a belt drive is that you can always make changes to see how it works.

The jackshaft is a GREAT idea. ONE motor is easier to use than two.

Dave

If you have 3:1 from the motor to the jackshaft, and 3:1 from the jackshaft to the pulley, you have 9:1

if you have a 20 tooth gear on a 20 dp gear rack, then each rotation is 3.14159 inhces (same as pi )

The wonderful part about using a belt drive is that you can always make changes to see how it works.

The jackshaft is a GREAT idea. ONE motor is easier to use than two.

Dave

HI Dave,

Thanks for the Thumbs up. Then the torque just went up by 9 times.

the pulleys have itself cost me 200 bucks and no more trying on them. I am using 8 mm pitch htd pulleys 20 and 60 teeth in combination. Hope things work well I will be using UHU drives which I have already made the control box.

I just ordered the pulley with the local manufacturer.

The jack shaft is a mild steel one. I need to know more about taper lock bushes, does any one has ideas on them and where I can get more info upon.

I am also on the build of the smaller precision m/c which is a probable 2.5' x 4' working area a la MADVAC.

I have got the ball screws for less than a 100 usd, for that and will start a new thread soon.

Keep coming back.

RGDs
Irfan

If you have a lathe, you can make your own shaft collars.

The taper lock are simple they have a taper on the collar, the pulley or gear has a matching taper. when you bolt them together, they grab the shaft.

Very nice to get a tight grip on the shaft.

Dave

If you have a lathe, you can make your own shaft collars.

The taper lock are simple they have a taper on the collar, the pulley or gear has a matching taper. when you bolt them together, they grab the shaft.

Very nice to get a tight grip on the shaft.

Dave

Hi Dave,

I have no lathe and might ask some on to machine them for me. since I already have a bored out pulley and a regaular shaft, how to go about making and installing the taperlock bushes. Any web links or pictures or any thing on cnc zone?

Thanks for all Help

RGDS
Irfan

Which pulley are you talking about ?

the motor to the jack-shaft will have the lightest load, the gears on the final drive will have the most load.

Dave

Which pulley are you talking about ?

the motor to the jack-shaft will have the lightest load, the gears on the final drive will have the most load.

Dave

I am talking about converting all to the taper locking types, going first with the jack shaft and the final pulley connected to the pinion.

Regards
Irfan

Look at Quick Disconnect. they have a large shoulde and are very similar.

however, you might find your options very limited on the drive parts. a 20 tooth gear for the rack will be 1.00 inches at the center of the tooth, slightly less at the bottom of the tooth. The bushings take space and might not come is a size small enough.

This is even worse for a timing belt pulley.

Typically, for such a small gear, one might expect to have it locked with a taper pin

An alternative might be to put the gear next to a shaft lock and key them together to give added strength.

Dave

Hi All,

got thte timing pulleys today and wow they turned out good around 5400 INR for 4 thats around 140 USD!

But the weight of the bigger one turned out to be 3 kg. for something that needs to be spring loaded against the rack i think its lot. so planing to reduce weight by turning it a bit , reducing the flange thickness.

I will post the 3d cad images later

Regards
irfan

here is the weight reduction idea! any comments!

The greatest retention of strength and protection against cracking is to be very generous with fillets - rounding of corners. Try to avoid any sharp or near 90 degree surfaces.

The method that I have seen in timing gears is to use a series of holes drilled through.

http://www.brecoflex.com/?CATID=1&SCATID=2&SMENID=11&PURA=22

beautiful pulleys.

did you buy them ? or did you have them made ?

Dave

The greatest retention of strength and protection against cracking is to be very generous with fillets - rounding of corners. Try to avoid any sharp or near 90 degree surfaces.

The method that I have seen in timing gears is to use a series of holes drilled through.

http://www.brecoflex.com/?CATID=1&SCATID=2&SMENID=11&PURA=22

Harryn,

I will have the thickness done to 10mm from the present 20 mm, then have the holes too.

Driller,

I got em made locally. Cost me nearly 150 USD.

RGDS
Irfan

McMaster would sell such gears for around $90 USD for the set of 4. plus you would have to have them machined.

If you ever need more, please let me know. I have a way for you to save big $$.

