
Darathian

Since I know some of you have used the Sabertooth and Kangaroo I figured I would ask opinions.
I have decided on the Parralax Arlo base for my next robot chassis. I will use the caster's from parralax.
I will most likely be using the Sabertooth and kangaroo combination for motor controller/PID but I am not decided on this and open to suggestions.
I also find myself in a heated mental debate between the wheel/motor combination from parralax or the Zagros Rex motors and wheels combined with the Sabertooth/Kangaroo.
Item 1:
One of the key items for me is how well the encoders between the two different motor/wheel sets works with the Sabertooth and kangaroo.
Item 2:
The other item floating in my mind is the ground clearance between the two motor/wheel sets. It seems at least to me that the Zagros wheels would provide more ground clearing but since the base plate of the chassis provides stability to the base platform I am not really sure if using the Zagros motors are feasible.
Item 3:
Since I am going to build a body, arms and head on top of the base the torque and weight carrying ability is important.
Item 4:
I need to be able to control both the position and speed of the motors at the same time. For example example I should be able to have to robot move lets say 1 feet at a certain speed.
I know this is kind of an open ended questions but if anyone have used any of these wheel/motor combinations please provide your 2 cents as it relates to the items listed above.
I appreciate any comments or insights you guys can provide.
http://www.ebay.com/itm/291057616929?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Here is what I mean...
If you had a motor that was geared 200:1 and you had an encoder on the back shaft of the motor that was a 500 count encoder, you would get 100,000 counts or ticks per revolution of the wheel.
If the encoder were a 100 count encoder and it were on the wheel end of the motor, you would get 100 counts or ticks per revolution.
The gear box and the placement of the encoder in relation to the gearbox has a lot to do with the level of detail by the number of ticks per revolution.
The issue comes in if the gearbox is say 127:1 and your encoder is before the gearbox, causing the encoder to spin 127 times per revolution of the wheel. This also gives you very accurate movement though.
I will start taking orders for these. Just send me an email. My email address in on my profile. They will be $8.00 each. If I already have an email from you then I already have you down for the number that you ordered. It will be about 2 weeks before I can have these made and shipped out.
This is a first come, first served deal. There will only be 20 available in the first order, of which 10 are still available.
Payment will be available through Paypal and the details will be handled through email for any orders.
The order for the boards will go in tomorrow. It will take about a week for me to receive these boards, and then about a week to make and test them before shipping.
I will update this thread with the current status as I know more.
Shipping inside the US will be done through USPS. Outside of US, I will have to see who has the best rate available. I know some have different shipping methods that they prefer. We can discuss the rates and all through email when the orders are ready to ship.
Payment will be due when these are complete and I have tested them and know that each one is working correctly.
I will provide post headers but wont solder them so that you have the option of using something else in this location. If you want me to go ahead and solder the post headers onto the board, just let me know.
Thanks
David
There are 10 of these logic divide by 2 circuits available still. The cost that is being charged will cover the cost of having the boards made. The cost of the other parts of this process except shipping are being absorbed due to the fact that this order is also helping me with the cost of having the (hopefully) final Rafiki prototype boards made. If it is found that these are wanted by more people after this initial order is fulfilled, I will make a run of just these boards.
Anyway, two weeks from today, I hope to have the orders fulfilled and shipped out.
Thanks
David
These are going into my next project, so whenever.
Thanks for doing this for us.
Sorry for no punctuation's I am talking to cell phone
Thanks for your patience. BTW, there are 22 available for sale if anyone needs these in the future.
Total cost for domestic with 2 day shipping is $22.80 for 2 of them. I have 4 more built, tested and ready to ship if anyone would like them. The others after this will be built and tested as ordered, but all of the components are here so it wont take much time at all to fulfill an order.
Thanks
David
Thanks for doing this for us David.
They are trying to come up with a basic robot platform that would be expandable and allow a novice to learn about robotics and compete in a competition that they have coming up. This is when I mentioned EZ-Robot to them and described the EZ-B and ARC to them. I don't think that they believed me about ARC and how easy it would be to build what they were designing. Anyway... next time I am down there, I will demonstrate it to them and also bring some built flip flop circuits down to them to use/buy. It always amazes me when I talk to expert robot builders about how simple things can be and they seem to discount it because it is easy. I thought that was the entire point of what they wanted to do, but I was new among them so there is no level of trust built yet for them to believe what I am saying, and I get that.
Anyone needing these in the future can order from CochranRobotics.com.
I am now finished posting on this thread
Thanks
David
I am in discussions with GLOBE to be a distributor for these motors now. I should have a quote in a couple of days for a purchase that will allow you to get these motors/encoders from me. I have asked for 2 different products to be quoted. One will use the Avago 500 count encoder and the other will use the Avago 256 count encoder. The 256 count encoder on these motors is not an existing part number at GLOBE meaning that they would probably cost me more, but we will see. The 500 count encoder on these motors is an existing part number and is what is sold by Zagros when in stock. It is also the one that requires the use of the logic divide by 2 boards for sale on my website to allow it to work with a DE Kangaroo controller. I should have news in the next couple of days and will update here if I will be able to carry these motors or not.
Thanks