One way is to use the nylon gears with a metal hub. remove the hub, make your own hub and you have a very simple way to get large gears for much less $$

Dave

McMaster would sell such gears for around $90 USD for the set of 4. plus you would have to have them machined.

If you ever need more, please let me know. I have a way for you to save big $$.

One way is to use the nylon gears with a metal hub. remove the hub, make your own hub and you have a very simple way to get large gears for much less $$

Dave

Hi Dave,

The pulley's cost me 135 to be exact for 4 numbers. If i get em from US the cost for shipping will offset any advantages on the mfg side. think nylon is the way to go.

do you have any idea's how they are manufactured though i may not go for them as I need the gantry to be heavy and might as well go with plain carbon steel.

I am on the design of a small machine with ball screws for which I might use the nylon pulleys and they are smaller. Just tell me how to pay you and I may as well get them from you for lot cheaper then what I can get here. I got the ball screws pretty cheap though odd diameters.

I will start a new thread soon on that. I will be using gecko 203v and keling steppers 640 Oz on them.

RGDS
IRfan

McMaster would sell such gears for around $90 USD for the set of 4. plus you would have to have them machined.

If you ever need more, please let me know. I have a way for you to save big $$.

One way is to use the nylon gears with a metal hub. remove the hub, make your own hub and you have a very simple way to get large gears for much less $$

Dave

Hi dave,

Just checked with Mc Master, the pulleys might have cost me around 175 usd + postage. So I think its ok that I got it done here!

meanwhile the acetal with Alu hub pulleys seem to cost less. doyou have any online source for them!

Regards
Irfan

If you have a lathe, you can easily make the hubs. you can use aluminum or steel. I prefer a solid steel pulley on the motor as the size is small enough. That pulley does not cost too much.

for the 60 or 72 or 78 tooth pulleys, you can buy nylon with an aluminum hub for less than $15.00, then make your own hubs.

20 tooth steel pulleys would be around $11.00 each.

2 plastic pulleys, weight less than 1/2kg The shipping should be less than $20. that would be $75 for the works.

If does require that you have machine work done there to make the hubs and the bores.

Just a thought.

Dave

Dave,

was checking costs on https://sdp-si.com/eStore/Direct.asp?Exp1=97&Exp2=98&CP=Pulleys.htm, great deals on the nylon pulleys. I will ask here if nylon pulleys could be made by my manufacturer and if so how much.

and will let you know!

RGDS
Irfan

Good u enlightened me about the cost! I am sometimes a dumb ass who looses a lot of money on thing like these! LOL

good site.

A 6Z 3-78SF03716

78 tooth pulley, 3/8 inch wide $15.01 USD each pulley.

Dave

There are two types of timing belts. the trapezoidal and the half round.

the half round fit in a hole that is more then just a drill. the tops of the holes have a pattern. I think the belt type is GT5 for 5mm between cogs on the belt.

Each gear would be made for the number of teeth. I think I still have the calculations/formulas to determine the tooth pattern.

If you can have plastic parts made, then getting the mould would be the key.

Dave

posted twice the same

There are two types of timing belts. the trapezoidal and the half round.

the half round fit in a hole that is more then just a drill. the tops of the holes have a pattern. I think the belt type is GT5 for 5mm between cogs on the belt.

Each gear would be made for the number of teeth. I think I still have the calculations/formulas to determine the tooth pattern.

If you can have plastic parts made, then getting the mould would be the key.

Dave

OH , I was of the impression that the plastic parts could be machined. cant they be machined anyway?

Check this out! , think its ok to go this way

I buy the nylon timing gears in the larger sizes and make my own hubs. I have made hubs for 24 tooth gears and 60 tooth ones. Under 24, they are pretty small and don't cost too much to buy in all metal.

I thought you were talking about having a bunch of nylon or plastic ones made. Yes, you can machine plastics.

I buy the nylon blanks for 60 tooth gears (the largest available from my supplier) for about $7.00 each with no hub at all.

I've tried to attach some photos. I have some MXL pulleys, some XL and a few larger ones.

I use XL for most of the stuff I do.

If you look at the assorted pulleys, there is one 72xL pulley with 72 teeth, a 1 inch bore and 7 large holes. this was a purchased pulley in all aluminum. The large holes show how one and remove weight.

Also, in the assorted photo, they are all sitting on one large pulley with a huge relief cut out. you can see it in profile in with them all standing up.


Dave

Hi Dave,

7 usd is just great! ans what is the width of the belt u use? I might require a few for my ball screw based machine. Can u give buy some for me when I require it? I can transfer money to you thru friends in US or thru paypal. and yes see my updated post I just thought of what u showed in your image.

I would still require some pulleys for reduction for my Y axis can I get them from you? 1:3 and then again 1:3, I will PM you when I want to get them. meanwhile can you PM me your email id for things to converse off the zone? I ailed the web site sdpsi.com if they would supply for India still no response.

I will keep you posted on this

Regards
Irfan

here are photos of my nylon pulley.

one side has a small hub, the other has a longer one.

I cut these off, make my own metal hub, then bore them to the size I need.

for shipping purposes, this weighs about 4 ounces. 4 pieces to a one pound shipment ???

your local machine shop could easily make the hub to fit your needs. Even a taper loc hub !

Dave

I use 3/8 inch wide trapezoidal belts. these are what McMaster sells.

the pulley is 0.575 inches wide at the teeth.

Dave

I use 3/8 inch wide trapezoidal belts. these are what McMaster sells.

the pulley is 0.575 inches wide at the teeth.

Dave

Dave Imight go for pulleys which can take up atleast 15 mm belt,

do you think those are available. I will run a search!

Thanks and regards
Irfan

I get my belts from McMaster and they only have 3/8" wide belts.

15mm is just a little larger than the white pulley in the photo.

Dave

I get my belts from McMaster and they only have 3/8" wide belts.

15mm is just a little larger than the white pulley in the photo.

Dave

I will run a search on sdpsi and order what i need dave , my friend in ttthe USA can get it and post me the stuff thru USPS!

I thinkthats theright idea

what say!, here i can get belts of any width!

The pulley is 0.575 wide and your 15mm belt calculates to 0.590 wide. only a very little bit different.

Dave

Dave how do taper lock hubs work and how do they look like. do u use any of them?

i want to get tehm made and have no idea how they work and how todesign tehm

irfan

https://sdp-si.com/eStore/Direct.asp?Exp1=115&GroupId=227&P1=5mm(HTD)

look at these dave,

Ready solution

There are two different ways.

one is to make a shaft collar that is close to the shaft diameter. the outside would have a flange and a taper.

make a hub in the pulley that has a taper on the inside.

if you slit the shaft collar, then screw the parts together, the taper locks the collar on the shaft.

hope this makes sense.

I think the ones SDP-SI sells have two tapers and the two parts are threaded.

when you screw them together, the tapers expand. one grabs the shaft, the other grabs the pulley.


Dave

There are two different ways.

one is to make a shaft collar that is close to the shaft diameter. the outside would have a flange and a taper.

make a hub in the pulley that has a taper on the inside.

if you slit the shaft collar, then screw the parts together, the taper locks the collar on the shaft.

hope this makes sense.

I think the ones SDP-SI sells have two tapers and the two parts are threaded.

when you screw them together, the tapers expand. one grabs the shaft, the other grabs the pulley.


Dave

got it dave, you made it look so simple thanks!

google QD bushing.

http://www.cptbelts.com/products/pulleysbushings/qdbushings/index.html

it is pretty simple.

Figure where you want the threads and where you want the holes.

The taper is pretty easy if you have a lathe.

Dave

Contactirfu,
Remember that I'm in the good ol USA, with my own machine shop. You could drop ship items to me for modification. and the few items I've shipped to you in the past were cheap ! So the offer is still good, the rest is up to you
tenmetalman

Contactirfu,
Remember that I'm in the good ol USA, with my own machine shop. You could drop ship items to me for modification. and the few items I've shipped to you in the past were cheap ! So the offer is still good, the rest is up to you
tenmetalman

Hi Paul,

Thanks for the thumbs up, however i talked to my past employer and he is eager to make the machining for me and that too most of it for free when his workers are free, i am only usually worried about shipping costs for the larger and heavier parts which eat away any savings.

i would mostly ask you for UHU components but that at a later date when kreutz is ready with the highpower board which is like taking for ever now!, I just took up a plac e and for now convincing my wife to manage it so that i can attend my regular job. pray for me!

Regards
Irfan

here goes, thanks dave for the leads,

nice, but I would try to put the taper under the pulley so all the twisting was directly in line with the belt and bushing.


Dave

nice, but I would try to put the taper under the pulley so all the twisting was directly in line with the belt and bushing.


Dave

Like this?

Check this out! , think its ok to go this way

That is much better. If you are a perfectionist, then you would also slightly round the corners of the drilled out holes, but that is approaching anal retentive. :)

Frankly, I am not sure about just how close your inner hole set is to the hub. Your load is fairly light, so it probably does not matter for a steel gear. If you were pushing the design strength limit of a plastic, that might be an issue.

That is much better. If you are a perfectionist, then you would also slightly round the corners of the drilled out holes, but that is approaching anal retentive. :)

Frankly, I am not sure about just how close your inner hole set is to the hub. Your load is fairly light, so it probably does not matter for a steel gear. If you were pushing the design strength limit of a plastic, that might be an issue.

Hi harryn,

Thnx for the comments, actually i believe strongly that iam not a perfectionist and i leave that to the guy's who machine out parts for me :D

i am not gonna implement this until i try the grub screw method which i mentioned initially in the thread. This method is to build confidence in me that if that method fails then I dont have to worry and i can go in for taper lock. more over finally i learnt it the easy way from Dave, thanks again Dave!

I might end up doing this for all the future pulleys

Regards
Irfan

I think the pulley should be directly over the taper.

I was thinking more like this.

Dave

I was thinking more like this.

Dave

Got it Dave, Have been awake since 4 am now its 12 pm here, so see you all in you morning tomorrow. Have a nice day !

Got it Dave, Have been awake since 4 am now its 12 pm here, so see you all in you morning tomorrow. Have a nice day !

I was wondering how you had the same hours as I do here on the East coast of the US !

Dave

Hi Irfan

How is your big router building? I've been watching your posts yet from machmate forum. Me too who got stuck with servo (before learning prices for reducers) :(. The only difference - I've bought drivers (http://granitedevices.fi/index.php?q=servo-drive-vsda) and now looking for motor + reducer affordable solutions. Going to build cnc similar design and size as yours.
I see you've got quite big motors. Is so big motor for X really needed? I've made a spreadsheet for calculations and it seems moving some 90kg gantry with twice lesser motor possible... Any suggestions from you (or anybody reading this)? Hope nothing wrong with my formulas. I only don't know efficiency (factor) coefficients for belt drives, what practical "t" (acceleration time) and cutting forces are (wood, 2-3hp spindle).

Hi Irfan

How is your big router building? I've been watching your posts yet from machmate forum. Me too who got stuck with servo (before learning prices for reducers) :(. The only difference - I've bought drivers (http://granitedevices.fi/index.php?q=servo-drive-vsda) and now looking for motor + reducer affordable solutions. Going to build cnc similar design and size as yours.
I see you've got quite big motors. Is so big motor for X really needed? I've made a spreadsheet for calculations and it seems moving some 90kg gantry with twice lesser motor possible... Any suggestions from you (or anybody reading this)? Hope nothing wrong with my formulas. I only don't know efficiency (factor) coefficients for belt drives, what practical "t" (acceleration time) and cutting forces are (wood, 2-3hp spindle).

Oleks, when I purchased my motors I was not sure what I should buy!

it was just made on instinct and my foolishness!

Now I have decided to use those motors on differently designed router where I have used ball screws.

and for the material I have used for this router I will utilize this for building a mechmate.

I have purchased steppers to keep up with the original design.

I think you values on excel are good enough, though I havent gone thru them entirely!

u can see my other build at http://www.cnczone.com/forums/showthread.php?t=46998

Good luck for your build.

Irfan

Irfan, I was unaware of your this built....:)..Very nice work u did so far... Why you start the second machine before completing this one???

Bcos it was going haywire, the time and money spent of that machine were just not justified and i then decided to go the mechmate way!

Just same thoughts attend me - to cover expenses and delivery costs have to oder set for two cnc and make one for sale. I see in Ukraine and Russia 2-3 years ago there were more discussions on cnc forums than now. I suspect that most gays who made good one started to sell them. :)
Here (http://www.lmwatts.com/cnc.html) is most professionally designed DIY CNC with ball screws I've seen in the web. Some info there very interesting and may help you some day.